# Hydraulic Cam Choice. Other suggestions



## Sonoma GTO (Jun 16, 2019)

If you had a 65 original matching 389, manual 4 spd, Tri-Power. and you had to pull the engine a second time because the rings didn't seal and scoring occurred with the initial rebuild, while your in there (different machinist and mechanic for sure), what would you do to improve performance while keeping the engine stock. Original rebuilt with Butler parts and Ross forged pistons. I bough the best stock parts Butler offered as suggested by them (compete kit, water pump etc). My machinist (new one) suggested a hydraulic cam shaft. The only other after market part I have installed on the engine is a Pletronics electronic distributor. 

Looking for suggestions. If you think a new hydraulic cam is a good choice, what would you suggest? Any other suggestions for improvement while still keeping fairly stock integrity.


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## O52 (Jan 27, 2019)

With a stock build it's hard to beat the 068 cam. Good for 9.5 and up compression and 91 octane friendly. 
It was the factory cam for the Tri-Power engine.


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## GTO44 (Apr 11, 2016)

Did he recommend a hydraulic flat tappet or hydraulic roller?


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## Sonoma GTO (Jun 16, 2019)

GTO44 said:


> Did he recommend a hydraulic flat tappet or hydraulic roller?


He didn’t say which tells me he may not be familiar with the older Pontiac engines. I tried to call Butler but they don’t answer anymore due to lack of personnel? All inquiries are now via email sad to say. The machinist is well versed in racing engines, maybe not specifically older Pontiac’s. I have not asked him yet but why I am inquiring here. I did see that option surfing Butler and Ames.


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## PontiacJim (Dec 29, 2012)

Sonoma GTO said:


> He didn’t say which tells me he may not be familiar with the older Pontiac engines. I tried to call Butler but they don’t answer anymore due to lack of personnel? All inquiries are now via email sad to say. The machinist is well versed in racing engines, maybe not specifically older Pontiac’s. I have not asked him yet but why I am inquiring here. I did see that option surfing Butler and Ames.



If you rebuilt the engine with the tri-power specs, you should have the factory "068" cam as noted.

To improve performance, what modifiactions are you willing to do? Stock heads or aluminum? Stock crank/rods or stroker kit? Factory exhaust manifolds or RA or headers?

Need a lot more info on what you are willing to do to the original engine and what more you expect to get out of it.


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## Sonoma GTO (Jun 16, 2019)

Hi Jim. Perhaps I misrepresented my intentions. I'm not necessarily looking to make it faster, just improved performance (sounds like an oxymoron) without a full modifications and without hurting its value as a stock GTO. Knowing next to nothing and reading internet articles is dangerous business and I'm not tearing her down again. I have read hydraulic cams are a better design in a manner that doesn't necessarily mean horsepower, but as a side benefit great. So stay flat tappet, go with hydraulic flat tappet, hydraulic roller? I dunno the difference. And like I said, last time goin in so if there's any suggestions you might have to make it simply a better running engine, I'm willing to spend some money to make the changes.


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## PontiacJim (Dec 29, 2012)

Sonoma GTO said:


> Hi Jim. Perhaps I misrepresented my intentions. I'm not necessarily looking to make it faster, just improved performance (sounds like an oxymoron) without a full modifications and without hurting its value as a stock GTO. Knowing next to nothing and reading internet articles is dangerous business and I'm not tearing her down again. I have read hydraulic cams are a better design in a manner that doesn't necessarily mean horsepower, but as a side benefit great. So stay flat tappet, go with hydraulic flat tappet, hydraulic roller? I dunno the difference. And like I said, last time goin in so if there's any suggestions you might have to make it simply a better running engine, I'm willing to spend some money to make the changes.


The roller cam has some advantage over the flat tappet cam in that the cam lobe is steeper so it opens the valve faster and the lobe top is flatter to hold the valve open longer.

See Pic #1. Flat tappet cam lobe on the left, roller cam lobe on right.

Roller cams put more side loading on the block's cast lifter bores - again, this is shown in Pic #1.

Pontiac did not intend to use roller cams, so the lifter bores don't all have bracing. The later Super Duty blocks did address this weakness and added the additional lifter bore bracing on all lifter bores.

Pic #2. Typical Pontiac block showing the 3 cross braces of the lifter bores. The other lifter bores do not have the additional braces.

Pic #3. This is the Super Duty 455. Note that the lifter valley has been modified with additional lifter bore bracing.

Pic #4. This is what a roller cam can do when too much side pressure busts out the lifter bore.

You can purchase an aftermarket lifter bore brace that will strengthen the lifter bores so they don't crack/break. The kit is sold through Butler Performance.



https://butlerperformance.com/i-24453570-sdp-mega-brace-lifter-bore-reinforcement-system-sdp-lbb1.html



If you decide to go with a roller cam, you want to get a roller cam kit like what Butler sells. It will have all the matching components you will need - cam, lifters, valve springs, valve retainers, valve locks, strong timing gears/chain, and pushrods. I would call them to get a recommended cam grind.



https://butlerperformance.com/i-31643339-butler-comp-custom-cam-lifter-master-kit-pontiac-hr-bpi-k-bp8010sp.html?ref=category:1272239



So adding the lifter bore brace, roller cam kit, and shipping costs you are looking to spend an additional $2,000.00. But, you will get a little more performance out of the engine.

On the other hand, you can purchase the Summit #2801 cam & lifter kit which could be a good choice or the #2802 cam & lifter kit which will be more aggressive and you will have to make sure your valve springs can handle the lift of this cam as well as check for valve retainer-to-valve stem clearance and coil bind. These cam specs show the RPM range that they work best at.









Summit Racing SUM-K2801 Summit Racing™ Classic Cam and Lifter Kits | Summit Racing


Free Shipping - Summit Racing™ Classic Cam and Lifter Kits with qualifying orders of $99. Shop Camshaft Kits at Summit Racing.




www.summitracing.com













Summit Racing SUM-K2802 Summit Racing™ Classic Cam and Lifter Kits | Summit Racing


Free Shipping - Summit Racing™ Classic Cam and Lifter Kits with qualifying orders of $99. Shop Camshaft Kits at Summit Racing.




www.summitracing.com





So the roller cam set-up versus flat tappet hydraulic cam set-up is $2,000 versus $167.00 (free shipping). And possibly valve springs.


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## Sonoma GTO (Jun 16, 2019)

Thanks a bunch Jim, that's quite an education. I did finally get some email dialogue with Butler. They suggested the Ram Air series with TPP valley pan.(TPP not an option in drop down menu) might have meant Tomahawk Valley Pan, of course most expensive. 

https://butlerperformance.com/i-316...2-241-507-541-hr113.html?ref=category:1234841

Why Ram not sure. I do have Ram (factory ordered, dealer installed) and they may have known that from the rebuild kit I bought 2 years ago. Other than that I think I'm set. If you have any other gotchas to look out for I'd appreciate hearing from you.


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## grotto107 (Sep 13, 2017)

Just a shout-out to Pontiac Jim. Thanks for all the time and knowledge that you contribute here on the board. We all are lucky and honored to have you here !
John Jackson


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## BearGFR (Aug 25, 2008)

Sonoma GTO said:


> If you had a 65 original matching 389, manual 4 spd, Tri-Power. and you had to pull the engine a second time because the rings didn't seal and scoring occurred with the initial rebuild, while your in there (different machinist and mechanic for sure), what would you do to improve performance while keeping the engine stock. Original rebuilt with Butler parts and Ross forged pistons. I bough the best stock parts Butler offered as suggested by them (compete kit, water pump etc). My machinist (new one) suggested a hydraulic cam shaft. The only other after market part I have installed on the engine is a Pletronics electronic distributor.
> 
> Looking for suggestions. If you think a new hydraulic cam is a good choice, what would you suggest? Any other suggestions for improvement while still keeping fairly stock integrity.


Hey Sonoma,

99.99% chance your engine already has hydraulic lifters. It would have from the factory, and unless someone at some point in the past changed it to have a solid lifter valve train, it almost certainly still does. You've got 4 choices: hydraulic flat tappet, hydraulic roller, solid/mechanical flat tappet, solid/mechanical roller. Because of the geometry involved with the relationship between the part of the lifter that contacts the cam lobe and the cam lobe itself, each one has its advantages and disadvantages. PJ already did a great job of showing those differences. Like everything else having to do with an engine, there are compromises. Hydraulic lifters, either flat or roller, normally are "set them and forget them" - meaning that you install them, adjust them properly, and you never have to do that again. Because they work using an internal piston and oil pressure, they pretty much 'automatically' adjust themselves for wear and run quiet. Solid/mechanical lifters have to be adjusted both initially and periodically in order to maintain the proper clearance (lash) between the face of the rocker arm and the valve stem. They also make more noise all the time. Hydraulic lifters though can experience a phenomenon where at higher RPM, they "pump up" so that the valve doesn't fully seat. They also are generally heavier than solid/mechanical lifters which means they're more prone to what's called "valve float" at high RPM. The speed of the spinning cam generates enough inertia to 'throw' the lifter off the lobe so that it bounces instead of staying in contact with the cam. Having this happen can kill an engine. Solid/mechanical lifters, usually being lighter, can tolerate higher RPM without this happening. 

So it's a trade off - choose the relative ease and low maintenance aspect of hydraulics and understand that you won't be able to spin it as high as you would be able to with solids, or go with solids and accept the maintenance and noise issues. 

The next choice is flat vs. roller. Flats are lead pipe simple and have been around for decades. Problem is, no auto manufacturers use them any more so getting quality parts can be a challenge, especially in the realm of camshafts. One hears "everywhere" about people who've "flattened" lobes on a cam during break-in or shortly thereafter because of poor materials and/or slack manufacturing tolerances. Also most of today's "off the shelf" oils no longer have the additives that help protect flat tappet systems - because no new cars use them - so one has to be very careful about their choice of oil The things they have going for them are cost and simplicity.

Roller systems are more expensive - much more expensive. You don't have to worry about oil choice as much, and also because of the geometry involved you can get a lot more valve duration (open time) with a roller without also having to live with large amounts of overlap (period of time when both intake and exhaust valves are open). Overlap is what causes that "rumpity rump" rough idle that people associate with a 'hot' cam. In reality, what's happening to cause that is that the engine is so inefficient at idle that it's stumbling all over itself just trying to stay running. This happens because at idle the valves are open too long and too wide, allowing spent exhaust gasses to get sucked back into the cylinder through the still open exhaust valve and push that nice fresh air/fuel BACK out through the still open intake valve. It's called reversion - and it's a bad thing. At higher RPM though, the inertia of the faster moving air through the engine takes over and stops that from happening. What you're actually doing with "hot cam" is tolerating that the engine is a dog at low RPM in exchange for making more power/torque at higher RPM. With a roller profile, it's possible to get more 'valve open time' without also introducing a lot of overlap. Sounds great, right? But... rollers, having more moving pieces and parts, mean that there are more things that can fail, and they can fail in ways that will take out the engine. What if one of the tie-bars that keeps the lifter from turning sideways lets go? When the lifter turns, the sharp edge of the roller will dig into the cam lobe and things quickly go downhill from there. Similar things can happen if the roller bearings/bushings fail and the roller falls out. But, yeah, with rollers you can get a lot more duration and quicker valve opening/closing ramps, all of which theoretically translate into more torque/power at higher RPM. 

So - no matter which way you go, you picks your poison, pays your money, and takes your chances.

For a street driven Pontiac, all things considered if I was starting fresh today and wasn't trying to build a high-horsepower engine, personally I'd probably opt for a only slightly more rowdy than stock hydraulic roller system because:

I wouldn't have to worry too much about oil additives
It would be relatively maintenance free and quiet
I could get a reasonable amount of duration without having to also tolerate a lot of low-end torque killing overlap
As long as I didn't go crazy on lift and duration, I wouldn't have to run really heavy valve spring pressures.
I say that, even though in my 400/461 I'm running a moderately rowdy solid roller  Because that's what I personally wanted and I'm willing to deal with the consequences. 

Regardless of which way you go, if you do choose a cam profile that's much more aggressive than stock, in our engines it's cheap insurance to also install a supplemental lifter bore brace to protect against ripping some of the lifter bores off the block due to higher side loading, especially if you choose to run an ambitious roller profile. 

Those look like this:









Bear


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## PontiacJim (Dec 29, 2012)

Sonoma GTO said:


> Thanks a bunch Jim, that's quite an education. I did finally get some email dialogue with Butler. They suggested the Ram Air series with TPP valley pan.(TPP not an option in drop down menu) might have meant Tomahawk Valley Pan, of course most expensive.
> 
> https://butlerperformance.com/i-316...2-241-507-541-hr113.html?ref=category:1234841
> 
> Why Ram not sure. I do have Ram (factory ordered, dealer installed) and they may have known that from the rebuild kit I bought 2 years ago. Other than that I think I'm set. If you have any other gotchas to look out for I'd appreciate hearing from you.


Yes, the valley pan they suggested, from what I read, is needed with a roller set-up because I think the link bars will hit the factory valley pan.

The kit is the RA IV specs which is kinda radical. That is some big lift numbers and totally too much for "stock heads." - my opinion. I see they tamed down the duration as stock RA IV is 308/320 advertised duration - so that is better, but still is going to put the engine in the lower mid-to upper RPM range with regards to engine power. It'll be fun with the 4-speed but might be a little sluggish on the bottom end. You may also have to raise idle speed and adjust the Tri-power to match the bigger cam. Don't look to get good gas mileage. LOL


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## PontiacJim (Dec 29, 2012)

grotto107 said:


> Just a shout-out to Pontiac Jim. Thanks for all the time and knowledge that you contribute here on the board. We all are lucky and honored to have you here !
> John Jackson


Thanks John. I'm nobody special, just an enthusiast like most here. Many others with more experience than myself, especailly with regards to the bigger race type builds. I just prefer the more mild builds that I feel are more "street friendly" without going into a debt equal to our national debt. It is all about matching parts to get your best build, and keeping costs down without what I regards as exoctic high end parts. Being able to smoke tires or chirp gears on an upshift for me is more fun than bragging rites that I have "X" amount of HP or my car turns 10 seconds in the quarter mile. You can throw a lot of money into your car/engine and then have some guy with a twin turbo 4-cyl car blow your doors off - and it will happen. So what was all that money worth when the 4-cyl guys kicked your butt? So I shoot for a solid, fun, build just like my younger days which got me in trouble with the cops and used up a lot of tires.


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## roger1 (Jun 25, 2020)

Just an FYI here. No expert at all. 
The Lunati hydraulic flat tappet cam choice was made by the guy who I bought my car from. He supplied all new components with the unassembled engine and all I had to do is get a machine shop to finish the machine work and assemble. I told him to put it on his dyno too. 425HP and 480 ft-lbs.


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## PontiacJim (Dec 29, 2012)

roger1 said:


> Just an FYI here. No expert at all.
> The Lunati hydraulic flat tappet cam choice was made by the guy who I bought my car from. He supplied all new components with the unassembled engine and all I had to do is get a machine shop to finish the machine work and assemble. I told him to put it on his dyno too. 425HP and 480 ft-lbs.


Pulled up the Cam Specs so people can see what they are.

*Voodoo Hydraulic Flat Tappet Cam - Pontiac V8 262/268*

Hydraulic Flat Tappet Cam. Great torque monster for 400-455 c.i. daily driven street performance vehicle. Excellent torque and HP production with heavier emphasis on the low to mid range. Will work in tri-power applications with 389-455 c.i. engines.

RPM Range: 1,300-5,500
Choppy idle. Advertised Duration (Int/Exh): 262/268; Duration @ .050 (Int/Exh): 219/227
Gross Valve Lift (Int/Exh) 1.5 rockers: .468"/.489"
LSA (Lobe Separation Angle/ICL (Intake Center Line - used for a cam degree wheel): 112/108
Valve Lash (Int/Exh): Hyd/Hyd


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## roger1 (Jun 25, 2020)

PontiacJim said:


> Pulled up the Cam Specs so people can see what they are.
> 
> *Voodoo Hydraulic Flat Tappet Cam - Pontiac V8 262/268*
> 
> ...


One thing I will say is that the idle is not choppy. It's actually pretty smooth. I've seen other comments from people that have that cam that say the same thing. Not sure why Lunati states that it's choppy.


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## BearGFR (Aug 25, 2008)

roger1 said:


> One thing I will say is that the idle is not choppy. It's actually pretty smooth. I've seen other comments from people that have that cam that say the same thing. Not sure why Lunati states that it's choppy.


Yeah, with 0.050 duration numbers of 219/227 I would expect it to be quite well mannered.

Bear


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## PontiacJim (Dec 29, 2012)

BearGFR said:


> Yeah, with 0.050 duration numbers of 219/227 I would expect it to be quite well mannered.
> 
> Bear


I think some of the descriptions are generic. I have seen this with other cam suppliers and can't see how the specs would include a "choppy" idle. It may have been that at one time the LSA was 110 and not 112. That would have made it more "choppy." I know over the years they will make minor tweaks to the cam specs and still keep the description.

The advertised duration numbers are really not that big either - less than factory numbers.

But, the cam can pull and has good dyno numbers.

Drop the idle down to around 450 RPM and you might get "choppy" as it attempts to stall the engine and then ramp up again?


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