[blykins]

Nice work, sir.

[gtofreek]

Thank you very much!

[harley3296]

What heads are you planning on running ,compression ratio and cam...

[pontibeast]

Engine porn...I feel all dirty after drooling on my keyboard I can't imagine any finer level of attention to detail.

[vidguy]

What heads are you planning on running ,compression ratio and cam...

SD Ported original 670's. Opened to about 80cc, Dave tells me. Probably end up at 10.5 to 1?
I know it's high but I hope a good cam and good gas can avoid detonation and make for a fun weekend cruiser that is very original. I can buy 101 and 103 octane gas near here.

I asked Paul to pick a cam, knowing that it is a street only Car that wont be raced more than a few times... I'll be cruising.. But I don't want to leave free power on the table!

[hurryinhoosier62]

Originally Posted by pontibeast

Engine porn...I feel all dirty after drooling on my keyboard I can't imagine any finer level of attention to detail.

DITTOS!! Every time Paul posts photos, I need a towel to mop up the saliva.

[gtofreek]

James, I come up with about 10.1:1.

[vidguy]

That's even more manageable!.

[gtofreek]

OK, I received vidguy's 670 heads from Dave at SD Performance. I must say, Dave does nice work. He surfaced every gasket surface on them, as well as CNC port them.

Here are a few pics.









Even installed a new water nipple!





Here is the flow sheet from Dave.

[gtofreek]

We received some Hydraulic roller lifters from Hylift/Johnson. These are some that they are starting to make for Pontiac. Only Problem is, I think they are making them from Chevy lifter bodies because the oil band is not in the correct location for Pontiac. So, I installed a roller cam[this one is a solid roller since that's all I have in roller for Pontiac at the moment] to check to see where the oil band fell. This cam has a .390 lobe on it, much bigger than most mild hydraulic roller cams. The base circle of this cam is 1.050"", and the base circle of the cam I would like to use would be around 1.135", so the oil band will be higher up on the smaller cam.
With the smaller base circle cam, the oil band did not come out the bottom of the lifter bore. It was about 1/8" from coming out. With the larger base circle cam, I don't see an issue running them. Here are some pics.









I just wish they could make some with actual Pontiac bodies instead of just Pontiac link bars. I'm so tired of hydraulic lifter issues nowadays. Noisy lifters has been an issue for a while now. Lunati says they get more noisy lifters complaints from Pontiac owners than anyone else. Maybe that's because they buy lifters from someone that has some parts made in Mexico, and the tolerances are not good. At any rate, I'm tired of spending my time and energy, trying to fix their problems. It's not just Lunati either. Hylift/Johnson is the only hydraulic lifter still made in America, and I can tell you this, none of the major cam companies get lifters from Hylift/Johnson. Some of these lifters made elsewhere, won't even oil the rockers because of a metering system that flat out does not work! How they sell parts like this is beyond me. I hope these lifters will be an option for us Pontiac guys now.

[blykins]

Have you tried Morel?

[gtofreek]

We used the ones Lunati supplies with their HR cams, and they are reportedly, and look like, Morels. They are quiet when cold[no noise at all, like a hydraulic lifter should be], but after the oil gets some heat in it[about 1-2 minutes, they get noisy as can be. Went from 1/2 turn pre-load, to 1 turn[with iron heads], and no difference.

[tom s]

Paul,the last 3 engines I did I used the Comps with no issue.Just got another set in to replace the solid rollers in my SD 421 engine.FWIW.Tom

[gtofreek]

Got it balanced. The front of the crank was off 95.9 grams, and the rear was off 86.4 grams. This was with the flexplate on.





Weight needed to be removed from the counterweight, so I removed the flexplate. Now it was off 86.1 grams in the front, and 35.4 grams in the rear. Weight still needed to come off the counterweight, so I neutral balanced it.





Got it balanced down to .4 gram front, and .2 gram rear.



Here is the balance sheet, and my notes.

[pontibeast]

Paul I am new to this level of engine's. What does neutral balancing mean? I have seen cranks that have been balanced, both drilled and with Mallory metal having to be added but I have never been taught what that term means. Thanks

[Squidward]

Glad to see an update. Getting closer!

[cnc]

Paul wow ....very impressive
I wish u were closer ....u sure are an attention to detail man....
James will be very happy and I'm sure impressed .with your work....

James .....lookin for a video when she's all back to ya :3gears

[gtofreek]

Originally Posted by pontibeast

Paul I am new to this level of engine's. What does neutral balancing mean? I have seen cranks that have been balanced, both drilled and with Mallory metal having to be added but I have never been taught what that term means. Thanks

Cranks are either internally[neutral] balanced, or externally balanced. What that means is that an externally balanced engine uses a counterweight on the flexplate/flywheel, or the balancer, or both. They use this counterweight to help balance the crankshaft. They go to counterweighted flexplates/flywheels, and balancers when there is not enough counterweight on the crank to internally[neutral] balance it. Pontiac had enough room to make the front counterweight big enough, but because of block configuration, they couldn't put a big enough counterweight on the rear, so they counterweighted the flexplate/flywheel only. So on a Pontiac, only the rear is externally balanced. Most externally balanced engines have counterweights on both the balancer, and the flexplate/flywheel. By going to lighter weight rods, and pistons, I was able to neutral balance the rear. Now I can neutral balance his flexplate. Pontiac flexplates did not have a counterweight welded to them like most counterweighted flexplates. Instead, Pontiac drilled four big holes on one side of the flexplate.

The problem with externally balanced engines is even though the crank is technically balanced, the flexplate/flywheel, and balancer are still have a counterweight on them that is pulling on the part, much like the moon pulls on the earth when it rotates. This counterweight, when spinning at several thousand rpm's, is trying to pull on the flexplate as it spins. External balancing is not really good for a performance engine. Performance engines are much better off if they are neutral balanced.

Mallory, or heavy metal is used to internally[or neutral] balance cranks. It weighs a little more than twice what steel weighs.

[gtofreek]

Originally Posted by cnc

Paul wow ....very impressive
I wish u were closer ....u sure are an attention to detail man....
James will be very happy and I'm sure impressed .with your work....

James .....lookin for a video when she's all back to ya :3gears

Thanks!

[pontibeast]

Thanks Paul, the machining side of engine assy has always been something I wanted to learn more about but it's hard to find someone in my area to learn from. This forum is a godsend.