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flathead 346c.i. crankshaft

Started by wicho46, February 20, 2014, 06:15:51 PM

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wicho46

I need to locate a crankshaft for my 1946 Cadillac.
What year's are these crankshaft interchangable. Any difference between an automatic/manual transmission crankshaft.
Thank You
L Lopez

Jay Friedman

According to my 35-55 Master Parts List, the crankshaft was the same from 1942 to  48.  It doesn't mention a difference according to transmission type.  I think the vibration damper, which Cadillac calls the balancer, was different from 42 to 48 depending on whether the transmission was manual  or Hydramatic.
1949 Cadillac 6107 Club Coupe
1932 Ford V8 Phaeton (restored, not a rod).  Sold
Decatur, Georgia
CLC # 3210, since 1984
"If it won't work, get a bigger hammer."

Steve Passmore

Having removed an automatic box and fitted a manual to the same engine I'm sure there's no major differences but you will need the manual flywheel.


















Steve

Present
1937 60 convertible coupe
1941 62 convertible coupe
1941 62 coupe

Previous
1936 70 Sport coupe
1937 85 series V12 sedan
1938 60 coupe
1938 50 coupe
1939 60S
1940 62 coupe
1941 62 convertible coupe x2
1941 61 coupe
1941 61 sedan x2
1941 62 sedan x2
1947 62 sedan
1959 62 coupe

markl

Mr. Lopez,
I notice your are in Lompoc CA.  Do you ever get up to the Bay Area?  If so, I would recommend a crank grinder, Sammy Hale, who is in North Bay.  Unless your crank is cracked or broken, the journal(s) can be built up and ground back down to whatever size you require.  Do take care removing the screws that retain the counterweights as these are difficult if not impossible to replace.  But other than that, this crank is rather simple having only 3 main bearings and the rods sharing journals (four).

If the crank is actually terminal, I think I can locate my "spare" crank, but as best I can tell, it is from a 39 Cadillac, and from what Steve is telling us, this may not fit.

BTW, how about giving us your first name?  I always feel uncomfortable referring to anyone as "Mr." who is younger than myself.  Don't actually know your age, but there is a very good chance that I, at 65 am more senior than you!

Mark Lowery, CLC#25216

hudson29

Quote from: Jay Friedman on February 20, 2014, 06:56:02 PM
According to my 35-55 Master Parts List, the crankshaft was the same from 1942 to  48.  It doesn't mention a difference according to transmission type.

That's interesting! What changes were made from the '37 - '41 models? Was it possibly something to do with wartime production increases?

Vintage Paul
1939 Cadillac 6127 Coupé
1929 Hudson Town Sedan
1926 Hudson Anderson Bodied Coupé
1923 Ford Runabout

Steve Passmore

You can discount 36 and 37 cranks completely as they have a totally different rear end along with a peculiar flywheel that's not interchangeable with later years, not to mention slight differences in some of the journal widths.
I have just looked through my stores where I have a 39 and a 41 crank and they are both interchangeable.   The main difference which confirms what Jay has said is that 38 to 41 the counter weights were held on with large screws which are near impossible to remove without destroying them and sometime during 1941 they changed to recessed bolts which give you a fighting chance.
So although interchangeable the parts book would list them as a different number because of this difference.
Steve

Present
1937 60 convertible coupe
1941 62 convertible coupe
1941 62 coupe

Previous
1936 70 Sport coupe
1937 85 series V12 sedan
1938 60 coupe
1938 50 coupe
1939 60S
1940 62 coupe
1941 62 convertible coupe x2
1941 61 coupe
1941 61 sedan x2
1941 62 sedan x2
1947 62 sedan
1959 62 coupe

harry s

On the '41 thru '48 crankshaft there is a shouder about 1/4" that sticks out past the block from the front journal that the timing chain drive gear rests on. The '37 doesn't have that shoulder. It also takes a wider timing gear and chain. I'm not sure about the '38, '39 or '40 cranks.   Harry
Harry Scott 4195
1941 6733
1948 6267X
2011 DTS Platinum

Steve Passmore

Its possible to replace that wide timing chain and sprockets with the later thin ones Harry, I have done this on my 37. These kits are still available I think, unlike the wide ones.
Steve

Present
1937 60 convertible coupe
1941 62 convertible coupe
1941 62 coupe

Previous
1936 70 Sport coupe
1937 85 series V12 sedan
1938 60 coupe
1938 50 coupe
1939 60S
1940 62 coupe
1941 62 convertible coupe x2
1941 61 coupe
1941 61 sedan x2
1941 62 sedan x2
1947 62 sedan
1959 62 coupe

harry s

Steve, When you used the later timing gears and chain was it necessary to use a spacer to take up the slack on the crankshaft? When I rebuilt my '37 I considered using the later timing set up but was concerned about extra 1/4" of space.    Harry
Harry Scott 4195
1941 6733
1948 6267X
2011 DTS Platinum

Steve Passmore

Harry,  the centre boss on both sprockets is the same size. its only the teeth end thats narrow.
Steve

Present
1937 60 convertible coupe
1941 62 convertible coupe
1941 62 coupe

Previous
1936 70 Sport coupe
1937 85 series V12 sedan
1938 60 coupe
1938 50 coupe
1939 60S
1940 62 coupe
1941 62 convertible coupe x2
1941 61 coupe
1941 61 sedan x2
1941 62 sedan x2
1947 62 sedan
1959 62 coupe

wicho46

Looks like my crankshaft will be grinded down to .030 I will be able to get a set from Egge.com (Bearings)
Thank You all for your input.
Luis Lopez

markl

Luis,
Good to hear that your crankshaft is salvageable.  I'm sure that your crank grinder has gone over this, but just for the purpose of discussion, it is always possible to build up just one crank journal if only one is badly scored.  And then grind the lot down a more modest amount.

But that said, I don't think 0.030" under is a problem on these relatively low stressed engines.

Mark Lowery, CLC #25216