I just pulled the lt4 HC last night out of the 383 for Bret's cam. I was looking at the timing chain and I was wondering. I pushed on the side of the chain and it moved about 1/2". To me it seemed a bit much but I would like other people's opinion. The timing chain had about a est. 35-40k on it with me doing 25k of the miles on it.

 

Sounds pretty normal to me. Chains start to strech as soon as they are rotated.

 

i believe i heard somewhere that 1/4" is the limit. i had 1/2" deflection with my new chain after a line honing so i had to get an oversized crank pulley. maybe 1/2" is o.k. though

 

Yea, I wasnt sure. I am putting a Lunati single roller timing chain soon, I just neevr tore the car down to the short block and I wasnt sure.

THanks!

 

1/2 inch is too much, especially with a linkbelt type chain.

I replaced one once with a cloyes chain only from O'Reillys, it had OVER 1/2 inch of slack out of the box !!! I went and picked up one from the local chevy dealership and it had right around a 1/4 inch out of the box with new gears !!

 

I read somewhere (probably here somewhere) that the reason for the added play in the LT1 timing chain is to keep the load on front cam bearing down because of the added strain from waterpump being driven off the cam sprocket ...but I'm no expert

 

I had to get a Cloyes oversized crank sprocket for my new Lunati chain. LT1's normally have alot of slop. The bottom gear fixed mine.


Frank

 

What's the part # for the Lunati chain and Cloyes oversized sprocket you used?

 

Chain is Lunati part number L3193092. The bottom sprocket is Cloyes part number S505.

Frank