[Ozzmann]

Does anybody make a .030 shorter chain?

[Will]

What would lead to needing a chain that short?

[dataway]

Align boring that leads to crank being .015 closer to cam?

[Ozzmann]

Originally Posted by dataway

Align boring that leads to crank being .015 closer to cam?

Correct!

[steve25]

Jez, .030"!

I would look into adding a small tensioner.
Actually I would be looking into this even if my motor did not need a shorter chain!

[mgarblik]

Cloyes does make short timing sets. They typically stock -.005, -.010 -.015 can be had by special order. Possibly Rollmaster has short sets as well. Typically, there may be .001"-.002", variation in the chain itself. The "short" set actually comes from machining the sprockets to carry the chain a tiny bit higher. Are you sure you need a -.030" timing set? I have line honed many Pontiac blocks, some race applications as many as 10 times. Typically a Pontiac block that has been line honed 10 times is still nice and tight with a -.010" timing set. How loose is a standard set when installed?

[hurryinhoosier62]

Originally Posted by mgarblik

Cloyes does make short timing sets. They typically stock -.005, -.010 -.015 can be had by special order. Possibly Rollmaster has short sets as well. Typically, there may be .001"-.002", variation in the chain itself. The "short" set actually comes from machining the sprockets to carry the chain a tiny bit higher. Are you sure you need a -.030" timing set? I have line honed many Pontiac blocks, some race applications as many as 10 times. Typically a Pontiac block that has been line honed 10 times is still nice and tight with a -.010" timing set. How loose is a standard set when installed?

Mike, if it was align bored using either a Quik Way or Sunnen align bore lathe there is no way to adjust how much stock is removed from the saddle. This why I prefer using Berco or Berco style align bore lathes. You can adjust the height of the cutting bar to remove a minimal amount of stock from the saddle. I’ve seen diesel main saddles that were .030 below gear height or more from the factory.

[mgarblik]

Wow. If the center to center distance has really changed that much, he may have to go to some type of tensioner.

[lust4speed]

Son-in-law's block ended up .022" removed to clean things up. We looked around and never found a timing chain set that would work. He will be going with a gear drive that he has purchased but not installed yet.

[firechicken]

If needed, I recommend the Milodon single idler gear drive which I have used for years on my engine after getting tired of slacked out rollmasters.

Easy to degree in the cam, makes no noticeable noise that I can tell and has rock solid timing. Install isn't bad with engine on stand but surely could be done in car I think and is set to the individual engine regardless of line hone tolerances.

My experience, yours may vary

[Dragncar]

Originally Posted by hurryinhoosier62

Mike, if it was align bored using either a Quik Way or Sunnen align bore lathe there is no way to adjust how much stock is removed from the saddle. This why I prefer using Berco or Berco style align bore lathes. You can adjust the height of the cutting bar to remove a minimal amount of stock from the saddle. I’ve seen diesel main saddles that were .030 below gear height or more from the factory.

Question, how do you tell just how short of chain you need ? My block was cap fit by Dan and you can still see some of the original factory line honing marks remnants in the block. I expect to need a shorter chain, but how short ?
Trial and error ?
I have not put the crank in the block yet, maybe this weekend so I can got some sort of idea. I believe Spotts sells .003 shorter chains, might start there. But it can get expensive if its still too lose. I don't expect to need a real short chain as Dan was a perfectionist and had a boring bar like the Berco or one like it.

[Scott65]

Originally Posted by firechicken

If needed, I recommend the Milodon single idler gear drive which I have used for years on my engine after getting tired of slacked out rollmasters.

Easy to degree in the cam, makes no noticeable noise that I can tell and has rock solid timing. Install isn't bad with engine on stand but surely could be done in car I think and is set to the individual engine regardless of line hone tolerances.

My experience, yours may vary

I've had good luck with mine as well.

[Ozzmann]

Originally Posted by mgarblik

Cloyes does make short timing sets. They typically stock -.005, -.010 -.015 can be had by special order. Possibly Rollmaster has short sets as well. Typically, there may be .001"-.002", variation in the chain itself. The "short" set actually comes from machining the sprockets to carry the chain a tiny bit higher. Are you sure you need a -.030" timing set? I have line honed many Pontiac blocks, some race applications as many as 10 times. Typically a Pontiac block that has been line honed 10 times is still nice and tight with a -.010" timing set. How loose is a standard set when installed?

Builder said we need.030, we were already running a .010 chain. I may look a drive gears, but I have read they can be hard on the valve train, as a chain helps damper some,
anyone have any thoughts on this?

[hurryinhoosier62]

Originally Posted by Dragncar

Question, how do you tell just how short of chain you need ? My block was cap fit by Dan and you can still see some of the original factory line honing marks remnants in the block. I expect to need a shorter chain, but how short ?
Trial and error ?
I have not put the crank in the block yet, maybe this weekend so I can got some sort of idea. I believe Spotts sells .003 shorter chains, might start there. But it can get expensive if its still too lose. I don't expect to need a real short chain as Dan was a perfectionist and had a boring bar like the Berco or one like it.

The best place to measure is the distance from the bottom of the cam bore to the saddle side of the main. I used to be able to quote the minimum spec, but middle age has set in. Someone here can probable tell you what it is. Another way is to measure the distance from the deck surface on a virgin block to the saddle and compare the measurement to your block. I seen very few blocks that couldn't use a slightly shorter setup.

[mgarblik]

Originally Posted by Ozzmann

Builder said we need.030, we were already running a .010 chain. I may look a drive gears, but I have read they can be hard on the valve train, as a chain helps damper some,
anyone have any thoughts on this?

Does your builder have an opinion on the situation? Seems like a gear drive may be your only real option at this point. A BOP belt drive would do the job but hardly appropriate in a street build in the street section. I am a little perplexed as to why they would have machined the mains that much without a plan? But I guess a gear drive would get you out of trouble.

[Ozzmann]

Originally Posted by mgarblik

Does your builder have an opinion on the situation? Seems like a gear drive may be your only real option at this point. A BOP belt drive would do the job but hardly appropriate in a street build in the street section. I am a little perplexed as to why they would have machined the mains that much without a plan? But I guess a gear drive would get you out of trouble.

The line boring happen before I ever had the block, sometime in it's previous life.
We have had this running already with a .010 chain, it was still a little loose but it ran great and I never had any issue with the timing. Just thought while we are in here again we should try and address the problem properly.

[dataway]

Could you measure from top of cam journal, to bottom of crank, then subtract 1/2 cam journal diameter and 1/2 crank diameter?

[gtobob67]

https://www.facebook.com/permalink.p...54349891267211

[mgarblik]

Originally Posted by Ozzmann

The line boring happen before I ever had the block, sometime in it's previous life.
We have had this running already with a .010 chain, it was still a little loose but it ran great and I never had any issue with the timing. Just thought while we are in here again we should try and address the problem properly.

OK, I understand. If a -.010" set is at least snug when new, a -.015" set may do the trick. If you want to PM me, I can get you the direct contact at Cloyes and you can ask the engineer if he can make you a one off set as short as possible and try that. Even though the cost may be higher than shelf parts, it should be must less than a gear drive.

[track73]

I had a similar issue with a late model engine I freshened. I used what was called Cam Correct. I don't know if is still around, but it consisted of a jig and a tensioner foot along with the spring. I still have the jig and have used it on newer builds. My engines were always fast and reliable. I suspect it could be fitted to a Pontiac with some adjustments because of the machined block front.