# 461 Stoker cam question.



## 64Original (Jun 21, 2017)

Quick question for anyone familiar with Butler's stuff. We are getting ready to order a top end package with Butler built Edelbrock heads that are 87cc and it is their Butler Edelbrock D-Port, 87cc, Hydraulic roller top end package. It has three cam choices listed, BP8019ASP, BP8022SP and BP8030SP. We are building more of a street/cruising motor as we like to drive the car and take longer road trips. The car has power steering, power brakes and AC so I don't want to have a vacuum issue. We are running a 200R4 transmission with a 3.73 posi rear end and should be turning around 2200 RPM on the highway at around 70. What are your thoughts on cam selection for this setup. I am buying the performer rpm intake with this package and having it port matched to the heads. Have already ordered the lower end package and going with Scat forged crank, Scat Forged rods with Ross flat top pistons at .030 over with the three center main caps upgraded with Program Engineering four bolt mains. The block had two center mains with corners broken so that is the reason for doing the new centers and we went with the non-splayed as the splayed have a long lead time. Any information on best cam selection will be greatly appreciatedl


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## Baaad65 (Aug 29, 2019)

Hello, I have a Butler 461 with iron heads roller valve train same manifold, here's my cam and I added















1.65 Scorpion Race rockers. I'm pulling about 13-14 inches of vacuum with an LSA of 114, I have an 8" dual booster with front disc brakes and they work good. The motor was dynoed at 472hp 526tq with a stock intake,q jet and 1.5 rockers then I swapped in the Performer rpm, 850 QFT, and the 1.6 rockers so I'm thinking it's close to 500hp with 9.36 compression...it's a fun beast 👍


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## Machinest-guy (Jul 19, 2019)

I would suggest purchase of an engine modeling software application and run simulations. Butler can provide you with input data not already gathered. The three cams you mention have well known timing values and the rest of the engine is a pretty" known build". Your modeling simulation won't have exact correspondence to a dyno run because air flow numbers will be a guess, but it will give you accurate comparison of one cam to another and what timing on assembly will put your torque peak at cruse speed. I'd suggest Engine Expert or a lesser cost (but just as good for this job) program by Rapid Line. I've used both almost from their inception more than 20 years ago when I bought my SuperFlow 600 test bench which generated a data stream via it's FlowCom unit. Now there are a half dozen applications out in the marketplace to chose from. It isn't having a familiarity with Butlers (well regarded) products which will make the difference here. It is using technology to assemble or fit the parts you buy in an optimum way which will lead to a bigger grin. Engine analysis software will enable that to be done very cost effectively. And modelling can lead you to avoiding excessive dynamic compression that may lead to detonation / failure. 

Best regards, Ladd

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## Baaad65 (Aug 29, 2019)

Pretty sure Bear has some software maybe he would crunch some numbers for you.


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## Jared (Apr 19, 2013)

I'd call Butler and chat with them. They should be able to help you pick the best cam for your particular set up. While your engine build it pretty typical, some of your car specs are not. What works in one car, does not work in another. Having power brakes and a 200R4 trans means you need some engine vacuum for the booster but not for the transmission. AC may play a roll for you as well but mine does not have it so that is a black box for me. I was able to go with a more radical cam in mine because of having a manual transmission and no power brakes. I based cam choice on the suggestion of the shop that ported my heads. I'm running a XE284H camshaft with ported 6X heads (9.5:1 comp), larger exhaust valves, and a torquer II intake based on those recommendations. I used Nitemare Performance for the work. Like Butler, Nitemare only does Pontiac engines. While I have not had mine on a dyno but I would be putting down similar numbers to Baaad65 with the combination I'm running.


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## PontiacJim (Dec 29, 2012)

Missing info, but assume 10-10.5 compression with the aluminum heads.

Here are the cam specs:

Do not see "BP8019ASP" on their list of cams, so may be something custom ground to order.

Instead, I will post "Item #: CCA-BP8020SP"
276/282, 224/230, .503/.510, 112 LS

Item #: BPI-CL-BP8022SP
282/288, 230/236, .510/.521, 112 LS

Item #: CCA-BP8030SP
288/294, 236/242, .521/.540, 112 LS

Personal Opinion on this one. I would select BP8022SP.

You only seem to want a nice street driver, not too radical, and good vacuum. However, your are building an engine capable of a lot of HP/TQ.

BP8020SP is a good choice, but with your build, I would want more lift than the cam offers. The duration is not bad, but the duration numbers will be tame as the larger the cubes, the smaller the cam will seem/act.

BP8030SP would work IF you were aiming more on street/strip and not so much a cruising car. Numbers all look good, but may be more than you want. As you increase duration numbers, you move the power band higher up the RPM scale, so with more duration, you can lose some bottom end power but pick it back up low-to-upper mid range. For a nice street cruiser, I would want lower to mid power, but this does not mean the power drops off, just means your best HP/TQ numbers will be more in tune with the cruising range you are wanting. The OD and 3.73 will really make things snappy.

You may want to ask if a 114 Lobe Separation Angel (LSA) on the BP8022SP might be a better choice for your application - which will provide plenty of manifold vacuum and a nice broad power curve.

No one cam will do it all and a lot of variables when selecting a cam grind. Basically pick one that seems good, and jump. The only way you will know the cam was a bad choice is once you get it on the road. Then you at least have a base to go on and can adjust your needs with the next grind.


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## Machinest-guy (Jul 19, 2019)

Good evening, I'll offer some guiding thoughts to consider, and hope for a "pardon me" if I get excited about designing camshafts. I put many years into learning how to do that then getting equipment to measure the things which need to be accounted for to maximize what a combination of parts can do.

Get some air flow data on the heads. Actual data, not advertising numbers, on the castings built you are buying. Everything starts there if you are more serious than just tossing darts at sales ads. Pick valve lift to be 110 % of max flow at whatever lift gives it. Like duck hunting you need to overshoot that target and lead it. There is no reason to build .600 lift into the engine if your heads don't flow more air past .450 and every reason to limit the lift if a head isn't as good as you thought it may be. 

Take advantage of roller cam technology to open the valve as quick as can be achieved to get into max air flow as soon as possible. This gets done with a custom grind and to some extent determines valve duration timing events. It also determines what valve spring to use. All production cams are conservatively ground insofar as valve-train acceleration ramps go to accommodate guys who don't buy good springs or the wrong springs. Or buy heads with generic springs set to some unknown average tension. You can pick up a lot of power by knowing how much spring to use and getting that aspect spot on a minimum value while making the valve move as fast as it can, exactly as it needs to, to create a combustible mixture. Bouncing or floating valves cause misfire meaning that game is over. Engine Expert software can calculate valve train inertia and required spring forces. That data is just as important as selecting what the lift and duration is. 

Next, Look at valve overlap area under the IN / EX lift curves and set intake valve opening / exhaust valve closing to minimize lost mixture charge to enhance low speed performance. Jim's mention of 114 degree lobe center is right on. Don't be afraid of 116 either. A big bore open chamber head design doesn't need much overlap. It really hurts BSFC (mileage) Overlap is to suck IN fuel mix into the chamber by association with what is leaving via EX valve when there are obstructions in the chamber to flow. Overlap is a band-aid for poor ports and manifolding that isn't used in modern engines as much. That is a high RPM gainer not a low speed advantage. The only number left is intake valve closing. That needs to be whatever establishes a workable dynamic compression ratio. Remember always the compression stroke doesn't start until the intake valve closes. It is the single most important valve timing event. 

Once you know these valve event points you can go through a catalog and see if something is close enough to what your combination needs it might work well. This is the point where your prior questions started. Hence there is a lot of ground to cover before anyone can give you an improved answer better than "pick item B from the menu".

When assembling your engine be sure max IN air flow is achieved at a point when the crank is at 90 degrees to rod. That is max piston velocity hence max suck and gets you the most intake volume inducted per degree of crank rotation. All production cams are a compromise on this aspect because they are designed for multiple engines in family series. Each engine has a different rod / stroke leading to each engine having a different piston position for max intake signal; but being fit with a "one size fits all" cam leaves power losses on the table to eliminate. This is what assembly timing is all about and the cam advance or retard bushings - keys - sprocket positions so many people talk about but don't ever check or set.

Recall it is compression pressure that brings a mixture to the point of controlled combustion. IF an engine with a mechanical compression ratio of any number is operated in a vacuum the compression pressure will be zero. Nothing in there so nothing got compressed. As you put better flowing parts into your engine the dynamic compression pressure will rise vs. a given static situation. Hence you need to know dynamic compression which is really hard to calc manually but easy for a computer to do to avoid problems with "top end" engine power kits designed for a generic family of engines. 

Most engine modeling software will calculate dynamic compression and also calculate an ignition advance curve and often times give you a fuel octane requirement. All things you need to have accounted for mechanically or risk failure when building a parts combination out to it's limits. The old SUN Equipment motto comes to mind - TEST Don't Guess. 

Go for it. Figure out your engine parts combination and model it. Then build it to the max it can be. Details count and can be thought through. Ladd


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## Baaad65 (Aug 29, 2019)

Good stuff even if my head is spinning 😉


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## 64Original (Jun 21, 2017)

Machinest-guy said:


> Good evening, I'll offer some guiding thoughts to consider, and hope for a "pardon me" if I get excited about designing camshafts. I put many years into learning how to do that then getting equipment to measure the things which need to be accounted for to maximize what a combination of parts can do.
> 
> Get some air flow data on the heads. Actual data, not advertising numbers, on the castings built you are buying. Everything starts there if you are more serious than just tossing darts at sales ads. Pick valve lift to be 110 % of max flow at whatever lift gives it. Like duck hunting you need to overshoot that target and lead it. There is no reason to build .600 lift into the engine if your heads don't flow more air past .450 and every reason to limit the lift if a head isn't as good as you thought it may be.
> 
> ...


Thanks for all of the information, it is a lot to consider.


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## 64Original (Jun 21, 2017)

PontiacJim said:


> Missing info, but assume 10-10.5 compression with the aluminum heads.
> 
> Here are the cam specs:
> 
> ...


Thanks Jim, this whole combination is put together by Butler with them doing all of the machine work and I was leaning more towards the 8020 cam since we like to drive more. Just trying to build a bullet proof engine that is going to last the rest of my lifetimel.


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## PontiacJim (Dec 29, 2012)

64Original said:


> Thanks Jim, this whole combination is put together by Butler with them doing all of the machine work and I was leaning more towards the 8020 cam since we like to drive more. Just trying to build a bullet proof engine that is going to last the rest of my lifetimel.



That will work and will be tame in a 461 engine, BUT, I would have the cam ground on a 114 LSA which may be a little safer with regards to detonation. Again, run this by Butler as I am no cam expert nor have the experience as Butler does.


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## 64Original (Jun 21, 2017)

PontiacJim said:


> That will work and will be tame in a 461 engine, BUT, I would have the cam ground on a 114 LSA which may be a little safer with regards to detonation. Again, run this by Butler as I am no cam expert nor have the experience as Butler does.


Here is the information from Butler's website on the heads and cam selections.

*Butler Performance Top End Kits*
Complete top end kit with almost everything you need to upgrade your normal Pontiac to a Butler High Performace Pontiac. These combinations have been used in Butler Performance builds for many years and have powered some of the highest performing Pontiac engines in the world. We now offer these kits to take the guesswork out of piecing together a good combination that works well together. All these kits are actual build kits used in our shops. If its on here we use it in our own shop!!

Edelbrock 61575 Complete Heads

(D-PORT 87cc Chamber): Flow Numbers as tested by Edelbrock's SuperFlo SF-1020 flow bench @ 28" H2OValve Lift.100".200".300".400".500".600".700"Intake64139200237251262266Exhaust5399131151160165167


They feature optimized oil return passages for increased oil flow. These heads are available in three heart shaped combustion chamber sizes, 72cc and 87cc. The 72cc and 87cc chambers are fully CNC’d to provide a 9.5:1 compression ratio when used with flat-top pistons. The spark plug has been relocated closer to the exhaust valve for improved performance. These heads are cast with extra thick port walls and a compact port size, making them ideal for CNC and hand porting. Complete cylinder heads include guide plates, rocker studs and high quality valvetrain for direct bolt-on application.
Edelbrock 7156 Performer RPM Intake
Maximum high-rpm power while maintaining good throttle response for street. Recommended for high-performance street, strip and marine. Has clearance for HEI distributor. Will not fit under Trans Am Shaker hood without
The intake will be port matched to the cylinder heads.

Cam Options
Butler/Comp SP Street Performance Billet Roller Cam (HR) BP8010SP 270/276, 218/224, .495/.503, 112LS (Std Firing Order/ Std Journals)
Butler Comp SP Street Performance Billet Roller Cam (HR) BP8022SP 282/288, 230/236, .510/.521, 112LS (Std Firing Order/ Std Journals)
Butler/Comp SP Street Performance Billet Roller Cam (HR) BP8030SP 288/294, 236/242, .521/.540, 112LS (Std Firing Order/ Std Journals)

Compression Ratio Numbers for Reference (Compression ratio with Block, Head, and Stroke with -8cc FT)

400 Block​Head cc w/-8cc Flat top​StrokeBore72cc87cc3.750"4.155"10.389.024.181"10.489.114.000"4.155"119.554.181"11.129.654.210"4.155"11.53104.181"11.6510.14.250"4.155"11.6310.094.181"11.7510.194.500"4.155"12.2510.624.181"12.3810.73
 
These are custom grinds done by Comp Cams for Butler and in talking to them they are very reluctant to offer any changes to these packages as they have built a lot of engines using these combinations with great results. Compression should be 10.09 with this package since I am going .030 over on the bore to clean the block up.


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## PontiacJim (Dec 29, 2012)

64Original said:


> Here is the information from Butler's website on the heads and cam selections.
> 
> *Butler Performance Top End Kits*
> Complete top end kit with almost everything you need to upgrade your normal Pontiac to a Butler High Performace Pontiac. These combinations have been used in Butler Performance builds for many years and have powered some of the highest performing Pontiac engines in the world. We now offer these kits to take the guesswork out of piecing together a good combination that works well together. All these kits are actual build kits used in our shops. If its on here we use it in our own shop!!
> ...



OK. looks good. Not questioning Butler as they specialize in Pontiac engines and builds and have the experience. 10 to 1 is what you want with aluminum heads as you want typically 1 point more compression than iron heads and a good number on iron heads is 9:1 for pump gas, but you can go higher if everything is perfectly matched.

I would still select the BP8022SP with the 461. You don't want your TQ numbers too be real strong too low since you will be using the 3.73 gears. You probably will be breaking tires loose fairly easy - which you may do with any cam. AS duration increases, the TQ/HP band moves up the RPM range.

The LSA is not something to focus on, but it can indicate parameters of the cam - like a basic number you can use to quickly compare cams. These are generalities with exceptions, but narrow lobe separations tend to increase midrange torque and result in faster revving engines, while wide separation result in wider power bands and more peak power but somewhat lazier responding engines. However, the engine configuration plays an important role as to what is wide and what is narrow. Longer stroke engines may need the wider separation to maintain good power output at high rpm, while shorter stroke engines may respond better to tighter separations to accentuate the faster revving ability and add needed torque.

With regards to iron heads on Pontiac engines, the lower numbers like 110LSA that many cams are ground on will increase cylinder pressure, so good for a low compression engine, not so good on a high compression engine IF you are looking to run pump gas. These seem to work best with under 9.0 compression. The 112LSA in my opinion, is a good choice for 9.0-9.5 compression and pump gas. Can I go higher on compression? Of course because there are a number of variables that come into play when building any engine. But I go with "safe." Over 9.5 compression I like 114LSA. However, if you apply the "add 1 more point compression for aluminum heads" application, the 112LSA cam should be fine with the aluminum heads and pump gas.

Cam overlap is another important number. The overlap is what can give you a smooth idle and good vacuum. As the cam's overlap number goes up, the idle gets more choppy and engine vacuum goes down. Typically, the more overlap a cam has, the higher into the RPM range of the engine the TQ/HP will be found. So not so good for a street cruising engine, but great for street/strip or racing engine.

Lobe separation and overlap are inversely proportional - increase the lobe separation, you decrease overlap. More overlap decreases low RPM vacuum, a smooth idle, and engine response, but more overlap will improve the filling of the cylinders by the fast moving exhaust pulling in the incoming intake charge in the midrange to upper RPM's. This increased in cylinder filling results in the improvement in engine acceleration, which drivers often notice.

Here is a very simplified means in choosing a cam:

Choose duration based on target operating rpm (for the cubic inch of the engine)
Choose lift based on head flow
Decide on duration and the cam's overlap number, then LSA fall where it may


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## 64Original (Jun 21, 2017)

PontiacJim said:


> OK. looks good. Not questioning Butler as they specialize in Pontiac engines and builds and have the experience. 10 to 1 is what you want with aluminum heads as you want typically 1 point more compression than iron heads and a good number on iron heads is 9:1 for pump gas, but you can go higher if everything is perfectly matched.
> 
> I would still select the BP8022SP with the 461. You don't want your TQ numbers too be real strong too low since you will be using the 3.73 gears. You probably will be breaking tires loose fairly easy - which you may do with any cam. AS duration increases, the TQ/HP band moves up the RPM range.
> 
> ...


Thanks Jim, I went with BP8022SP and I think it will give me plenty of what I want and still be a great driver. Appreciate all your knowledge and explanation. Was supposed to get three packages today but UPS only left one so hope the other two show up later or on Monday so we can move forward on the bottom end. I have to say the Ross pistons are a thing of beauty and the Scat forged rods don't look so bad either.


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## Baaad65 (Aug 29, 2019)

That's the cam I have but 114 LSA, good luck and keep us posted 👍


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## 64Original (Jun 21, 2017)

Baaad65 said:


> That's the cam I have but 114 LSA, good luck and keep us posted 👍


Will do. What heads are you running? I am going with the Edelbrock 87cc chambers built by Butler. Looking at a 12-16 week lead time they are so backed up and I think having trouble getting the heads.


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## Machinest-guy (Jul 19, 2019)

Good day , 
I believe Jim makes a number of good points. May I add a perspective on the air flow table 64Origonal provided by examining the delta between lift tests. 

Edelbrock 61575 Complete Heads


(D-PORT 87cc Chamber): Flow Numbers as tested by Edelbrock's SuperFlo SF-1020 flow bench @ 28" H2OValve Lift.100".200".300".400".500".600".700"Intake64139200237251262266Exhaust5399131151160165167

On the intake side: between .100 and .200 lift you gain 75cfm. between .200 and .300 gain is 67, .300 to .400 gain is just 37 then .400 to .500 gain is 14 cfm. Between .500 and .600 gain is 11cfm and to finish the data set off between .600 to .700 gain is 4 cfm. At no point does the rate of gain increase. This means to me no inertial ram effect is happening. Maybe the port is too short ? Too small ? 

On this sort of engine I'd target - assume - try to achieve, about 500 hp based on displacement and modern engineering which can yield about 1.1 HP per cubic inch naturally aspirated pretty easily. 461 CID x 1.1 = 508 HP. This is an initial guess-ta-mate for making some calculations and sorta keeping some sort of evaluation process of pro / con for any build decision in perspective. 

This would lead one to mentally target each IN cfm of flow being worth about 2 HP at .500 lift. So a gain in power of 22 HP going from .500 to .600 lift may be expected. But a gain in power of just 8 HP would be had if you built the valve train to lift up to .700 inch from .600. In my experience building valve-trains to lift .500 is pretty easy. Creativity starts about .550 by selecting great parts. Then design / machine work / longevity become more difficult when getting into the .700 inch range. I'd try to build an intake valve train which would capture those 22 HP at .600 lift and give up getting the max possible. But I sure wonder if the head has more to give than the numbers indicate.

Similar evaluation of the EX side should be done. The delta gains are 46 CFM from .100 to .200, 32 from .200 to .300, 20 cfm .300 to .400, and then 9 cfm from .400 to .500. .500 going to .600 gets 5 more and .600 to .700 gets you maybe 2. (Flow bench accuracy is +/- 2 cfm unless you use lab quality fixtures and control air temp test run to run.) (Super Flow benches make a mathematical compensation for temperature variation which is close to being exact but isn't as good as actually controlling the air temp externally) This way of doing data analysis makes each EX CFM worth about 3.1HP to stay on target. That is a high number. Sorta. It doesn't work exactly that way but it's a good starting perspective for conversation. In this cylinder head the EX flow falls off at .500 inch but its so low in relation to IN flow I'd build the valve train to favor the exhaust a lot.

Switching from what is in the table to whats missing. 

There are no low lift flow numbers. Cams are measured at various points to give duration advertising specifications. Some companies use low lift at .003 some .025 some .050 etc. It really helps to know what the flow is when the cam starts to open the valve. Flow is a function of volume over time. Time can be measured in degrees of rotation or milliseconds. The time starts when a valve moves off its seat. Example: a valve flows 20 cfm at .025 lift and it's on an acceleration ramp of the cam so it is around .025 lift for, say, 8 degrees of rotation. And it does that twice. Once when opening and once when closing. Now consider flowing 250 cfm over the nose for 4 degrees of rotation. Once. There is only one time the valve goes over the nose per combustion cycle. So half of 250 cfm divided by 2 for the rotation factor gives 125 cfm and divided by half again for the times of occurrence you'll start to believe 75 cfm over the nose per rotation cycle is an important relationship to 20 cfm at .025 lift flow on a cams acceleration ramp. Which one is easier to improve ? Sorta. Gas dynamics have a huge effect depending on the port and RPM. But my point is the importance of low lift flow should not be ignored and it will help an engine a lot to improve it. 

The take away for me on this combination is: the intake side is disappointing. I'd really like to see flow knocking on the door of 300 cfm by .500 lift to assure getting to 500 HP. The EX side needs help too. I'd like to see intake flow of 1.5 times exhaust flow so to achieve that the EX side needs to come up in proportion to IN flow. But that doesn't seem to be the case using this parts combination. None of these cams lift into the .600 range so the heads have a bit more to give than is being used. And a maximum lift number possible for the head / spring combination isn't offered up. Maybe around .500 lift is all they can be built for ?? Something not specified is the effect on flow when the intake manifold is added to the system. Generally IN flow goes down while headers make EX flow go up. This can effect flow balance a cam grinder needs to know about. A quick test would be to run flow without any valve in the flow path. See if the restriction is the valve or the port. Then put a stick in the valve guide hole and see what happens. A stick can act like a flow guide increasing flow if the valves backside shape will exit the mixture into a combustion chamber as rapidly as it enters. Changing valve styles is not costly if you haven't spent your money yet.

What can be done to enhance this build while using the same parts ? I'd thermal barrier coat the head combustion chambers and ports. Calico Coating does a nice job of that. So does Swain Coatings. What you get is a head that runs cooler to water temp because quite a bit of heat never enters the casting. This helps intake charge density. The aluminum head will act like an iron head compression wise. That is to say you don't need to suffer a horsepower loss pumping mechanically to 10 to one compression ratio when the head will give that extra point of compression heating for "free" because of the coating (point and a half if you do the pistons too). The EX port will stay hotter maintaining exhaust gas velocity down the pipe which helps minimize need for valve overlap. And a dual pattern cam is indicated with high ratio rocker arms.

I'd believe you need a bit more flow testing be done with manifolds in place to select an optimum cam for your intended use. These parts may have more to give on a big stroker motor than is being found so far. 

Ladd


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## PontiacJim (Dec 29, 2012)

Machinest-guy said:


> Good day ,
> I believe Jim makes a number of good points. May I add a perspective on the air flow table 64Origonal provided by examining the delta between lift tests.
> 
> Edelbrock 61575 Complete Heads
> ...



The OP is not building a race engine, nor trying to maximize HP output to do so. He is looking for a street friendly engine that can be enjoyed. Providing flow calculations on anything over .550" is no longer a street friendly build. Intake lift on the cam selected is .510" and the duration numbers are very safe - both less than the factory RA IV cam. With the bigger cubes, the cam will be mild as opposed to a smaller cubed 400CI. You also failed to mention the possibility of breaking a lifter bore and/or taking out the engine with the side loadings imposed on the lifter bores when using big lift roller cams. Another thing missed or not addressed by those who are not familiar with Pontiac engines.

What you also seem to miss is "port velocity." I can have a port flow 300CFM's and be a pig on the bottom RPM end until the higher RPM's can take advantage of it. I can have a tire shredder with a port that only flows 230 CFM's. With a street engine and something that is dependable, idles smooth, is quick to respond to the throttle application, has plenty of low end grunt, and probably won't see 6,000 RPM's, and an engine with .700" lift flowing 300 plus CFM's just doesn't seem to fit in the description of a street friendly build. Pontiac's are built for torque, not HP.

You also did not bring in measuring CFM's of the intake or Carb. I suspect gas mileage is also a concern with the PO since he stated he wanted something he could "take on longer trip."

With 500HP plus and more, you also want to suggest all the other mods that will be needed to handle the big HP/TQ numbers so stock torque converters & transmissions, 10-bolt rear ends, and frames do not get destroyed. Keep in mind some guys still have drum brakes and I for one would not want 500HP with drum brakes. So as HP/TQ builds go up, you had better include the additional costs in beefing up the drivetrain and frame areas. Many guys will get those big HP numbers in their heads wanting to go fast, but don't think about the additional cost needed to get the rest of the car to handle the big number and be safe. When they hear of the reality of what it will cost to bring the "rest of the car" up to a safe level, they typically decide to drop their dreams of the 500-600 HP engine and go more reasonable on their engine build. 

This forum is not a race forum, most of us like a fast car, but we also want to enjoy our rides. Not many here can build or afford the 14K engine builds that are methodically tested and run in on dyno sessions to squeeze every 1/10 of a HP out of out engines. Your info may work if we were building top fuel race cars or attacking national records, but we aren't. There are also many who never had a big HP car let alone grew up with these cars, and these older cars when new, had engines that over-powered the suspensions, brakes, & tires. So when giving advice, you want to give a complete picture and not send someone willy-nilly out to kill themselves or others - let alone total out or damage their cars. 

You may want to email Butler themselves with your observations and let them know they aren't very good at maximizing their head flow numbers and give them some of your knowledge so they know better how to flow heads.


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## Baaad65 (Aug 29, 2019)

64Original said:


> Will do. What heads are you running? I am going with the Edelbrock 87cc chambers built by Butler. Looking at a 12-16 week lead time they are so backed up and I think having trouble getting the heads.


I have the 7K3 heads with Butler's street porting about 220-240 cfm they told me and I'd be glad to trade you when you get your heads 😀 I wanted the Kaufman 85cc heads so bad but I didn't plan on doing a motor this soon and had to tell the wife I needed to buy this 7500.00 motor, then needed a 3000.00 trans and a 500.00 driveshaft to support the beast like PJ is saying so I couldn't justify spending another 3000.00 when I had nice heads already. Maybe someday if the motor ever has to come out but it be mostly for bragging and showing off, this can get a little scary just the way it is and I'm trying to save for a paint job...talk about big bucks 🤦‍♂️


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## 64Original (Jun 21, 2017)

PontiacJim said:


> The OP is not building a race engine, nor trying to maximize HP output to do so. He is looking for a street friendly engine that can be enjoyed. Providing flow calculations on anything over .550" is no longer a street friendly build. Intake lift on the cam selected is .510" and the duration numbers are very safe - both less than the factory RA IV cam. With the bigger cubes, the cam will be mild as opposed to a smaller cubed 400CI. You also failed to mention the possibility of breaking a lifter bore and/or taking out the engine with the side loadings imposed on the lifter bores when using big lift roller cams. Another thing missed or not addressed by those who are not familiar with Pontiac engines.
> 
> What you also seem to miss is "port velocity." I can have a port flow 300CFM's and be a pig on the bottom RPM end until the higher RPM's can take advantage of it. I can have a tire shredder with a port that only flows 230 CFM's. With a street engine and something that is dependable, idles smooth, is quick to respond to the throttle application, has plenty of low end grunt, and probably won't see 6,000 RPM's, and an engine with .700" lift flowing 300 plus CFM's just doesn't seem to fit in the description of a street friendly build. Pontiac's are built for torque, not HP.
> 
> ...


Well said Jim, although I am getting close to having the race engine investment you totally understand what I am trying to do. Great street cruiser that is bullet proof and can still suck the paint off the young guys cars when leaving a red light. I think Butler has this entire bottom and top end pretty well figured out.


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## 64Original (Jun 21, 2017)

Baaad65 said:


> I have the 7K3 heads with Butler's street porting about 220-240 cfm they told me and I'd be glad to trade you when you get your heads 😀 I wanted the Kaufman 85cc heads so bad but I didn't plan on doing a motor this soon and had to tell the wife I needed to buy this 7500.00 motor, then needed a 3000.00 trans and a 500.00 driveshaft to support the beast like PJ is saying so I couldn't justify spending another 3000.00 when I had nice heads already. Maybe someday if the motor ever has to come out but it be mostly for bragging and showing off, this can get a little scary just the way it is and I'm trying to save for a paint job...talk about big bucks 🤦‍♂️


I am retired and worked hard my entire life. The wife is not overly joyed but not really complaining either. I wished I had of built this engine when we redid the car but I guess I will look at it as a life lesson learned.


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## Baaad65 (Aug 29, 2019)

So reading and learning great stuff about cams from you way smarter than I will ever be people, I'm curious about my setup and don't mean to butt in just looking for an opinion. So if I have the same cam as 64 picked (230/236 - .510/.521) except mine has a 114 LSA and my iron heads were ported to 220-240 cfm according to Butler how did adding 1.65 rockers affect the performance..better, worse, no effecct? The head build sheet shows it would have .573 lift but doesn't give the duration, the heads were prepped for 1.65 rockers and the spring pressure shows it would increase to 361lbs. I have an 850 QFT carb, Performer RPM intake and aftermarket ram air exhaust manifolds 2.5" exit. Also running about 9.36 compression according to Butlers calculator ecept I didn't know the gasket crush but the head sheet shows chambers are 92cc, this is a 461 by the way. Thanks


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## armyadarkness (Dec 7, 2020)

I just installed the 8030, last week, and it's a very nice cam. A bit milder than I wanted, and as Jim said, it did move my power band up, but I have 336 gears and a TH400 with a 400. Your 461 and 373's would keep your powerband lower and make it much more fun. I think it's a good cam for your build and others with 461 seem to love it.


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## Baaad65 (Aug 29, 2019)

Just wait until you have that TKX with the 3.27 first gear then it will be more fun when you drop the hammer 👍 maybe 1.65 rockers will make the cam a little bigger if your heads are prepped right...better ask Santa for some new tires 😉


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## PontiacJim (Dec 29, 2012)

Baaad65 said:


> So reading and learning great stuff about cams from you way smarter than I will ever be people, I'm curious about my setup and don't mean to butt in just looking for an opinion. So if I have the same cam as 64 picked (230/236 - .510/.521) except mine has a 114 LSA and my iron heads were ported to 220-240 cfm according to Butler how did adding 1.65 rockers affect the performance..better, worse, no effecct? The head build sheet shows it would have .573 lift but doesn't give the duration, the heads were prepped for 1.65 rockers and the spring pressure shows it would increase to 361lbs. I have an 850 QFT carb, Performer RPM intake and aftermarket ram air exhaust manifolds 2.5" exit. Also running about 9.36 compression according to Butlers calculator ecept I didn't know the gasket crush but the head sheet shows chambers are 92cc, this is a 461 by the way. Thanks


Some basic thoughts:

Increasing rocker arm ratio's can open the valves sooner, faster, and higher, and closes the valves later. It can also multiply the loads on the pushrod, rocker arm studs, and rocker arms Going too big on rocker arm ratios can open the valves too quickly and may cause valve float at high rpm. It also multiplies the spring pressure seen on the cam lobes, so too much of a rocker arm ratio can wipe out a flat-tappet cam in no time.

The cam lobe is still the same and the point where the cam starts to move the lifter (generally measured at .006") is still the same. The same is true for the closing side of the ramp. But, the rate at which the valve opens is faster because of the higher ratio of the rocker arm, so the *effective duration *of the camshaft is increased slightly (not the actual duration as it cannot be changed). This effect on the cam timing *acts as if *you increased the duration about two degrees for each point of rocker ratio. So going from 1.5 to 1.65 could effectively increase duration 2-3 degrees more.

But, with the valve opening more, you may actually increase the open valve area and the engine may respond *as if *the cam increased four degrees in duration per point of rocker. On some engine builds, you might find that an engine builder might select a cam with as much as ten degrees less in duration when going from 1.6:1 to 1.8:1 rockers and still maintain their horsepower numbers while increasing torque.

But, higher lift will theoretically flow more air earlier in the lift cycle and this may not be needed or productive if the heads or induction system is already flowing enough CFM's for the engine at the lower lift numbers. And no need to open a valve to .500" lift when the head no longer flows any more air past .450" lift.

When changing rocker ratios you want to make sure the valve springs have enough clearance between the coils so the springs don’t bind. Make sure that the slot in a stud mounted rocker can accommodate the increased travel without hitting the stud and snapping it off. And, make sure the valve keeper doesn’t hit the top of the valve guide when the lift is increased or the rocker arm hits the valve retainer. Of couse valve-to-piston clearance can also be an issue and you may not know until you fire up the engine and bend valves - so you need to know that the added lift from an increase in rocker arm ratio will work with your engine combo.

Sometimes adding the higher ratio rockers on both valves can lose power. You may find that power increases when the higher ratio rockers are only installed on the intake valves, or only installed on the exhaust valves. If you have good scavenging of the exhaust side and add more lift, over-scavenging can occur and you will be robbing some of the air/fuel mixture during the valve overlap period - resulting in a reduction of HP.


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## Baaad65 (Aug 29, 2019)

Thanks for all insight, well I didn't get to do a side by side comparison but the heads and springs were prepped for the bigger rockers and it ran great this summer plus I sold the old rockers so I'm running what I brung, thanks again for all the education. I know I asked about this in another post but was to lazy to look it up 😉


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## Jared (Apr 19, 2013)

64Original said:


> Well said Jim, although I am getting close to having the race engine investment you totally understand what I am trying to do. Great street cruiser that is bullet proof and can still suck the paint off the young guys cars when leaving a red light. I think Butler has this entire bottom and top end pretty well figured out.


The close to 500 hp number is not that difficult to get to when you're dealing with a 461. You are going to be pretty close with the top end you are choosing. That being said, it should still be fairly well mannered on the street. The cam that Jim recommended is very similar to what I have in mine. I don't think you'll find that it feels too tame in a 461. It should have a pretty lumpy idle without completely robbing the bottom end. The only thing I see that you may want to reconsider is the 3.73 rear gears. You may find it tricky to take off without spinning.

There are a lot of guys on here that have built, or are building, very similar engines as you. While there are a few that race, I agree with what Jim said. Most of us are not building full blown race cars. Honestly, when I built mine I made some compromises to keep the HP down.


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## 64Original (Jun 21, 2017)

Jared said:


> The close to 500 hp number is not that difficult to get to when you're dealing with a 461. You are going to be pretty close with the top end you are choosing. That being said, it should still be fairly well mannered on the street. The cam that Jim recommended is very similar to what I have in mine. I don't think you'll find that it feels too tame in a 461. It should have a pretty lumpy idle without completely robbing the bottom end. The only thing I see that you may want to reconsider is the 3.73 rear gears. You may find it tricky to take off without spinning.
> 
> There are a lot of guys on here that have built, or are building, very similar engines as you. While there are a few that race, I agree with what Jim said. Most of us are not building full blown race cars. Honestly, when I built mine I made some compromises to keep the HP down.


With the 200R4 there should not be a problem taking off with the gear ratios. With the 3.73 we should be turning around 2200 rpms on the highway cruising at around 70mph.


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## 64Original (Jun 21, 2017)

PontiacJim said:


> Some basic thoughts:
> 
> Increasing rocker arm ratio's can open the valves sooner, faster, and higher, and closes the valves later. It can also multiply the loads on the pushrod, rocker arm studs, and rocker arms Going too big on rocker arm ratios can open the valves too quickly and may cause valve float at high rpm. It also multiplies the spring pressure seen on the cam lobes, so too much of a rocker arm ratio can wipe out a flat-tappet cam in no time.
> 
> ...


Jim, I am sticking with the 1.5 rockers and went with the 8022 cam. If it is not wild I will not be disappointed. Butler offered the 3 cam choices with top end package and I am sure all 3 will work extremely well.


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## 64Original (Jun 21, 2017)

What pushrods are everyone using with these strokers? Seems like a good place not to skimp and go with the wrong ones once length is determined.


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## Jared (Apr 19, 2013)

Got mine through Butler. They are Chromoly made by Smith Brothers. I went with the 0.116" wall. I didn't think I needed anything thicker with running a moderate flat tappet cam. The thicker 0.120" are only a little bit more but have a bigger outside diameter.


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## armyadarkness (Dec 7, 2020)

I have oil restrict push rods, so I can adjust my valves without any mess. They're a real blessing while tuning


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## 64Original (Jun 21, 2017)

Jared said:


> Got mine through Butler. They are Chromoly made by Smith Brothers. I went with the 0.116" wall. I didn't think I needed anything thicker with running a moderate flat tappet cam. The thicker 0.120" are only a little bit more but have a bigger outside diameter.


I am looking at the same ones you bought. I just need to get the final length but will be awhile since there is such a long lead time on the Butler built top end package.


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## 64Original (Jun 21, 2017)

armyadarkness said:


> I have oil restrict push rods, so I can adjust my valves without any mess. They're a real blessing while tuning


I bet they are, I am going to be running the hydraulic roller cam and lifters so hopefully once setup will not have to mess with them very often.


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## armyadarkness (Dec 7, 2020)

Same. I have a full roller. I take my VC's off and can let my engine run indefinitely.


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## Jared (Apr 19, 2013)

64Original said:


> I am looking at the same ones you bought. I just need to get the final length but will be awhile since there is such a long lead time on the Butler built top end package.


I highly recommend getting a pair of the test springs for when you measure. I ordered them from Amazon, they were less than $10, but worth their weight in gold. They allow you to measure the pushrod length using the lifters you're going to run with no chance of depressing the plunger and getting a bad measurement. They have just enough pressure to keep the valves closed. This was my first build so an added bonus for me was I get a couple practice runs of removing and installing valve springs while the engine was on the stand rather than my first go being in the car. I colored the tops of the valves with black Sharpie.









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## lust4speed (Jul 5, 2019)

All this discussion about cam size and nothing about converter stall speed? Nothing more aggravating than having too tight of converter and having it lunge every time you drop it in drive. 

I do like the cam choice and the SD Performance version of it is the Stump Puller. Have about eight or nine cars in the club with this cam and surprising how well it performs with its great street manners. Funny, but the range of those three cams probably covers about 95% of the club cars. Only a few chose smaller or larger durations outside of the range.


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## PontiacJim (Dec 29, 2012)

lust4speed said:


> All this discussion about cam size and nothing about converter stall speed? Nothing more aggravating than having too tight of converter and having it lunge every time you drop it in drive.
> 
> I do like the cam choice and the SD Performance version of it is the Stump Puller. Have about eight or nine cars in the club with this cam and surprising how well it performs with its great street manners. Funny, but the range of those three cams probably covers about 95% of the club cars. Only a few chose smaller or larger durations outside of the range.



We have not gotten that far yet with the converter. Trying to get *Army* to buy one for his ride to improve performance.


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## 64Original (Jun 21, 2017)

Jared said:


> I highly recommend getting a pair of the test springs for when you measure. I ordered them from Amazon, they were less than $10, but worth their weight in gold. They allow you to measure the pushrod length using the lifters you're going to run with no chance of depressing the plunger and getting a bad measurement. They have just enough pressure to keep the valves closed. This was my first build so an added bonus for me was I get a couple practice runs of removing and installing valve springs while the engine was on the stand rather than my first go being in the car. I colored the tops of the valves with black Sharpie.
> 
> 
> 
> ...


We are going to let the machine shop build it. He will blueprint it and mic everything along with degreeing in the cam and setting the valves. We just need to install the serpentine system, carburetor and misc. items to fire it up and break it off n.


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## 69 orange (Jan 16, 2021)

64Original said:


> Quick question for anyone familiar with Butler's stuff. We are getting ready to order a top end package with Butler built Edelbrock heads that are 87cc and it is their Butler Edelbrock D-Port, 87cc, Hydraulic roller top end package. It has three cam choices listed, BP8019ASP, BP8022SP and BP8030SP. We are building more of a street/cruising motor as we like to drive the car and take longer road trips. The car has power steering, power brakes and AC so I don't want to have a vacuum issue. We are running a 200R4 transmission with a 3.73 posi rear end and should be turning around 2200 RPM on the highway at around 70. What are your thoughts on cam selection for this setup. I am buying the performer rpm intake with this package and having it port matched to the heads. Have already ordered the lower end package and going with Scat forged crank, Scat Forged rods with Ross flat top pistons at .030 over with the three center main caps upgraded with Program Engineering four bolt mains. The block had two center mains with corners broken so that is the reason for doing the new centers and we went with the non-splayed as the splayed have a long lead time. Any information on best cam selection will be greatly appreciatedl
> 
> 
> Reply Quote


I have a Butler 461, pump gas, with Edelbrock 87cc D-Port Heads, Hydraulic Roller Lunati Cam #20510711LK (270/278 219/227 515/530 112 LS). It has power steering and power brakes. No Air Conditioning. I am using a M20 4 speed Muncie with a 3.55 rear gear. It has an Eagle cast crank, Eagle forged rods, Ross flat top pistons. 2 bolt mains & 1.65 rockers. Butler dynoed the engine 450 HP & 560 TQ. Engine runs well no problem with vacuum.


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## 64Original (Jun 21, 2017)

69 orange said:


> I have a Butler 461, pump gas, with Edelbrock 87cc D-Port Heads, Hydraulic Roller Lunati Cam #20510711LK (270/278 219/227 515/530 112 LS). It has power steering and power brakes. No Air Conditioning. I am using a M20 4 speed Muncie with a 3.55 rear gear. It has an Eagle cast crank, Eagle forged rods, Ross flat top pistons. 2 bolt mains & 1.65 rockers. Butler dynoed the engine 450 HP & 560 TQ. Engine runs well no problem with vacuum.


Thanks that is good to hear. Your build is similar to mine.


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## 64Original (Jun 21, 2017)

Butler really surprised me as I have received my complete top end package. Still waiting on the ARP head studs and the lifter bore brace but the machine shop has sent the block to their specialist to get the center 3 bolt caps machined and line bored. Christmas has really come early this year.


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## cal kid (Dec 19, 2018)

Hi 64 Original, Have you recieved your motor from your builder yet ? Very interested in your build as I am gathering my parts together for a build much like what you are doing, Forged 461, KRE 85 CC heads, Performer RPM, Holley Sniper, 6.8 rods, Ross flat tops, 2 1/2 R A cast W 2 1/2 exhaust, 2004r, 3.70 gears with 28.0 tires, all to run on $h!tty 91 Ca. pump gas !


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## Fxnjetz56 (Mar 21, 2015)

69 orange said:


> I have a Butler 461, pump gas, with Edelbrock 87cc D-Port Heads, Hydraulic Roller Lunati Cam #20510711LK (270/278 219/227 515/530 112 LS). It has power steering and power brakes. No Air Conditioning. I am using a M20 4 speed Muncie with a 3.55 rear gear. It has an Eagle cast crank, Eagle forged rods, Ross flat top pistons. 2 bolt mains & 1.65 rockers. Butler dynoed the engine 450 HP & 560 TQ. Engine runs well no problem with vacuum.


I have a very similar 461 build just completed with that Lunati cam, but a set of mildly ported 670 heads. It dyno’d at 420 Hp/540Ft lbs. I’m running a quadrajet, (which the builder apparently not real familiar with). The carb went from way lean, to now a bit rich (12.08 Afr) after some tweaking.

Just curious what carb setup you are running?


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## geeteeohguy (Feb 2, 2008)

Fxnjetz56 said:


> I have a very similar 461 build just completed with that Lunati cam, but a set of mildly ported 670 heads. It dyno’d at 420 Hp/540Ft lbs. I’m running a quadrajet, (which the builder apparently not real familiar with). The carb went from way lean, to now a bit rich (12.08 Afr) after some tweaking.
> 
> Just curious what carb setup you are running?


The neat thing about mild builds like yours that nobody mentions is that they tend to hold together for a long, long, time and not break. I've been touting the benefits of reasonably built, sub 450 HP engines for years, but most folks want 500HP plus in their street cars. I'm content to have less power but being able to say I haven't had my valve covers off in 30+ years with no down- time or broken 'upgraded' parts. (now watch---I just jinxed myself!!.....Last time I bragged about my original 240,000 mile power steering gearbox, it blew a an input shaft seal the following week.)


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## PontiacJim (Dec 29, 2012)

Fxnjetz56 said:


> I have a very similar 461 build just completed with that Lunati cam, but a set of mildly ported 670 heads. It dyno’d at 420 Hp/540Ft lbs. I’m running a quadrajet, (which the builder apparently not real familiar with). The carb went from way lean, to now a bit rich (12.08 Afr) after some tweaking.
> 
> Just curious what carb setup you are running?


Nice numbers.

Keep in mind that using the A/F ratio as a means to dial-in _what you believe the engine should run at may not be as you believe._ These engines are not stock, so things like cam choice/specs, ported heads, headers, intake type/style etc. can affect the A/F ratio's and what you may think is too rich, may be perfect. Too lean would be my biggest fear as this is where you can get detonation, a hot running engine, and even a destroyed engine if you mix it up with the wrong timing settings. It is better to be a bit rich than too lean. A little rich is a bit of security and can aide in engine cooling versus too lean and running hot. Look at your plugs which can help, but harder to trust with the ethanol blends, but can still be used for comparison between cylinders.

The modern reformulated conventional and oxygenated gasoline of today will cause the A/F mixture to shift leaner when compared to the leaded gasoline of the 1960s and 1970s. This means if the A/F mixture was lean with leaded gasoline it will be even leaner with today’s gasoline blends.

The A/F mixture always varies from cylinder to cylinder, therefore we tend to tune the average A/F mixture slightly on the rich side to avoid engine misfire in the leanest cylinder. It is possible to target an A/F mixture leaner than 14.7:1 for maximum fuel economy but this can lead to driveabilty problems if any one cylinder is leaner than the others. The power mixture we target for maximum horsepower is in the 12.2:1 – 13.5:1 A/F range, depending on the engine package and its combustion chamber design.


Leaded gas Air/Fuel ratio's as recommended by a paper put out by the Ethyl Corporation *1967 *is:
Idle - 11-12.5:1
Cruise - 13.5-17:1
Full Load - 12-13.5:1

The use of a portable 5-gas exhaust gas analyzer and/or a wideband sensor based A/F meter can allow a tuner to observe the A/F mixture the engine is getting from its fuel system at any engine operating condition.

A starting point for A/F mixtures for most mild performance engines is:
• Idle: 1.0% to 3.0 % CO or a 14.1-13.4:1;

• Cruise rpm: 1.0% CO or a 14.1:1 with a mild performance engine; or 1.0% – 3.0% CO or a 14.1 – 13.4:1 with high performance cam;

• Power mixture and acceleration: 6.0% CO or a 12.5:1 for a “normal” engine or high performance engine with improved combustion chamber design such as a Pro Stock or a NASCAR engine; in some cases you may be able to use a slightly leaner power mixture of 4% CO or a 13.0:1.


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