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Old 08-11-2020, 12:49 PM
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Default Loose Timing Chain

How can you determine if you need a .005 or .010 short timing set?

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Old 08-11-2020, 04:33 PM
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This is what it looks like with a STD chain
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Old 08-11-2020, 04:53 PM
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That a brand new std chain?

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Old 08-11-2020, 05:04 PM
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Yes

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Old 08-11-2020, 05:19 PM
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Based on that picture I would order the .010 chain and see if you can install it.
Tom V

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Old 08-11-2020, 05:32 PM
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Default Are the gears new, too ?

If they are new gears, I agree with Tom V that the .010 might fix it.

Good luck!

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Old 08-11-2020, 05:47 PM
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Tim,
How much were the main saddles cut?
Jeff

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Old 08-12-2020, 05:59 AM
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I don't see that even .010" is going to help that much!
You may very well only beable to save that with a two gear drive set up .

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Old 08-12-2020, 07:11 AM
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That’s a problem. This a new build ? If so I’m on the same thought as Shaker on the caps.

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Old 08-12-2020, 07:20 AM
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Default Need Mike G

How did the ends of main bearing shells line up with the parting line?

Question is, did a linebore go high or is this a bogus chain and gear set?

Clay

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Old 08-12-2020, 11:12 AM
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Unknowingly at the time I let a butcher put this engine together, a pontiac guy butcher. Unfortunately this is not the only thing he ****ed up.

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Old 08-12-2020, 12:00 PM
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Quote:
Originally Posted by steve25 View Post
I don't see that even .010" is going to help that much!
You may very well only beable to save that with a two gear drive set up .
Except for the noise, Not good on a street car at all, (A chebby SB guy installed one and it was on the engine for two weeks max). Race is a different story.

Who makes a two gear set-up? Two gear would make the engine a reverse camshaft rotation boat deal. $$$ with getting a cam grinder to do one of those for a Pontiac.

Tom V.

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Old 08-12-2020, 12:03 PM
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Sorry, 2 gear with the idlers.

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Old 08-12-2020, 12:44 PM
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Quote:
Originally Posted by Tim Corcoran View Post
Unknowingly at the time I let a butcher put this engine together, a pontiac guy butcher. Unfortunately this is not the only thing he ****ed up.
I feel for you guy! In my case the cam to crank center line distance was shortened by .045" ! I had to throw away a fully prepped block ( $$$) because of botched line hones (3 times).

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Old 08-12-2020, 03:17 PM
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Can a machinist fix the line hone or is the block trash. I'm not going to put a gear drive on a street car too noisey

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Old 08-12-2020, 03:31 PM
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Maybe try another (brand) std timing set?
Was it line honed, bored and honed, or neither?

Another cut and run will only put it deeper in the block.

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Old 08-12-2020, 03:46 PM
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Quote:
Originally Posted by Tim Corcoran View Post
Can a machinist fix the line hone or is the block trash. I'm not going to put a gear drive on a street car too noisey
I'd put a guide plate or tensioner on passengers side to take up slack.

And they do make "quiet" gear drives. Don't know how quiet they are but can't be loud like the "noisy" version. They make them that way on purpose just for the noise.

Clay

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Old 08-12-2020, 03:49 PM
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Have someone measure the center to center measure from the crank to the cam. I would say a .010 under will be short enough.

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Old 08-12-2020, 03:51 PM
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Quote:
Originally Posted by Tim Corcoran View Post
This is what it looks like with a STD chain
I bet a .010 chain will fix it. You'll be surprised how much tighter it's going to be.

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Old 08-12-2020, 05:47 PM
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Yeah but by the looks of my main bearings I may need work on the bores to fix it. I will know more after I get the machinist to look at everything. It may be the crank mains and the bores may be OK.

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