View Full Version : R3/R4 Crankshafts

01-23-2006, 08:07 PM
OK, I get my Avanti manuals on CD today, and I'm going over the engine stuff. The parts book shows a different crank for the R3/R4 cars than the R1/R2 engines. So what's the difference? I was under the impression that the difference in engine size was due to a larger bore size. Are these cranks offset?

Tom - Sterling Heights, MI

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1964 Studebaker Daytona - Laguna Blue, Original 4-Spd. Car, Power Steering, Disc Brakes, Bucket Seats, Tinted Glass, Climatizer Ventilation System, AM Radio (136,989 Miles)

01-23-2006, 08:16 PM
I suspect just a blueprinted version of the 289 crank. The stroke is the same.

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64 GT Hawk
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01-23-2006, 09:14 PM
If you are ever lucky enough to see a R3-4 crank you will see that there is a little more meat on the counterweights and the fillets on the journals have a larger radius than a 289. It is mainly because the R4 used much more weight in the rods and pistons. but the lifters are 1/4 ounce lighter.

01-26-2006, 12:25 AM
The bearing journals were sized to provide a little more clearance than the standard R1/R2 cranks.

David L