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Stan Weiss · 09-09-2019, 07:10 PM

Quote:

Originally Posted by Formulajones

Not that I've seen Stan, but I'd bet Paul could help with that if it's Lunati specifically that you're looking for.

I should clarify when I said TDC I was talking TDC on the overlap stroke. Specifically looking for the intake valve to be about .030 further open than the exhaust valve so that when the piston travels to BDC it's pulling more on the intake and filling the cylinder with "less" hot exhaust gasses. This helps to keep temps down on the following compression stroke. Advancing the camshaft more accomplishes this but harder to do on cams with wider LSA.

Thanks. I am not sure how many cam companies show this information. Comp Cams has 106 and 110 listed in their master lobes and Ultra Dyne has 104 106 108 110 listed in their master lobes list. Crane shows 104 as Intake and 114 as Exhaust and Isky does not have this information in their master list.

Stan

Stan Weiss · 09-09-2019, 07:14 PM

Quote:

Originally Posted by pastry_chef

Scroll down to page 175.
https://www.jegs.com/VendorInfo/Luna...ti-catalog.pdf

Thanks Mike

Stan

pastry_chef · 09-09-2019, 07:27 PM

Here is a quote from Harold Brookshire, regarding lift at TDC overlap. This in context to giving an average street guy an easy way to cross-check.

Quote:

The intake lifter should be about .030" higher than the exhaust, with an OK range being .025" to .040". If the intake is anywhere in this range, your engine will run good. If the exhaust valve is the same height or higher than the intake, the cam needs to be advanced, either by a bushing, or even by advancing a whole tooth. It just depends how far off it is. And this does not mean the cam was ground wrong, but that all the clearances involved have stacked up the wrong way. As long as you get the intake lobe in the 'sweet zone', the engine will work as promised..

LPI · 09-09-2019, 11:26 PM

This is by far one of the best quality timing chains that many people have never used.

Progear

Formulajones · 09-09-2019, 11:30 PM

Quote:

Originally Posted by LPI

This is by far one of the best quality timing chains that many people have never used.

Progear

I've used the Avon/Pro gear and it is good quality but the problem with those is they are very hard to come by. Especially for Pontiacs.

I bought one more than a year ago for one Pontiac cam install I did here, but when I went back to get another one for a Pontiac cam install just a couple months ago, they were unavailable with no ETA when they would come in. Internet search tuned up no other vendors. I couldn't wait so had to go another route.

There are very few vendors that even carry those things so you have very little shopping choices.

PAUL K · 09-10-2019, 12:08 PM

Quote:

Originally Posted by 70GS455

I would bet money most people's measurement error is more than one degree (except a professional engine builder)

Sent from my SM-T817V using Tapatalk

Agree

PAUL K · 09-10-2019, 12:09 PM

Quote:

Originally Posted by Formulajones

Paul Carter has.

Matter of fact his experimentation with Voodoo cam lobes, as well as knowing Harold, typically has those cams installed a degree or 2 further advanced than what the cam card recommends, as he has found they work better like that.

Specifically why I installed the custom piece with Harold lobes on a 106 ICL rather than the 108 that comes with the cam card.

Also looking for a specific intake/exhaust valve relationship at TDC that seems to confuse a lot of people here.

Hopefully he'll have the time to share the results

gtofreek · 09-10-2019, 12:42 PM

Quote:

Originally Posted by LPI

This is by far one of the best quality timing chains that many people have never used.

Progear

Do you sell them? I remember you telling me about them, but not sure where to get them. We couldn't find them through our regular vendors. Sure would like to try one some day.

Formulajones · 09-10-2019, 02:07 PM

I think you're the one that told me about them Paul. I put one in dad's car when we did that cam swap. I had to order it from some place back on the East coast and it took a week to get here. It was the only place that had a Pontiac chain in stock and one of the only active vendors on the list that still carried Avon.. There were a couple other places on the vendor list but one had went out of business and I assume the other did as well because I had no luck contacting them. None of the normal speed shops and vendors carry the brand. Can't find them at Summit, Jegs, or Speedway.
Tried to get one for my Firebird, no dice. So when it came time to install the cam in this most recent 455 build, again I tried to get one, the place on the East coast I found one before didn't have anymore for Pontiac and no ETA when they might. Had plenty for Chevrolet's though

As far as the chain, it's a nice piece. I used the 4,000 series for Pontiac with 9 keyway, and they even make the chain specifically for the type of camshaft you're running. I still had to monkey around on the keyways to get the ICL on the cam where I wanted it, and it wasn't where you would expect it to be, but as you already know it seems common to run into that with every camshaft no matter what chain is used.