Thanks for the information. I want to put some nice watershields/aircleaners on my engine, to replace the plastic plenum chamber. I have MFI(an RS pump) but I have 911T plastic velocity stacks. I hear that S stacks are required to fit air cleaners. What modifications to the plastic T stacks would be required or will they work at all?

Thanks!

http://forums.pelicanparts.com/uploa...1189312966.jpg

That equipment looks like stock stuff to me, probably from a 2.7 engine. If the throttle bodies are larger, then they were probably ported out for a larger engine. Good find, but as someone else mentioned, the factory race stuff usually didn't use stock parts like these - they were all custom slide-valve setups and PED (Porsche Engine Development) pumps. The racing pumps are small, and don't really look much like the street pumps. I'll see if I can dig up a photo of my setup from my 3.4 MFI motor...

-Wayne

Sorry, I disagree. I've only seen MFI on a handful of motors larger than 3.0. I can think of only two off the top of my head, and I think that Henry at SuperTec did both of them.

-Wayne

Get 70/71 Magnesium stacks, You can then bolt on K&N stlye air cleaners...With only minor modifications.

Wayne your right, I have built a few large bore MFI engines. These come to mind.

http://forums.pelicanparts.com/uploa...1189479698.jpg

http://forums.pelicanparts.com/uploa...1189479354.jpg

http://forums.pelicanparts.com/uploa...1189479446.jpg

Then I remembered this one. Wayne should recongize this one, it belongs to him. 3.4-3.6 ? MFI built by the factory?
http://forums.pelicanparts.com/uploa...1189479565.jpg

Aarons suggestion is a good one for ease of installing the K&N air cleaners.

Question. Have your T stacks been bored out to S spec? If not then your motor has a lot left on the table for producing HP.

Also, mounting the air cleaners on T,E or S stacks is the same for all plastic stacks. Holes have to be drilled.

If your stacks have not been bored then the 70/71' 2.2 stacks Aaron mentioned would be ideal. They E stacks have plenty of meat in them for boring out. If you find S stacks then, all the better, you don't even need to bore them out.

You're right - I forgot about my Porsche factory experimental 3.6 with MFI built for Vasek...

-Wayne

I had a 3.2 SS built with MFI and had no problem with a 2.7 pump and modified stacks and throttle bodies

Michael

Wayne, your engine has a 91-92 front crank pulley on it. That pulley would be hard to fit on a 3.6 crank. I wonder if that might be a 3.3 turbo crank stuck in a 3.6 case. That would make it 74.4 mm stroke and 100mm ? bore. 3.5?
The bore is the big question mark. Because of the stud spacing you would expect to find a 100mm cylinder but they could also be 102mm. The funny thing is there were some 95mm high compression pistons and cylinders made for use with the 3.6 case and heads but I never found out what they fit.
74.4 X 95 ? wouldn't that be weird ?

The stacks are a modified version of the Motronic 926 stack/ butterfly housings. They had a 4 bolt flange so my guess is that the stacks were modified (cut and welded) to fit a three bolt intake as found on the 964/993 heads.
Seem right? any feedback would be appreciated.



Here are some pictures of Wayne's engine back in the nest. Check out the company it kept.

http://forums.pelicanparts.com/uploa...1189557093.jpg

http://forums.pelicanparts.com/uploa...1189556710.jpg