Engine S/N MB621398
Machining date: 8-29-45

Picked up a late 45 MB some years ago, parted it out. Kept engine for times of “great national emergency” LOL, cleaning out garage, time to get rid of it…  Came out of a compete MB.

I get a little carried away with pictures and web pages… sorry if this writeup is a bit “much”…. just having fun with “wordpress”.

I prefer to sell things in a known condition. If you purchase a “pig-in-a-poke”, where the seller has not torn it down as I have, you may find cylinders that need to be sleeved, and/or a crank in need a heavy grind… So I tore this engine down, see attached pictures.

General condition:
Needs general refresh, including valve grind, perhaps some valve seats, surfacing of head and block, be bored to .060, and a set of rods.


Recently bored to .040 by previous owner, needs to be re-bored to .060 due to water damage during storage by me (mice ate hole in tarp, ack!)
Crank mains: .010 undersize, excellent condition, could use a polish only
Crank rod: .010 undersize, excellent condition, could use a polish only
Crank rear seal surface: needs emery-cloth & polish treatment or a quick grind and polish
Worn timing chain and sprockets, s/b replaced
Rods are mismatched set, better investment to replace all four rather than checking/straightening existing in my opinion
Main and big-end bearings look pretty good, you could consider re-using as this was a recent rebuild, but only with this crank
I suspect cam & cam bearing are good, again, it was a recent rebuild
I think the valves are fine, could use a little wire wheel cleanup, and will need to be ground/reseated.
Probably magnaflux on area around dist, and other known weak points would be a good idea… but you might not bother with crank, it looks good

Besides the usual gasket set, pistons & rings, head studs & nuts, frost plugs, etc. it needs:
Oil pump – current one is incorrect aftermarket, but looks to be in excellent condition
Crank nut
Water pump & water pump pulley

Other issues:
Small crack in oil pan lip due to impact, does not look to be serious (see pictures attached)
Front mounting plate ears where engine mounts bolt need a little straightening in a press
Oil pan is incorrect and is junk anyway

This “long block” also includes:

Flywheel, clutch plate, pressure plate, bell housing, starter ear, generator mount, valve cover & bolts, pulley, dip-stick & housing, etc. and a collection of nuts and bolts.
Fairly nice late intake manifold, junk exhaust manifold
Does not include a fuel pump, distributor, oil filter assy, fuel and oil lines, starter, generator,  etc.
(I might be talked into selling the starter and generator for additional $$, which are correct for this engine, if you need them. )

What you see in the pictures is what you get…

Delivery/Shipping: Can deliver for free to Minneapolis/St. Paul area, and might also be able to drop it in southern WI sometime, otherwise buyer pays shipping and insurance. Willing to drop at LTL truck loading dock on pallet per buyer arrangements (Fastenal LTL is good option, typically around $150 to CONUS).

Price: See spreadsheet at end of this page. Asking $500 or best offer, as-is. Will refund purchase amount  upon return of long block to me if block does not clean up at .080 or major crack discovered during machining that affects coolant, cylinders, or valve area, within three months of purchase.


Here is a quick spreadsheet on what it will cost to rebuild this engine, is my guess, don’t hold me to it….

Estimate of Cost to Rebuild MB Engine MB621398      
Parts Required for Long Block rebuild of this engine (i.e. not including manifolds, oil filter, gen, starter, dist, etc. )
Note: using the recent aftermarket oil pump that was on this engine (melling?), not original style
Q Req. Desc         $ ea. Subtotal
1 Complete overhaul gasket set L134, Felpro -A17402   85 85
1 Starting crank nut -387633     20 20
1 Cylinder head stud long -A1548     2.75 3
15 Cylinder head stud standard -349368     2.5 38
16 Nut, 7/16NF -638539       2 32
1 Oil pan bolt and spacer set     20 20
1 Engine piston and pin set .060 -637041-060 (4ea. Sealed Power) 100 100
1 Engine piston ring set .060 -A6794-060 (1 set for 4 pistons) 45 45
1 Camshaft sprocket, upper -638458     35 35
1 Crankshaft lower sprocket -638459     37.5 38
1 Timing chain -638457       75 75
4 Camshaft gear lock tab -315932     1.25 5
5 Expansion plug 1 1/4 -51091     1.5 8
1 Expansion plug 1 3/4 rear cam bearing -51460   2 2
4 Flywheel bolt -632157       5 20
2 Flywheel dowel bolt -632156     5 10
1 Engine Oil pan (late style, exact repro w/plate) A-7238 150 150
2 Connecting rod with cap 1 or 3 -640071   30 60
2 Connecting rod with cap 2 or 4 -640072   30 60
1 Water pump w/pulley (exact repro)     98 98
          Parts Subtotal: 902
Machine Work for Long Block Rebuild (approx)        
Note: Crank is good, so 0 req. for crank, assuming only 2 valve seats need replacement, and existing valves have good stems etc.
Q Req. Desc.         $ ea. Subtotal
1 Boil out         65 65
1 Magnaflux check for cracks     50 50
4 Bore & hone to .060       40 160
1 Re-surface head       45 45
1 Re-surface block (deck)       45 45
1 In seats         15 15
1 Ex seats         15 15
8 Grind/Seat valves       10 80
0 Cam bearing       30 0
0 Grind & check crank       150 0
1 Grind/polish crank rear seal surface only   30 30
          Mach Work Req Subtotal: 505
If you pay me $500 for this core:          
          Run-of-the-mill core value: 500
          Typical rebuilder price: 2500
          Rebulder gets: 1093
        If you assemble the engine, your cost will be:
          My core, w/good crank: 500
          Parts:   902
          Mach Work:   505
        You would have a nice engine for: 1907
        (I belive typical cost of a rebuilt MB/GPW long block, where no exchange core is provided (i.e. “outright”),  is going to be more like $3K per above)