I'm no expert but I suspect 48IDA Webers might not be enough for such a large engine. Remember, the small block cars used them, but the big block cars had to run Holleys.

EMPI makes 52mm (I think) versions of the Weber carbs which might prove better?


Gus, Webers are another level of complexity above and beyond typical 4bbl carburetors. Do you have a set? If not, I'd consult Jim Inglese (he has a web site) and have him work with you on the linkage as well as the appropriate set up based on you engine parameters. It would likely save you a lot of time, money and hassle.
I have Webers on my Race car, my AC Ace and on my Cobra.... I know a thing our two about Webers. I was just curious to see if anyone had set them up on that specific engine, just to see what would be a good starting point for tuning.
I would agree with the suggestion of contacting Jim Inglese. He really knows his stuff. I have a 351 windsor stroked to 427 with 48 IDAs. I had Jim rebuild them and set up the linkage properly (needed a new pivot point to avoid locking on full throttle!). The key is definitely having the floats set right, the timing set right (more timing than other carbs) and also the fuel pressure (2.5 - 3). Jim will definitely steer you right. It is not cheap, but certainly not overpriced for the experience and amount of work.

Sorry guys, my experience with Inglese was VERY poor. Incredibly crappy initial set up and not much better after sending the carbs in for rebuild... Still had a twisted Throttle shaft.... I am far more impressed with Pierce Manifolds... But, regardless... I found some decent starting numbers on the SAAC website. I just would like to not spend $1000 on tuning parts that turn out not to work on this engine....

If you'd like, I'm running a hot-cammed 393W with 48s. Runs like a scalded cat. I can see if I can track down the jetting for you. Unfortunately, the car is in a shop 150 miles from me at the moment, so I can't just run out there and look.

PS, I'm running almost 12:1 compression, and the cam is marginally streetable. My setup may not be all that similar to yours.
Probably not, Mine is 10:1 but larger displacement.. If you have the info, it may get me in the right direction. Particularly the Choke size.



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I have a set of Webers setup for a 408 waiting to go on, but I need to swap cam as what I have is too much overlap for the Webers. When I get home at the weekend I could look at the specifics.

I contacted Jim Inglese and he was extremely helpful, I'd heard the stories about 48IDA's running out of steam over 500HP and he was quick to dispel that myth saying he ran them on 600HP engines all the time.

Sorry guys, my experience with Inglese was VERY poor.

Gus, was that with the Inglese company, or Jim Inglese himself?

Two completely separate entities now.

I would not be surprised if you had a poor experience with the company. I would be very surprised if it was with Jim himself.
I worked with Jim himself and also found him very helpful. He was very insistent on certain things to make sure everything ran right (timing and fuel pressure), He was also keen to make sure you called if there was any issues. The Inglese company that now does the EFI setup is different from Jim Inglese.
Not a large block, but on a 331 CI, I have a set of 48 IDAs. At idle, a little rough (the cam) but they run best under WOT. They do have that look. See attachment. Fortunately, I have access to a Ferrari mechanic that knows them inside out.
On the MKII the 427 (496 CI), a high dollar, and dyno tuned Holly 950 cfm is the best I've seen. You get the correct amount of fuel and a higher volume of air.


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Looks nice Grady. Does it boil the fuel being near the header? What are all your thoughts on running unfiltered air? I love the looks but if I had to cover them up with air filters then what is the point I thought?

Looks nice Grady. Does it boil the fuel being near the header? What are all your thoughts on running unfiltered air? I love the looks but if I had to cover them up with air filters then what is the point I thought?

Only has about 450 miles on the car...I've looked into filters. I liked the domed fine mesh, but the paper is probably the best way to go. I'll let the new owner (whoever that maybe) decide that. The Weber's do have a unique sound when you hear them on the road going by. There is much chrome on the engine when you look at the plated intake.
Since this picture was made I had Dennis add a high temp insulated sleeve over the loop around the rear of the carbs. No problems with fuel overheating. I saw the same problem potential you did and fixed it. I'm lucky to have Dennis near. I ask him to go through the car...every nut and bolt and had everything done or looked at. My touch started with a $10 K repaint to Guardsman Blue. Time to make some pictures and sell it. An NO, you don't need more that I've got. I love my Viking Blue MkII. Probably the best in the country per the people in California and Dennis. It had years in the tweaking and improving to be what it is now. Toot toot.


Yes, and you can only choose Viking Blue if you live in Minnesota (although Swedes and Norwegians have been grandfathered in).
Grady, I think you mean your Acadian Blue MK II! This is "Viking Blue"

Yes Rick you are correct....I get the two names crossed. It is a a beautiful Arcadian Blue with dark blue/white stripes.
You know what the Viking and Guardsman blue look close in color when passing by.
But back to the thread...Webers on a big block FE.