Cam and crank question 59A

[deuce5wndw]

I recently removed a 59A from a 1946 that looked like a spray can restoration but with head bolts and one was broken. On removing head to repair the broken bolt I found a engine bored to 3 5/16, relieved, ported and polished, adjustable lifters and camshaft with Lishin 5 and drag stamped into the end. Has anyone heard of that brand cam? On further research It has a 4 inch stroke but some one used 99A rods with the big end the same as inserted rods with enough clearance that you can get a rod knock by hand! My question about the crank is they have ground the crank to 2.088 which is .051 under! Is there enough meat left to offset grind for 1/8 stroke? If not the only way I can save the crank is grind at 4 inch stroke for 91A rods. Thanks guys.

[Barn Junk]

What stroke pistons did they use to even get it to run? Maybe the crank grinder didn't know what he was doing. I don't understand what kind of bearing could be used with that crank pin size. I think it takes about a std or 10 under Merc crank to get a std 91A bearing to work with the added 1/8 stroke. A thicker 91A bearing would help the situation.

[Bored&Stroked]

No, you can't put an 1/8" stroke into the crank - without at least a 2.125 journal . . . and you usually need more than that for them to have something to work from. About the only option is to use 21A or 91A rods and take the journals to the 1.999 221 cubic inch size. The only problem is that this all gets expensive --> if you need to buy 91A or 21A rods, then find the full-floater bearings, then have the crank offset ground. Unless you already have the rods and bearings - you might consider using H-Beams and the later insert bearings (will cost about the same on the rod/bearing side of the deal). Hopefully you now a good crank grinder that puts a good fillet/radius into the journals . . . which is how it should be done. Best of luck!

[deuce5wndw]

I thought you were going to tell me that! Correct me if I'm wrong but with the size they have ground it the only option to save the crank if to grind it on a 4 inch stroke like it is now only for the 91A rods. I have NOS rods and bearings on the shelf. Thank goodness they didn't screw up the mains too! Thank you for your input, Dale.

[Tim Ayers]

This might sound ridiculous, but did it run before you took it apart? If so, how did it run? If it ran I'd be tempted to but it all back together and run it as is.

[flatheadmurre]

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If running floater bearings you can cut the caps and hone to undersize.
The take some off the bearing inserts to make them undersize.

[40 Deluxe]

Originally Posted by deuce5wndw

I thought you were going to tell me that! Correct me if I'm wrong but with the size they have ground it the only option to save the crank if to grind it on a 4 inch stroke like it is now only for the 91A rods. I have NOS rods and bearings on the shelf. Thank goodness they didn't screw up the mains too! Thank you for your input, Dale.

While you can't do the 4 1/8" stroke, you can gain a little, especially if you have undersize 91A bearings. Just do the math to determine how much offset grinding you can do. Use 4" stroke pistons. They will come up a little higher in the bore, which may give the right piston-to-head clearance. Thus kill two birds with one stone!

[rotorwrench]

I can't tell if that is a crank with two oil ports per journal or just one. If it's the old single port type than 8BA type rods are out. The 4 -inch cranks are generally Mercury type from the 8CM era. Offset grind to 4-inch can be done on an earlier 3 3/4" stroke crank. You never know what you'll find out there.

[deuce5wndw]

Tim, it did sound good without a muffler and I would reassemble except for the .017 clearance in the rod bearings and the top ring grooves are worn bad.
Rotorwrench it has two oil holes per throw. It doesn't have any markings other than the one shown in the photo and I have never seen that one before. Thanks for all the replies, Dale.

[Bored&Stroked]

Originally Posted by rotorwrench

I can't tell if that is a crank with two oil ports per journal or just one. If it's the old single port type than 8BA type rods are out. The 4 -inch cranks are generally Mercury type from the 8CM era. Offset grind to 4-inch can be done on an earlier 3 3/4" stroke crank. You never know what you'll find out there.

Actually not - you can only offset grind a 3 3/4" stroke crank with a 2.138 journal to a 3 7/8" stroke crankshaft - with 1.999 journals (then use the 21A or 91A rods and floater bearings). This was done quite a bit before the later 49-53 Merc cranks were available. You may have issues finding pistons at that stroke.

[Bored&Stroked]

Originally Posted by 40 Deluxe

While you can't do the 4 1/8" stroke, you can gain a little, especially if you have undersize 91A bearings. Just do the math to determine how much offset grinding you can do. Use 4" stroke pistons. They will come up a little higher in the bore, which may give the right piston-to-head clearance. Thus kill two birds with one stone!

This can sometimes be done - and having a little extra "pop-up" can help if you already have heads with too much piston to head clearance (which is common). What one does need to validate is the top ring position in reference to the "relieved" block. Depending on the depth of the relief, you may not be able to do this as the upper ring may be getting very close to the relief. It is not good to have the top-ring too close to the relieved chamber - as it takes a lot more heat into the ring . . . which can cause it to lose some of it's temper. Now if you're having custom pistons made, then you can move the upper ring down a bit and run 1.5, 1.5, 3.0 mm metric rings (which give you more room in the piston ring area).

[deuce5wndw]

Any ideas on the camshaft? Thanks again

[Bored&Stroked]

Have no idea on that cam . . . never heard of that manufacturer. You could pull it and have somebody with the necessary setup run a profile on it . . . but that may cost you more than it is worth.

[GOSFAST]

That is a "Lishin" cam from really way back!!

Thanks, Gary in N.Y.

P.S. Probably somewhere around 1950 or thereabouts??

[Pete]

All I can add is I had a core pass through my hands with that stamp on it back in the 50's.
I just ground the name off, reground it into a street grind and sent in on it's way.

[deuce5wndw]

Thanks guys, you never know what you are going to get when you take a flathead apart! Kinda like a box of chocolates, now where have I heard that before? Would be interesting to know how this engine wound up in a bone stock 1946 Ford Siebert ambulance!

[Bored&Stroked]

Originally Posted by deuce5wndw

Thanks guys, you never know what you are going to get when you take a flathead apart! Kinda like a box of chocolates, now where have I heard that before? Would be interesting to know how this engine wound up in a bone stock 1946 Ford Siebert ambulance!

Maybe the BEST ambulance to take you to the hospital at the time . . . .