View Full Version : 230 flathead speed

03-22-2001, 06:08 AM
Can anyone tell me how Lee Petty got a flathead six in a 53 plymouth to go 125mph?

03-22-2001, 08:48 PM
I thought he raced a Chrysler New Yorker with a V8.

04-01-2001, 12:46 AM
I don't think it would take anything too exotic to get them up to 125. They would do 100 bone stock. Try adding some compression, cam and ignition timing, another carb, headers, porting and relieving the block, lighter 3 ring pistons, a good balancing job, etc. and you'd be there.

04-01-2001, 04:05 AM
I (used to have) a book on Dodge Trucks, part of which detailed how to get more power out of the flathead 6's. There were a lot of hot parts available for them back in the day! Edmonds, Fenton, and others made parts (such as heads, headers, intake manifolds etc) that raised the power considerably. According to the book, these parts are still to be found at swap meets. The engines respond to typical power increasers, such as higher compression and hi-flow exhaust etc.

04-01-2001, 04:55 AM
Thanks guys for the information. I guess my question should really have been,
How did he manage the speed for 100 miles with the rev limitations imposed on the
230 flathead , of 3700 rpm, due to the offset rod design?

My Dodge has a 4.11 rear end and I reach the rev limit at about 62mph with the Gyromatic Tranny.


04-01-2001, 01:12 PM
One of the things the book I had mentioned was that higher RPM's can be tolerated with significant upgrades to the oiling system and bottom end; the author detailed how to beef up the flathead in these areas. Modifying the crank bearings, high strength fasteners, souped up oil pump, strong bearing caps, and some other things I can't remember. Also, Lee's car probably didn't have 4.11 gears either. Actually, most modern (read: high rpm engined) cars would have trouble getting over 100 mph with 4.11's (w/o overdrive). My Mercedes runs 3500 at 60 mph with 4.10's and there's no way it could hit 100 without blowing something in the engine.