Would you like to get a big crayon out and draw me a picture of this as I'm lost.

It had been explained to me by someone in the know that this is not needed. The real issue is oil starvation at the sump. Early engines are more prone to this due to the smaller oil pan capacity.
Crossdrilling the crank is fine but not the solution. The oil under pressure will seek the passage with the least resistance, just simple physics. By adding passages we are reducing oil pressure somewhere else.
Keeping the oil from moving away from the oil pickup and keeping the oil at the proper level is the key.

Since I baffled my early pan and added the oil pickup extension, I have not had a single oil pressure issue. According to my aftermarket VDO gauge, my pressures never drop below 35 psi, even in 110 degree weather. I have been running Castrol TWS 10W-60. I recently switched to Lubri Moly 10W-60. And pressures were still excellent.

If racers are experiencing oil pressure drops, I would start by checking the OPRV.

-bj

Is this with out a cross drilled crank?

And I am guessing the OPRV is the oil pressure relief valve?

I've lost 2 engines to #2 rod bearing failures but they were stock style without cross drilling, sump mods, etc. I now have all of the legal mods, an accusump, big oil cooler, and I run aftermarket oil pressure and temp gauges with idiot lights. This is the end of the 2nd season on this engine. I send my oil out for analysis when I change it which will be soon. We'll see if they detect anything of interest.

I guess that is my long winded way of saying that any oil mods that help should be legal. Whether you believe they work or use them is another story. Something like this certainly isn't going to make more power.

On the subject of rewards weight, the intention is great but execution is a pain. You have to scale the top finishers, track the weights, worry about setup ($$ if you are paying someone) etc. I'm assuming all of the tracking would fall to the series directors? We need to be careful about what we ask of people if that is the case.

The beauty of spec racing is the simplicity. Be careful not to over-complicate it. We don't want to turn into that other 944 series

cbuzzetti wrote:


I have an 83 crank, thus it is cross drilled from the factory.

Yes, OPRV = oil pressure relief valve. I think a lot of oil pressure problems can be attributed to this. Many people think that the later or updated early valves don't have problems. This isn't the case. The problems they cause can be very intermittent dependent upon oil temperature and oil viscosity. They also wear out over time. The springs that are responsible for keeping the oil pressure as high as it should be loose tension with age. I don't know if this is simply from normal use or from heat cycling from cold to race temperatures repeatedly. Additionally, the one piece units have o rings that will deteriorate over time. When these start to crack and loose their seal, oil pressure will be reduced.

Additionally, I think a lot of spun bearings are a result of contamination--either water or fuel. I'm not saying that oil starvation doesn't cause bearing failure or that wear can't cause it either, but I think that often a spun bearing is blamed on oiling to the crank when it is really cause by something else.

-bj