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Crank journal specs?


thebeebe5

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Can anyone direct me to a source for some crankshaft journal specs for a '37 201cid motor?

Trying to get a rough idea of where this crank is in its current state and get some bearings on the way so we can spec the grind on the crank. 

 

Thanks!

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42 minutes ago, Don Coatney said:

Suggest you let the machine shop specify and purchase the bearings. Get the bearings for the final grind. Don't grind the crank to fit the bearings. If the machine shop buys the bearings the monkey is off your back for the final "fit"

I work at the machine shop, Don.  This isn't an engine we routinely deal with.  Looking up bearings in Clevite, Fed Mogul and King books and we can get back as far as a 218cid.  No 201cid.  

Would like a link to a published spec for both crank and rod journals. 

Edited by thebeebe5
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56 minutes ago, Plymouthy Adams said:

no online publication to quote....

@Plymouthy Adams

Would be happy to have your numbers as a reference because I have nothing else.  If you wouldn't mind reposting.  Or PM me?

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My understanding is that the 201 and 217 engines use the same journal size.... (AND I WAS SHOWN TO BE WRONG, SEE MY POST BELOW)....my 46-53 workshop manual has the Crankshaft Bearing Journal Diameter as a Nominal Size of 2 1/2 in. (selective fit)........the 36-42 workshop manual does not list the nominal bearing diameter..........bearing clearance listed is .001 -.002 .............dunno if this is much help..........btw you mention the 218 engine.....I assume you mean the 217.8 Plymouth/Dodge not the 218 Chrysler/Desoto............andyd 

Edited by Andydodge
incorrect info posted
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Thanks @Andydodge

Found the nominal sizes for the (i guess 217.8?) in the bearing books, but that would mean that my crank had been turned .250" already because I am measuring mains at 2.2450 (roughly).   Certainly excessive, and the bearing shells were thin, not super thick as if the crank had been turned to death...   

Still scratching my head ATM....  :(

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I don't know if there is anything here that will help . This is from a very old Motors Truck & Tractor Repair Manual . I see that for the 1937 1/2 ton truck that the engine model number is T38 .  T23 , T25 , T68 , T92 , T105 are 201 engines .   T38 is a 218 engine . 

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Edited by Jerry Roberts
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Just went & checked my1953 Motors Auto Repair Manual........

Plymouth 1935-1941 (All) Crank Journal Diameter...... 2.249 to 2.250

Plymouth 1942-1953 (All) Crank Journal Diameter...... 2.499 to 2.500

.....so it seems your mains ARE NOT as worn or machined as you and me(lol) thought........1942 went to larger mains.......so you have roughly 4thou wear.......lol.........andyd   

     

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4 hours ago, Jerry Roberts said:

I don't know if there is anything here that will help . This is from a very old Motors Truck & Tractor Repair Manual . I see that for the 1937 1/2 ton truck that the engine model number is T38 .  T23 , T25 , T68 , T92 , T105 are 201 engines .   T38 is a 218 engine . 

IMG_0351.jpg

IMG_9718.jpg

IMG_0850.jpg

IMG_2362.jpg

 

3 hours ago, Andydodge said:

Just went & checked my1953 Motors Auto Repair Manual........

Plymouth 1935-1941 (All) Crank Journal Diameter...... 2.249 to 2.250

Plymouth 1942-1953 (All) Crank Journal Diameter...... 2.499 to 2.500

.....so it seems your mains ARE NOT as worn or machined as you and me(lol) thought........1942 went to larger mains.......so you have roughly 4thou wear.......lol.........andyd   

     

Thanks fellows.  

Jerry, I'm guessing the T25 would be the specs for my motor....  Here are the measurements I posted earlier today in my "overhaul" thread.

Andy, can you confirm this with your information?  We doubted this motor had been apart ever in its life, but it's obvious that at least a valve job had been done as a couple of exhaust valves had been changed.  

 

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A search for 1937 motor specs Never can up with specs in this manual.

www.pwchryslerclub.org/PlymouthManual_OCR.pdfPLYMOUTH SERVICE MANUAL lor ... Car serial numbers and engine numbers. ..... DATA AND SPECIFICATIONS. Year. 1942. 1941. I 1940. 1939. 1938. 1937.

One page described setting bearings clearances with shims. If it needed more= replace crank with new?!!

 

DJ

 

 

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1 hour ago, DJ194950 said:

A search for 1937 motor specs Never can up with specs in this manual.

www.pwchryslerclub.org/PlymouthManual_OCR.pdfPLYMOUTH SERVICE MANUAL lor ... Car serial numbers and engine numbers. ..... DATA AND SPECIFICATIONS. Year. 1942. 1941. I 1940. 1939. 1938. 1937.

One page described setting bearings clearances with shims. If it needed more= replace crank with new?!!

 

DJ

 

 

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Thanks DJ.   Yep. Have that service manual.  Frustrating that little bit of information isn't in it, but it's not an all encompassing publication. 

Will figure this puzzle out piece by piece. 

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Beeb, as per the 1953 Motors Auto Repair Manual.........

Con Rod Bearings

1935-1941 Plymouth (all).......Journal Dia....1.9365-1.9375  Bearing Clearance 001-002

1942-1953 Plymouth (all).......Journal Dia.....2.0615-2.0625      "           "               "

 

....does this help?...........not sure what you actually wanted?........looks like your big ends have been ground down a bit, is that correct?........lol............andyd

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37 minutes ago, Andydodge said:

Beeb, as per the 1953 Motors Auto Repair Manual.........

Con Rod Bearings

1935-1941 Plymouth (all).......Journal Dia....1.9365-1.9375  Bearing Clearance 001-002

1942-1953 Plymouth (all).......Journal Dia.....2.0615-2.0625      "           "               "

 

....does this help?...........not sure what you actually wanted?........looks like your big ends have been ground down a bit, is that correct?........lol............andyd

Well, judging by my journal measurements compared to published specs for what we think might be the same as my 201 I'd still say nothing has been done to the bottom end on this one.  Right now I'd be confident ordering +0.010" bearings for both the mains and rods and, once line hone is done, assemble to determine where I want the relief to land.  We usually shoot for 0.0020-0.0025" for racers running a 20w50 VR1 oil which works out nice. Great  oil pressure bearing life at that spec.  On this motor I'm leaning toward the factory spec of 0.0015-0.0020" and will likely run a thin synthetic.  I like having cases of just one weight of oil at the house for all the cars and might go with the Amsoil Signature 0w30 I run in all our modern stuff.   The only deviation would be the hot 390 I built for my 67f250 where I run the Amzoil ZRod oil for the zinc content.  That truck has a high lift cam with some reasonably high spring pressures for a non-roller sold lifter motor.  Likely a non-issue with thr Plymouth's well worn in cam at pressures between 45 closed and 100 open psi.  Heck, I can almost squeeze that much in my hand.  Nothing compared to the high lift cams and high spring pressures for something more modern. 

The numbers you folks have provided have been a big help 

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