Weber question

[ERA Chas]

Can anyone provide CFM spec's for 48 IDA's and 58 IDA's?
Thanks,

[Cal Metal]

Contact Gene Berg Enterprises using Google search. They can give you the answers on the 48s as well as the 58s. I have never seen any written material on Weber 58mm down or side drafts.

[Bluedog]

I've been looking at the 58 Bergs too. In fact, I just received a flyer from them today. They really look sharp! I'm still trying to ascertain if the 58s are the same size as the original Weber 58s, e.g, venturi size, flow, etc. One thing I did discover is that you will need to port the intake manifold to support a 58mm butterfly. The $64K question is whether there is enough material on a 48 IDA Holman-moody or Blue thunder FE manifold to enlarge to 58mm while still using the 48IDA bolt pattern and gaskette. I've got a call out to Pierce Manifolds who is investigating.

Bluedog

[PERUCH]

330 cfm flowed on my 48 IDA's
Regards,
Bernie

[Mike I]

Bernie,

I assume that is the total CFM flow through both throats of a single 48mm IDA, or is that the flow through a single throat? Also, what size chokes are installed?

Mike

[PERUCH]

330cfm per barrel with 42 choke and slighty better with good porting work on manifold (12cfm),
Regards
Bernie

[427Aggie]

I guess I don't see the use in going with 58's or bigger chokes unless you are racing. I actually just changed my chokes out to 40's on the dyno to see what happened...Didn't see any noticable increase in power (course I really needed alot more Main Jet) but I could see a huge difference in the way the car felt when I went from the idles to the mains. 48's with 37MM chokes is perfect for the driving I do which is around town.

Matt

[Cal Metal]

Aggie is correct. The larger the choke, the greater the signal loss one has at low and intermeidate speeds. No free lunch.

[427Aggie]

Hehehe...Actually Dan I am very close on mine....I had it on the Dyno with the 37's and I need to take the Air Corrector down to 200's and the idles down to 60's.

That will make it 37MM choke's, 160Mains, 200 Air Correctors, 60 Idles, 120 Holders and 55 bypasses with F7 tubes.

I was just a little rich at idle and went just a hair lean but back to normal after I got on it hard..when I put the 40's in and changed the jetting to correct for teh increased airflow there was a HUGE hesitation when I pressed the gas hard..not good.

Also on a good note I got to play with Bob last weekend and I am happy to report that he is taking great care of the 40 It looks wonderful and was cool to cruise with...now I just need one!

Matt

[ERA Chas]

Men,
Thanks for all the excellent information.
Bernie Peruch; if I understand you correctly, that's 1320 cfm of flow , on a 289? If you care to share cam specs, cylinder head type & mods, and exhaust info, I'm fascinated.
I'm carrying 1304 cfm [Holleys] on 427 inches with a lot of cam and Shelby stage II ported heads.
Appreciate any and all discussion on this topic.

[ERA Chas]

P.S.,
Cal,
Ronnie Miller at Ford Power Parts did a big build and dyno on a 454" stroker in the 1980's, for a Ford magazine. Used 58's on two different manifolds, cross mount and in line. Nearly touched 600 HP [had to use boat headers for dyno]. The owner was Austrian guy, and he took everything [including his gennie Cobra] back home. Many pics of the Webers in the articles.

[PERUCH]

Chas,
Heads are gt40 early type (C6FE)1.88/1.625 flowed at 219@.550,195@.550,
exshaust stepped 1.5,1.5/8,1.3/4,23in long,
long rod engine (5.506),10.9 CR,
4.020 bore,287stroke,
Custom flat tappet cam:
.601 IN,.595 EX valve lift,duration @.050:265/260,107lobe separation.
Made 463 HP/375 lb torque with stock 1.6 cast iron rockers (FIA rules)!!!!
Regards,
Bernie

[ERA Chas]

Bernie 289,
You have a very unusual and well thought-out combination. I'm amazed because everything I've read here and elsewhere re. Webers says they hate dual-pattern cams, .050 duration over about 230 deg., and an LSA under 110deg. [107?!] You knock the hell out of those theories. Your head flow numbers are strong, but I believe AFR 185's or possibly 205's may out-flow yours and work well with the combo. I realize they might not be "FIA legal." Your power numbers are great. The stepped headers allow velocity and volumn. Too bad your stuck with stock rockers. [8000 rpm?]
I've been studying this swap to Weber's
for a long time. My side-oiler has a 613"-633", 244-255 @ .050, 110 LSA Ultra-Dyne, which I read would not work with Webers. The heads flow 320 / 235 @ .600" so no worry there.
I'm amazed we share nearly the same carb CFM [you have more!] on engines 138 cubic inches apart! You're making 1.6 HP/CI to my LAZY 1.3 [550 HP]
Anyway, I really love the idea of a Weber project and you've given me hope I can get it to work with my moderately aggressive cam.
Sincere thanks for your replies, and welcome any further insight from your experience.

[48 IDA]

Bernie 289 FIA,

What is your idle speed? Mine is 1400 with 37mm chokes. The
cam is 260 degrees @ .050. .630 lift. Timing 12 degrees BTDC
38 degrees total.

Don

[Cal Metal]

Aggie:

The GT-40 is a nice one. I sold that to Snakeeyes with only 166 miles on it. I think if you back in and out of his "hanger" full of cars, you put at least 170 miles on a vehicle. He doubled the mileage in one drive through.

ERA CHAS:

You can run cams with more duration than 230 degrees @ .050. I actually used one that ran at 280. That is about the limit. The jury is still out on split duration cams.

[ERA Chas]

Cal,
Any thoughts on my 110 deg. LSA for Webers?

[Cal Metal]

No, but Cam Dynamics who grind cams for Webers should have an answer to your question.

[ERA Chas]

Thank you Cal.

[Cal Metal]

Chas:

My apologies. It is Cam Techniques not Dynamics. 941-727-5552. Sorry for the mistake.

[ERA Chas]

Cal,
No apologies needed. Thank you AGAIN!