360 to 375 question Offset grinding????

JumpPilot Dave · #1 06-19-2012, 08:16 PM

Hi All,

I was wondering if anyone has taken a large rod journal 200hp crank and offset ground the rod journals to 4.500 stroke with a small journal 180hp rod journal size to create a 372CI engine..

I have a beautiful AEIO360 large journal non counterweighted solid flange constant speed crank...and was thinking offset ground with 180hp small journal rods with 7:1 pistons would make a nice 9:1 372 engine.
Questions that come to mind are rod to cam clearance and rod to case clearance???? The crankshaft itself already clears the case...
Has anybody tried this ??? What engine shops would have the specs to do this..Aviation engine builders tend to be kind of tight lipped about mods..

This is nothing new...It's quite common in Nascar lower divisions to make 355 chevy v-8's into 363ci V-8's by using this practice..

Any thoughts or names to go to would be appreciated,Thanks, Dave

Mike S · #2 06-19-2012, 08:23 PM

Try talking to Bart at Aero Sport Power, I believe that may be what they are doing.

http://www.aerosportpower.com/375.html

Dan Langhout · #3 06-20-2012, 07:51 AM

When I talked to Bart about his -375 engine a couple of years ago before I ordered mine, he explained that he has ECI grind their standard virgin crank forgings to give the longer stroke. He also has them ground with a larger fillet radius on the journals. Don't know if there would be enough "meat" on an already finished crank to do this though. I'm sure Bart would know.

rocketbob · #4 06-20-2012, 07:55 AM

Should work just fine.

Another factor to consider is the deck height if the case is being resurfaced. As the case halves are fly-cut the cylinder decks are brought closer together and there's not a whole lot of room between the counterweights and the crankcase. This used to be one of the old ways to bump compression up before the different CR pistons that we now have today were available.