The Stovebolt Site Forums The Shop Area Engine Shop 1bbl to 2bbl adapter RESULTS

Well, I mentioned on here a while ago about going to a 2 barrel for my inline 6 through the use of a Summit Racing adapter. And the results...

I got the motor to run. I drove it around and right away I could tell, it definetly had power. I only pushed in the accelerator a slight bit and it just opened up and asked to race. I was feeling really good about it. The only negative side was that I could not get the darn thing to idle steady. It wanted to run too lean or too rich. It was really bad in gear and at a complete stop and liekd to overlaod on fuel. This is with a brand new Rochester 2bbl by the way.

Anyway, that's it. The one barrel is back on and actually isn't too bad. It turns out the float levels on it were WAY wrong and that's why it kept overloading on gas. Now I'm not afraid to floor the motha'. :lol: But it's still slow. :whine: I know some had their doubts on speed imrpovement, but I felt it. It felt like it was giving the motor all the gas it could and would have no trouble supplying more. Do y'understand? It felt like it had more muscle behind it basically.

As for the 2bbl, I returned it to Kragen and got credit back for a used one from the scrap yard. As for the adapter... it makes a lovely paper weight.

Anybody who'd like to shed some light on the subject of why my 2bbl wouldn't idle right, I'm willing to read lengthy essays. It's not like I have a V8 yet or anything. The 6 pack is still under the hood. And the adapter is right here next to me (holding down papers). :gi:

Here's a picture by the way. Hope you like my Kustom throttle linkage

[img]http://i27.photobucket.com/albums/c157/DiscoDanny/Truck/IMG_0141.jpg[/img]

good to hear the results!

to me, seat of the pants feeling is alot more important that numbers on a dyno...i mean, who cares if you make X amount of horse power, if you can't feel it or notice it?

sorry. i have a thing against numbers now. just started a College Alg. course, and realized i remember NOTHING about math. ew.

but, -ahem-, i digress.

congrats on your experiment!

i know nothing of why it wouldn't idle. ask the experts. lol

.later days.
.sam.

I ran a 2 barrel rodchester on a 261 years ago with modified stock manifold with good luck. I used a 2 barrel from a 283 and had to rejet the main jets smaller. At the time I was doing this smaller jets couldn't be had so filled the old jets and redrilled them to the proper size. Also the old 261 had the head shaved for more compression and had a mild cam that might have helped with the extra fuel air mixture. Sounds tome like you may have had leaks or to big of a carb.

Leaks were my thoughts as well but we had every vacuum entry or exit on the carburetor sealed or leading to it's "proper place" and sealed tight there. My only other guess is that there was a gap somewhere between the spacer and adapter or carburetor and spacer.

some carbs have holes on the bottom for vacumn.i changed a gasket on a 235 and ran into that problem.i had to notch the gasket.

I tried a few different 2G's and had idle problems with all of them. The one that I got to run the best (best in this case - the least crappy), I actually tried to make it a ported vaccuum using a Dremel. It didn't work.
If you do a search, I posted a bunch about this a couple years ago. About idle and vaccuum and timing.
Glad the 1 bbl is workin' for ya.
-David

Carburetors pull fuel from the idle wells because of air velocity across a pickup point creating a negative pressure in the wells. The pressure in the bowl then pushes the fuel into the throttle area.

For best results, when migrating any O.E. carb from one application to a different application, do not exceed 3 percent CID differential. 3 percent of 235 CID is about 7 CID. So, WITH A NORMAL INTAKE SYSTEM (NO ADAPTER), you should expect to see decent results using a two barrel from an O.E engine of displacement 228 CID through 242 CID.

The eddy currents created by the short adapter will mess up the velocity anyway, so it really doesn't matter which carb doesn't work with the adapter.

If you modified the intake manifold for normal two barrel application, the Carter from a 232 CID A.M.C. would work well on a 235, but not with the adapter.

Jon.

Has anyone ever thought about removing the top of the stock intake on a mill and reconfiguring the intake to accept a different carb ?

Well, it's a little more complicated then just "changing it to fit". There's drilling and welding and I pretty much suck at both

I'm going V8 unless for some reason a brand new/rebuilt I6 just suddenly appears in the garage.

That doesn't mean I won't still interact on the site or throw away the old 250. I'm gonna store it and later on learn how to rebuild it and then tune it up and all that jazz.

John thats what I did on the old 261 manifold. I opened the top of the manifold where the carb mounted cut out the tee in the heater box. Made a plate to close off the bottem of the heater box and made a plate for the top of the manifold for the carb. I did this 30 some years ago with a hack saw and a torch with a milling machine I think you could do it with out doing any welding.

Carbking's points are to be taken into consideration no matter what carb is used,even hi performance carbs must be matched to the manufacturers recomendations for best results.
I posted earlier on this same subject how I milled off the top of a stock 261 intake to adapt a 2 barrel carb with excellent results a few years ago.Yes, the job required a little welding,and yes the cast intake can be MIG welded,but the modification were done with common hand tools,hand held grinder,files ,drills and taps.

Hmm... well I suppose just for the Hell of it I could do some measureing.

But hey, you know the integrated head inline 6's? I hear that they're garbage but they came stock with a 2bbl carburetor. Do you think it'd be logical to assume that one could cut it from the head at the 3 "arms" and weld on new ends from a removeable intake manifold? This having a two barrel, BOLT-ON intake manifold?

how did it work out.. Rusty Rod is watching with eyes wide open!!!

next target!! :p

the carb on the integrated head engines is this weird two stage thing that any junkyard guy will laugh at you for trying to run.I had mine apart about 6 times trying to figure out wht the idle circut wasnt working.finally gave up last week and im going with a 2g.working on an adapter in tech right now that should be done monday(cnc machines are great)and then im gonna open the intake up a bit to make it flow a bit better. should work out okay.