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On 31 May 2001, at 9:57, Martinez, Leon wrote: > Is redlining the engine a function of oil starvation and internal > engine vibration , if balancing and oil availablity is enhanced , > would this not raise the redline limit ?? Is this correct ? I don't think oil starvation has anything to do with it since the oil pump pumps more oil as the RPMs go up; in fact, I suspect that the relief valves tend to open up at high rpm to dump excess oil. While it may seem obvious, I don't think it is true that an engine needs more oil as the rpms increase. The redline is just a matter of the forces on the moving parts of the engine. A balanced engine with a counterweighted crank relieves a great deal of force on the main bearings and the main bearing webs in the case, but the forces on the rod ends and the pistons just continue to increase with RPM until something gives. There is also the question of valve float, where the valve springs are no longer strong enough to accelerate the valve train down the trailing side of the cam. I think the "red line" on a std engine is around 5000 RPM, while a well balanced engine with a CW crank can go to 6000. Stronger valve springs can push this higher, but you can't do much about the forces and the strength of the rods and pistons. Note that this is one reason that the red line for large displacement engines will be lowered due to the larger pistons and/or the proportional effect of longer stroke cranks. - ******************************* Jim Adney, jadney@vwtype3.org Madison, Wisconsin, USA ******************************* ------------------------------------------------------------------- List info at http://www.vwtype3.org/list or mailto:help@vwtype3.org