weber carb setup anyone ?

[chev355ci]

i have a sbc weber carb setup (48ida)x4 im going to install on my camaro this coming spring after paint job. has anyone run these before
to roadrace or otherwise ? any info would help or tips. alresdy have a
sync meter and weber book,but am working on linkage. anything
would be great. thanks and great board !

[David Pozzi]

I have them on my Lola T-70.
What manifold do you have? Moon, McKay, Inglese?

[chev355ci]

its a moon manifold,

[David Pozzi]

What vernturi diamiter do they have? There might be a raised number on the venturis (chokes)
Do you have any throttle linkage?
Do you have any questions?
David

[Twin_Turbo]

I have a custom Dellorto DCOE side draft setup but I used to have 48 IDF downdrafts.

If I can give you a good advice, do not use the unisyn for synchronising those carbs. Get a 5 column water manometer (bike stores usually have those) as they are much more accurate than the unisyn.

Webers are a good choice, the jets, holders & stuff are pretty plentyfull (unlike dellorto stuff), RedLine Weber has all the stuff you need.

[Larry Callahan]

Does it look like this pic below?

If you ever decide to sell it I'd love to get my hands on another Moon manifold.

[Twin_Turbo]

It kind of looks like that but it's not the same. It's not a moon manifold but a custom cast piece. (It's also 1 piece, not like the moon one 3 pieces welded together, a bottom and 2 sets of runners)

Mine has more spacing between the front & rear runners and I have a pedestal in the middle that holds the linkage. I would have posted a pic but my server hosting it is down at the moment.

[Twin_Turbo]

It's back up

[Larry Callahan]

Pretty cool! Thats going to be wild!

I need to find some better shots of mine.

[Twin_Turbo]

Oh NICE throttle bodies, are those TWM or luninention(SP?) ? I have always wanted a set of those but they are $$$$$.

Here's a pic of a setup one of my buddies runs, the filters have been changed since for custom made billet airboxes w/ long square filters.

[BRIAN]

Larry, I think those manifolds are obtainable from any of the Weber dealers or maybe even Moon themselves. Try Inglese they even have them on their website.

[chev355ci]

they did have 45mm chokes but i installed 42mm.the linkage i have is the interconnect between the pairs connecting them.i am trying to figure how and where to mount a bellcrank on side to actuate by pull throttle cable.also air filters are another issue,the K&N's seem to need cutting on the base to clear each other at front to rear pairs.know of any other options besides single foam or the Lynx's ?
dave-do they work and respond as well as the say?did you add the third idle progression hole to help of idle response?
thanks

[David Pozzi]

I have 45 chokes in mine, they came with 42, some came with 38's, the Moon setup has the carbs sligntly closer togther than my McKay manifold.
42 is OK for a street engine if you don't rev over somethinglike 6000. If you have good flowing heads and will rev to 7000 I think the larger chokes are needed.

Here is some throttle linkage setup info I posted to another site a while back:

Take a good look at the throttle linkage, it should pull from the middle between the front and rear carbs, not the front or rear ends of the manifold, the soft brass throttle shafts can easily twist due to too much load. Make sure the idle speed screw you use is on the throttle arm nearest the throttle cable attachment. Let the other 3 carbs hang on the linkage so when the cable is pulled, the play or flex in the linkage does not change, and throw the carbs out of syncronisation. Attach the throttle return springs to the throttle cable attachment, not the outer ends of the carbs.

When you attach any linkage to the carbs, do not hold the opposite end of the shaft, hold the end you are working on or the shaft can be twisted. A twisted shaft will show up as a vaccum variation between the front and rear barrel of a carb. You can twist it back to even the vaccum readings up.

don't use over 2.5 psi fuel pressure. I use the Holley Red fuel regulator but it can allow the pressure to creep up at idle and when downshifting into a turn, because I use the old Bendix impulse style electric fuel pumps that pulse a lot. I added a Hilborn type fuel injection spring loaded relief valve set at 2.5 psi that helped a lot.

If you want a pick of how my linkage is set up, send me your email address.

The carbs are very responsive if set up right.


Larry, would you be interested in a similar manifold but with larger ports? I think they are made for 58mm Webers so have a wider bore separation. Some were used for fuel injection as this one was.

[kmracer]

how much do one of those setups cost? that would be cool to have...

[David Pozzi]

This one is very rare, was a GM prototype with a /00 part number. It was used by Mickey Tompson on a Stock Block Indy car, and used as a side draft weber manifold on the old Cheeta's. Was also used on old Can-Am cars in 65 up until fuel injection took over around 68.

I had heard some were going to be re-cast outside the US for vintage racers. If there is some interest in these, I'll check into what it would take to get some of them.

I'd expect the cost to be $1500 or so, but that's just a guess.

[David Pozzi]

Here is the same manifold casting but with 58 webers in a Cheetah.
The FI nozzle bosses are used for carb linkage mounts.

[Larry Callahan]

David, Sorry I took so long to reply.

Pretty cool manifold. I like the fact that the butterfly doors are part of the manifolds. Any idea who makes these? I could do away with my throttle bodies?

Larry

I have 45 chokes in mine, they came with 42, some came with 38's, the Moon setup has the carbs sligntly closer togther than my McKay manifold.
42 is OK for a street engine if you don't rev over somethinglike 6000. If you have good flowing heads and will rev to 7000 I think the larger chokes are needed.

Here is some throttle linkage setup info I posted to another site a while back:

Take a good look at the throttle linkage, it should pull from the middle between the front and rear carbs, not the front or rear ends of the manifold, the soft brass throttle shafts can easily twist due to too much load. Make sure the idle speed screw you use is on the throttle arm nearest the throttle cable attachment. Let the other 3 carbs hang on the linkage so when the cable is pulled, the play or flex in the linkage does not change, and throw the carbs out of syncronisation. Attach the throttle return springs to the throttle cable attachment, not the outer ends of the carbs.

When you attach any linkage to the carbs, do not hold the opposite end of the shaft, hold the end you are working on or the shaft can be twisted. A twisted shaft will show up as a vaccum variation between the front and rear barrel of a carb. You can twist it back to even the vaccum readings up.

don't use over 2.5 psi fuel pressure. I use the Holley Red fuel regulator but it can allow the pressure to creep up at idle and when downshifting into a turn, because I use the old Bendix impulse style electric fuel pumps that pulse a lot. I added a Hilborn type fuel injection spring loaded relief valve set at 2.5 psi that helped a lot.

If you want a pick of how my linkage is set up, send me your email address.

The carbs are very responsive if set up right.


Larry, would you be interested in a similar manifold but with larger ports? I think they are made for 58mm Webers so have a wider bore separation. Some were used for fuel injection as this one was.

[David Pozzi]

Larry,
Yes, no throttle bodies needed which would save space and money.

I checked with my contact and this is not the manifold that they are going to reproduce. they will do a downdraft weber manifold reproduction of the McKay manifold.

This one is neat, the only flaw is the runners get a little narrow where they cross each other, but can be ported bigger there, when you turn it over the bottom view looks like "folded fingers" if you get what I mean...
this manifold has a -00 GM part number so it's a GM prototype, was used on road race cars Like Lola T-70's McLaren's and the Cheeta, and Mickey Thompson's indy effort.

[L78396]

David,
I'm new to the forum but have been reading your messages about the 00 GM prototype weber manifold. I'm planning on building a 63 Corvette Grand Sport Replica. They came with the 00 prototype manifold and 58mm DCOE Webers. I would love to know where I could get the complete setup. This would be the bomb for my project, to make it as authentic as possible. Any help would be greatly appreciated. In the future, I will need some advice as to what suspension parts to use and how to best set it up for road racing.
Darrell

[David Pozzi]

There is another manifold that was used on the Grand Sport Corvettes. The difference is, the runners run parallel in pairs, not alternating like mine or the Moon version. They don't have the restriction where the ports cross but have a little more angle to the pairs.
This pic shows the GS mainfold, the throttle bodies are Hilborn. A 58 mm Weber side draft carb will also bolt on, and was used on this type manifold, but may need an adapter.