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making a custom intake adapter for weber
Posted by: lugog ()
Date: July 15, 2011 04:48PM

What's an easy way to create a custom intake manifold? I have one dual barrel 48idf weber I want to hook up to the corvair crossover pipe. I was thinking fiberglass but I think the resin would break down from gas. Maybe take a pipe slice it on the end and weld it together smaller there. Ideas anyone? Just about given up on the stock carbs and my new weber would sing! Application is a dune buggy. Budget is cheap.

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Re: making a custom intake adapter for weber
Posted by: Am-Iron ()
Date: July 15, 2011 05:42PM

Are you thinking of mounting it to a turbo crossover? Maybe weld a couple of tubes to a 1/4" plate with the carb mounts drilled in it? I think those carburetors like to feed individual runners, so maybe you could modify the intake with a couple of bends that go up into a carb plate? It would help to see what you are talking about.

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Re: making a custom intake adapter for weber
Posted by: lugog ()
Date: July 15, 2011 05:59PM

[vesquared.com]

This is it.

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Re: making a custom intake adapter for weber
Posted by: MattNall ()
Date: July 15, 2011 06:18PM

Take a base gasket and make the plate....

Go to your local private exhaust shop.. and they will weld it up for you.





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Re: making a custom intake adapter for weber
Posted by: Scott V ()
Date: July 15, 2011 10:12PM

lugog Wrote:
-------------------------------------------------------
> What's an easy way to create a custom intake
> manifold? I have one dual barrel 48idf weber I
> want to hook up to the corvair crossover pipe.

before going to all that work - to find out it wont run too good w/that carb - maybe sell the 48idf & get a center mount 2bbl carb & maifold that was made for the vairs. these are around & cheap - seeing that cheap fits your needs.

id say it will cost you more to have a manifold made for the idf than you can get a used 2bbl carb & manifold. the $$ you get for the idf will just be $$ in your pocket.

-Scott V.

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Re: making a custom intake adapter for weber
Posted by: davemotohead ()
Date: July 15, 2011 10:24PM

I agree with Scott,, but sell the webber and get some good stock carbs because IMO the stock carbs work better than the 2bb centermount.



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Re: making a custom intake adapter for weber
Posted by: Danthesignman ()
Date: July 16, 2011 12:53AM

That definitely needs some sort of plenum under it like the 2bbl mounts have . It will run better that way . But I agree for a low buck trouble free solution sell it and use the money on 2 stock carbs . If the stock setup intimidates You just post Your questions and ask for help . You will get the most fun per $ out of a stock set up .






Des Moines , Iowa

If You tell the truth , You don`t have to remember what You said .

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Re: making a custom intake adapter for weber
Posted by: Danthesignman ()
Date: July 16, 2011 12:59AM

Although.... I do have a Dellorto (same basic idea as a weber) DHLA daul 40 mm side draft on My chopper . I have this recurrent dream to make ( 2) 140 intakes and hang 2 40mm sidedrafts pointing towards the center of the motor . One for each bank and control them with some sort of cable .






Des Moines , Iowa

If You tell the truth , You don`t have to remember what You said .

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Re: making a custom intake adapter for weber
Posted by: Chilly Willy ()
Date: July 16, 2011 01:05AM

Scott is right... the manifold will be the first of your problems. You will still have to dial in the weber. of course, after you figure out the linkage and fuel delivery issue.
you touched on the leaking throttle shafts. what is exactly the running problems with you're car ?



Edited 1 time(s). Last edit at 07/16/2011 01:06AM by Chilly Willy.

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Re: making a custom intake adapter for weber
Posted by: Danthesignman ()
Date: July 16, 2011 01:18AM

Oh , and tuning a Weber is a nightmare....took Me better part of a summer to get the Dellorto tuned . Sometimes cheaper isn`t worth the price You pay .
I just checked Ebay , if that 48 IDA is in good shape You could sell it and have enough money to buy a COMPLETE good used running set of stock carbs and linkage from someone on here . Just sayin`.... it`s cool , but not worth the hassle.


out.....






Des Moines , Iowa

If You tell the truth , You don`t have to remember what You said .

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Re: making a custom intake adapter for weber
Posted by: lugog ()
Date: July 16, 2011 06:03AM

I can't sell the 48's because alternatively I would use them on my 302 but I don't want to spend the money on the intake manifold right now and I think I'd need two more 48's to complete the 302 setup...

I almost finished a custom intake manifold...I have no idea whether this is going to work, but seems like it might. The passage has some threads that the air will pass across. This might be problematic, but hey they sell the tornado which spins the air so maybe I'll get away with it.

A few complications yet.. Vacuum advance distributor - not sure where the right vacuum port is on the weber, there look to be lots of them. TV rod will need to work in some fashion.

Maybe I'll put this on ice. I have a girl I'm meeting up with tommorow and I want to give her a ride. Fixing the idle back would probably be doable a bit faster than getting this running. And like you guys pointed out I'm probably closer on figuring out the carb problem then creating an entire new setup.





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Re: making a custom intake adapter for weber
Posted by: lugog ()
Date: July 16, 2011 06:06AM

Working image links ->








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Re: making a custom intake adapter for weber
Posted by: lugog ()
Date: July 16, 2011 06:13AM

Chilly Willy Wrote:
-------------------------------------------------------
> Scott is right... the manifold will be the first
> of your problems. You will still have to dial in
> the weber. of course, after you figure out the
> linkage and fuel delivery issue.
> you touched on the leaking throttle shafts. what
> is exactly the running problems with you're car

I have a hard time getting a slow enough idle under 900rpm. around 900 half the engine runs a little rough. Latest problem was the right bank was not giving me hardly any fuel on the idle circuit, but I think this was because the idle set screw was set too high on it. I'll play with it again tomorrow and make a video maybe. I kind of have things all apart at the moment. Thanks for your offer to help. -Mike

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Re: making a custom intake adapter for weber
Posted by: j3m ()
Date: July 16, 2011 06:24AM

This should give you very useful inspiration!
[www.mooreparts.com]

Obviously that one if used on a normal center mount will be TOO HIGH for the engine lid.

THE WEBER IDF /IDA carbs are fairly tall.

THE Zillion Dollar Question is if you constructed a custom intake using a junk turbo crossover tube. Having a welding shop/exhaust-muffler shop, etc weld up a sort of flat top boxed tube area for the center of the crossover.
Large enough so that exact mounting area/openings for the IDF footprint/&bore.
You'd be better off cutting the old junk crossover tube as it curves on to horizontal and weld a new horizontal pipe that widens at center such that it is closer to cigar box sized or size of an old VHS tape. Obviously, it needs to be level and flat on top. You are going to need to be extremely precise in cutting and pieceing this crossover back together so that it is neither Longer or Shorter than the original junk crossover that you start building from. This is a must because it has to fit. You could possibly make it some mm or cm or more less tall (less height on the horizontal, than the oem junk turbo crossover)

Many years ago, when I adapted a Weber Progressive 32/36 DFEV as a center mount to my 110, I simply designed it so that I simply had a 1/4" thick steel plate welded on top and centered on the crossover tube. I mounted the carb so that the throttle bore holes of the carb were in-line with the horizontal crossover tube. I had my machinist simply DRILL HOLES THRU the 1/4" thick steel plate and into the crossover tube, THAT MATCHED EXACTLY THE 32mm & 36mm THROTTLE BORE HOLES. There was no fancy divided manifold. You did not need that with the progressive. Secondary remains closed until it gets about 2/3 throttle or so,
It Worked Great, though it required 1.40mm primary main jet and 1.45mm secondary main jet, other than that it was a brand new Weber 32/36 DFEV sold for 1600cc Type 1 Volkswagens. It did require an electric fuel pump of 3.5psi maximum. Webers do not like more psi than that. Stock Corvair fuel pump, I'm guessing is in the 6psi range. Oh yeah, I closed up the original right of center factory large round hole on the junk turbo crossover by grinding the "bean can sides" down and welding that original hole completely closed.
Remember, I said that with the progressive 32/36 Weber , there was no fancy manifold needed.........just needed a flat and strong mounting area. Because the crossover tube diameter was big enough in stock form so that the in-line throttle bores of the carb would fit when the carb was positioned so that the in-line of the throttle bores were horizontal like the junk crossover tube.

With the IDF, you are going to need to be more creative and build a center section to weld on to the ends of a junk turbo crossover tube.
One crazy thought that, probably won't work, would be to obtain an old VW intake like that in the link above------- mount it as low as possible AHEAD OF THE FAN (turkey roaster) centered as low as possible near the rear windshield (AS OPPOSED TO OVER THE FAN). Then use the left and right mounting bases of the turbo crossover tube. Cut the bases of on each side. Discard the horizontal portion. Have a curved tube made that begins very very low and curves around/over the back of turkey roasterFAN SHROUD to where your VW intake for single IDF is. It would allow you to get it perhaps low enough to use.
Linkeage and air cleaner concerns will not be as great as the intake design and placement in this case. Don't kid yourself, linkeage design has to be top notch in function, even if it looks like Fred Sanford built it. Same thing, it might look like the greatest design team built it but if it doesn't work at all times, or binds, or doesn't give full throttle, it is just a fancy lookin' piece of s---. Ask yourself????? Do you know what you're doing???? If not get some help and figure it out before proceeding.
It ain't Rocket Science.....but you will certainly know for certain if the linkeage set up is Trash or Really Good. There isn't any in between.
I'd recommend using a braided 24" throttle cable adapted to the stock throttle rod. You're also gonna have to make certain that the stock throttle doesn't have excess slop.

THE BIGGEST OBSTACLE THAT I SEE IS THAT IDF WEBER IS GOING TO HAVE A VENTURI THAT IS JUST WAY TOO BIG FOR CORVAIR USE. You might be able to jet it so that it works but you could also end up with a 7mpg Corvair. I'm speculating as I don't know for sure what will happen. I do have experience with having a pair of IDF 40mm on an 1835cc VW twenty five years ago. The VW dual port heads breathe better than Vairs do and VW's are capable of far more power output at less than 2/3 the displacement of Vair. Too large of a Venturi area and it will be less effective than other carb(s). There is so much that can be done with Weber carbs, it simply matters how well the one you intend to use is sized.

I think if you want to experiment and you possess enough knowledge and skill to do so, GO FOR IT!
DON'T IF YOU DON'T REALLY HAVE A CLUE.
Things have to compatible for a particular engine. Don't expect a giant four barrel from a Hemi v-8 to work well......
The other thing is how well do you know the particulars of the IDF Weber.
You don't have anything but "seat of the pants" knowledge on how to initially jet it and then basically see and trial & error in gettin' it right.
If you like that sort of stuff, challenges, it will be fun, but there will be a lot of cursing, and bad moods while you are fighting it.

I still think the best method is to embrace the BROWN method and go EFI & DIS.
Certainly nothing is wrong with MacGyvering around with carb(s).
As Bob Benzinger pointed out in a speech at CORSA convention circa 2002 as well as a much earlier convention, the GM engineers had a tough time developing a carb system for the Vair. He was one of those GM engineers. In the nearly 50 years since the engineers stopped further development on fuel delivery system for the Corvair, much has been adapted, and modified. The thing is you can not count on the exact method that someone adapted a particular carb(s) in the distant past, e.g. 390cfm Holley 4bbl, as todays oxygenated gasoline is quite different from the pump gas from 1978.

You just might want to unload the IDF on ebay if you're not an expert on those carbs. At the end of the day, the system that just works the best and is most reliable is what you should be after........Brown EFI & DIS may be the direction that you may want to head.

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Re: making a custom intake adapter for weber
Posted by: j3m ()
Date: July 16, 2011 06:47AM

lugog
the idea that you have going with the threaded GAS pipe pieces seems decent.
The pipe itself is too heavy. Do the same with strong thinwall lightweight exhaust tubing, in the same context as the original tubing of the turbo crossover. I would consider making it a one piece intake and would place the carb dead center in the middle.

The GAS pipe is too heavy in my opinion and a one piece lightweight exhaust tubing construction would seem to better than using rubber boots & hose clamps, etc.

Seriously , with a Weber, you're gonna have to at least regulate your fuel delivery at 3.5 psi maximum. You'll be chasin' your tail if it gets fed a larger amount.

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Re: making a custom intake adapter for weber
Posted by: davemotohead ()
Date: July 16, 2011 05:20PM

Why did you not mount the carb in the center so both runners are the same length? thats why they call it a "center mount"confused smiley



Edited 1 time(s). Last edit at 07/16/2011 05:23PM by davemotohead.

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Re: making a custom intake adapter for weber
Posted by: SpyderMan ()
Date: July 16, 2011 06:14PM

Why is it so wide?

Sam Russell
Chapel Hill NC
1962 Monza Wagon
1964 Spyder coupe


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Re: making a custom intake adapter for weber
Posted by: lugog ()
Date: July 16, 2011 07:03PM

I haven't cut the pipes to the correct length yet. I'm bailing on finishing for now. I put the old carbs on. Did the two turns of the idle screw out on each side from full closed. Barely ran changed it to 3 turns and ran w a sputter. switched Carb sides and problem followed the Carb. If I spray Carb cleaner in the bad Carb it speeds up. No air leaks that I can tell. It has a New throttle shaft and seal kit. Blocked off choke, no vacuum advance on it. Sprayed all around and no speed change unless I spray into the Carb. I could keep it reved independently on that side so i know there is gas. So I think its a plugged idle circuit. Which I swear I had a problem like this before on the Carb I just switched out.I've done duals on vws before that's why its got me doubting corvair carbs with hows many problems I've had w them..

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Re: making a custom intake adapter for weber
Posted by: MattNall ()
Date: July 16, 2011 07:31PM

lug,, the carbs are simple... you are just not familiar with them... My 8 yr. old son was setting them up with no problems after he did few...then he moved to VW's and Webers..

This is why we stress it's so important to "hook up" with a knowledgeable Corvair mech.... usually found in the local chapter..

When I was young.. no one could afford a manual....it was all by experience...but in the 60's - 70's your neighbor had a few.... same with VW's..





MODERATOR
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Click HERE for My Website...Click HERE for My TechPages!
.............................PG...................................Turbo

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Re: making a custom intake adapter for weber
Posted by: lugog ()
Date: July 16, 2011 07:47PM

Found two power enrichment needles in the one that wasn't running well.

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