Engine and Transmission Tech

(Google search image, found several locations, seems widely shared)

In my shed I have a 300 with no intake or carb. It’d probably sell if it was running, and I don’t want to junk it.
I’ve removed the intake from a RV8 4.0.
I have an old Rochester 4bbl carb. (Or could splurge for something more current.)

What if I…
Like the image above, yank out the trumpets and radius their holes.
Build a little box plenum above that (or mod the side inlet 4.0 plenum, removing the side inlet)
Mount the old carb on top of that plenum.
Plug the injector ports.

Woulditwork?

I’m guessing it would be hard to feed 1 & 8 with enough fuel, is my 1st obstacle.



Edited 1 time(s). Last edit at 04/13/2024 07:59PM by Roverbeam.

I had that idea for a 4.0 Ford V6. 2" high plenum, using a baffle plate with 1" risers. folded down on the sides and ends with 1" square notches along side of the ports. Crosshatch the baffle with 100 grit to prevent pooling, Identical virtual ports for equal distribution. I was going to use a 390 cfm Holley, on the V6, on the 300 I'd use a 500 cfm Summit carb or 500 cfm Edelbrock AVS because of their annular boosters. Carb should be centered on top of plenum.



Edited 1 time(s). Last edit at 04/14/2024 10:49AM by mgb260.

Will it run? Yeah, probably. Will it run well? Not so much. Will you spend way more time and money doing this vs. just getting a factory 4bbl intake? Absolutely.

Jim-
Hmm. Looking at the parts, I was thinking of sort of the opposite - removing all the webs between the intake holes as deep as I dared, creating something like a single plane intake feeding from a common gallery/plenum. So the horizontal flow to the ports happens down low, rather than over the top of the intake…

Joe, there’s one a couple hours from me on Marketplace. That’s still the safe fallback option, if more creative (and so far, free) options become unworkable.



Edited 1 time(s). Last edit at 04/14/2024 09:41AM by Roverbeam.

Chad, in case it might help, I do have a 300 4-BBL intake I'm not going to use. Not sure how much it's worth (and I'd have to find it). But if you're interested and it helps, let me know.

Thanks Eric. I've been keeping an eye on Marketplace and Ebay and have seen the iron 4bbl's going for $400 and up to about $700, and there's currently an aluminum one that's asking $250. So far I'm leaning toward the aluminum. The iron ones have a worth to the 300 community that is beyond what I'd want to pay!



Edited 1 time(s). Last edit at 04/15/2024 11:24AM by Roverbeam.

Jim Nichols,
Would you happen to have a sketch of this "baffle plate"?
I can't picture it in my mind, and am curious since I made an
upper plenum for my Ford V8. The plenum is open in the interior, with
radiused entry to the lower manifold runners. Perhaps due to my use
of port injection, this arrangement works ok?
Thanks,
Dennis

Dennis, You would use a factory lower intake.I forgot to mention the base plate that the baffle plate would bolt to. Also the upper part of the plenum would bolt to. The baffle plate is bent down on the sides and ends with 1" notches along side the ports. 1" spacers for the baffle and 1" space for the top of the plenum. Hope this description helps. I'll try to do a sketch sometime.

Chad, I would definitely snap up that aluminum manifold--they are typically more valuable than the iron ones, so it would be a good one to grab.

@Roverbeam, I imagine your OP might work better with 2 x 2bbl carbs. At lest as regards distribution.

Chad, have you seen these VW Rabbit flares on a Sunbeam?

[forum.sunbeamalpine.org]

Hi Jim,
I thought I had read most of the threads even remotely touching on altered Alpines, but I missed that one! I've seen that those flares were (once?) popular for mgbs I think? I didn't really consider them, honestly (nor the repurposed Bug fenders that one guy used...). I want to keep closer to the original arch shape, to keep the car looking more Alpine-ish, at least at first glance. Thanks for sharing your search-engine like knowledge, and thinking of my plight when you saw that thread!

Not much car work the last couple weeks - but I ordered the driveshaft, an aluminum jobbie from the Driveshaft Shop, thus heavily denting this month's car allowance. Kid graduates in a couple weeks, big party, in-laws coming, gotta finish some home projects for now.