# High compression 455 street engine



## Thumpin455 (Feb 17, 2010)

Im building a mild 455 to run on E85 and my home brewed fuel, but not as an ultimate power source or race engine. Just a mild 455 with small chamber big valve heads to find out how much mileage I can get back from raising the compression. This one will not run on pump gas at all, the compression is and will be far too high for 93 octane.

I have a set of 48 heads that need rebuilt, they are going to get milled to raise the static compression to about 13:1 on a 462. I might have them ported while they are in Tennessee since I will probably use them in a sleeper after I find out what I need to know. Also because the low compression pump gas 455 has ported 5C heads on it. More of an apples to apples comparison that way. The first set of heads going on is a ported set of 670s from a 428. These have stainless valves, 995 springs, good locks and retainers. Static compression will only be around 11:1 with these since the pistons are .03 down the hole, but still it is far more than we can make with pump gas. I will swap the 48s on when I get them back.

It has a 4.181 bore, Eagle crank, RPM rods, Icon pistons, and Total Seal rings. The block sat for a while so it got some flash rust on it, but it came off only leaving some stains after brushing it. Shouldnt be a problem even if it doesnt look pretty. The cam is going to be an old UltraDyne 288/296/110 I have had for a long time. The pump gas 455 has a 280/288/110 in it, so that is different but not huge.

Its going in a 1979 Trans Am I painted a couple years back. the TA is a non AC car with only power steering and brakes as options. It also has 2.41 gears in it, so that fits perfect with my idea of mileage. Being a Trans Am it has decent aerodynamics and lower drag than a GTO. I have gotten 20mpg from a 403 powered 79 TA, so that is the first goal on ethanol.

Right now I am waiting for new pushrods and the crank key to get here, the crank has a deeper keyway in it so the stock one wont fit. Not sure why its that way, maybe just a mistake when they cut it. Not a big thing to fix, I just ordered a taller key for it. I just got the shortblock assembled and torqued yesterday, and now its just waiting for the small parts, cleaning the oil pan, front cover, valley pan, and swapping the distributor gear on my old HEI. Then a bit of metal work under the TA since the floors are rusted, and it should be running this summer for lots of cruising on cheap fuel.

RPM rods.










Pistons.










Dirty block.










Bottom end.


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## Thumpin455 (Feb 17, 2010)

Race stuff is different than street stuff. You can run alcohol quite rich and still make good power. Also were you using methanol rather than ethanol in the sprint car? Methanol is different in that it requires twice as much fuel as ethanol to make the same power, and its very corrosive.

But hey, if nobody gives a damn about it, I just wont let you know what happens with this project. Not a problem for me, just less writing on this forum. Maybe I will wait until its all done and show the results.


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## Instg8ter (Sep 28, 2010)

Hey Thumpin,I'm interested in the results and how you get there as i have been pondered doing an extra Holley 800 i have for my 463. was looking, and like you i am in MI and it appears that all Meijers gas stations have E85 so its available to me. I was wondering what your numbers were on consumption and cost. Looked like last i checked E-85 was around 2.60 here with 93 around 3.70. Is a 30% rise in consumption accurate as you have to re-jet 30% richer? would still average out to a .30 savings a gallon or 5.00 a tank or so. Every little bit helps these days....


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## geeteeohguy (Feb 2, 2008)

I too am interested, because it's interesting stuff!!!! Keep posting when you can. I appreciate it.


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## likethat (Oct 5, 2007)

I want to do this to my 67 Camaro's 427. I have seen your post at the e85 forums also. If it works out well then the GTO's will get the same.


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## BearGFR (Aug 25, 2008)

Thumpin455 said:


> But hey, if nobody gives a damn about it, I just wont let you know what happens with this project. Not a problem for me, just less writing on this forum. Maybe I will wait until its all done and show the results.


I'm interested too - and ignorant about such things....

Bear


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## ALKYGTO (Mar 29, 2010)

I'll recommend you call Ultradyne/Bullet about that "old" cam. I can tell you that exhaust duration plays a significant role in controlling heat, and a "gas" cam will make it run hot and you'll have to run it "fat" to control the heat. I'm no expert, just speaking from experience. And thier tech department is real helpful, they have all thier grinds (even custom) recorded and will tell you what you need. And cams are'nt that expensive if you find something that might work better. Or not.


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## Thumpin455 (Feb 17, 2010)

Then I will show you how to do a Qjet too. I've been waiting to do one for a member here until I can put it on a car and road test it. Need the weather to be decent with no salt on the roads before I can do that. Right now I am studying on what to do with the idle circuit, Cliffs book has been very helpful with the Qjet project.


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## Thumpin455 (Feb 17, 2010)

ALKYGTO said:


> I'll recommend you call Ultradyne/Bullet about that "old" cam. I can tell you that exhaust duration plays a significant role in controlling heat, and a "gas" cam will make it run hot and you'll have to run it "fat" to control the heat. I'm no expert, just speaking from experience. And thier tech department is real helpful, they have all thier grinds (even custom) recorded and will tell you what you need. And cams are'nt that expensive if you find something that might work better. Or not.


I plan on going through Bullet/UD when I get a custom cam made for this, I had this one laying around so I am using it as a baseline. Need to find out what this one does compared to race gas, because that is what I have the experience for with the 670s and this cam. I also have a 2802 on the shelf but I want to use that in the 400 thats going in the 65 GTO. 

I havent decided if I will use the RPM intake or a stock one for this engine, might go stock first then RPM after since the heads are ported. Definitely not using the Torker II on the shelf, might modify one of those for EFI at some point.

You run methanol with the blower dont you? That has to make for a serious amount of power. I cant wait to see how the other blower engine on the forum comes out. I wish I could build one, nothing meaner looking than a 6-71 sticking out the hood. The reason Im not using a blower or turbo to make the cylinder pressure is because with added air it needs added fuel, also the static compression needs to be lower to prevent detonation or lifting the heads. The blower cars I have driven and worked on were hellish fun despite only being 355 sbcs.


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## ALKYGTO (Mar 29, 2010)

> You run methanol with the blower dont you? That has to make for a serious amount of power. I cant wait to see how the other blower engine on the forum comes out. I wish I could build one, nothing meaner looking than a 6-71 sticking out the hood. The reason Im not using a blower or turbo to make the cylinder pressure is because with added air it needs added fuel, also the static compression needs to be lower to prevent detonation or lifting the heads. The blower cars I have driven and worked on were hellish fun despite only being 355 sbcs.


Yeah, straight meth. The supercharger actually ice's up on the outside when it's somewhat cool outside. It made 750 RWHP last time (shut it down at 5400 rpms too because I did'nt have a tach to work off my magneto.) and this season I've got a set of Dart heads to replace my munched 990 square ports. Really hoping to get some track time here this season.

I'm not sure about the E-85 (I've considered it) but it also makes the motor quieter than on gas, not as "violent". 

Eric's project is just outragous and should be one of the nicer GTO's on the planet when it's done. I'm sure I'm not alone in my excitement to see it done. arty:


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## Eric Animal (Oct 28, 2007)

Thanks Alky.....I don't know about on the planet, but in my neighborhood I hope! I would like to learn about this magical juice called E85....I don't see it too much around here.....I'm more of a 105 Octane gasoline kind of oldER Dude......Eric


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## Thumpin455 (Feb 17, 2010)

Its interesting that you dont see it. Long Island has 27 pumps carrying E85. Its more available to you than it is to me. 

I am really looking forward to your build. That is a badass GTO right there.


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## Eric Animal (Oct 28, 2007)

Thumpin, Thanks for the compliment on my car. I probably don't see it because I never really look!:seeya:


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## Thumpin455 (Feb 17, 2010)

I got cleaning done today, need to get a dipstick tube before I can put the oil pan on. Yanked one out of a 400 core but it was rusted out near the head. The rest of them are in Nebraska, so I will just order one from Butler Performance. I think one of the best tools I have ever bought is my bead blast cabinet. It makes short work of rust and crud that would be a pain to get off otherwise. It would be nice if I could stick an oil pan in there, but the oil and sludge would really plug that thing up. I need a parts cleaner and some good solvent, that is the next purchase after a new tool box.

Clean parts!









Long block.









Filthy oil pan from a 400 core. Tomorrows cleaning project.


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## Eric Animal (Oct 28, 2007)

Great pics! That oil pan will clean right up....I use a 3800psi power washer with warm water on stuff....works great but you will be filthy when you are done! E


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## Thumpin455 (Feb 17, 2010)

Yeah I am about to head out to clean it now, no warm water outside though. Just brake cleaner and some rags. Might just light it on fire and let it burn out of there..  

I decided to go with a hydraulic roller cam, so the flat tappet is coming out. I have concerns about flat lobes and no zinc in the oil, so a roller fixes that. Also it will have less friction, like newer engines do so its a double plus. Full roller valvetrain should free up some horses and use less fuel. Im sending the 48 heads to Butler on Monday to get worked over, might have them do a street port job. Why not make good power along with good mileage? This engine will probably find its way into my T37 when I get it up here.


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## BearGFR (Aug 25, 2008)

Thumpin455 said:


> Yeah I am about to head out to clean it now, no warm water outside though. Just brake cleaner and some rags. Might just light it on fire and let it burn out of there..
> 
> I decided to go with a hydraulic roller cam, so the flat tappet is coming out. I have concerns about flat lobes and no zinc in the oil, so a roller fixes that. Also it will have less friction, like newer engines do so its a double plus. Full roller valvetrain should free up some horses and use less fuel. Im sending the 48 heads to Butler on Monday to get worked over, might have them do a street port job. Why not make good power along with good mileage? This engine will probably find its way into my T37 when I get it up here.


So, why not a solid roller? Lighter lifters = less stress on the valve train. The usual argument of having to adjust lash "all the time" isn't really valid any more. Once a year - maybe. Plus with a solid you'd most likely run oil restrictors in the lifter bores = better oiling to the crank where that big 'ol 455 needs it. Use the Comp Cams Endurex lifters that have positive oiling to the roller bearings.

Bear


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## Thumpin455 (Feb 17, 2010)

Well a solid would be slightly cheaper, but I didnt want to change valve springs, valves, and install bore restrictors because the heads I am starting with are done already with hydraulic springs (comp 995). Also its difficult to find a solid small enough to do what I am doing. Most of them are quite large with long duration, not exactly what I want for this engine. Max power isnt the goal, a good vacuum signal with lots of bottom end is what I am looking for, along with a wider LSA than most solids have. I have a solid in my 79 Formula, not a problem with lash on it, but it is 270/[email protected] Kinda freakin HUGE.

Its not going to be running over 5000 rpm, so the lifters wont hurt it that much. The rest of the system is pretty light.


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## Mike_V (Mar 10, 2006)

How do you know what the real compression ratio is? Is there some table you put everything in and it spits out an answer? Sorry if this is one of those 'give me a break' questions, but this topic is why I switched to body and fender in school lol.


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## BearGFR (Aug 25, 2008)

Mike_V said:


> How do you know what the real compression ratio is? Is there some table you put everything in and it spits out an answer? Sorry if this is one of those 'give me a break' questions, but this topic is why I switched to body and fender in school lol.


Hey Mike ---- it sort of depends on what you mean by "real" compression ratio. There's a thing called static compression ratio and that's the one that people usually mean when they just say "compression ratio". That one is calculated from the various dimensions on the engine. The general formula is (swept volume + clearance volume) / clearance volume. It's the ratio of maximum cylinder volume (piston at BDC) to minimum cylinder volume (piston at TDC). Bore, stroke, piston deck height, head gasket compressed thickness, size of piston valve reliefs/dish/(or dome), and combustion chamber volume all influence this ratio.

There's also such thing as dynamic compression ratio. This measurement is more closely related to the actual pressure that's created in the cylinders as the engine runs. Static compression ratio is part of that, but it's also influenced a great deal by the timing of the various valve events - mostly the point in the compression stroke where the intake valve actually closes (because the cylinder can't really begin to create pressure until that intake valve is shut). Dynamic compression ratio will almost always be less than static compression ratio, because the intake valve almost always remains open until some time after the piston has passed through BDC and is already on it's way up inside the cylinder. This is determined mostly by the cam shaft being used.

I worked up a spreadsheet to calculate static compression ratio, in fact if you'll search on here for "my" posts talking about compression you'll probably find a post that has it as an attachment.

Bear


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## Mike_V (Mar 10, 2006)

Yeah, the dynamic is what I meant. I'll search for your post - because how you factor all this in with CAM selection is beyond me. Thanks...


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## BearGFR (Aug 25, 2008)

Mike_V said:


> Yeah, the dynamic is what I meant. I'll search for your post - because how you factor all this in with CAM selection is beyond me. Thanks...


The concept is simple. The later in the compression stroke that the intake valve closes (thus being closed for "less" of the compression stroke), the less pressure the cylinder is going to create by compression. The devil is in the details of when to consider the intake "closed".

There's a dynamic CR calculator on various web sites, such as the one on the KB/Icon site here. Be aware that there's some debate about how to determine dynamic CR because there's debate about how to exactly determine the point at which the intake valve can be considered "closed" so that compression can begin. Then, too, if you have a well tuned intake system (carb, manifold, and heads) that flow well and keep flow velocity high, then it's possible that pressure can begin to rise even before the intake closes due to the inertia of the incoming intake charge "resisting" the action of the piston that's trying to make it reverse direction even though the intake valve is still open a little bit. Of course all that changes with RPM, so peak cylinder pressure can and will vary with RPM.

In short, there are so many variables to this question that, in my opinion at least, there's not a definitive way to determine exact dynamic CR. The best you can get is "reasonably close". For this reason, make sure you use several different tools to calculate dynamic cr - they can and will differ.

For all practical purposes, especially on a street engine, it's really not worth the risk of trying to push compression right to the limit. On my 461 that has a moderate solid roller cam and good heads, the difference in power between 9.4:1 (static) and 10.0:1 is less than 10 hp. For me with this engine that's already making right at 500 hp and over 540 lb ft. of torque, it just isn't worth the effort to try to push it and risk all the bad things that happen with detonation.

On a race-only motor that sees a steady diet of "good" fuel and where even one or two HP can make the difference between a payday and a long haul home with empty pockets, sure - it's worth it to squeeze every last pony out of it you can.

Bear


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## Mike_V (Mar 10, 2006)

THANKS FOR THAT WEBSITE LINK!! 



BearGFR said:


> On my 461 that has a moderate solid roller cam and good heads, the difference in power between 9.4:1 (static) and 10.0:1 is less than 10 hp.


That's it? I guss it's just seeing the power drop in the 1973+ cars that has me so focused on compression. What a huge hit those cars took.


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## BearGFR (Aug 25, 2008)

Mike_V said:


> THANKS FOR THAT WEBSITE LINK!!
> 
> 
> That's it? I guss it's just seeing the power drop in the 1973+ cars that has me so focused on compression. What a huge hit those cars took.


Yes they did -- but then they dropped compression a ton more than just .5 and also did other weird stuff - EGR valves, "smog pumps", hotter thermostats, retarded timing, different cam profiles... it definitely was not a happy time for performance. 

Cam design has come a long way since then.

A decent "rule of thumb" you'll find quoted for street motors with iron heads is to try to stay "close" to the octane rating of the fuel you'll be running. 9.3:1 for 93 octane, 8.9:1 for 89, etc. Can you get away with more? Sure. My 461 is happy on 93 with 9.46:1 because it has a somewhat rowdy cam. With "even more cam" (later intake closing event) I could get away with more static compression ratio --- provided I stayed on top of the tune up, kept the fuel mixture 'dead nuts' on, and made sure the cooling system was top notch --- but it still wouldn't be worth that effort if all I was trying to do was raise compression. Now, if I did it because I put in a lot rowdier cam with more duration and NEEDED more static compression to keep my cylinder pressure where it was before (later intake closing event) then that might be different. 


Ooops - I just realized that I've been hijacking Thumpin455's thread about his build --- and I'm really interested in that too! (sorry Thumpin') 


Bear


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## Thumpin455 (Feb 17, 2010)

Mike_V said:


> THANKS FOR THAT WEBSITE LINK!!
> 
> 
> That's it? I guss it's just seeing the power drop in the 1973+ cars that has me so focused on compression. What a huge hit those cars took.


A big part of why the power ratings dropped in 72 was because of how they measured the engines. The SAE system before had just the engine with no accessory drives being powered and in a certain temperature of air. The one they implemented in 72 had the engine as installed in the car, driving the alternator, power steering, water pump, etc. It wasnt due to the drop in compression, although that did cost some power.

The reason I am running high compression is to a certain extent, depending on lots of variables (like chamber shape, displacement, materials etc) the amount of work you get from a certain amount of fuel goes up with more compression. In other words you get more out of it and the engine is more efficient. 

This engine isnt about max power, but I do want cylinder pressure, so valve timing makes a difference. A wide lobe separation angle (LSA) and early intake closing will increase cylinder pressure, where as a tight LSA and late opening bleeds off pressure so you can squeak by with more compression on crappy gas. Since I dont have to worry as much about detonation, I can run lots more compression. The properties of ethanol also allow me to do other things to increase mileage that we cant do with gas, mostly in the area of utilizing heat. More on that later...


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## Mike_V (Mar 10, 2006)

So you did all the paint and body on the T/A, and now you're doing a custom engine build. Shocking how much people on this site know, unless you do this for a living; I'd only be semi impressed then :rofl:

Seriously, I can't wait to see the results of this - too damn curious.


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## Thumpin455 (Feb 17, 2010)

Mike_V said:


> So you did all the paint and body on the T/A, and now you're doing a custom engine build. Shocking how much people on this site know, unless you do this for a living; I'd only be semi impressed then :rofl:
> 
> Seriously, I can't wait to see the results of this - too damn curious.


Thanks. I painted the engine today, just waiting on the cam and stuff to get here now.

Ive been working on cars since I bought my first one at age 13. Before that I worked on farm equipment so I had a basic understanding of mechanical stuff. I went to school for automotive tech between my enlistments, but the only things in school I learned were rebuilding automatic transmissions, some electrical/electronics, and how to do alignments. I had already picked up pretty much everything else. I started doing body work and paint back in 2006, just dug in and learned how.

I was a cargo guy in the Air Force so I didnt pick anything up there. I just cant afford to pay someone to do all of this, so I learned how by doing it myself. I think anyone can learn to do all of this if they really want to. I wanted to have cool and fast cars so the only way I could do it was to do it myself. 

The fuel and ethanol conversion thing is the same situation, I do it so I can afford to enjoy my rides after I get them done. At $4 a gallon I would just be driving around in the soulless 98 Gran Prix because it gets good mileage, while the GTOs and Trans Ams just sit and rust. I would rather use them than have yard art. I do it because I love to do it, I dont make any money doing these projects, I just stay busy with them.


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## Thumpin455 (Feb 17, 2010)

87 octane is $3.99 today, yesterday it was $3.81. My days of buying it are now over, simply cant afford the stuff. That gives me motivation to get this engine done, and also ramp up production of my cattail vodka. I will harvest some cattails next week and get that process started for the year. Last year was impossible for me to do much, this year things seem to be working out for me.

I ended up ordering a hydraulic roller cam and all the related parts. I figured since I will be swapping cams I might as well make it easier, less break in, small chance of flat lobes, and I can reuse the lifters and pushrods. Should be here by Friday so I can get this engine together. Right now its looking like it will go in the 70 GTO since it is pretty much road ready, but with a 700R4 trans behind it to tame the 3.42 gear. I just ordered the rebuild kit for one of my cores, and the GTO is a nice car to break it in and do some testing. The fuel system is already cleaned from running ethanol, so that is one less thing to worry about too. Jim Butler is helping me with this build, and I will share everything with him so maybe they can come up with some things I dont think of.

Im starting on the Qjet for Scott tomorrow, the weather is nice enough I can start testing the changes. Once it is figured out I will share the info with you guys and send it out to him. Hopefully he will let us know how it runs on his GTO.


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## Mike_V (Mar 10, 2006)

When do you think you'll fire this up?


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## ALKYGTO (Mar 29, 2010)

Cattail vodka?!? 


I need to figure out how to make tequila from dandilions :lol:.

Back on topic.... Late model engines are back up in compression, mostly due to efficiancies in engine design and materials construction. Aluminum heads, plastic intake manifolds and low friction internals contribute to the octane tolerance of these engines. 

I know they have plastic intake manifolds for SBC's now, It would be relatively simple to do a classic Pontiac manifold out of composite compared to the Chevy unit. 

What about fuel injection? Even on your existing manifold you could incorporate a TBI unit with integral injectors for a low buck system. I believe they have stand alone control units for the 90's GM truck units. Port injection would be the best to optimize fuel distribution (and efficiancy) but would be more complicated and expensive. :cheers


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## Thumpin455 (Feb 17, 2010)

It will get fired as soon as it is all together and in either the GTO or the TA. I might be selling my 71 Mustang project so that would open up space and funds for the TA. Still thinking of putting it in the GTO for a while, I love driving that car. Im pretty sure that the 98 Formula is going to sit this year, it needs tires and premium gas because I havent switched it to E85 yet. So that means I will need the GTO for my car fix this summer.

How many dandelions you have? It would take lots of them, tons really..lol.

Chamber design, bore size, and materials play a big part in being able to raise compression on pump gas. I want to raise the compression in my LS1 and possibly the 3800 V6 in my Gran Prix too, with the modern engine designs it should be easy to get good mileage from one of them. Low friction helps more than you might think. Raising compression increases efficiency as well, you get more work out of the same amount of fuel if you squeeze it harder, it produces more torque than a low compression engine. Ethanol can withstand much more compression than pump gasoline can.

I have been thinking about EFI, the FAST EZ efi would work pretty good if it will handle the flow needed for ethanol. Not sure if it has the flexibility to tune for it since it doesnt use a laptop and it learns on its own. I still might try one, its worth a shot. Could always raise the fuel pressure.

A stock TBI from a truck would work on a milder engine, say a cam in the 067-068 range, but then again tuning is an issue since those used PROMs instead of the OBDII setup that is so easy to tune.

I want to stick with throttle body injection for now, might go port later on. One thing we can do to increase efficiency and mileage with ethanol is to heat it so it boils into a vapor as it hits the intake tract. You raise the pressure in the system, get the fuel temp over 200F, then when it hits the vacuum of the intake you get the pronounced cooling effect of the charge as well as a fog of fuel, rather than a spray. To put it simply, the smaller the fuel particles the faster, more efficiently, and more completely they burn, making good power and using less fuel since less fuel is wasted by being pushed out the exhaust pipe. 

Heat is something you want to avoid with gasoline, since the components of gas have differing boiling points, so by the time you have the high end hot enough, the low end has already boiled into vapor in the fuel lines causing vapor lock. You would need very high fuel pressures with gasoline to control it, and much more heat. Somewhere in the 400F range to achieve the same thing. Ethanol on its own has a boiling point of 173F, so it works very well for the heated fuel vapor system.

One reason why ethanol burns so much cooler than gasoline is due to more of it being used to do work than is used to heat the engine. The droplets burn faster but in a more controlled way, without spikes in pressures, and more of the fuel is used to power the engine. Gasoline is still burning long after it stops pushing on the piston, that ends up heating the head, block, and piston, creating excess waste heat in the process. Heating ethanol takes advantage of this along with the benefits of its cooling when it goes from liquid to vapor. This is why I am pretty sure I can get equal or better mileage from ethanol than I can for gas, provided the engine is configured in such a way to take advantage of its properties, and that negates using low octane gasoline in the engine.

Sure it has fewer BTUs, but BTU is a measure of how well a particular fuel heats water. If you want to heat water then gasoline is better. I would rather not have to have a large cooling system to keep my engine from overheating. It adds weight, expense and complexity, not to mention the majority of the fuel is going into waste heat that just warms the air outside the car. There is more to a liquid fuel for an internal combustion engine than just BTU content. 

If you run ethanol the same way you run gasoline, even in a high compression engine, you will not get the best mileage. You will probably make more power than on gas, but it still wont be quite as efficient. A big part of that is how we have to run gasoline cool in the fuel lines, how it has issues with detonation at higher temps, and how it lacks the latent heat of vaporization properties of ethanol requiring you to run cool air to get more power from it. If you run ethanol the same way, you will use more of it because you arent taking advantage of it as well as you could be. This is why most flex fuel vehicles lose 10%-20% in mileage between ethanol and gas, you are running it like its gasoline in a low compression engine.

EFI will allow me to heat the fuel before it enters the engine, since the system is pressurized the boiling point is raised over what we have with a carb. 60psi vs 5 to 7 psi is a big difference. Also once the fuel hits the float bowl, it is open to atmospheric so not enough pressure is on it anymore and it will boil in the carb. Carbs dont like to run on vapor, so I am limited in how much heat I can use with them. I have a few other ideas I will try with the carbs though, and that is also why I am using a Qjet instead of a Holley or Edelbrock. Better fuel management is possible with the Qjet. 

Eventually I will go with a port fuel system that also controls the ignition for me. Right now its not in the budget, and it would add to the complexity of the project. I need a baseline to start from to see what works and what doesnt, so we start with something simple, then go from there.


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## Thumpin455 (Feb 17, 2010)

BearGFR said:


> Ooops - I just realized that I've been hijacking Thumpin455's thread about his build --- and I'm really interested in that too! (sorry Thumpin')
> 
> 
> Bear


Your info is pertinent. Feel free to add whatever seems to fit, because this is a comparison between a low compression gas engine and a high compression ethanol engine. Showing the limitations of gasoline from other perspectives helps show the differences.


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## ALKYGTO (Mar 29, 2010)

I have'nt seen it mentioned yet but Alcohol is also an oxegenated fuel which is one reason it requires more volume, makes more power and runs cooler along with the diminished BTU count. 

As a side note, I also have a late model Grand Prix, a '97 GTP that I'm currently doing an engine "freshening" on. Pontiac equiped the GTP supercharged engine with "port" injection with the injectors in the cylinder head, where as the NA motors had the injectors in the intake manifold. Pretty neat stuff. Also has cross bolted steel mains and cap screw conecting rods. With minor mods, this front driver put out 240 hp to the front wheels and _averaged_ 26 mpg. I'm upping injector size and switching to E85 (with a cam change) for power _and_ economy. :cheers

I think a mild 400 cu in turbocharged motor on E-85 would be sweet, and I have my eye on a cantidate right now. Also would like to build a OHC six turbo motor some day. 




The thought of drinking cattail vodka reminded me of smoking banana peels lol.


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## Thumpin455 (Feb 17, 2010)

Gas is almost to $4.10 here now... looks like its gonna keep goin up.

Did some bead blasting today, getting things ready to make this new Qjet run real good on E85. I will show what I do to them as I go, lots of pics coming.











Also started the 70 today, made a video of it running yeast pee, thought you might like to see a Qjet instead of a Holley. It doesnt have a choke and it was 40F out so it didnt want to idle very well. The next carb will be fully functional, chocke and everything. This was more of an experiment.


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## ALKYGTO (Mar 29, 2010)

Please oil your hinges. :shutme


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## Eric Animal (Oct 28, 2007)

I'm drinking Grey Goose and 7-UP as we speak. If gas prices keep going up, it'll be cheaper to drink the E85 and burn the Grey Goose in the GTO!!! FAST E-Z EFI now has a dual quad add on system that plugs into the existing set up and will "support up to 1000HP"....saw it in June 2011 Hot rod Mag......I gotta find out if the system will work an a 871..... Especially after I just bought these QFT 750s ( they are sweet) ! Eric


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## Eric Animal (Oct 28, 2007)

ALKYGTO said:


> Cattail vodka?!?
> 
> 
> I need to figure out how to make tequila from dandilions :lol:.
> ...


You can't make Tequila from Dandelions.....by it's very definition, tequila is made from the juice of the Agave cactus!!!.....arty:


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## ALKYGTO (Mar 29, 2010)

Did you know it's illegal to export agave outside of Mexico? So I'm back to dandelions..... much more plentiful around these parts. :cheers

On a side note, I had a neighbor once who took a shot of Nitro and it almost completely shut his kidneys down.


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## Thumpin455 (Feb 17, 2010)

Got the paint done, still waiting on the cam, dipstick tube, and a few other things. The cam is an XE276HR, its as good a place as any to start. The intake, pan, and front cover are just sitting on it, but it looks kinda purdy like this.



















The thing about the EZ EFI is I dont know if it will let me richen the trim enough to run E85. I know it will flow enough since they say it will feed a 1000hp engine, I will call them before I buy one, but I still might pick one up for the 65 when the funds are available for it. Maybe I can trick it with more fuel pressure, right now I have no idea since I havent even seen one let alone ran it, set it up, or found anyone even thinking about E85 in one.

I got a load of cored pineapple skins and other spoiled fruit from my bud who works at the grocery store, about 150lbs of the stuff. I wonder how much sugar they have in them. Well tomorrow will be spent getting it all into barrels and started fermenting. First load of the season! I will use whatever I can get to make some fuel, its not waste to me.


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## likethat (Oct 5, 2007)

Watch out for the revenuers once the pots start thumping.:cheers


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## Thumpin455 (Feb 17, 2010)

Its legal to make fuel with the federal permit that is free and easy to get. We can make 5000 gallons a year without being bonded. Im not planning on making that much. You dont want to get caught selling it as moonshine though, they wont fine you based on what you have made, but on what your still could have made. Besides why would anyone want to drink fuel? Maybe the middle of the run would be ok if my still hadnt been assembled with lead solder, but you drink it now you get sick from it eventually. Doesnt smell good anyway, and that is by design.


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## Thumpin455 (Feb 17, 2010)

We got two inches of heavy wet snow last night, now it is melting. I am collecting that water so I can use it in my fermentation barrels for the first batch this year. Sometime in the next couple weeks I will put gutters up on the big shed and the shop to catch rainwater for the same purpose. That means I dont need electricity to pump it out of the ground. This run is going to be made from pineapple I got from the grocer for $1, its about 200lbs of cored stuff that is left over or cant be sold.

So while the engine is waiting on parts, the fuel is coming right along. Im not going to pay $4 for gasoline in my GTO, it just isnt going to happen.


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## Thumpin455 (Feb 17, 2010)

The first batch of the year is set up and already fermenting. Tried a couple different methods to see what works better. All will make some fuel, some just might make more. After the first of May I plan to get more barrels and set up more things fermenting, right now its whatever I can get, but in the next few weeks I will start on the cattails and make some serious fuel. What I would be spending on two tanks of gasoline is enough to buy 15 barrels that I can reuse over and over all year. 5 gallons of fuel from each one every week. Add that up.


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## Thumpin455 (Feb 17, 2010)

Finally got the cam, lifters, pushrods, rockers, and other small stuff. Decided to go with a shiny new aluminum valley pan too, keeps the crud out of the new engine. Its too chilly to work on engines today, but its supposed to warm up tomorrow and the next day. 30s are just too damn cold, my hands dont work so good and I dont want to mess with building a fire. Everything is finally here so I can build this sucker and get it moving. The only thing left to buy is a constant pressure valve body and adapter plate for the 700R4. Might just order that today. I already have a rebuild kit for the trans, just need to make sure it doesnt burn out from the TV and will bolt to my Pontiac.

Here is a pic of the parts!


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## ALKYGTO (Mar 29, 2010)

X-mas! Love it when the big brown truck comes around.


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## Thumpin455 (Feb 17, 2010)

All those parts on on the engine, and Scott's carb is done. Going to put it on the GTO tomorrow and see how close it is. Just in the event anyone wants to know how to do it, here is a good starting point to convert a Qjet to ethanol, its pretty easy and straight forward. If I forgot something I will add it later.

Ok here goes. This is a starting point for an 400-470ci engine with a decent sized cam and about 11:1. The main changes you would have to make for less or more compression/cam/ci is to the idle circuits, and of course the jets. There are only a few changes from what Cliff has in his book, but I showed what I did today. It is just like rebuilding one and you modify all the same parts, it just depends on how much more fuel it needs as to how far you open things up. Sorry for the blurry pics, the camera doesnt have a macro setting.

First disassemble the carb and clean it up. I like to bead blast them gently to get the crud off. This one came from a boat so it was covered in rust and oxidized pretty bad. It might have even sat outside for a while. 










This one wasnt bad since boats dont have throttle return springs and thus they dont have asymmetrical loads on the throttle shaft. Still it is going in a car and I want it to run right, so I do the bushings anyway. To do this you will need to get the kit from Cliff, it comes with a drill bit set up to self guide and open up the bores just enough to fit the bushings. First you need to grind down the bottoms of the screws that hold the throttle plates to the shaft. They stake them at the factory to keep them from falling out and killing the engine. If you dont grind off the protruding part it will break off in the shaft and then you had just as well find another one. Here they are ground off so I can unscrew them.










Then after removing the spring holding the linkage to the secondary shaft, you can pull the primary out, then you drill the bores with the special stepped bit.



















I wrapped tape around it to give me a guide as to how deep to make the new bore, you dont want to go too far in. 


























This is plugging the main jet wells, they tend to leak and did on this one.


























Now the meat. 

Ethanol and gasoline have different specific gravity, so the float will ride higher in ethanol. You either need to add weight to it, or set it a bit higher, I am still figuring out where they run best with brass or plastic floats, so I cant give an exact measurement just yet.


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## Thumpin455 (Feb 17, 2010)

Accelerator pump restriction. I opened it up to .046 Its where the drill bit is sticking out in this pic, kinda hard to see. Also the idle bleeds are .070, some need to be opened more, some less. Not pointed out in this pic is the booster passage, now its .040, it is on the feed side of the booster directly behind the brass nozzle. This actually made a pretty big difference in my first carb, its something I did last week and it worked. The two brass tubes coming out of this piece also get a drill, I made these .046 as well, they will richen the secondary circuits. The passages seem to flow enough fuel as they are, you just need the orifices and restrictions in the carb opened up a bit to flow more fuel.










Idle down tubes. Pull em out and drill the ends to .046. Pulling them out is described in Cliffs book, and he provides new ones in his kits. Simply you use a .090 punch to drive the inner tube down inside the collar, then you use a sheetmetal screw to grab them and yank them out with some ***** and a screwdriver as a fulcrum. This can be a huge pain in the butt, and one on the first carb gave me fits, but its out now.










Then reinstall them carefully. You can see one pressed in and the other sticking up above the housing. These are a big source of idle problems with Qjets, and they are sized to the engine specs, they are small on smaller engines, larger on larger ones. Most often they are plugged with the gunk that builds up in carbs, just cleaning them can often make a POS carb run great.










Idle mix bores. Drilled them to .106 These were of the sealed variety and I had lots of fun getting them out. If you dont do the down tube modification these will have almost no effect. With the down tubes sized right they work just like normal mix screws on a gas carb. The bigger holes make sure you can get enough fuel to let the engine idle correctly.










Drill the needle seat from the bottom to .152, use a check ball and a punch to make a new seat. Be sure to whack it on a piece of wood so you dont screw up the threads. Cliff says the windoed version flows the same as the solid version like this one, and he has new ones already at .150, so if you specify that he will include it in the kit and you wont have to drill and seat it. I forgot when I ordered it.










I drilled the jets from the bottom to .082, there were .074 before, so they should be close, maybe a bit rich. Its ok, you can get jets sized on either side of it. Currently i leave the secondary metering rods out, Im not sure we can get some small enough without turning them down on a lathe or in a drill press with a file. I know it will provide enough fuel for it, but I also know that all the stock rods I have now are way too lean. They need to be quite a bit smaller to work right, but if you can get the right sizes it should work just like normal. The best way to do final tuning is with a wideband O2, otherwise it is very difficult to read the plugs since they come out very clean without the normal discoloration.

Doing this will allow it to run on E85 and idle well. You still need to know how to tune a Qjet and what changes affect what part of operation. They have lots of adjustments and capability, that makes them more complex than a Holley or E carb, but it also makes fuel metering more precise.


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## Mike_V (Mar 10, 2006)

God, I understood your 'whys', but I'd never try that because I know I'd F it up :willy: Even when I was brave enough to try anything, I never opened a carb or used a rebuild kit because I have crap luck with small parts.


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## Instg8ter (Sep 28, 2010)

waiting for your Holley tutorial, have a 750 on the bench ready to go....


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## Thumpin455 (Feb 17, 2010)

It will be a little while before I do a Holley, I am putting one on my 67 Cougar and it still has lots of work to be done before its ready to run. 

Well here is what I start with on a Holley. I got this from one of the guys who does lots of Holley carbs, he is going to do my 1050 sometime this year. I would but it needs the boosters changed and I cant see buying a $200 tool to do one carb.

Primary Jet – 85
Secondary Jet – 94
Power Valve – 4.5 Primary, blocked secondary
PVCR -- .080 <-----important because of the jet spead above.(smaller and you're lean)
IFR .047
IAB -- .065
HSB -- .028
Booster -- .170 (your stock one is .160 or less) ( i swap these)
anti-siphon -- .028
eholes -- . .028-.031 and should be 2 of them one at top and one in middle.
Accel pumps are both 30cc (50cc is ok)
pump cams -- Orange/
squirters -- .037-.042 (hollow screw)


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## ALKYGTO (Mar 29, 2010)

Very nice writeup. :cheers 

Q-jets can still be found in the boneyard, so now's the time to snatch a few up. I'm planning on switching out the dreaded electronic Q-jet on my Riviera some day soon. 

I'll add also that some of the Holley metering blocks are "thin" in the casting areas around #1 and #22 and drilling them out much larger can break through the outside. The cast HP metering blocks they sell are "meatier".


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