sbc timing chain jump?

M

M249cummins

New member
I know its not diesel related but figured this was the best place for it. whats the best way to tell if a timing chain had got soo worn out that it has jumped a tooth or so? its on a 82 small block chevy. I run open headers in the truck so its hard to hear for noise.


should turning the motor over to tdc and looking at cyl 1 rocker tell me if my mechanical timing is off?
 
The thing is pulling the timing cover is a 1 minute job, leading up to that is several hours of work baking in the sun lol. I'm looking for alternative ways to make sure it is what it is.


hard to explain, just runs like crap. just changed the oil, put new plugs in, new msd distributer, new msd wires, checked firing order, checked timing. did all of it in a weekend. driving down the road and all of the sudden felt like a plug blew out or something. power loss, problems idling, truck shakes more than usual, wants to die in 5th gear.

I noticed some slack by turning the crank pully but I don't have anything to compare it to.

I did drive the truck a week before this happened.
 
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sounds fuel related to me regardless. Watch the timing light while giving it small revs, should see it bounce the light some, if its timing chain is that bad.
 
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it stays fairly consistent but does hop around a few degrease or so while watching it. I just assumed it was the cam in it causing that.


it has a Edelbrock performer carb. took it off today, put several cans of carb cleaner in it and put it back on with new gaskets.
 
Common Chevy smallblock ailments that can happen suddenly:

Dropped a valve.
Flattened a cam lobe, or 3.
Timing chain slipped a few teeth.

Mark.
 
Mark Nixon said:
Common Chevy smallblock ailments that can happen suddenly:

Dropped a valve.
Flattened a cam lobe, or 3.
Timing chain slipped a few teeth.

Mark.
Click to expand...

The sbc we had with a cam lobe wiped off would pop back through the intake and run like crap.
 
M249cummins said:
The thing is pulling the timing cover is a 1 minute job, leading up to that is several hours of work baking in the sun lol. I'm looking for alternative ways to make sure it is what it is.


hard to explain, just runs like crap. just changed the oil, put new plugs in, new msd distributer, new msd wires, checked firing order, checked timing. did all of it in a weekend. driving down the road and all of the sudden felt like a plug blew out or something. power loss, problems idling, truck shakes more than usual, wants to die in 5th gear.

I noticed some slack by turning the crank pully but I don't have anything to compare it to.

I did drive the truck a week before this happened.
Click to expand...
Did you check timing before and after it happened? 8° per tooth iirc.

Sent from my SM-G965U using Tapatalk
 
cam sprocket was chewed up, chain way stretched and skipped a tooth. found the problem. got a new double roller cloyes setup on the way.
 
I think 120,000? its a 82 c10 body on an 81 1 ton chassis. just enough wires are hooked up to make it road worthy. no spedo, fuel guage, tac, odom, ect. choppy ass cam and open headers, my daily driver.

stupid sideways picture...
 

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