Quote:
Originally Posted by winders
The consensus from the builders I talked to is with air-cooled engines, the 76.4mm stroke Porsche Motorsports GT3 crank should not be drilled. Modify the case appropriately and use a GT3 oil pump and you will get the oil where it needs to go for an 8000 RPM engine.
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You made my point, I guess. I suggested blanket statements that have been commonly used and thought, have no place in this business. That every engine and the parts used have to be looked at in entirety and not individually. This is what is needed in this community. There are many reasons to do certain mods. Every engine and its use will dictate what is done.
A GT3 crank is different to the early cranks too. Oil galley drillings are bigger, in fact the later cranks have to drillings on some cranks. Pump size is different, so in some cases, the center rods needs a little more help. The testing we have done on the Sprintron has shown it does help the early crank/rod supply.
I personally do not like the center feed oiling on these lower speed engines. Direct is better but this cannot be done on the earlier cranks. The overlap etc just will not allow it.
But the oil that is pushed to the main bearings from the pump has other difficulties to over come, even before it enters the crankshaft. GT3 oil pump or not, there is one major issue that should be taken care of as well. If not, it negates the larger pump and any cross drilling or grooving of journal or bearing shell.
I am including this is the paper about case assembly to come.