I know you want to expell/remove as much pressure build up in the crank case as possible...
Some use vacuum pumps on their motors to scavenge that pressure build up out.

 

the more turbulence or air circulation in areas that the crank/rods and pistons hit the more they will be impacted, almost like weight as they have to move the air born oil slinging off the rotating parts.

so if you take a sharp square edge and round it off there is less air disturbance at high rpm's

if you have enough windage problems in the bottom end to create pressure the pistons have to fight that in essence reverse pressure to come down to BDC, before they go back up again.

every little bit helps when your trying to push the possible limits of an application.

 

Straight cut gears have more backlash. makes a very hard cam timing process damn near imposable.

 

Thank you guys. Interesting to see that these mods are in a ballpark that is relevant enough.

Andreas

 

Well, I started acquiring parts for the rebuild. Just received a GT3RSR crankshaft and dual pick up oil pump. Rods and 3.8 pistons/liners to go..

 

whoa... I like that, John!!

 

Thanks Henry. It was a deal a couldn't refuse. Came out of a 2007RS with 8000 miles. The owner is building a 4.2L and completely stripped the motor down and is parting it out. New crank, pump, pistons, cams, etc..

 

I cant imagine,, but I don't know these engines, how off it can be?, Especially when a gear is loaded in one direction it would be constant then..
I do believe in any high output engine straights are better and especially how our gear is at the end it would make it better for less side loading to put stress on things,, IMO.
Plus all gear drive cams I have seen on HP applications are straight..

 

Subscribed. Amazing info in this thread!

 

Those look lime some nice parts, great find. I've got a refresh build coming at some point myself, maybe this next winter. My use is the same. Do you run a certain class in TT or w2w?

 

No wheel to wheel. Pretty much just run the black group at all of our PCA de events and then lapping days. Just racing the clock and having fun with my buds. Plan on getting my feet wet in some Boxster spec racing this summer.

 

Lapping Days? Do you run at Miller?

 

A group of us are planning on running Miller this fall. I think their big event is in September.

 

i also have this rsr part for the rebuild. love it

 

Cool, I just just ask because one of the groups I instruct for is called "Lapping Days" they do 2 or 3 events a year at Miller and is a great group to run with. Let me know if you come in, I have a garage with air hose and a few tools refrigerator, BBQ ect. Makes a nice base for a track day, your welcome to use it. I'm there for all the PCA and NASA events.