Timing chain......

[Small Block]

.....slack? How much is acceptable. 440 motor. Not a big horse motor. Just a driver. It looks like the slack may be about 1/2" or maybe a little more. Is this acceptable or should it be changed out. I've got a new kit coming but if this is within spec i'll shelve the new kit for later. Your opinion guys. Thanks.

 

[1968FormulaS340]

I would change it out.

 

[dodgetkboy78]

1/2" total? LIke in the middle, 1/2" both ways, pulling on the chain back and forth?

Thats tight............

 

[Small Block]

....but here is what the book says:
To check timing chain slack, place a scale next to the timing chain to detect any movement in the chain. Place a torque wrench and socket on the camshaft sprocket attaching bolt. Apply 30 ft lbs{cylinder heads installed} or 15 ft lbs(cylinder heads removed) of force to the bolt and rotate the bolt in the direction of crankshaft rotation to remove all slack from the chain. While applying torque to the camshaft sprocket bolt, the crankshaft should not be allowed to rotate. It maybe necessary to block the crankshaft to prevent rotation. Position the scale overthe edge of a timing chain link and apply an equal amount of torque in the opposite direction. If the movement of the chain exceeds 1/8", replace the chain.

The kit is cheap insurance. I'll change it. Thanks guys

Small Block

 

[65barracudadude]

Ya, I would

 

[dodgetkboy78]

Me too.

Buuut, in 15,000 miles, he will have a 1/2" of slack again.........

 

[68383GTS]

Change it timing chain kits are cheap enough.
Jim

 

[RedFish]

If I'm in there measuring slack I'm gonna change it. Dont forget to prelube the new one or it might have the same slack far too soon.

 

[Max340]

Me too.

Buuut, in 15,000 miles, he will have a 1/2" of slack again.........

The solution that I used was to get a double roller from a friend of mine thta freshened his race engine. THe chain is "pre stretched" and has little chance of jumping time. I degreed the cam, and figure it stayed fairly close to where I put it. Beyond that, its a street engine, losing 5hp isn't losing me any fun at all.