Matching Crankcases Atlas?

I'm considering buying a pair of crankcase halves for an Atlas. Seller says they are matching "to the best of his knowledge"
My question is whether there is/are any identifying marks on cases that identify them as a matched pair.
A second question is what perils to expect if they are not a matched pair.

Thanks,
Ed

APRRSV said:

I'm considering buying a pair of crankcase halves for an Atlas. Seller says they are matching "to the best of his knowledge"
My question is whether there is/are any identifying marks on cases that identify them as a matched pair.
A second question is what perils to expect if they are not a matched pair.

Thanks,
Ed

Click to expand...

ED
In 1965 they had batch # inside the cases. It is not "to the best of his knowledge" but rather " I see #xyz on the inside of the right and left case. That's still no guarantee they are any good :roll:

Later...commando had them on the outside, on the bottom

Thanks Dave. I see from photos that the #'s don't match.

To my second question, are unmatched cases an explosion waiting to happen?

APRRSV said:

Thanks Dave. I see from photos that the #'s don't match.

To my second question, are unmatched cases an explosion waiting to happen?

Click to expand...

Unmatched cases = misaligned main bearing bores. Cases are bored pinned together .... the only way to ensure the bores are dead on.

Slick

Thanks Slick. That is what I thought but wasn't sure.

APRRSV said:

Thanks Dave. I see from photos that the #'s don't match.

To my second question, are unmatched cases an explosion waiting to happen?

Click to expand...

Not necessarily :?:
At a flea market I'd give $25-50, but would expect to spend a LOT of time($) to measure and fix problems if any.

I'd hate to risk a crank and all the bottom end parts to maybe save a few bucks. I rather buy a complete basket case engine for good money and rebuild it. There are a lot of them out there, You just have to wait or pay the bigger bucks for a good core. Take two to make a good one....Sell the good leftovers to help fund the project.

I never paid over $1500 each of 3 pretty complete, almost runners atlas, then $600 for my 4th featherbed hot rod frame. 63 ($1500), 2-66, 68 Dunstall ($1200)