Added plenum on tunnel ram.

[Steve.k]

Picked up tunnel ram at swap meet with this fabbed up plenum? What would be the gains in this. The owner said they had a single carb top. He had the original dommy top there to.

IMG_2441.JPG

[F-BIRD'88]

You can use any carbs on that just by swapping the top , now.

You can fill the inside to adjust plenum volume, and internal shape.
You can even try out my 2x Q jet "six shooter" carb scheme, now.

The floor of your plenum need not be flat. You can make up wedge shaped inserts
to create a V shaped plenum floor/runner entries.

You can add a spacer between the plenum top and base to add runner length.

[Steve.k]

Very interesting f-bird 88. He said they had a single top on it he used on a sheetmetal intake they fabbed up. The floor is flat as you say so angle in to runner egde you figure?

[F-BIRD'88]

Very interesting f-bird 88. He said they had a single top on it he used on a sheetmetal intake they fabbed up. The floor is flat as you say so angle in to runner egde you figure?

Yes... You can experiment inside the plenum to your hearts content.
Make inserts out of wood and epoxy and coat with epoxy primer paint like Por-15 etc.

or use aluminum...or...

Floor V... runner entry shape,,, divider.rib... fuel directors etc.
Corner fillers etc. Various carb spacer(s) types, shear plate, for carb height above runners etc for effect.

What is that,,, A Ford manifold?

[Steve.k]

Its a weiand 2994 dommy flange cleveland intake. The guy was running a 393 cleveland with heavy nos. He switched up to a 360 ci nascar c3 headed engine now.

[Steve.k]

I just dynoed a 438(400 base) motor that i fit a ur19 on. Hear the weiand worked better thought i might try. Do have original top also. The ur19 seems to have bigger plenum and little longer runner.

[Newold1]

What does the transition between the floor of the fabricated plenum and the inlet to each runner opening in the base look like?

[Steve.k]

I tried posting pic now says file to big. Port top is flat. I'll try and get pic to post.

[Steve.k]

IMG_2448.PNG

. Finally figured this out.

[Steve.k]

IMG_2449.PNG

heres another.

[F-BIRD'88]

Lots of room and potential in there for Plenum floor inserts to create a more streamlined bell mouth radius ed entry to each port entry and or create a V floor with center rib.
Don't be afraid to experiment there. You have a good baseline to play with now.

[Newold1]

That's why I asked for a picture of the plenum to top of runner transition.

You need to take the bottom floor of the plenum and grind out some smooth bell shape transition into those runner openings. It will definitely help the fuel /air mixture enter the runners better. The biggest problem with this flat floor plenum with carbs is the fuel dropping out of suspension and puddling before it enters the actual port runners.

Glad to see the top cover is made thick and bolts on. In my experimenting with box like plenums I had an engine backfire into the plenum and the resulting explosion blue the top off with such force it flew up and jab and stuck in the ceiling of the shop. Got my attention real quick!

[swampbuggy]

Newold i am LMAO !!!

[Steve.k]

Ok thanks guys. So the way it sits the stock top would likely work better. I'll get the neighbor to weld some pieces in. Very good sheetmetal/aluminum fab guy.

[F-BIRD'88]

I would not weld anything in permanently until seeing if it is working right.

Make any inserts removable so you can tweek it.