Weber 32/36DGV verses the Weber 38DGES

yodta
(pooh bah)
Thu Apr 14 2005
07:25 PM
Sarge
(carpal tunnel)
Fri Apr 15 2005
03:21 AM
yodta
(pooh bah)
Fri Apr 15 2005
01:42 PM
venturis. The 4.5's larger outside diameter also forces a better signal to the main circuit since the outside bore is closer to the
main venturi's diamter.
There really is nothing wrong with the jetting you had before or the F50 tube. It only required that jetting to work with what you
have , no big deal . The F6 is pretty extreme in richening the circuit at low end. If you can't run a significantly smaller idle jet then
you are pretty much stuck with that size. The only other way around this is to reshape the plenum under the carb to increase flow
to the outside where the transition dumps.
Try the F50's jetting and note it's response. Then try the other Ftubes with that jetting. I'll have to look up that other F tube you
ordered and see what it's map looks like. There should be one close enough to the F50 to respond the way you want it to without
any lag.
As far as suppliers, I have over a dozen. Pierce is one of my favorites in the US , otherwise the best ones are overseas but it
takes extra time.
Sarge
Re: Weber 32/36DGV verses the Weber 38DGES
Quote:
This is just a lack of signal, probably from the intake having a bit too large of an internal runner diameter.
Offenhauser typically runs pretty large runner bores to help larger valves and high compression work like it should .
As a result the air moves slower, but more volume. The speed of the air going through the carb's venturi is the signal
the carb recieves.
I should note here that the Offy intake I'm using is the dual plane manifold; the runners for the primary and secondary barrels are
isolated. this intake is advertised as designed for providing better low end torque and throttle response. my understanding is that
dual plane manifold designs are the "opposite" of oversized manifold runners, in that the air should move faster and more
violently than those open plenum designs.
I believe the venturis in this carb are 26mm & 27mm. I was trying to find a picture to corroborate this, but I can't seem to turn it
up. I'll check the stamps on the side of the carb body again to make sure.
I will revert to the jetting I was running that was crispest before the tube swap and play with the other tubes over the next couple
of days and make notes.
how about we lay out some guidelines for testing, like throttle positions, load, etc. so we're testing and comparing the same thing
on each change.
as I mentioned in a previous post, the F81 is identical to the F50 tube except it has two more small holes at the bottom of the fat
section of the tube. you can see what I'm talking about in one of the e-tube diagram images 17 posts up. look at the diagram with
the F6 & F50 marked on it and then in the chart to the right. the F81 is just below the F50 in the second group.
Re: Weber 32/36DGV verses the Weber 38DGES
Wait a minute, just exactly how are those runners in the manifold oriented? Is there a common plenum at all or not?
Testing really should be done on maybe a daily commute route or somewhere that usually drive in basically the same conditions.
It's pretty hard to get control points from day to day but at least if the route is consistent it helps .
Sarge
Re: Weber 32/36DGV verses the Weber 38DGES
no common plenum at all. there are two holes at the carb mounting surface on the manifold, and the aluminum spacer they
provide has two holes, as well, so it keeps the barrels isolated the whole way down. the runner divider inside them manifold is
oriented horizontally, and I believe the secondary runner is on top of the primary at the head mounting flanges.
ooh, I just thought of something. the insulating spacer I just ordered from pierce is an open plenum design. crap... wonder how
that's gonna play in...
yodta Re: Weber 32/36DGV verses the Weber 38DGES
just got the garolite in today. holy crap is that stuff heavy! I don't know what I'm going to use to cut it, though. thought about the
rotozip, maybe, but not sure how tough this stuff is yet.
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