2-barrel intake modifications [2.8 60*]

[TheFly]

2-barrel intake modifications [2.8 60*]


Just call me a glutton for punishment or wired wrong [ I am left handed ]

Not gonna spend $500 on a 4-barrel intake, id pay $100 maybe.

So searching for intake mods ends up with allot of unrelated stuff.
So any first handers here or anyone member such a thread?


I can get enough machine-able block fill for cheap to do the EGR passage and smooth that out.

But if ya notice that relief cut near the barrel divider, that is done as the carb didn’t line up well. And that sharp flat turn can’t be good it could surly use some rounding off. Or even run a hole saw straight down following that relief cut if there is enough meat. Have a nice straight shot like it should be.


Dunno if I could block fill the whole area and just redrill.
[how do ya block off the bottom, then remove it once done.]

And come on I know who in their right mind would waste time on such a thing, I would just to see how it works.

Has to help too. Unless you wanna sell me a 4bb intake for $100 or less.

So come up with ways to be helpful, saying you wouldn't bother is no help

[SappySE107]

sometimes rounding off and smoothing areas makes things worse. Carbs and TBI depend on turbulence to keep the fuel mixed with the air. I have no idea if modifying that piece would help or hurt.

[ezrollin]

I have seen 4 bbl mainifolds made using the base of a FI unit,the upper was fabricated from alum plate and aftermarket alum 4 bbl adapter plate and they worked very well.

[geoffinbc]

The stock manifolds were used for racing back in the day. Often the top was machined off and a plate was welded in to fit a Holley 2bbl. Under the stock Rochester I would not hesitate to open up the area under the carb. It is rare you see a carb manifold with bores that are the same size as the throttle bores. Carbs always sit on top of an open plenum area.

[blownarrow]

Yep, and yep....
I'm also left handed.....

I'm running a 2bbl Holley 500 on a modified Fiero EFI manifold.. easy-pesy...
for less than a 100 bucks... not including the carb... :-)
Pulled the manifold at the yard.. took it to work, welded up all the un-needed holes
smog sh*t and stuff, heat transfer port....
Then built a plenum to mount the carb (side ways) "more room and better flow"
panted and then bolted on!
Runs awsome!
I'll post pic's in a few have to run out to take a pic.... :-D it's my daily driver!

[TheFly]

I was thinking of doing that but worried about equal flow to all ports with their wide layout. afraid for them two outter cylinders. Also thought of using 2 single 1-2bb carbs. With the EFI layout they would cover better. 1 for 3 ports. Can kinda see it here.

[TheFly]

Any build or closer pic? Or want to share the size n area you used to have enough plenium space???

[blownarrow]

Well the spread of the 500 is enough to supply all ports, but at this point I'm running an open plenum the carb sits 1.5" off the base flange. Both carb flang and intake are 3/8"..
I'm currently working on a split plenum, one port per three intake runners.
Should have up and running tuesday of this week..
I'm also working on a draw through turbo plenum for the 60* with a 2bbl 500
based on the late 70's early 80's Turbo Firebird 301 V8... ha ha ha
Got the headers done, turbo sorted, and in the process of fabing the manifold and laser cutting the flanges.....

[the.e.dean]

Well the spread of the 500 is enough to supply all ports, but at this point I'm running an open plenum the carb sits 1.5" off the base flange. Both carb flang and intake are 3/8"..
I'm currently working on a split plenum, one port per three intake runners.
Should have up and running tuesday of this week..
I'm also working on a draw through turbo plenum for the 60* with a 2bbl 500
based on the late 70's early 80's Turbo Firebird 301 V8... ha ha ha
Got the headers done, turbo sorted, and in the process of fabing the manifold and laser cutting the flanges.....

Since your building the split plenum, would you like to sell the single plenum version?

I would be interested.

[blownarrow]

Well I cannibalized the single to build the split, but I could possibly build another
suited for the carbs you would like to run... that double single barrel sounds cool..
I would also like to build a triple carb set up using VW singles or Rochester's.. that woulds be sick... a three pack..lol .look like a mini 6pack setup...

[the.e.dean]

PM me specifics and prices. It would be like your current setup, holley 500 on a fiero lower intake. But 3 strombergs would look cool on a 3.4....

[blownarrow]

Waaaooooo!~
Update. Duel plane manifold works bitch-in with 500 2v
Seat of the pants dyno and Gtech both noticed a large gain, better throttle response,
smoother Idol, and no 4300rpm bog...
Much easier tune-ability...

[bszopi]

[TheFly]

Don't know if you could get 3 of them so close and still have all the proper linkage n stuff work right.

[TheFly]

Any update on the new build?