quote:Originally posted by Rocky:
Hi Peter.
We had a guy here (PanteraDoug) who runs Webers and I think I recall him posting about cams for them.
Try the search function.
He used to post a lot, so it might be hard to find the real detail you are looking for.....
Rocky
Here is a link to one thread on Webers....
Weber IDA/IDF Thread...
I can't think of anything that hasn't been said here already on the subject.
The 4 x 48ida is intended as a competition induction but it has enough flexibility to be streetable.
It will run with virtually any camshaft irregardless of whether or not it was designed specifically for them or not.
If you are asking me, I find that this is a "package" along with the cubic inch displacement of the engine, the flow characteristics of the cylinder heads, the changes that headers make and the usage of the vehicle.
TO ME, this is a vehicle, engine and drivetrain that is aimed at about a 6,800 rpm peak in top gear, produces power and response from off of idle to just over the peak rpm and fits the performance capability of the original chassis concept and the vintage maximum performance of the era.
For longevity there are a couple of things one needs to do. One is to provide vacuum to the engine through a pcv system.
The other is to lean down the idle system with current idle holder jets and idle fuel jetting.
Camshafts are just going to be a preference thing. Every racer had their favorites. Every street driven car will have it's own desired characteristics. "You" have to work that out for yourself.
Some people are just going to be "happier" (but not necessarily happy) with an EFI system BUT having said that, no one can explain to you what the differences, the compromises and the misconceptions of what induction systems like this are about.
Only "you" can determine if they are all "worth it".
I matched the camshaft to the head flow characteristics. The reversion is secondary and to me not a significant issue at all. The headers are also "theoretically" matched to this.
I used the "Gp4" car configuration as a guide, and worked from there. Others will have their own theories based upon other factors.
Having said all of that, the issue still remains, "people just don't realize what to expect from the Webers and many are just disappointed".
A nice reliable iron 4v head 5.7 is going to put you right at about 550hp at about 6,000rpm. Good aftermarket heads (probably aluminum) will show about another 35hp.
Torque on both should show you around 495ft-lbs at about 5,000rpm. Strokers may show you more total tork but the big differences are going to be where the power comes in which is 1,500 to 2,000 rpm.
Personally I went with a Comp Cams solid lifter profile.
http://www.compperformancegrou.../store/merchant.mvc?
Screen=PROD&Store_Code=CC&Product_Code=32-239-4&Category_Code=F351MFTCM
Some will love it, some hate it, some say it is too much, some say too little.
It works for me with the criteria I set and within the known restrictions.
The 2" primary tube headers work well also. Some will argue they are too big. I'm not here to argue with anyone. They can go argue in the mirror with themselves.