201 Crankshaft Question

[RobertM]

I have a 237 engine and I'm wondering if a 201 crankshaft will fit? Im wanting to do a short stroke big bore combo.

I keep doing web searches for questions and the web keeps leading me to the answers here, so I must be in the right place. Thanks everybody for all the answered questions.

 

[greg g]

Are both engines the same length??  In the US made engines the 201 has a 23 inch block and the 237 was the longer Chrysler DeSoto version .  So cranks would not interchange, north of the border they might be the same block length and might interchange so more info is needed.

Edited April 10, 2021 by greg g

[Plymouthy Adams]

journals are smaller

[RobertM]

Hmmm, bummer. Do you know of any other cranks that have a smaller stroke than 4-1/4 that will fit in a 25" long block?

[RobertM]

On 4/9/2021 at 5:38 PM, Plymouthy Adams said:

journals are smaller

Other than the journals being smaller are there any other differences that you know of?

And when you say "journals" which ones are you referring to, the rods, the bearings, or both?

Edited April 11, 2021 by RobertM

[keithb7]

The 201 engine is a pretty mild engine . The crank would be a weak point.  I don't think I'd want a 201 crank in a 3 7/16 bore 237 engine. I'm imagining the 201 crank not lasting long with a 237 bore engine.

 

FYI the 201 engine is 3 ⅛ bore x 4 ⅜ stroke.  237 ci engine is 3 7/16 x 4 ¼" stroke,

 

 

Edited April 11, 2021 by keithb7

[keithb7]

Seen here is a 201 (23" long block) crank beside a 237 (25" long block) crank.

 

Edited April 11, 2021 by keithb7

[RobertM]

Thanks for the pic. All the info I can gather helps.

The only reason I'm looking at the 201 is its the shortest stroke I could find. Here are the numbers I found on the web. Bore 3-3/8 x Stroke 3-3/4. The stroke would be reduced by .5 of an inch. To me thats worth investigating.

By shortening the stroke it reduces stress on all the parts. I would have rods made and choose a flat top piston to go with it. Then I'd work on getting the engine to breathe.

The size of the rod journals won't matter if I have rods built, but if the main journals are different it could be expensive to adjust that.

[TodFitch]

9 hours ago, RobertM said:

Other than the journals being smaller are there any other differences that you know of?

And when you say "journals" which ones are you referring to, the rods, the bearings, or both?

Parts book shows that both the rod and main bearings changed when they went from the 201 to the 218.

[RobertM]

Found someone local that can weld and grind the main bearing journals. I just have to find a 25" crankshaft with the 3-3/4 stroke. If anybody has one please send me a message.

I have an engine dyno to test all the changes. Although it might be some time before I get to the engine I can post the results if anybody is interested.

My main focus right now is building the frame, drivetrain and body which I've already made a lot of progress on, then the engine will get built. The vehicle is a 46 Power Wagon.