Gap Between Timing Side Main Bearing And Case

[kuromochi]

Hi
I wonder if someone out there could help me. I'm putting back together the engine on my 1976 T140V after fitting new bearings etc. One thing I have noticed now that the crankcases are bolted back together is that there is very little to no space between the inner part of the main bearing on the timing side and the crankcase, although the crank turns freely. Does anybody know what this distance should be or if anybody has their timing cover off could they measure it with a feeler gauge?
Many thanks

 

[grandpaul]

I don't know, but probably in the neighborhood of .010 - .020" clearance total both sides

 

[kuromochi]

I don't know, but probably in the neighborhood of .010 - .020" clearance total both sides

Hi GrandPaul
That's sounds reasonable to me but I only have between 0 and 2 thou, so I guess something isn't quite right.
Thanks for the reply.
Regards

 

[grandpaul]

One or both main bearings may not be totally seated in their respective case halves.

 

[kuromochi]

One or both main bearings may not be totally seated in their respective case halves.

Yes, this is what worries me apart from the bearing's moving part touching the casing, although the drive side bearing seems ok, so the timing side bearing may not be all the way home on the crankshaft.

 

[grandpaul]

You might carefully consider what I am about to say, before you decide to do it yourself.

I personally, on my own engine, would take a small hand-held torch to the case area around the main bearing, for a few minutes, to heat it up pretty good. Then, I'd take a piece of hardwood and buffer the crank nose (with nut in place, just covering threads) on the opposite side; smack it smartly AND SQUARELY with a 5 pound sledge.

Measure your free play again.

If it has moved at all, but is still short, heat it some more and give it one more smack.

If it's still tight, do the above procedure on the opposite side. Measure again. Repeat again if required.

I'll bet you fall into tolerance after the first or second smack.

 

[kuromochi]

You might carefully consider what I am about to say, before you decide to do it yourself.

I personally, on my own engine, would take a small hand-held torch to the case area around the main bearing, for a few minutes, to heat it up pretty good. Then, I'd take a piece of hardwood and buffer the crank nose (with nut in place, just covering threads) on the opposite side; smack it smartly AND SQUARELY with a 5 pound sledge.

Measure your free play again.

If it has moved at all, but is still short, heat it some more and give it one more smack.

If it's still tight, do the above procedure on the opposite side. Measure again. Repeat again if required.

I'll bet you fall into tolerance after the first or second smack.

Thanks for the idea but what I decided to do was to put the clamping washer and timing pinion on, bolt it up and hope this has some effect. I'm going to put the engine all back together, run it gently and see if everything appears OK.
Thanks a lot for your help.