All Big Six Clifford Plenum Divider

Relates to all big sixes

Firepower354

Famous Member
others -- Still would like an answer to post #36 above.

Apples & Aardvarks.
All the formulas are geared around WOT acceleration, and have little to do with what you're theorizing.
IMO, on your intake, the plenum/runner line is more vague. And practically irrelevant.
A bent 8 isn't an inline 6, and each case is different anyway.
Some manifolds, on certain combos, like a split plenum. Unless it's a common combo, there's a lot of trial & error. Mostly error.

Stronger mixture signal seems the goal, and the ways to get it are several.
Splitting the intake, more thoroughly.
Reducing plenum volume, as FTF and I have mentioned.
 

old28racer

Famous Member
Firepower354 -- I get where your coming from and I really feel like I am over thinking this whole plenum thing. As I have the setup currently I am sure I have improved the mixture signal somewhat.

1st -- Like I said before I will try the intake with the adapters like they are with my Holley 2300 350cfm / 62 jets / 6.5 PV.

2nd -- I will leave intake alone & install 59 jets & maybe 57.

3rd -- When I get the jetting ware I want it I will build a 1/2" thick aluminum adapter with studs to replace the Clifford 4V & 4x2 adapters and retry my 2300 with best jets.

4th -- I will replace my 2300 with a fresh rebuilt Autolite 2100 1.08 venturi with 57/55 or 54 jets & 6.5 PV, get the best jets.

Will get new AFR numbers at idle & 40-60 mph cruising.

Like you said "trial & error" the old school way, I can handle that.
 

old28racer

Famous Member
Well as much as I would like to finish my Clifford Plenum Divider tests it is not going to happen. Medical issues are stopping work on the project. I will be listing the manifold for sale on this site in the next week or so. If interested PM me and I will try to answer any questions you might have. Thanks Tom
 

old28racer

Famous Member
Frank, thanks for the good word. The grass is still under my feet, things could be a lot worse, just some changes in types of projects I can take on.
 

MikeyLawless

Active member
Sorry to hear of your troubles old racer. I, for one, would have liked to see it completed.

A week ago, I would have been buggin' you about that manifold. Maybe then I would have picked up where you left off, and see what kind of results could be attained. I ended up going in a whole 'nuther direction though.

Keep after it the best you can. Like you said, the grass is still under your feet!
 

old28racer

Famous Member
ML-- Sorry that you could not do it, I would sure like to see someone test it out that has some 300 background. I get through the days knowing that lots of others have medical issues that are much worse. Thanks for the good word.
 

old28racer

Famous Member
Looking for someone to buy my Clifford 300 4x2 plenum divided intake that will take a Autolite 2100/2150 or a Holley 2300 2bbl.
PM me if interested, can send pictures & answer questions.
 

old28racer

Famous Member
Listed this manifold in the "Big Block 240/300 For Sale" section today 10/26/2021.

The Clifford intake is unchanged. This intake will run a 4bbl carb by removing the the current 4x2 plenum adapter and running the included Clifford 4V adapter that bolts onto the intake. Pictures are in the ad.
 
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