4spdcuda66
Well-Known Member
Should the timing chain be taut on both sides, or is there an acceptable amount of slack? If slack is allowed, how much is acceptable?
Allowable slack in timing chain?
- Thread starter 4spdcuda66
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Just don't spend less than $100 on a timing chain and gears & always run one of these.........
https://www.summitracing.com/parts/clo-9-5387/overview/
Yes it says for silent chains, but I use it on all the small blocks.
https://www.summitracing.com/parts/clo-9-5387/overview/
Yes it says for silent chains, but I use it on all the small blocks.
furrystump
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I have had bad luck with tensioners. The spring loaded guide cracked right near the pivot and the flat spring fell down into the bottom of the cover. It also chewed up the inside of the cover. Didn't make any noise but had been like that for awhile. I installed it during cam change about four years ago. I won't put another one in. Don't go cheap on the timing set.
65wgn440
Well-Known Member
Normally you would rotate engine clockwise until you are at TDC on timing indicator, then rotate engine counterclockwise slowly while carefully watching distributor rotor. Stop rotation as soon as you see the slightest movement of rotor. Read how many degrees crankshaft has turned on timing tab. The less the better obviously. 10 degrees on a stock engine would be on the outer limit of acceptable, I would think.
4spdcuda66
Well-Known Member
OK. Thanks guys.
nm9stheham
Well-Known Member
1/2" of side-to-side timing chain slack sounds like a 'service limit'. At service limits, the timing will be retarded 3-5 degrees. That will very much adversely effect low/mid RPM throttle response and torque.
nm9stheham
Well-Known Member
10 degrees would run pretty badly.... if the chain was still on there! IIRC, one tooth off is right at 15 degrees.
nm9stheham
Well-Known Member
Then you are in the right place LOL.... I am just wondering how long I have to spend in jail because I spent less than $100 on a chain....!
Just run a gear drive if it bothers you.
I used a tensioner with a double roller. I don't think that is necessary after I did it. A good double roller will work great for a long time.
If you have a doubt about how loose is acceptable, just replace it with at least a name brand double roller kit and as far as tensioners are concerned, practically every car built in at least the last 10 years come with them. They are a good addition as long as you use a quality part. An oldie but goodie quote, " Quality is remembered long after the price is forgotten "
4spdcuda66
Well-Known Member
Looks out of spec to me. If I remember correctly, once it's on, both sides are pretty taut. This one is 1/2 inch out anyway. I've read a lot of mixed reviews on adding tensioners. Thanks for the input, FABO!
So true!
Saw a chevy chain so loose it rubbed through the timing cover.
Renember to tighten the bolt that holds top gear, a drop of loctite too. I learned the hard way,my power wagon quit when i was breaking trail in 3 feet of snow. A chevy had to drag me home. How embarassing. The eccentric came loose and fuel pump stopped chooching....
Renember to tighten the bolt that holds top gear, a drop of loctite too. I learned the hard way,my power wagon quit when i was breaking trail in 3 feet of snow. A chevy had to drag me home. How embarassing. The eccentric came loose and fuel pump stopped chooching....
Ran this timing chain and gear set on a 600 HP small block.............
https://www.summitracing.com/parts/clo-9-3603x9/overview/make/chrysler
and this tensioner.................
https://www.summitracing.com/parts/clo-9-5387/overview/
Ran the combination for over 1-1/2 years with the owner driving to work daily and street racing with some autocross thrown in. Almost no wear on the tensioner at all. The engine is back for a freshen up and the chain/gear set & tensioner can be reused. Please, go the cheapest way you can. We'd love to race you!
https://www.summitracing.com/parts/clo-9-3603x9/overview/make/chrysler
and this tensioner.................
https://www.summitracing.com/parts/clo-9-5387/overview/
Ran the combination for over 1-1/2 years with the owner driving to work daily and street racing with some autocross thrown in. Almost no wear on the tensioner at all. The engine is back for a freshen up and the chain/gear set & tensioner can be reused. Please, go the cheapest way you can. We'd love to race you!
65wgn440
Well-Known Member
Been working as an automotive tech for about 30yrs, I've seen MANY engines with more than 10 degrees of chain play still run decent enough that customers just requested to check tune-up. We would advance initial timing and advise them of chain stretch. Most would decline chain replacement after driving their vehicle. My test is not determining degrees of cam timing change, just degrees of slack in non-tension side of chain (which would also include tooth to chain wear) as measured in crankshaft rotation. 10 degrees of chain slack measured this way is a hell of a lot different than a chain that has jumped a tooth. This is just an indicator of chain wear, BEFORE it jumps time. I too have seen engines still running that have chains that have completely rubbed through covers. Customer's only complaint with a couple of those was an oil leak problem. How much play do you think those had ?? I know original poster had his cover off, while my reply is more relevant if engine is completely assembled, but just thought I would throw it out there.
nm9stheham
Well-Known Member
I guess I should have said 'badly compared to how it should run'. My wife's cousin arrived for a visit from TN, and complained of an oil leak and I found the classic Chevy timing cover groove opened up by the chain slack. It cleaned it and epoxied it and he went on his way; he never replaced the chain LOL.
I am sure those customer did not want to spend the $$. But if you took an engine with 10 degrees of timing slack (retarded)and could take the slack out all of a sudden and restore that timing, then then the change in operation would be dramatic. I've taken 4-5 degrees of slack out by replacing a worn chain, and seen quite an improvement in throttle response and and briskness in drivability.
I am sure those customer did not want to spend the $$. But if you took an engine with 10 degrees of timing slack (retarded)and could take the slack out all of a sudden and restore that timing, then then the change in operation would be dramatic. I've taken 4-5 degrees of slack out by replacing a worn chain, and seen quite an improvement in throttle response and and briskness in drivability.
65wgn440
Well-Known Member
Well, even though we're going back always, these were probably mostly old beater vehicles that would make their owner's happy by just starting and running. Plus they were nothing to rave about back then (performance wise), even when they were new. I still can't believe all the time/labor we would spend, trying to get that junk to run decent. (late 70's to late 80's stuff)
Just because someone got away with doing something one way does not make it recommended practice. Some people have survived falling out of a plane but I doubt any of them would do it purposely just because there would be a chance of survival.
famous bob
mopar misfit
I wouldn`t run a 1/2" slop in anything !
abodyjoe
Well-Known Member
so its apart now? have any pics of the slack?
i i'd tend to think if you ar questioning it then maybe you should just replace it. be piece of mind for me..
"Allowable" and what makes sense under the circumstances are two different things.
If you know it's 1/2", then you have it apart. Why do all of that work and then put it back together, knowing it'll have to come apart again?
Get a good double roller and then you can use it if/when you rebuild.
Maybe try advancing it a few degrees for some low end. I've done that on stock engines to try to help with MPG.
If you know it's 1/2", then you have it apart. Why do all of that work and then put it back together, knowing it'll have to come apart again?
Get a good double roller and then you can use it if/when you rebuild.
Maybe try advancing it a few degrees for some low end. I've done that on stock engines to try to help with MPG.
Why should anyone listen to you? All you do is build record breaking engines for a living. What's that got to do with anything?
Cannot agree more with you liking the tensioner. I even modified one to use on my 331 Hemi. Fits like a glove now. Double roller and all. I cannot wait to hear it bust a move.
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