Technical 331 Cadillac to ford 3speed/od (1951) flywheel help

Hi everyone,


I'm currently working on putting a 1954 331 Cadillac into my ford shoebox. I'm using the offenhauser 0304 adapter that mates the Cadillac to the original ford 3 speed + overdrive trans.

I'm wondering if I will have to change the flywheel, since the trans that was on the Cadillac was a hydramatic? Would anyone know what flywheel I need to use here?

Many thanks. Hoping to start a build thread here soon.


George

 

Caddy flywheels exist but are as rare as hens teeth, early olds 303 324 flywheels are the the same and slightly less rare.

 

Yes, you'll need to change to a standard transmission flywheel. Also, you will need a pilot adaptor, and may need to drill the crank if it isn't already.

That's funny. I easily found a Caddy flywheel, but had trouble finding an Olds flywheel. Go figure.

 

Would a 176 tooth flywheel from an Olds work?

 

You need to match your starter to what tooth count on the flywheel.

Cadillac changed from coarse to fine teeth right around that time, and I don't know the exact year..

Olds flywheels are coarse teeth on 50-53 which are 303 cu in I forget the teeth count, maybe 155t ?
54-56 Olds were fine teeth for the 324's 176t

You cannot use an Olds flywheel from 1957 or newer because those are external balanced. So, the only Olds wheels that are not counterweighted are 50 through 56. Look at the engine side of any Olds wheel to look for an obvious counterweighted spot. It's very obvious, if it's 1957-type

All that considered, you really should get a tooth count on your Hydramatic ring gear, to be sure that your starter will mesh with that Olds 176 wheel.
.

 

I forgot to mention the stock Cadillac standard shift flywheels for the new OHV engines that came out in 49, and that the last Cadillac standard trans was in 53..

These stock Cadillac stick wheels from 49-53 are all coarse teeth, just like the Olds 50-53, 303 cu.in. coarse flywheel teeth.

.

 

I believe tony at ross racing and wilcap has what you need if you cant fined it

 

Asking a question of a statement made several years ago. Are the diameters of the course Olds flywheel (155 tooth) the same as the Olds fine tooth (176 tooth)? AND are they same as a Cadillac flywheel?

 

You can also remove the ring gear off your Cad drive and fit it to whatever flywheel works for you.
It’s only tacked onto the tin drive plate so easy to remove.
I machined a Y block flywheel to fit the Cad crank and turned the OD down to shrink fit the ring gear. There is room to machine a step into the OD to position the ring gear correctly.
The Y flywheel needs opening up to suit the Cad crank spigot and then redrilled to suit the bolt PCD.

 

To clarify, the Olds small flywheel is 145 tooth with a 6 volt starter that has a 9 tooth 1 5/32 drive. In 54 Olds changed to 176 tooth with 12 volt starter and a 9 tooth 1 inch drive.
To add some confusion to this in '53 Olds changed up to 12 volt with the small flywheel for one year only making that 12 volt starter rather hard to find.

 

Thank you Barrelnose pickup & vtwhead for the replies. Here's the root of my question. I have a 1953 Cad 331 engine that I'm putting in a 39 Ford Tudor, mating it to the Ford 3 spd trans. I did not have a flywheel for the Cad engine (so I have nothing to swap per what barrelnose suggests). I've heard and read that the Olds flywheel is "the same" as the Cad flywheel. I have a 176 tooth Olds flywheel. It bolts on fine until I try to put the starter on (it is an aftermarket, 12v, gear reduced starter). I believe the tip of the starter gear shaft is hitting the ring gear portion of the flywheel as about 3/16" from the starter mounting flange engaging the mounting surface on the bellhousing is stops due to inference - everything is inside the bell housing so I can't see to make absolute sure. Hence my question - is there a difference in the OD of the two flywheels? If there is, is the 176 tooth wheel too big, and what I need is the smaller 145 tooth wheel - which from what I'm seeing happen, and per what vtwhead says - that there is a large and small wheel - sounds rather obvious.

 

You may need a later 54+ lower torus cover. Seems I recall that the 176 flywheel required that unit as the clocking of the starter is different moving the drive further out.
Was the reduction starter universal or for a specific year Olds?

 

Ill try to mesure mine today

 

Crawled under the project and grabbed the number off of the lower cover. Mine is stamped with a 54 date code, part number 564020 and has the very rectangular inspection cover on the bottom that is roughly 3inches x 4. IIRC Tony @GOATROPER02 told me I needed the 54 cover for the larger 176 tooth flywheel but that conversation was a long time ago.
Perhaps @Paul will see this and chime in as he has a shop full of Olds product.

 

here is copy from the Classic Olds sight where Charlie addresses this subject

Olds used three different ring gears on their early 'Rocket" V-8s
49 thru 53 used a 145 tooth ring gear .
54 thru 60 used a 176 tooth ring gear .
61 thru 64 used a 166 tooth ring gear.
Every time they changed the ring gear they also changed the design of the lower bellhousing , where the starter mounts , as well as the starter itself .

If you have a 176 tooth flywheel , then you will need to have a 54 thru 60 lower bellhousing and starter .

 

I count 145 teeth

 

Heres the starter number i have that i believe is the correct starter for the wheel i pictured

 

Thanks vtwhead - my starter is for a 53 Cad which probably means is fist 50-53, and probably not a 54. I'll probably pursue a 49-53 flywheel before looking for a 54 lower. Oliver Westlund - thank you for the pics and info. Very helpful. I'll try to PM you as we likely don't live to far apart. I'd like to look at your flywheel.

 

Most Olds starters start with 110xxxxxxxxx
here is a list:
7922 42-48
7050 42-47 6 cyl
7930 42-47 8 cyl
7955 49-50 6 cyl
7956 49-51 8 cyl 6 volt 145 flywheel
7997 52 all 145 flywheel
7603 53 12 volt 145 flywheel
7623 54-55 12 volt 176 flywheel
7638 56 12 volt 176 flywheel

 

Great info rite there.

 

Call Wilcap. I believe they can supply you with a flywheel. They were very helpfull on my Cad 390 build.

 

I brought this years ago as a 53 Cad flywheel, just showing the measurements and where the ring gear sits compared to the mounting flange.

 

It’s been done, but remember that Cad will lunch the early ford trans or the rear end without a lot of effort. Skinny rear tires are your friend.

 

Thanks for the pics and running the tape measure over the flywheel barrelnose. I'm pulling my flywheel off this weekend to measure it. Might be able to compare it to what Oliver has if time and schedules permit. And yes miker98038, I'll baby that 3 spd and will be retaining the stock size bias plies. I'm not building a race car/burn out machine

 

BM, Marty Strode is starting this same process but with an Olds engine. Good read. Might check in on his post:
Hot Rods - Olds Powered '29 Roadster Build. Marty Strode | Page 11 | The H.A.M.B. (jalopyjournal.com)

 

Found my list of housings for reference:


you would need a 558709 if you came across one in your searches to work with that 145 tooth.

 

FWIW, there are 2 020's on that selling site....probably less than buying a 145 flywheel

oldsmobile lower torus cover | eBay

 

Was 57 years ago that one of my buddies adapted a Olds V-8 to his old Ford flathead 3 speed.
I rode in that Ford on only 3 occasions, each ended with a trans shucking its teeth halfway through 2nd gear.

 

Any updates BM?

 

On the hunt for a 145 tooth flywheel. Have a couple of possibilities I'm looking at.