Thread: help me Henry!!
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Henry Schmidt Henry Schmidt is offline
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Join Date: Apr 2004
Location: Fallbrook, Ca. 92028
Posts: 5,918
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It seems I always find myself in a position to contradict my friends on the board. I guess it just my curse.
Here goes.
There is no comparison between the 2.8 SS and the Mag case 2.7 based 2.8.
First. The case .
There is no better case built by Porsche than the 3.0 Turbo. It has been proven to handle over 700 hp (935). The mag case seems stressed at 200+ Porsche didn't even use the mag case to make 280hp in their 2.8 RSR..
Second. The crank. The 66 mm crank has been proven in racing for 40 years that it could run at 8000 forever, the 2.7 crank needed to be replace in the RSR because it couldn't handle sustained 7400 for any prolonged period. 2.8 RSR crank is great but hard to find. I loaned a VARA racer at 2.7 based engine to run in his 914/6 gears of a short stroke engine. He ran it at 8000 RPM and broke the crank in one weekend. Few people run that hard but if you might you can't.
Third :The heads. the 2.8 SS uses 3.0 heads. Bigger valves, better valve angle (improved flow) Larger volume for easier combustion control. (flatter dome)
Forth: Engine design. The short stroke has better rod to stroke ratio which means longer piston dwell (more efficient fuel burning), less side loading (less wear and reduced friction) and higher potential rpm .
Fifth : Cams, the cams in the 2.8SS are four journal. This means they have better support and the larger journal size allows for higher lift cams with larger base circle.
End result: The engine will run better at all RPMs. The fact that it will run at higher RPM does not mean that it won't run well at lower RPMs. How the engine performs at lower rpms is a function of the cams you choose. Choose a cam the performs at 3500 and the SS engine will perform there as well or better than the long stroke version and still be functioning at 8000.
It is more reasonable to compare the 2.8SS with the long stroke 3.0. These engine are cheaper to build and offer similar performance. The 3.0 even has some benefits over the 2.8SS. 9 bolt crank being the most obvious.
9.5 to 1 compression, idle smoothly, easy to drive on the street and 315 horse power on street gas. What could be better.
BTW: KobaltBlau's avatar is the 315 hp 2.8SS

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Last edited by Henry Schmidt; 10-18-2005 at 09:41 AM..
Old 10-18-2005, 06:15 AM
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