Bill Ball

I guess no problem with interference at 180 as well as 45?

I'm a little puzzled as to how if you lock the crank at 45 BTDC, when you put the balancer back on and don't see 45 rightside up or upside down...what did you do next?

I'm not trying to rub this in, as I know you have good company when it comes to this mishap, but I'm just trying to understand what the steps are that allow you to even time it this way.

Garth S

The timing is not out 180 deg, as the crank keyway in not indexed to TDC as I recall ..... probably far less than half of a crank rotation, although I've never stopped to measure it. Nonetheless - anything 'off' is too much!
Reinstalling backwards does really beg the question of how one can confirm the timing marks at TDC???? This is the most critical step of installation, and must be done to get a true and REPEATABLE TB tension value
As this situation appears too frequently, the precautionary instructions need to be rethought and/or better communicated. Wished that I had an engine apart in front of me to do and measure the backwards installation .....

Jim bailey - 928 International

the key way is about 90 degrees off TDC so flipping it over moves the mark from 12:00 to 6:00 . If the crank shaft were locked down with the flywheel lock it would seem that the misalignment might be more obvious. Fortunately I only see this happen on the 16 valve engines because on an interference 32 valve it could get ugly.

Bill Ball

Oh, 16 valve. I forgot this was a 1980. So, no 45 degree mark, no interference, no run. Very good.

Tony

How would it be effected?
Maybe im missing somehting obvious in it, but once he has the pulley at the propper point and the lock installed for belt removal it doesnt matter which way the pulley goes on...it wouldnt effect any timing. When he puts the belt back on the motor the cams or the crank shaft havent moved..due to the lock.(well the cams may jump a little) The crank pulley doesnt trigger any igntion event, if it were on backwards it would just casue a little head scratching trying to read the numbers as you turned it to the proper point to set the tension..
The engine should still start....correct??

Bill Ball

Well, I assume even if backwards, he tried to get cam zero to match with the now incorrect crank zero when he put the belt on. That's why the cam timing (relative to piston TDC) would be way off and the car would not run. But, if he just slipped the balancer on backwards and did not move it, then the crank would be unbalanced, but, yes, the car would run.

Also, regarding ignition timing relative to cams, in early cars, aren't the distributors driven by a crank gear as in most V8s?

Jim bailey - 928 International

Tony I think part of the problem is no flywheel lock and then the assumption of "Wow the crank must have moved, I'll just move it back......." Plus it gets really tricky if the prior "mechanic" put it on backwards the time before but never moved the crank simply aligned the cams with paint marks on the crank and cam gears. Theory being it drove in it will drive out as long as the paint marks line up...so much easier than all that reading!

SharkSkin

I have the same question as Tony... Worst case, you might have a frustrating experience checking your ignition timing, on those cars where checking the timing makes sense...

SharkSkin

Bill, 16V distributors are driven off the DS cam.

PorKen

This was evident on my engine when I bought it. Big pipe wrench marks on either side of the belt pulley!

Bill Ball

Thanks, Dave.

laneskelton

I flipped over the harmonic balancer and the car fired right up and it sounds better than it ever has. No more noisy water pump, but now my clutch pedal is on the floor and it isnt functioning properly. It seems like things all go wrong at the the same time and the wrong time. I am doing a DE event in a week at sears point so hopefully I can get everything buttoned up before then.

Bill Ball

I assume you pulled the clutch slave cylinder to put on a flywheel lock. May need to look at that to make sure it went back together correctly.

Jim bailey - 928 International

Damn Bill you are getting to be too logical .... or schooled in the "What did I touch last"

laneskelton

I didnt use the flywheel lock tool, or touch the slave cylinder, which is why it is very strange that the clutch would all of the sudden be at the floor