AB 150 Gold motor

Did you mean 20 thou undersize and are you metric or imperial? Best way to measure big end clearance is with plasti-gauge which gives you a real world reading. My own experience showed that shells can be more than 002" different between brands for a given size. If you can get away with just polishing and crack testing the crank that is a good thing and preferable to a re-grind.

I have purchased JP piston rings a few times, reasonable price and no problems. This 1929 Nash Standard Six was bored out 30 thou, pistons and rings from them. Have only done 2500 miles, a few trips of 10 to 20 miles at up to 40 MPH with no dramas.
David.

I did think perhaps Precision International might have offered pistons for the 240, but looking just now it seems they don't. Also thought of Southern Hemi Media as a long shot, but no luck there either.

It's good to hear of David's success with JP's, like i said i had heard of failures just as John K has, but maybe they have either been sorted with time, or were just bad luck stories. We do often tend to hear about the failures sooner and louder than we hear about the successes, so the failure rate might actually be quite low in comparison. I just wanted to offer what i had heard and read, to help you make an informed decision. If your re-conditioner man has used them before, and has been happy with them, then that has to boost confidence in using them.

Brett.

I have used JP pistons for years in both my 26 Chev and 34 Plymouth, as well as customers vehicles. Never had the slightest problem. I believe that the failures reported are more as a result of bad or poor assembly.

As for 2 thou under bearings, I just fitted a set to my 1950 Morris. The shaft miced up ok, within reason, and I couldn't get standard shells, so 2 thou under fitted just fine. Repco used to make them for most engines at the time.

Thanks to all for the feedback. Dave.