qud webers (help

[Tim Kay]

Glen,

Pays to listen to Mike. He's good at trouble shooting. It seems with Webers if you take it as a learning experience the enjoyment, when mastered, is all the more satisfying. In other words, enjoy the journey. The're actually fun to play with when in the right frame of mind.

Mike,
I don't know if you remember but, oh about two years ago, you advised me of similar issues and your help was most appreciated. Boy do I know how Webers can frustrate, although they are very rewarding when mastered.

[Oliver]

They dont have seals!

Take that whole circut and put it in another carb and see if the same problem exist...if the problem moves with the changing of the circut, than you just localized the problem.. If all else fails. If you cleaned the circut and jets, it is may be damaged. Start changing the circut ,jets with the other circuts to isolate what part of the jet is not working properly.

Oliver.

[Tim Kay]

Oliver,

Pull your head out, IDF have o-rings just as Mike explained.

[Oliver]

Sorry!!! Thought they were 48 Ida...how ever the isolation theory still applies!!,,,

Oliver

[SpyderMike]

Tim, I remember well. I had just tackled my issues when talking with you. Some day we will have to get together -maybe after my SPF GT is up and running! I'd like to check out your car...

UltraBlue, I don't know where you live, but I have a weber manual, a bunch of extra jets, some jet reamers and some jet gauges you can borrow to work out your issue - just return when done.

Mike

[muggle]

Mike thankyou for your offer,
if you would like to send them to Melbourne Australia
i would be rapt !!!!!!!!seriously thankyou for your offer .
i will try all these combo,s tommorrow and let you know how
we get on .....ps oliver are these discs still available?

[Oliver]

Yes! getting ready to ship next week!

[muggle]

how would you like to be paid,,,,,western union or ?????????????/

[Tim Kay]

Oliver,

No need to apologize, I was just taking advantage of the opportunity to give you a hard time [img]/ubbthreads/images/graemlins/1poke.gif[/img]

I figured you were thinking IDA [img]/ubbthreads/images/graemlins/beerchug.gif[/img]

[347]

Hey Glen

Did you have any joy with those numbers I gave you?

Cheers Dave

[David Briggs]

The 160's are probably the main jets' not the idle, if your problems is all across the the rpm range than you increase this to maybe a 170. If your problem is only at idle-2500 rpm then you are still on the idle circuit and you need to be looking there. You seem to have isolated a problem with one cylinder, once you have verified the jetting for that barrel is the same as the others and you have the same float setting and when you put the carb synchroniser on all venturis and verify those are the same and you still have a problem you need to forget about the carbs and look for a bad plug, wire, valve adjustment or some other problem. If problem goes away by backing out the mixture screw then your idle jet is too small. I am assuming that timing (ignition and valve) is good and that your advance mechanism is right on, max advance 34-38(at the crank) total by 3,000 Rpm. People have a tendency to go to the webers first but they are really pretty simple and reliable(if they are in good condition and not modified by some backyard rocket scientist).

[muggle]

i have talked to the people who designed the camshaft and unfortuneately the overlap on the camshaftmight be a problem here are the specs (
W A D E C A M S H A F T S P T Y L T D
A.B.N 62 004 544 996
27 Wells Road, Oakleigh, Vic, 3166
Phone (03)9568 0333 Fax (03) 9568 2633 Email info@wadecams.com

Profile Actuation Make/Model R/Ratio
629B Flat Tappet Holden V8 253-308 In1.65 Ex 1.65
--------------------------------------------------------------------------
Cam Lift Duration Duration Valve Valve Cam Lift Phase
Adv @050 Clr Lift tdc <)
--------------------------------------------------------------------------
Intake 346 322 266 0.024 0.5461 165 100
Exhaust 346 322 266 0.024 0.5461
--------------------------------------------------------------------------

Timing Timing
Adv @050
Open Close Open Close
Exhaust 82 60.5 56.5 29
Intake 62 80.5 36.5 49

122 66
Deg Over-lap Deg Over-lap
this cam has a certain rpm range from 4000 to 6500,at around 3000 rpm now the car backfires through intake and exhausts and runs like shit i really want to keep them but i am loosing my mind here ..IF SOMEBODY WANTS TO SEND ME THERE TELEPHONE NO I WILL GIVE YOU A CALL AT YOUR CONVENIENCE THANKS GLENN

[Jac Mac]

Glenn,
That is a huge cam duration wise. I dont know what sort of application you are trying to use it in but the fact that you are trying to run at 3000 tells me that the application is wrong. According to the info you have supplied the cam has a lobe centers of 100 degrees which is very short and suited to 1/4 mile sprint cars etc. This explains why the top end of 6500 rpm is so low.
I would biff the cam . Look for a grind somewhere along these lines:: 280deg advertised duration, 250deg @ 0.050" camlift, 108deg lobe centers and about the same camlift as you have now(0.346"). One other thing that you may not have tried is incorporate anti reversion cones in your header primary pipes at the cyl head face or in that immediate area of the primary pipe. Whatever happens biff the cam, if you towed it into my workshop and asked me to fix it that would be the first thing that would happen.(You would have to tow it because the driveway is so steep that your clutch/trans would be fried with that cam).
BTW the .050" intake numbers that you have given dont add up and I have assumed you have transposed figures here.


Cheers and good luck.Jack.