Weber 32/36DGV verses the Weber 38DGES

Gnarly4X
(carpal tunnel)
Sat Oct 29 2005
02:44 PM
yodta
(pooh bah)
Sat Oct 29 2005
03:40 PM
Attachment
the midrange of the primary.
The DCNF project is on hold for awhile, I need some parts to make this old 40DCNF a better test candidate. The bearings are
bad as well as some other issues. Plus, I have to track down a local wheeler and borrow his truck for awhile to test it. The real
fun part will be figuring out which F tubes to use. Since the Toy engine is such a torque motor, the whole flow pattern is much
different , should be interesting.
Sarge
Re: Weber 32/36DGV verses the Weber 38DGES
Quote:
well, keep everything in your current setup until you're completely satisfied with the 38. you might end up like me and
find out you want to go back
I just got an email from a guy at LC Engineering. he think an adjustable cam gear might sort my pinging problem -back
my base timing off and compensate with the cam gear.
I'm having a hard time understanding what happens if I retard my timing from 9? to say 5? to stop the pinging and
then adding a cam gear. what do I do? advance my cam timing to compensate?
I mean, what's happening? I retard the timing and the spark comes in later. If I were to do that with my current setup,
with the loss of power I experience at 5?, I would assume the valves are opening resulting in a loss of power,
whereas right now, at 9?, I'm getting preignition, and it's lighting the air/fuel charge before getting proper
compression, banging before I'm at TDC, which results in a loss of power as well, correct?
First, you should NOT let the engine PING!! Back off the ignition timing until you can figure out what's going on. Have you pulled
plugs and checked the color? Did you try going down in heat range? There could be a number of things going on that are causing
your pinging at the ignition timing advance you have set. You can find cams that are not perfect regarding advertised specs in the
profile, however, the centerline would have to be off several degrees before you'd run into a seriously induced "pinging" issue.
Your pinging is probably more related to fuel/air mixture. If you do decided to get an adjustable cam gear, I'd bet you'll find, after
careful measurements, that the cam is very close to right on spec. You might also try adjusting your valve lash. Go 2 thousands
tighter and see what it does. I recommend checking your compression ratio to see what the readings are. Based on your
experimenting with carb/jetting adustments, you should absolutely invest in a good air/fuel meter!! Then you'd see what's really
happening with your air/fuel. That's just my worthless opinion.
Gnarls.
Re: Weber 32/36DGV verses the Weber 38DGES
Quote:
That distributor is the whole problem, look at the curve and relative rpm, there's the pinging problem. The advance
should be a bit more aggressive at a lower rpm at the same point as the transition circuits in the carb. This way they
match, when the carb is fairly rich for acceleration the timing will help it pull better. Your current setup is jumping the
timing up pretty high right where the carb will lean out for cruise. If you were running a 38DGAS or the DCNF, the
curve would better match the carb.
actually, this distributor is pretty agressive down low. the advance is maxing out at 2000rpm and there's 20? built into it. I've
always figured cruise to be anything higher than 2000rpm in small engines, say 2200-3000rpm for this vehicle. it starts to come in
at around 1400 and ramps up pretty quickly and is all in by 2000rpm.
my pinging is around 2000-2200rpm. I think if the timing is any more agressive, it will ping worse.
I understand what you are saying though about the synchronous carbs. if they truly are fatter at the transition and otherwise the
same as the 32/36, it may be a better fit for the response I'm looking for while still being economical at cruise. it may be that this
32/36 is truly meant simply as an economy stock replacement. I've been thinking about getting to work on that 40DFAV here
shortly.
my current jetting is the best I've been able to get it. the idle circuits are good, and deviation to either side in the mains, lean or
rich produces mildly adverse effects indicative of lean (holding back) or rich (bogging) condtions respective of the jetting change,
so I'm really leaning toward the timing at this point.
I guess the next thing to do would be to play with the stock distributor and find out exactly what the timing is doing, or is supposed
to do. I thought I had some data on this from Gnarls from months and months ago, but after pulling up the old email, it turns out
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