2.7L Crankshaft Limits Vs. Bearing Availability

[scootermcrad]

Hey everyone,

I have a 2.7L crankshaft I've been using as a doorstop, and after purchasing a 2.2L project that will need to be completely gone through, I'm thinking of swapping to a counterbalanced 70.4mm crank while I'm at it. However, I have a feeling this crank shal remain a doorstop. It came with a car that I bought with a machine shop hang tag showing the mains and rod journal dimensions (I come up with very close to the same measurements) - 56.502 mm and 51.500 mm, respectfully. Seems like this was cut beyond what I can get bearings for. Or am I missing something?

Looking at the prices on crankshafts to do this swap, I figured it was worth at least asking about my doorstop. I'm assuming it's unusable, but if cut beyond available bearing sizes, WHY would anyone have even done this? Curious, more than anything.

Thanks everyone!

[Flat6pac]

Things that were readily available decade or two ago weren’t profitable after cost of production and sitting on the shelf.
German and Austrian products are now South Africa and Brazil production and the quality has dropped.
Bruce
Look for a PM

[phunt]

The mains are supposed to be 56.99-56.97 so just say 57. If you measure 56.500 how is that out of spec ? That is 1/2 mm. 0.020” that is nothing. Bearings come in .25mm increments so that is only second over so how are bearings not available? Rod big end is easy. Grind the to 2” and use small block Chevy rod bearings. Better bearings and a lot to choose from what am I missing

[scootermcrad]

Originally Posted by phunt

The mains are supposed to be 56.99-56.97 so just say 57. If you measure 56.500 how is that out of spec ? That is 1/2 mm. 0.020” that is nothing. Bearings come in .25mm increments so that is only second over so how are bearings not available? Rod big end is easy. Grind the to 2” and use small block Chevy rod bearings. Better bearings and a lot to choose from what am I missing

Yeah, that's why I asked. I'm just learning about these motors. Wasn't sure if I was understanding the bearing sizing correctly, in this instance. I definitely misunderstood, so that's good news. In my mind that didn't seem like a lot, but then comparing STD sizes listed in Wayne's book and non-STD bearings I think I confused myself. (easy to do).

That's pretty interesting about the SBC rod bearings. Hadn't heard that trick. 2.0275" would be easy to take to 2" for sure. Didn't realize rod widths and ID's were comparable. Tell me more!

It will need a polishing since it's been sitting around and since I don't know the history I should have it magnafluxed and checked out.

[brother911S]

Stay away from bearings for the crank made in South Africa.

[scootermcrad]

Originally Posted by brother911S

Stay away from bearings for the crank made in South Africa.

Okay! Great! Thanks for the tip!