FI Plenum Design, MS'ing my 2270 Options

[Tom Perso]

Hey Guys,

I am designing a MS system for my 2270 (163.86b cam, 48x38 valves, future Triad header). I am looking at running stock intake runners and possibly making a new plenum to run my Ford TB (probably from a 4.0L Exploder/Ranger).

Are there any "design guidelines" that should be followed when making a new plenum, such as a certian volume required for engine displacement?

Looking at space requirements, I see running the TB on top of the plenum is the only way to go. That, of course - begs the question... Is the stock 914 2.0L plenum a good starting point to modify to allow for the Ford TB?

Here are some pics for reference... I had a Bus 2.0L intake system to borrow, so I am basing my measurements and ideas off of that.

http://www.qtm.net/~persot/MS/

Any ideas, suggestions, etc, are appreciated!

Thanks,
Tom

[Brett W]

Tom
I will have to agree with Jake on this one. That cam (which is a barn burner) makes awesome power and I can make it idle glass smooth with Webers. But if you slap a common plenum on there I doubt it will idle at anything below 2000rpm. It will sound like a late model dirt track car at idle. V8s suffer from this problem when running big overlap race cams.

Why do you want to go to a common plenum? I remember Shad's plenum as well. His car was nice but I just wasn't impressed with it all that much. Maybe it was just a big heavy car that slowed that nice motor down, I don't know.

You should be looking at plenum volumns of 3.5-5 litres in volumn. A 65mm TB will probably be a little too big. I would try and find a TB from an integra 58mm or a prelude 62mm. Both should work well if you intend on going with a common plenum.