Stroker FE and RPM intake

[BigM460]

I have a 447cu. FE Ford(4.090 bore, 4.250 stroke) with the Performer RPM heads and intake, and a small solid roller cam 227/230@.050 and .565 lift. Peak HP is at 5400rpm. I am thinking about pulling the heads and intake off and cleaning up and gasket matching everything. Basically wanting to get everything I can from my combo. Would like to have CNC'd, but just seams like too much cash!

Was wanting to know about maybe putting a notch, or cutting down the divider in the intake plenum? Any tips or tricks for these parts on an FE? Am also running the 70001 nitrous plate w/100 shot.


My Car is a 1968 Mercury Monterey, 4520# with driver, 2400 stall and 3.89 gear. Has run a best ET of 12.01, and best MPH of 113.6, 1.79 short time on drag radials!

[CE_BRENT]

If you've got the time, and can be careful, there is the brass tube trick. Go to a hobby store and buy some 5/8 O.D. brass tubing. You'll press/epoxy pieces of it into each push rod hole in the manifold. Then you can port the manifold in the push rod area all the way untile you begin to see the brass color and you know you've max'd out the width of the window. Warning: the potential problems are1) Oil leaking past the push rod holes into the intake runner, 2) you'll have less push rod clearance, so you make need new length push-rods to achieve a perfect fit 3) If you break thru it may be so difficult to fix that you've junked your manifold.

Otherwise, a standard port match to the gasket should help. The Nitrous plate is almost like an open spacer. You could play at the track with open (no divider) .300" thick carb heat insulator gaskets. These act the same as dropping the divider wall without making any permanent changes.
good luck

[BigM460]

Thanks for the info! Was thinking that maybe with the 447ci. I could use more plenum volume, but don't have the hood clearence for a spacer. Other than the plate. Thoughts????

[CE_BRENT]

The plenum needs to be larger if the carb is on the small size. If the carb is big enough (750+cfm) then the RPM plenum will be fine. If your carb is smaller spacers will help, but you don't have the room.

[BigM460]

I have a Demon Annular 850 vacuum sec. I sure think it would help to take down the divider a 1/2 inch or so. Thoughts?

[CE_BRENT]

Your Nitrous plate already acts like a dropped divider, so I'd be cautious because when you go too far with a divider drop you just lose torque and make no gains in HP. To see if you need to drop the divider add a .300" thick heat insulator gasket under the carb with the plate and see if the car responds. If it helps try a 1" open spacer. This way you don't have to cut the manifold until you really know if it works.