What Specs are critical on Cams for use with Webbers?

[dave harris]

Looking at specing my cam and would like to know what specs are considered critical for use with Webbers? I've heard that the Webbers don't like too much overlap?

so
Ranges of overlap?
Ranges of duration?

will probably go with a flat tappet solid lifter version.

Thanks everyone,

 

[Tim Kay]

You might try contacting Inglese (www.inglese.com). They can be real helpful regarding cams /ubbthreads/images/graemlins/cool.gif

 

[Russ Noble]

I was under the impression that a single choke (venturi) per cylinder smooths out a lumpy cam. That's in the four cylinder world anyway, maybe V8's are different. That's the trouble with cutting your teeth on the wee pommie stuff, the experience is not always relevant. /ubbthreads/images/graemlins/frown.gif

Regards

 

220 degrees @ .050 is a maximum for street use with 26° overlap
Bernie

 

[dave harris]

Thanks Bernie!

 

[DMatt]

Dave, I would call the tech guys at Comp Cams or Crane Cams or any other company you like. Tell them your set up and they will point you in the right direction. Picking a cam has alot more factors involved than what carbs you are using. You must take into consideration what trans you are using with what ratio, the weight of the car, what ignition you are using, pistons, headers, At what RPM will this motor spend most of its time? And the list goes on. How you are going to use the car, and what you expect to get out of the motor. Speaking for myself, I could not pick the correct cam until I could answer all of the above questions. I have used Comp Cams before and they made the process very easy. They will walk you through it and make several recommendations...

 

[dave harris]

Thanks Dan,

Yes - I am planing on contacting a number of cam specialists, but I just wanted to have some basic background limits that I could look to during my conversations. I've spec'd a number of cams for engines I've built over the years, but multiple webbers are still too new to me!

thanks again everyone - I'll let you know what the cam builders come up with!

cheers

 

I was wondering the same myself. Thank you all for the info.

 

[Neal]

Webbers don't like a lot of overlap and tend to like more exhaust lift. [email protected] is pretty much the norm for cams using Webers. I spoke with Comp Cams but they had little experience with individual runner induction. I ended up with a Gordon Levy Racing / Isky grind with split duration / split lift. I'd publish the specs but it is a proprietary grind Gordon developed. Inglese and Pierce Manifolds are two good sources for info.

 

[Ron Earp]

Gordon's cam specs are out there, on this site for those that are really interested. There are very close cams off the shelf as well, at least there was one about 4 years ago.

 

Here's the specs of the Cam Techniques cam that Inglese sells.Lift both intake and exhaust,.298 at cam .477 at valve,Duration,both 290 advertised,222 at .050 cam lift.Valve timing at .050 cam lift,intake opens 5 BTDC, closes 37 ABDC,exhaust opens 45 BBDC,closes -3 ATDC.4 degrees advanced ,106 intake C/L.I don't know what the C/L stands for. Hope this helps,it's a nice running cam ,doesn't sound real lopey but seems to rip when you floor it.I'm just getting it sorted out,now my brake lights died,so I need to fix them before I can really try these Webers out.These are on my ERA FIA Cobra with mid built 302.I wanted to try them out as that's what I want for my RF when it comes in next year.

 

tested several cam back to back on dyno supplied from mass production cam specialist and IR specialist as David Wizard among them marginnally better is Buddy Rawls,check his website: [email protected] and you will understand!!!.
Bernie

 

Sorry,
Rawls website is www.wighat.com

 

Sorry again now is correct:
www.wighat.com/fcr3/