[aceaceca]

Anybody have a motor that had a loose timing chain even with a new one installed. My current motor has this malady to the point of chain slap. I thought it was the fan hitting the shroud but it is not. My machinist buddy says it does happen. I tried 2 roller chains and each was loose. I have to find the factory one that came off it and see if it too was loose. Never run into this before.

[Tom Vaught]

Get in touch with Paul Spotts if you still have the sloppy chain. Spotts Performance.
http://www.spottsperformance.com/

He has a few of the slightly shorter center to center chains.

Tom V.

[ponchjoe]

Isn't the cause something to do with the main saddles being trued up usually?

[highrisk]

Spotts Performance is a great place. I would also give Jim Butler with Butler Performance a call. http://butlerperformance.com/

[Tom Vaught]

Originally Posted by ponchjoe

Isn't the cause something to do with the main saddles being trued up usually?

Correct!

Tom V.

[aceaceca]

I am going to wait till I have the front cover off and then just try putting the original chain on there for a look see. I do not remember if it was loose. The engine was a wet stand test engine that never went into a car so it had very little run time.

[mgarblik]

If you determine your chain is loose no matter what chain and sprockets you install, Cloyes Gear Co., in Paris AK. has chain sets available in -.005 and -.010 sizes. They can even custom match a set for you as tight as -.015". It is very unusual for a Pontiac to require a timing set more than -.005. Typically, the line hone operation can be performed 5 to 6 times properly before any undersize timing set is needed. But if a machine shop really screwed the block up, or there was severe damage to the main bearing area, it is possible. Give them a call if you get in a jam.

[aceaceca]

Thank you for all your input. What about going to a gear drive?

[Tom Vaught]

Originally Posted by aceaceca

Thank you for all your input. What about going to a gear drive?

Oh My! Don't even think about that deal.

Had a Ford Buddy who bought a 64 GTO Hardtop.
His brother owned a Chebby older car.
His brother decided to install a Gear Drive Gear set-up on his Chebby.
First week the car sounded like a Roots Blower car on Sterods.
Second week it started to get irritating for the people that rode with him.
With-in a month we had swapped out the Pete Jackson stuff for a normal Chebby Chain and gears deal again.
Are you getting what I am saying?

Tom V.

[aceaceca]

10/4 I knew that but now they sell loud and quiet sets. I have no idea what they mean by quiet. Anyway I retrieved the original gear and chain set. It is the alum cam gear with plastic teeth but if it fits tight I may use it. I received the McKellar #8 cam and lifters and the cam has the correct part number cast into it and a small 8 stamped on the front. All lobes and lifters look good. Lifters in a numbered block of wood.

[Tom Vaught]

The Plastic Gear stuff worked well as far as wear and camshaft harmonics.
Problem was heat over time would crack the plastic teeth off the upper gear and then the engine would slip timing and not start. I changed a bunch of them under GM Warranty in the early 70s for my uncle, a Pontiac Dealer. You had to clean the plastic crap out of the oil pan and oil pump screen too or the engine would run without oil and kill the bearings from the pick-up being plugged with the plastic teeth material.

If you never accelerate the engine and the Timing Set parts are new (not likely) you probably will be ok.

Tom V.

ps ALL roller chain type deals seem to have some slop in them over time running.
I always advanced the camshaft 2 degrees and then with the chain breaking it the timing was right on spec.

[aceaceca]

Been there, done that as well. Both on Chevy 350 and Pontiacs. Too old now to worry about it.