40 Merc block sleeved from the factory?

Sleeves are roughly .040, look way bigger in engine because of upper step flange.
I would turn the driver blocks by test-feel to biggest diameter I could stuff in by hand, then use biggest all-thread I could find down to some sort of padded bar in crank saddles. Official test was to push through a new piston to spot any bulges.
Shoot, just check-baggage your block and do a quick family vacation trip to NYC...
The family will love the Statue of Liberty and the back warehouse at Joblot automotive!
 
Thanks for all the advice and information. I'm just finishing my valve job and general block clean out and am going to put the engine back together as is so I can enjoy the rest of the summer driving season. This winter, I will tear it back down, pull the pistons and take a look at what I've got to work with. If the bores aren't too bad and the pistons look OK, I will just lightly hone the block, throw in new rings and let her go. If the pistons are shot, I probably will pull the sleeves and try the oversize piston route. If the pistons look good but the bores are shot, I'll try the new sleeve route and reuse the pistons. Until I get her all apart to see what I have to work with, I won't know for sure what to do. You guys have sure been great at educating me!
Thanks,
Dan
 
Sleeves are roughly .040, look way bigger in engine because of upper step flange.

I was out in the shop tonight mocking up a fan on the '42 Merc 99A engine that's going in my '28 rpu and got to thinking about that flange on the liner. My block, which was just bored .060" over, and relieved at the factory, didn't have liners. Seems like the blocks with factory relief could not have them installed because of the "dip" in the deck, which would preclude a proper counterbore for the flange. True?

Bob
 
check with a ford tractor dealer or carpenter in N.C you may be able to get the sleeves , another place to check is Falcon sales, They are listed on the net, I buy my sleeves from them both thick wall and thin wall .
Hope this helps!
D.Estes
 
'39-40 engines were commonly produced both with and without sleeves. Don't know if sleeves were carried into '41-2 blocks to any great extent. I personally believe that relieved '42's were actually wartime blocks made for the military...most have the extra boss at rear as a drilling point for the factory full flow filter and cooler setups.
 
I personally believe that relieved '42's were actually wartime blocks made for the military...most have the extra boss at rear as a drilling point for the factory full flow filter and cooler setups.

I'm still uncertain as to what my block is exactly. It had 29A heads on it, which are '42 Merc, but I can't find "99" stamped in the usual location. I realize heads can be changed, but I think these were original to this engine. It is 3 3/16 bore, factory relieved, has the raised intake mounting surface, no liners, has the trapezoidal coolant holes in the deck, but doesn't have the raised oil passage boss on top the bellhousing. Seller said it came out of a firetruck. It had very little wear, and appears to have never been rebuilt when I got it.


Bob
 
Engines after some time in '40 no longer got the "99" stamping...allegedly, and this is unverified, the "99" was for assembly line use to distinguish the 99's from the almost identical 81A's, especially since early 99's used heads with a 221 designation.
I think the "raised" intake surface solidly identifies yours as 1941--WWII. I don't think there is enough solid info around to sort much beyond that...my ID of WWII developments is based on only a few shards of info...and in your case, with original bore and firetruck origin, you have pretty good reason to believe that yours actually left Detroit in that truck! Most firetrucks except in big cities lead sedentary, low mileage lives.
 
Most firetrucks except in big cities lead sedentary, low mileage lives.

Mine is evidence of that. The crank was pristine, with the standard sized journals showing no more than .0005" wear, and very little ridge in the bore. I bored it .060" over because of some rust pitting in a couple of the cylinders. It was obvious that it spent more time parked than running, and probably benefited from routine maintenance.

Bob
 
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