Engine numbers

m37jarhead · Post by **m37jarhead** » Fri Apr 03, 2009 6:27 pm

I recently "inherited" 3 used M37 engines in various states of
dis-repair. I'd like to re-build one of them. Are there any preferences
to which one I should try to re-build?
Here are the engine numbers:
T 245-56347
T 245-36134
T 245A-260859

I tryed, with no luck, to do a search on this site for more info. on engine
numbers. I'm assuming all of the above engines are 230 c.i. but don't
know for sure.
Any advise would be much appreciated.
m37jarhead.

Lifer · Post by **Lifer** » Sat Apr 04, 2009 5:42 am

Judging from the numbers you have provided, my guess is that the one marked T245-36134 is the oldest of the bunch and that the "T245A" engine is the newest. Their ages should not be a major determining factor in deciding which one to rebuild, though. I'd recommend thoroughly inspecting each and rebuilding the one that's in the best condition. You might also consider making the other two "available" to other forum members who need a new engine.

m37jarhead · Post by **m37jarhead** » Sat Apr 04, 2009 7:29 am

Lifer....thanks for the info.
I've done compression tests on all 3 engines. Two of them have
miserable PSI's. 0's to 60's. But the third one, the T245A has upper 70's to 110's. It has a re-build tag on the side... says: bore-standard,
mains and rod bearings 0.30, done in Japan 1976. Overall, it's
the best "looking" engine from outward appearences. I pulled the
head and valve covers. All looks good with no score marks in the
bore and all valves operating. Don't like the 0.30 for the rods
and mains. It may have reached it's outer limits there.

One of the other engines shows a rebuild tag with 0.10 bearings
and bore. Poor, if any compression, suspect stuck valve(s).

The second engine has no re-build tag on it. Poor compr. Also suspect
stuck valves.

So... looks like I'll have to jerk the pans and heads on the other two,

as you suggested to eyeball the innerds and take some measurments.
Thanks again fur yur input.

Lifer · Post by **Lifer** » Sun Apr 05, 2009 3:44 am

I'm guessing that the undersize measurement on the mains and rods is closer to 0.030" than it is to 0.30". Thirty thousandths is no big deal. Three tenths of an inch is a humongous deal.

NOS replacement crankshafts should be available from "the usual sources." It is also possible to have a seriously worn crankshaft built up and then reground to standard diameters. Restorers of rare ancient cars do it all the time. A friend of mine had it done for the engine of his Willys-Knight touring car last year because no replacement was to be found (not surprising). His engine runs like a Swiss watch, now.

Wayne64 · Post by **Wayne64** » Sun Apr 05, 2009 6:42 am

As Lifer pointed out, .030 under is not a problem. In some racer circles they claim less friction with the under size which they claim means less heat and more RPM. Also crank journals used to be offset ground after adding weld to increase stroke for more inches. Bottom line is ground cranks are not worth worrying about as long as they were ground right and the radius done at the sides.

m37jarhead · Post by **m37jarhead** » Sun Apr 05, 2009 6:43 am

Ooops.

Forgot a zero. You're right... 0.030, thirty thousands.
not 0.30....... duh on me.

I might use a crank from one of the other two engines
if the 0.030 crank is in poor shape.

Thks again for the input.