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Looking forward to this rebuild man. Similar thing happened in my audi, except it was 1200 miles after rebuilding the motor. just died smoothly... tried to crank it, didn't sound bad but definitely not firing... timing belt was on (connectiong the crank to the exhaust cam) but the timing chain (connecting the two cams) was toast. massive damage as it was off time and its an interference motor.
rebuilt it and she ran for 2 long years before dying again last week
such is the life of a track car! hopefully you git er dun and hit the track again this season man. good luck! in for tons of pics!
rebuilt it and she ran for 2 long years before dying again last week
such is the life of a track car! hopefully you git er dun and hit the track again this season man. good luck! in for tons of pics!
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5,501 Posts
Actually, just the opposite…
The belt became loose, the valve was down and cam lobe was down. When the piston came back up, it pushed on the whole assembly, cracked the rocker arm, the opener shim fell off and so did the closer. They will simply rattle off without the rocker arm in place, hence the reason why clearances are so important.
So the big fifty thousand dollar question is… how did the belt come loose? Maybe it was simply too worn? Most people replace belts at 15k miles, so 28k miles is a lot. Maybe my theory of the mobile roller coming loose on its own or the rollers not in line with each other, causing edge wear?
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5,501 Posts
Ohh, you CHANGED the belts at 16k… sorry, I thought you put them back on for some reason… didn't read your post.
Your valve is stuck, the stem has most likely mushroomed. So the cam is under a lot of load. Straight-edged screw driver, inside the pulley where the T is, with a rubber mallet, pushing up… it should pop right out. You can't yank on it because you need to generate some vibrations, thats what the tapping will do.
Unhook the spring from the cam follower and see if you can turn the cam
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5,501 Posts
Maybe… but my guess is, the cam is stuck between the opener and closer. So releasing the spring, won't make any difference, as the valve is stuck in place, holding the cam from moving.
Just a guess, but it seems to fit the issue.
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5,501 Posts
OK so the first step is to see if the valves move. Obviously start with the ones which are all assembled. Then slowly put that cylinder at TDC and see if those other two valves move. If they do, and they move smoothly, you can basically go grab a beer and relax. If they don't move and they're locked in place, then you probably got some mushroomed valves.
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