Inliners International Forums General Discussion Hi Performance Carb adapters for multi carbs

Saw these on in Speedway the other day and got me thinking, gee they used the 97's on flatties so would they work on our inlines?
http://www.speedwaymotors.com/Two-Plain-9-Super-7-Carbs-on-Single-4-Bbl-Intake-Manifold-Adapter-Kit,37447.html
I have no idea if this would work or not. They even have it in a three carb set up
I bet the plenum volume would be too much and would be a nightmare to tune.
If they had it in twin 2GC's that might work maybe???

I don't think those adapters would work well on an inline but several manifolds especially for GMCs used two BBL carbs. The coolest of all was the Harper 3X2 set up.
Harper Link

Here is one from Vintage speed, for 2GC's. I have a 390 on ther now mounted straight ahead, not sideways. I thought this might be a way to add a little cool factor. I do like the tri power set uo you shows the link to, but I have not seen where you can buy the intake for that set up. Forgot to mention it is for a 250

You probably won't find a Harper they haven't been made in a while. One of the main reasons to run multi carbs on an inline is to space them out along the length of the runner. The tendency is for the cylinders at the ends to starve and the center ones to be rich. It is also easy to over carb these engines especially a fairly stock one. I think a 2X2 setup where the carbs are spaced like a traditional 2X1 setup could be made to work well. You would have to set up the carbs carefully. Maybe someone else here can give some real specifications. We'd need to know what has been done to your 250 and what you want it to do for you.

The three-1s are more common than the three-2s - but they are around. In fact there is one on ebay right now:
ebay Harper 3X2 Intake


And they are not cheap. To Beater's point multi-carb setups improved fuel distribution in log manifolds. An adapter mounted in the center of a 4BBL manifold doesn't help in this regard. Adding another plenum above the entry into the main-manifold will likely result in to-much plenum volume for the cylinder displacement.

regards,
stock49

This was more of a "bench racing" thing. I do not have any immediate plans to change my set up of a Offy intake and 390/stove bolt header.
I wish that the made a twin two intake for 2GC like this one for two ones

The only adapter I have found for the 2GC carbs is a trans dapt piece that mounts the carb sideways, I would not like that

I would think that two 2GC would make a great set (set up 1:1) up for a moderate street strip set up for a stick car.

They do have a 2x2 intake for 2GC carbs for these engines. You simply take a 3x2 intake and block off the center carb. Most all of the early inline triple carb intakes were done this way because 3 carbs were simply too much for them. There is one on ebay right now.

I have seen plenum intakes like this with removable tops like what a tunnel ram


Could they be made to run with a twin two set up?

That works for the Ford sixes they were made for, but since there isn't one made for the Chvey's, and a lot of engineering knowledge is required to design one correctly and specific for these engines, why not just buy one that is already designed and made for these engines.

I think these are not sold for performance today these adapters were originally made before four barrel carbs became available. Now I think they are being sold as a nostalgia thing.

It is a nostalgia thing. I love the look of multi carbs. From what I have read in the past the 3x1 and the 2x1 intakes made less power than the 4bbl intake and 390 4bbl. I am not planning on changing anything any time soon, I am after theory and the science behind power by intake and carb combos.

I really like the look of these
http://www.jalopyjournal.com/forum/attachments/kse-034-jpg.1671372/
http://www.jalopyjournal.com/forum/attachments/kse-029-jpg.1671373/
http://www.jalopyjournal.com/forum/attachments/phone-pictures-134-jpg.1672487/
I have even seen a plenum bolted on Weber side draft intakes with carb spacer welded to top of plenum. The sky is the limit. Heck I have even wondered about using two throttle bodies off of a TBI 2.5L I4 to make a cool TBI set up. My brain is always going on what could be next.

It takes a lot of engine mods to run 3 single barrels efficiently. More than that is almost surely total race or just for show with some carbs not functional. There are a lot of dummy carbs out there if you look closely. The idea of TBI conversion has been discussed here on several threads. I think you could run two or even three of the GM single barrel TBIs through a Megasquirt. There was one post here by Diceman that covered using three TB injectors that resembled 2 BBL carbs. It wouldn't fool most of us but it sorta had the look.
It amazes me that partial Harper setups go for so much money. Usually the pieces available are the ones easiest to make. Check out the link in Stock 49's post and look closely at the high quality of the one remaining piece of linkage. There was originally a lot more of it and 3 two Barrels with split throttle shafts and linkage to both sides. I was in awe when Tim showed his Harper setup to me at the 2012 Convention. No linkage sold today is of that quality.

A lot of people have done the TBI conversion successfully. I do think you get much better fuel distribution on these engines with multi-carb setups as opposed to a centrally located single carb because of the somewhat log type design on most intakes for inlines. There is also a double and triple TBI intake option available for these engines now also. I'll try to get some pics posted as soon as I can take them.

Cool thanks. I have medical conditions that prevent me from working so I spend most of my time coming up with crazy ideas for car stuff. I really like the megasquirt controller. I was going to use one on a tunnel ram motor I was building for a MPFI set up. Two TBI (1 or 2 BBl) really interest me. There are a gazillion TBI motors ranging form little bitty 4 bangers to big block V8.

Yeah, using new technology with the old is a growing trend and usually has good results.

It is. Cars today are boring. The old stuff has flare and personality. I like being outside the norm hence to sixer and 4 door Chevy II, and with that I do like the ease of cold start with the EFI. TBI throttle bodies look clean and simple , once all the emission crap is gone, put a classic air cleaner and they will be right at home on any old car.

Here is a link to the demo we did in 2008 at the Inliner Picnic at Speed Week. Some of the links don't work anymore but most do. Like everything else I do this is unfinished but has a lot of good info. TBI Conversion Link

Another link to My plan to put a Turbo TBI 292 in my '68 flatbed. It never got done but in the process I built a Megasquirt. This could still happen. Never Ending Turbo TBI 292

More Megasquirt Pictures: MS1
Stem Board
Runnng

Thanks for the link. They seem to be pretty easy to install and get to work right.

Speedway Motors has some new carb adapters for Stromberg 97 3-bolt carburetors. They fit both stock intakes and the Offenhauser multi-carb intakes. Best of all, they orient the carbs so that connecting the linkage is easy (rearward pull throttle arms).

The GM 63-75 L6 2-Bolt Big Pattern to Stromberg 3-Bolt Adapter (2-15/16" bolt spacing) works with 1963-up factory intakes, as well as the Offenhasuer 5415 , Offenhauser 5415 , Offenhauser 1409 , and Offenhauser 1035 intake manifolds.

The GM 36-62 L6 2-Bolt Small Pattern to Stromberg 3-Bolt Adapter (2-9/16" bolt spacing) works with 1962-older factory intakes, as well as the Offenhauser 1034 and Offenhauser 1177 intake manifolds.

I'm using an adapter from Vintage Speed (Charlie Price) it adapts my 3 2 bbl carbs to a 4 bbl intake. He has some interesting adapters. If you go to his web page mine are the second or third ones down I think. I'm running a 4-71 blower on my 292 so my options are limited for multiple carbs. I also think the central location would make for more even fuel flow front to rear but I am no expert in this area. I also think that making it taller may help with even flow. Plus chicks dig carbs hanging out the hood so there's that.