Standard shift flywheel - 1949

[Patrick Knapp CLC #16376]

Would anyone happen to know if the standard shift flywheel on a 1949 - 331 - will fit on a 390 crankshaft?  I am trying to put a 1960 - 390 into a 1949 standard shift Cadillac.  Also, would anyone have a standard shift flywheel that they want to sell?   Thanks for your help.  Patrick

[Mike Simmons (938)]

Yes sir- it will as will the 1950 Olds piece. When I put that combo together in the late 70s, I had purchased the last adaptor in captivity-according to the dealer. Do you have of those rarities?? Mike

[Mike Simmons (938)]

I realize now how vague that reply sounds, so Ill ampliy. Yes,the flywheels (Cad, 50 Olds ) bolt to the crank; But,the 49 through 54 engines have an extended "skirt" sort of covering the flywheel and mating to the stick bellhousing. The 55 331 and later engines, including 390s, do not have that "skirt". I cannot recall seeing a 55 in the car,so dont know how the factory filled the gap, but my adaptor ( probably Offenhauser,though not sure) fills it, and acts as a place to hang the starter. I still have that stuff and am planning to use it in the near future. It is not the most straightforward piece of equipment, but if you have one, I will fill you in on the little extra efforts needed to use it.

[Jay Friedman]

Patrick and Michael,

The 55 and later engines covered the "gap" described by Michael with a larger bell housing on the Hydramatic transmission.

Even though stick shift was no longer available in 54 either, the "skirt" (actually called the flywheel housing by Cadillac) was retained since replacement engine blocks for 53 and earlier stick shift cars were still made in 54.

My understanding is that 56 and later Cadillacs with the new Hydramatic introduced that year had crankshafts especially balanced for the new Hydramatic and, as such, would cause unspecified problems if used with a manual transmission. I dont know if this is really true. Do either of you 2 guys know?

Jay

[Patrick Knapp CLC #16376]

First of all, I would like to apologize for not getting back to you sooner.  I have been away for a few days.  Thank you very much for the information.  I do have the adapter, but probably will have a few other questions.  My phone number is 262-245-9395.  If you wanted to e-mail me your phone number, if it would be okay with you, we could talk.
Pat

[Patrick Knapp CLC #16376]

Hi Jay:  Good to hear from you again.  I dont know about the balancing, but I guess I am going to find out soon.  I will let you know.  Thanks again.
Pat

[Mike Simmons (938)]

Jay- I cannot remember if I had my engine balanced-probably did after boring,but that was 30 years ago.In any case, to my knowledge, all Cads through 1962 were internally balanced-that is there was no off-set weight added to either the flywheel or the harmonic balancer. The crank counterweights were sufficient to offset the piston and rod mass and control vibration. What you do is just get your flywheel-pressure plate combination balanced as a unit-and then bolt em on. Also, from my experience, the clutch shaft on the 1937 (only) Cad trans is about 1/4 inch too long (the OHV cranks are not drilled quite as deep as the flatheads). 38 and later sideshifts are fine in this respect.