76.4 GT3 crank in 964 case

[MST0118]

I wanted to see if a new GT3 crank 76.4 will drop into a 964 case without having to shorten the crank to fit. I thought they were longer and possibly needed to be shortened but not sure. I know Rothsport has a pulley that works and a different pin is needed. Is that it? Or does the crank need to shortened by 4mm or so? Thanks for any response on this.

[MoreGAS]

It bolts righ-in and the longer snout is the potential issue, this offset is handled by using the correct RS pulley.

Kevin
GAS Motorsport

[winders]

I have a 76.4mm stroke GT3 crank in my race engine with a 964 case and, as Kevin stated, the crank fits fine. I am using a Clewett Engineering serpentine belt setup with their pulleys. The crank pulley is made specifically made for the longer nose of GT3 crank in a 964 case.

[MST0118]

That’s good news. Thanks Kevin and Scott for tips on the pulleys.

[stanglife]

Is there any additional cross drilling or grooving typically done on a GT3 crank in a 964 case? I'm in the middle of convincing myself to do this..when I have a perfectly good 964 crank

[winders]

Originally Posted by stanglife

Is there any additional cross drilling or grooving typically done on a GT3 crank in a 964 case? I'm in the middle of convincing myself to do this..when I have a perfectly good 964 crank

Some people cross drill the GT3 crank and some don't. It is certainly not required assuming you are also using a GT3 oil pump. Porsche did not cross drill for use in Cup Cars....

[Bill Verburg]

Originally Posted by MST0118

That’s good news. Thanks Kevin and Scott for tips on the pulleys.

Neil Harvey engineered a modified ATI Superdamper for use on the Gt3 cranks

Here's one on a 4.0

[prschmn]

Ohhhhhhh, I like that damper!

[MST0118]

It sure does look nice. I’m sort of backdating the look of the engine by putting on early fan like Scott and others have done here and still trying to research the various pulley options.