[DHVoorhees]

Hello All, I'm new here and have been following the threads about Cam selection. I have a question about cam/spring tension to use. I just bought a 66 LeMans with a stock 326 block and heads(094). Been buying parts for a restoration and engine rebuild. Based on recomendations from another Pontiac forum I bought a Comp Cam from Summit #CCA-51-224-4 Camshaft, Hydraulic Flat Tappet, Advertised Duration 274/286, Lift .488/.491 . What I'm wondering is if anyone has a recommendation for springs and lbs of tension they should be for this cam. I'm still in the learning stages of this engine since I haven't had a Pontiac before. Thanks in advance, Daryl

[Singleton]

Looking at the summit page for that cam, they recommend the comp 995 spring.
What rear gear and transmission are you using? The duration @.050 for that cam is 230/236, which is fairly radical for a 326

[gtofreek]

That #995 spring will probably be way too much spring for the 326 heads. You need to check the spring installed height and find some springs that will achieve 115-130 lbs. on the seat[because the intake seats are 30°, they need more seat pressure] and 300-320 lbs. open, and it will be happy. IIRC, the 326 heads will set up around 1.550-1.600 or there about. The #995 spring will give about 150-170 lbs at that height.

It's easy to find a spring from the spring catalog. Just follow these steps:

Write down the installed height. Let's say for this example it's 1.565".

Now write down what the valve lift will be. Let's say it's .489" in this case.

Now, you can look up the springs in the dual spring section by O.D. to find a spring that is the right size.

Now, write down the valve spring rate, in this case we will use the Comp # 995 spring, which is 402 lbs. per inch.

Then we need to know what the spring is rated at. In this case, the # 995 spring is rated at 115 lbs. at 1.700 height.

Write down the coil bind height. In this case it is 1.020".

Now you have all the info, so you just need to do the math.

The spring is rated at 1.700, but your installed height is 1.565". You need the difference between them, which is .135". Now you multiply the spring rate by the difference of .135" which is 54.3 lbs.

Add the 54.3 lbs. to the 115 lbs. the spring is rated at when installed at 1.700". This gives you 169.3 lbs. on the seat.

Now you have a valve lift of .489", so if you multiply that by the spring rate of 402, you get 196.6 lbs.

Add the seat pressure of 169.3 lbs to the 196.6 lbs., you get 366 lbs. open pressure.

Now if you subtract the amount of valve lift, or .489", from the installed height of 1.565", you get 1.076".

Subtract the coil bind height of 1.020" from the open height of 1.076", and you have .056" of spring travel before the spring becomes solid, or coil binds. Here you want a minimum of .050" coil bind clearance.

In this case, the #995 spring would be way to stiff for a hydraulic flat tappet cam, but just right for a hydraulic roller cam[if one could be found with only .489" lift ;^].

[gtofreek]

Agree that that is a lot of cam for a 326. If it's mostly a stock build, you will not be happy with that. If you want something that will drive and behave nice, but have good power, I would suggest something like the Lunati VooDoo # 10510700, which is 207/213 duration at .050". This cam will idle nice and pull real strong in a stock type326 build. If you want a little more attitude, you might look at the 10510701 which is 213/219, but unless you make other mods like good exhaust and 4 barrel carb, maybe even a bit of stall converter, and gears I wouldn't go this route.

[rexs73gto]

I agree, that cam is way to big for the stock 326, plus with that kind of spring pressure you'll pull the studs right out of the heads after a short time of running. That cam would be more suited for say A 400 or 455 with a little bit of compression , something close to 10-to 1 comp. Those heads won't breath enought for you to get anything out of that cam. Go with something a little smaller or you won't like the way it runs or TRYS to idle.

[1967Tempest]

First off, welcome to the forum. You are now connected to the most elaborate, comprehensive and helpful use of the internet ever! The people here are top notch and you are in good company!

I am glad that you are rebuilding a 326. They usually get the "Cheaper to build a 400" mantra and people usually scrap them.

That said, the 326 is an awesome mill. But over camming is an issue. While they rev great, the combination of parts usually do not allow the use of higher HP parts. The 094 heads are the lower compression heads of 66. They will live on pump gas better than the 095 heads that will bump up compression to over 10:1.

Here is a good link to see the config of the 094 heads. They have relatively small valves compared to the rest of the Pontiac engines, because the bore is small on a 326 and if they were bigger, you would have issue with the valves hitting the block.

https://sites.google.com/site/ksmsin...ontiac-head-id

The first cam that GTOFREEK recommended will ROCK in a 326!! If this is your first Pontiac, the 326 is NOT a 327 Chevy. 207/213 SOUNDS small, but in a Yak will explode with torque off of the line! But will run out of breath at 4500 or so. Which is fine as 99% of cars live in the 2-3K RPM range.

I currently have a stock rebuilt 1966 326 with 094 heads that had a 2BBL. It was a replacement engine from Sears I think in the 80's by a previous owner of my 1967 Tempest Wagon. All I did was swap to a 4bbl intake and slap on a Holley 570 CFM carb. I did make it has a 4 speed, and it came with 2.56 rear gears. Car runs great! I Just took it on a 350 mile cruise Friday and Saturday. Kept up with traffic at 70-75 mph and got close to 18-20MPG even with my foot into it.

P.S. Buy the correct heads gaskets. DO NOT BUY FEL-PRO 8518!!!!!!! They will not fit! They look like they do, but you will have too much quench around the bore and will blow the head gasket..

[DHVoorhees]

Thanks for the quick responses and suggestions on the cam. In my initial post I should have mentioned the other mods that I have planned for the 326 and the rest of the car. Only bought it a week ago so I haven't gotten to everything yet.
I would like to keep this car for the street only, but with some aggressive features that won't break my bank account.
My plan is to do a full restoration, ie lift the body off the frame but not a full rotisserie. Clean up the frame and patch a couple of small rust holes in the floor pans and a couple in the trunk pan. Do the usual POR15 on all the vulnerable rust prone areas. Restore and paint the body which in fair condition except the rear drivers side wheel well needs a new panel welded in. Re-wire the car with all new harnesses. I tore out the interior yesterday and will be replacing it with a completely new interior and keep the gear shifter on the column(maybe).
Restore and upgrade the drive train. It currently has the stock two speed transmission and I would like to upgrade it with a four speed automatic or possibly something maybe easier make fit with a TH350 3 speed. I understand there is a th350 available somewhere that bolts right into place with minimal modification to the transmission crossbar and mounts. I don't know what's in the rear-end yet.
If I keep the 094 heads I'll port and polish them to open up any restrictions and improve air flow.
Replacing the original exhaust manifold with full length headers and stainless dual 2.5 inch exhaust.
Replacing the stock 2 barrel carb and intake manifold with an Edlebrock Performer RPM intake and a Summit 650cfm 4 barrel carb.
Convert the front drum brakes to 11 inch disk brakes and swaping out master cylinder with a new master cylinder and an 8" booster.
Eventually swap out the original distributor(points) with an HEI unit(electronic).
I'll go through the engine and see what the bottom side looks like when the time comes. Thanks

[1967Tempest]

Originally Posted by DHVoorhees

Restore and upgrade the drive train. It currently has the stock two speed transmission and I would like to upgrade it with a four speed automatic or possibly something maybe easier make fit with a TH350 3 speed. I understand there is a th350 available somewhere that bolts right into place with minimal modification to the transmission crossbar and mounts. I don't know what's in the rear-end yet.

TH350 will bolt right in with ZERO modifications. Driveshaft is the same size, because the TH350 and ST300 are the same length. You can even use the torque converter from the ST300 2 speed. Not that you would want to.
Just make sure that it is a BOP TH350.( Buick,Olds,Pontiac)

[DHVoorhees]

1967Tempest, you mention to not use the FEL-PRO 8518!!!!!!! because they don't fit and will blow out. What have you used that works better for head gaskets? Thanks Daryl

[gtofreek]

Originally Posted by 1967Tempest

First off, welcome to the forum. You are now connected to the most elaborate, comprehensive and helpful use of the internet ever! The people here are top notch and you are in good company!

I am glad that you are rebuilding a 326. They usually get the "Cheaper to build a 400" mantra and people usually scrap them.

That said, the 326 is an awesome mill. But over camming is an issue. While they rev great, the combination of parts usually do not allow the use of higher HP parts. The 094 heads are the lower compression heads of 66. They will live on pump gas better than the 095 heads that will bump up compression to over 10:1.

Here is a good link to see the config of the 094 heads. They have relatively small valves compared to the rest of the Pontiac engines, because the bore is small on a 326 and if they were bigger, you would have issue with the valves hitting the block.

https://sites.google.com/site/ksmsin...ontiac-head-id

The first cam that GTOFREEK recommended will ROCK in a 326!! If this is your first Pontiac, the 326 is NOT a 327 Chevy. 207/213 SOUNDS small, but in a Yak will explode with torque off of the line! But will run out of breath at 4500 or so. Which is fine as 99% of cars live in the 2-3K RPM range.

I currently have a stock rebuilt 1966 326 with 094 heads that had a 2BBL. It was a replacement engine from Sears I think in the 80's by a previous owner of my 1967 Tempest Wagon. All I did was swap to a 4bbl intake and slap on a Holley 570 CFM carb. I did make it has a 4 speed, and it came with 2.56 rear gears. Car runs great! I Just took it on a 350 mile cruise Friday and Saturday. Kept up with traffic at 70-75 mph and got close to 18-20MPG even with my foot into it.

P.S. Buy the correct heads gaskets. DO NOT BUY FEL-PRO 8518!!!!!!! They will not fit! They look like they do, but you will have too much quench around the bore and will blow the head gasket..

You would be surprised with these VooDoo cams. The duration at .200" is a lot more than other cams with the same .050" numbers. More high lift area. This cam is good to 5000 RPM in a 400. In a 326, I bet it makes good power to 5500 or so.

[gtofreek]

Originally Posted by DHVoorhees

Thanks for the quick responses and suggestions on the cam. In my initial post I should have mentioned the other mods that I have planned for the 326 and the rest of the car. Only bought it a week ago so I haven't gotten to everything yet.
I would like to keep this car for the street only, but with some aggressive features that won't break my bank account.
My plan is to do a full restoration, ie lift the body off the frame but not a full rotisserie. Clean up the frame and patch a couple of small rust holes in the floor pans and a couple in the trunk pan. Do the usual POR15 on all the vulnerable rust prone areas. Restore and paint the body which in fair condition except the rear drivers side wheel well needs a new panel welded in. Re-wire the car with all new harnesses. I tore out the interior yesterday and will be replacing it with a completely new interior and keep the gear shifter on the column(maybe).
Restore and upgrade the drive train. It currently has the stock two speed transmission and I would like to upgrade it with a four speed automatic or possibly something maybe easier make fit with a TH350 3 speed. I understand there is a th350 available somewhere that bolts right into place with minimal modification to the transmission crossbar and mounts. I don't know what's in the rear-end yet.
If I keep the 094 heads I'll port and polish them to open up any restrictions and improve air flow.
Replacing the original exhaust manifold with full length headers and stainless dual 2.5 inch exhaust.
Replacing the stock 2 barrel carb and intake manifold with an Edlebrock Performer RPM intake and a Summit 650cfm 4 barrel carb.
Convert the front drum brakes to 11 inch disk brakes and swaping out master cylinder with a new master cylinder and an 8" booster.
Eventually swap out the original distributor(points) with an HEI unit(electronic).
I'll go through the engine and see what the bottom side looks like when the time comes. Thanks

Personally, I think that not only would you be happier, but it will probably run better also if you aced the header idea and went with RamAir Restorations 2 1/2 " RA manifolds[http://www.ramairrestoration.com/pon...tml?mode=list], with their 2 1/2" system with X-pipe. This complete system with mufflers barely lost 16 HP from a set of open headers on a 500 HP 400. On a 326, it would be great! Quiet, no headers leaks constantly having to be fixed, no fitment issues, looks stock. The RA manifolds are like small, cast iron headers.

The RPM intake may be a bit much also for a 326. I would find and run a factory 68-72 iron intake. Damn good intake manifold and very hard to beat on an engine like this. I would then get Cliff Ruggles[on the boards here] to build you a Q-jet instead of running that Holley. You would have one awesome running 326 that looks stock, then!

[PunchT37]

Agree with Paul on the manifold. Either `68 to `72 cast or the regular Performer. Maybe even look into a light stall converter, depending on the gears/trans used.

[1967Tempest]

Originally Posted by DHVoorhees

1967Tempest, you mention to not use the FEL-PRO 8518!!!!!!! because they don't fit and will blow out. What have you used that works better for head gaskets? Thanks Daryl

Either use a NOS set, (Ebay every once and awhile) or you get the good stuff and buy the Cometics. They ain't cheap, but you'll never have an issue with them. Not sure about the part number on the Cometics..

[PunchT37]

I`d also look into getting the rocker studs pinned or swapped out to a screw in stud to keep em from pulling out with more spring pressures and rpm`s. Those Voodoo cams will wake up that little engine.

Once again, that 274 cam is way too much so, return it if you already bought it.


See what starting a new thread does?

[Tim Corcoran]

As already stated the comp cam you selected is not the correct cam for your build and it would idle terribly and have no power. That cam would work if you had ported heads, headers, a high stall converter and 3.90:1 rear gears and then you would need forged pistons and rods etc and it would be noisy and not too much fun to drive on the street. I second the Lunati VooDoo # 10510700 cam that would be a great cam for the 326, good idle great off idle power and lots or torque for the small cube long stroke motor. I also agree the RPM manifold is way wrong for your build, the best manifold would be the factory 68-72 Q-Jet manifold and forget about the Holley. And make sure you use made in the USA Hy-Lift Johnson lifters unless you want to have ticking lifters. Good luck with your build.

[gtofreek]

Originally Posted by 1967Tempest

Either use a NOS set, (Ebay every once and awhile) or you get the good stuff and buy the Cometics. They ain't cheap, but you'll never have an issue with them. Not sure about the part number on the Cometics..

The problem with the Cometics, in this case, is they do not have the kick-out's to clear the cylinder chamfers for the combustion chambers. The gasket will actually cut across the chamfer just enough to allow it to hang into the combustion chamber which would burn it out over time. Cometic's only come configured for the open chamber heads and cylinder chamfers. You can't use them on 67 and older engines, already been down that road. I have a factory style, steel layer gasket for a 326 at work, I will look to see if it has a brand or part # on it.

[gtofreek]

I did some math based off of Comp cams catalog spring specs and I figure you will need the #994 spring and have it installed anywhere from 1.625"-1.650". That should give you around 120-130 on the seat and 295-315 open, depending on rocker arm ratio and installed height. You need to see where your installed height is now, and decide what needs to be done to get it to 1.625"-1.650". There are several different things that can be done to change installed height, so it would help to know where you are now, to avoid speculation. I don't remember where the 094 heads setup at, or if I have even done a set. Done 092's, 093's, and such, I'm pretty sure the 094's will setup about the same.

[DHVoorhees]

Originally Posted by gtofreek

I did some math based off of Comp cams catalog spring specs and I figure you will need the #994 spring and have it installed anywhere from 1.625"-1.650". That should give you around 120-130 on the seat and 295-315 open, depending on rocker arm ratio and installed height. You need to see where your installed height is now, and decide what needs to be done to get it to 1.625"-1.650". There are several different things that can be done to change installed height, so it would help to know where you are now, to avoid speculation. I don't remember where the 094 heads setup at, or if I have even done a set. Done 092's, 093's, and such, I'm pretty sure the 094's will setup about the same.

gtofreek and all people in this thread, I really appreciate your help. Those details you have provided are extremely helpful and have saved me time and minimal stress. Thanks very much.
So now my shopping list is almost complete. I'm going to use the more aggressive VooDoo #10510701 camshaft and your recommended #994 springs. I can return the other cam that I had purchased from Summit. It's just shipping costs!
I'll have to take off the valve cover to measure the Installed Height but it will have to wait till the snow storm clears here in Maryland. We got hit by snow/sleet and freezing rain today and now it's too cold to deal with that tonight. I wish I had another garage for this project but it's outside till I get my 34 Ford Coupe finished and out of the way.

[goatwgn]

And dont forget, as stated before, install a TH350 trans for more off the line than any engine mod will give you. The ST300 is "missing" 1st gear from the vantage point of a Turbo 350 or 400. 2.52/2.48 vs 1.76. Keep us updated.

[1967Tempest]

I thought the Cometics had the correct "bulges".

this is a 350, but it is similair to the 326.

Incorrect 8158.


the correct 326/350 victor Reinz gasket. Which you cant get