Aaah what a read!
I wonder if things changed over the last 10 years.
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Aaah what a read!
I wonder if things changed over the last 10 years.
And 5 years further on, what a treasure trove for the enthusiast engine builder! Sad that Grady Clay, Chris Seven and Steve Weiner are all no longer with us. Please PELICAN don't lose this information trove!
Well I've had my 72T for over 20 years. Since I'm a road racing nut, I started out autoxing, well before I got my Porsche. Then I got into driving at the "track" days. With the help of 'Mike Bruns' in Florida we came up with a 'bullet proof' engine. I had found a 1981 3.0L before I left the west coast for Florida. Mike helped me build this engine, twin plugs and webers and able to turn 8500rpm. However, driving on a race track I found it's torque that pulls you out of the turns, sooo. With the help of another friend with a 72 track car, I contacted Dougherty racing. He had a cam, I think it was a 902-102, that had a lower torque peak, about 4600rpm and 230 ft/lbs and max Hp at 6900rpm. Now when I'd downshift my 915 transmission I'm at 4-4500rpm and it will pull like crazy out of the turn up to the redline, I use, of 7200rpm. I've run this engine for over 10,000 miles and all I have to do it adjust the valves and change the oil once a year.
I like these old posts . I do know that the 70.4 RSR crankshafts have a bigger radius on the main journals , not the rod journals .
Boy, some real heros of these motors posted on this great thread; some no longer with us. Long live the kings!
That said there are limits to these motors that are not just mechanical. It's a 2 valve overhead cam motor; most will reach reach peak HP below 8k. You might be able to turn them faster and survive with remedies to valve train, crank and oiling; however, horsepower will likely be dropping off. There is a reason why porsche has tried to live within these limits on 2 valve motors.