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posted on December 6th, 2005 at 12:05 PM
Carbs, manifolds and restrictor plates
I'm currently rebuilding an offroad racing buggy with 1600tp engine, with a balanced bottom end, Scat C35 cam, skimmed heads and a 40DCNF carb with
an individual runner manifold setup. Due to the competition class restrictions, I've got to add a restictor plate (3mm think with a 23mm "hole")
between the carb and manifold. Given the current dual throat carb, and individual runner manifold, I don't think I'd be getting the best performance
out of it. I suspect a single choke carb and a plenum manifold would be a better combo - anyone got any ideas on carbs/manifold combinations ?
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posted on December 7th, 2005 at 02:23 AM
try it and see how it runs. it shouldn't make to much difference as the venturi size isn't probably that much bigger.give it a good run and check
the plugs. the dcnf isn't really the ideal carb setup for offroad as it has a heavy brass float Float, will bounce in the fuel and run rich
Desert Moose
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posted on December 7th, 2005 at 02:39 AM
before you start doing anything, you may want to take a look at the NEW rules for that class..... I would contact CAMS or an Off Road club in your
state and see what the rules on Class are going to be next year..... There is talk about a total class 6 change next year, but no one know whats
going on right now :o
Kimbo
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posted on December 7th, 2005 at 09:13 AM
Moose - you have got to be f*ckin joking - surely not - after the amount of time taken to get it to where it is !!! In fairness I don't mind what the
hell they do with it, just so long as they make up their minds, and stop farting around. What's strange is I haven't heard anything about this at
the club meets - where did you get your info from ? Ahh bugger it - might just as well stuff the restrictor and run it as the class 2 it's already
log-booked as !
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posted on January 12th, 2006 at 01:19 PM
Moose, FYI, from a club meeting this week, it appears the only discussed change for Class 6, that the Offroad Panel are looking at, is to increase to
the size of the hole in the restrictor plate, which made me happier as hopefully I don't have to worry about anything else being impacted (at this
stage).
However, the question of whether the Weber 40 and individual runner manifold would be a good combination still stands, and as I'm trying to rebuild
with what I've got, I'd rather not change unless it makes sense. I've been recommended Solex 30 or 34 (?) with the correct manifold as being better
options than the Weber - anyone got any comments or ideas about varients, cost and availability ?
The other option suggested was a lead in or lead out to the restrictor while still maintaining the required thickness (the regs don't state that you
can't have lead in/out, so currently it's OK). Any comments on this ?
TonyKTM - appreciate the comment on the DCNF float weight, hadn't thought of that, but bearing in mind that the donk's still in bits, and therefore,
assuming I don't change if for anything else, I won't have chance to test it for a while.
