Tuning HELP! Crank wont spin!

[dbith57]

I've torqued down my main bearing caps on my 1300, (haynes says 58ftlbs) and it wont turn. is there anything that i could have done wrong?

thanks in advance

-D

 

[jimbro1000]

It sounds like one of the bearing sets is wrong. I know its a stupid question but did you measure everything before reassembly?

There is a very simple but hugely effective product called plastigauge that is used for checking the bearing clearance that you have.

What I should have asked first is "does the crank turn at all?" - ie is it binding completely or is it turning a bit and then sticking?

Have you got the bearing assemblies all the right way around and properly seated?

 

[dbith57]

These are new bearings from the manufacturer, so no we didn't measure. I guess we should have, but it seems like only #5 is really the one giving us the problem. The crank shaft will turn untill we torque it down, that is with or without the thrust bearings. I am tending to think the crank is out of balance or even bent? Is there any way I can check this without taking it in?

 

[unomad]

check the bearing caps they should have a single number stamped on the end or on one side make sure they are all facing same way or if no numbers try turning the no 5 cap around

 

[jimbro1000]

It is exceptionally rare for a crank to bend on one of these engines but it is not so unusual for block itself to distort but not to the extent that the crank binds completely - it normally only causes power loss at higher revs.

The point about the bearing cap being the wrong way around is the most promising culprit (or even on the wrong bearing - you wouldn't be the first and definitely not the last).

 

[dbith57]

well, i took the #5 cap off and removed the thrust bearings, and re-torqued everything and now it spins. (only without the trust bearings)
i think maybe the #5 cap is too thick and is putting to much pressure on the end, making my crank not spin.
is there a specific "thickness" the cap should be?
im thinking shaving down one side could be an easy fix...

 

[unomad]

are you sure trush washers are correct type ,shape or even size they may be oversize ??if all this looks ok try filing the ends of washers till it turns free . i stuck a set of 131 washers in my engine they were totaly wrong shape its great what you car do with a ginder may sound rough ok it was but raced 2 seasons no prob and never failed

 

[jimbro1000]

I've just spoken to my race mechanic - his first guess is either the cap on the wrong way or the shells in with the notch in the wrong way.

If you are going to grind something, don't touch the caps.