Advantages of modified upper plenum, if any? (I did a search first)

[Buicksx3]

Help! I did a search for "modified upper plenum" and "modified doghouse" going back 6 months but most of what I found turned into debates about the merits of larger TBs.

Within a week or so a new motor will be going into my car. The buildup is as follows: girdled stock block, .020 over J&Es, 212/212 cam, and ported iron heads/intake. I'll be stripping the 72's, TE-45 (the car has a V2 FM already), and 62mm TB off the tired old stock motor. I have two upper plenums: my old stock doghouse that was "matched" to the 62mm TB, and another in a box that's been modified (has a curved plate welded/blended in it, very nicely done, I don't know what vendor it came from) that I bought months ago from the Parts For Sale forum but never used.

Would there be any gains to running the modified doghouse, or should I just stick with my old one? The car went low low 11's on the old motor and the goal is medium-high 10s on the new one. A friend felt that the modified plenum might cause the rear cylinders to run a bit lean, hence my inquiry. To anticipate a possible question, no I don't have, nor have I used, an RJC Powerplate.

Thanks in advance for any "been there, done that" replies!

Morgan

 

[Louie L.]

The answer to that unequal flow to the rear cylinders is the Power Plate. This is the best way to equalize the flow across the intake. You can find lost of info on that subject in the archives.
Good Luck

 

[Two Lane]

Also search for:

Jay Jackson

This is properly entered for SEARCH as: Jay AND Jackson


HTH

 

[bruce]

Originally posted by Buicksx3
Help! I did a search for "modified upper plenum" and "modified doghouse" going back 6 months but most of what I found turned into debates about the merits of larger TBs.

Thanks in advance for any "been there, done that" replies!

http://www.gnttype.org/techarea/engine/plenum.html

I went the route of instead of looking pretty, went for generating as much volume as possible.

Had to add several percent more fuel. Which is an indicator that it was flowing several percent more air.

 

[Buicksx3]

That was just what I was looking for. Thanks all!
Morgan