8 replies to this topic

[Carlos W]

Stripped my engine down today and the flywheel end of the crank is a bit horrible, will I get away with having this reground or is it only suitable to be added to the pile of stuff to be weighed in?




Thanks
Carlos

[Surfbluegarage]

seen worse and ran worse. i suggest getting yourself a new flywheel bell (if its verto) and using some valve lapping paste on the end of the crank using the bell to lap them together.. if most of the surface area comes into contact with the flywheel nose/ bell id say it would run again just at a quick glance at that picture.

if after youve lapped it together that there are still loads of bits and not much surface contact between them then bin it.used ones with big gouged out rings before after lapping and ran completly fine in my engines im just being realistic. too many people (including me) have thrown cranks in the bin before because of a little surface rust or a couple of marks on the end of the crank.
yes if its for a race engine then toleraces change but for a normal road engine is say ud get away with it.

p.s most of the damage on that crank in the picture is not on the surface are where the flywheel sits anyway so try lapping.

[racingbob]

i can remember having a crank metal sprayed once

[mk1leg]

Use emery cloth and linnish the end, and then lap paste the fly wheel on and off ..... used worse.............

[Ivor Badger]

i can remember having a crank metal sprayed once

i can remember someone doing that to a racing crank, failed miserably when the flywheel fell off. the 2nd attempt resulted in the taper bit falling off with the flywheel. i'll see if I can do a photo. For reasons that will become obvious, I have never thrown it out.

[bmcecosse]

As others have suggested - I think that one could be saved - but you would need to put a bit of work into it. And make sure the bolt is TIGHT when you rebuild the engine.

[dklawson]

You can try to save this as mentioned above. However, I suggest a bit of a different approach than others.

Degrease and spray paint the crank tail. Allow the paint to dry. Then carefully, gently go over the crank tail with a fine flat file just enough to find the high points. Use a paint pen or permanent marker to outline the high points then carefully attack each one gently with a smaller flat file. Remove the high spots and leave the base diameter of the crank alone as much as possible. When the high spots are gone, gently sand the tail to remove the remaining paint. Do not use the sandpaper to do more than remove the paint. With the paint gone, lap the crank tail to your NEW flywheel. Lap as little as possible/necessary to get a matte finish on the crank tail. Remember to carefully clean the crank tail and flywheel bore when you are done. NO abrasive material should be left on either.

Whenever you are working on the crank tail it is important to remove as little material as possible. For every 0.001" taken off the diameter the flywheel will move "UP" 0.007" on the taper. This may not sound important but it is easy to move the flywheel too close to the flywheel housing.

[Carlos W]

Thanks for the advice guys, I may see if I can get a better one, the project is a long way from engine rebuild stage so we'll see what else comes up in the mean time!

I won't bin it though!

[tiger99]

Don't bin it, recycle it! The scrappy might even give you some cash for it.

But I agree, it probably can be saved, if the bearing surfaces are good, not forgetting the faces the thrust washers run against. I had to scrap a crank once because the thrust faces were ruined, because someone fitted the washers backwards, with the steel backing against the crank, but it was not a Mini.