crankshaft resizing

[Lawrie]

Is it posible to grind a later crank with the 2.139 rod journals down to 2.00 and the mains down to 2,399 from the 2.499,
I have an abundant supply of std rod bearings for the 2.00 journals,and thought this would make them useful again.
Lawrie

[Ken/Alabama]

I don't see a problem. That's what you wind up with when you offset grind a Mercury crank to 4 1/8 stroke .Been running one for years.

[Walt Dupont--Me.]

I don't see why not Lawrie, the 2.399 main bearings seams to be scarcer than the two inch rod bearings. I think around here the crank grinding would quite expensive. Let see what others say. -12F below nothing this morning in Maine. Had the dog in bed with us all night. LOL Walt

[42merc]

Walt, not trying to one up you, but it was 15*below in southwestern Michigan this AM.

[Ol' Ron]

I put an 8ba crank in a 37 block for Paul Howard, he wanted to keep the 21 studder looking stock. The only problem I had was the width of the front and center maines had to be widened .050" +/- some. The rod bearings will require 21A rods. You might want to consider re balancing it. You could also uz a 4" crank and build a 255. Just thinking. Good luck.

[scooder]

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No problem at all, no mechanical reason for it not to be done.
Martin.

[Lawrie]

Thanks guys,
I had a rearrange in my shop this last week and can now find all my stuff,
so I can dummy up a 33 or 37 block and see what is the easiest.
I was worried about taking that much off the rod journals,
I thought about roughing the mains down on the lathe first and getting the grinder to do the last .010 or so,but the rods are not posible for my lathe.
Lawrie

[oldford2]

[QUOTE=Walt Dupont--Me.;1011979]I don't see why not Lawrie, the 2.399 main bearings seams to be scarcer than the two inch rod bearings. I think around here the crank grinding would quite expensive. Let see what others say. -12F below nothing this morning in Maine. Had the dog in bed with us all night. LOL Walt[/QUOTE]

Walt, If you start itching you might want to dust a little flea powder under your arms in the morning. LOL
John

[Bruce Lancaster]

'33 and '37 are different worlds! Ron covered the '37 type...
I know of examples of early ('33 type) engines using a 4" Merc crank, but have no personal knowledge. What I have been told, however, is that the cut on the mains is so extreme that the oil passages are opened up, so those have to be welded shut and redrilled to get oil back over to the right places and that in all it is a LOT of work.

[Lawrie]

Bruce, I thought that taking the mains down to 2.00 for the 33 would be a problem,but if you used the 36 or 37 block you could maybe only go down to 2.399 which is only ,.100,
Lawrie

[Brian]

,but if you used the 36 or 37 block you could maybe only go down to 2.399 which is only ,.100,
And what are you really going to achieve Lawrie? apart from lightening up the wallet!! Why not just use a 21 stud crank in a 21 stud block, that 'buggered' 24 stud crank you recently got; put it to use holding up a letterbox, like we've previously mentioned! lol.
I know I go against the grain on here; 99% of you guys believe there is no substitute for cubic inches, and 8BA's are the holy grail of flatheads, but I still maintain those little 221's best attribute is their ability to rev, what with their smaller, lighter rotating/reciprocating mass, and when building one, you should enhance these very attributes. Sure, in theory, stroking a 221 by using a later crank, suitably machined, is going to add torque, but, realistically, you're still not going to be any better off than if you just used a later 24 stud 239, but it's gonna cost you a lot of coin!! The 221, with stock crankshaft, will be a more revier engine than with a stroked crank.
Lawrie, you're currently running that 99 engine in the 33, now you've sorted the timing, you're quite impressed with it- eh? But, honestly, is it that much better that a good 221?

[Lawrie]

Brian don't tell any one but the 99a is a great engine,BUT,as soon as I get time its out and back under the bench,the orig 33 eng is resembled and I will refit it as soon as.
The 33 221 towed the caravan nicely and while not as torquey as the 99a eng is still real nice.
What has bought up the idea of the cranks is I only have a couple of early cranks for spares,one is std and the other is .010, and as I said I have plenty of std rod bearings,
I also have a nice std bore 33/4 block a 37 and a 36 LB,so I was just sorting out spares for much later when my boys have the 33 and 34.
I must have too much time on my hands.
Lawrie

[Elmo Rodge]

With all that time on your hands, when are you coming to the Rodge Mahal again? Wayno

[Ol' Ron]

Wayno, you ever get that tank to run yet??

[Lawrie]

Wayno , you going to bonneville this year?
Brian, the reason for thinking about the later crank is I have a pile of nos 2.00 std rod bearings and no std crank,so thought I could get one with the 2.139 and grind it down,the -.060 cranks was a 2.00 rod one so thats cactus.
I have a couple of later blocks 36 and 37 so the mains would be not such an issue,
But if I found a good std 2.00 crank that would be easier,
Lawrie

[scooder]

Brian, I believe that Lawrie stated "as smooth ad the 33 engine but with twice the torque!, pulled like a F250"
I'd say that's better than a 221.
Any flathead with a good cam will rev crazy. My 239 would buzz 7000rpm any time it wanted.
Martin.

[colin1928]

Lawrie this is what you need then you do it yourself
made to work in the car or on a lathe

[Elmo Rodge]

Ron, I've been 150 in the car so far with a 4 barrel. I'm looking for a lot more this year with the help of Ray's (Flat32) Injection Manifold and AEM Engine Management. Lawrie, yes I'll be at Speedweek. Wayno

[Ol' Ron]

150, WOW really got it moving. Good luck and Keep safe.
Ol' Ron

[scooder]

Originally Posted by colin1928

Lawrie this is what you need then you do it yourself
made to work in the car or on a lathe

Is that a crank grinder attachment? Or a tool post grinder? Pic is small.
Martin.