Weber 32/36DGV verses the Weber 38DGES

yodta
(pooh bah)
Wed Nov 02 2005
09:59 PM
Gnarly4X
(carpal tunnel)
Thu Nov 03 2005
12:07 AM
Now on the subject of a properly tuned engine pinging. Yes, they should ping, a little under certain conditions.
Engineering is a field of compromise. You want the most power, the best fuel economy, the cleanest emissions, and
the longest longevity out of any engine. But each of these conditions requires different tuning, generally opposite
from each other.
An engine needs to be tuned to operate at a sweet spot that is the compromise of all requirements.
As I said earlier, pinging can be the result of high combustion temps, and this is the type you would expect to occur.
High temps are caused by a combination of lean fuel and advanced timing. Lean fuel produces higher combustion
temps and hence more power. It also produces higher emissions and potential engine damage.
When the engine is under sever load and a low RPM (like climbing a steep hill in top gear) then engine temperatures
rise and will begin to ping. That is normal. That is desired. Yes, you are damaging the engine and melting the piston.
(More on that later). That means that you have crossed the line are no longer is that compromise zone. That is good
because engines are not meant to be operated in that fashion. PINGING MEANS IT IS TIME TO DOWNSHIFT.
Engines, particularly motorcycle engines, make their power in the upper 1/3 of the RPM range. If you are under
sever load, you want the tachometer up near red line. That is where the engine was designed to run and it is by far
the easiest on the motor. When you are lugging an engine, the oil pressure drops and the piston rods begin
hammering against the crank shaft because there is no longer a high-pressure film of oil to prevent it. Likewise, the
crankshaft in turn hammers against the block (or case). In either case, the damage you are doing to the bearings is
far worse than the slight amount of aluminum being burned away. If you switch to a higher octane fuel to prevent the
pinging, you may not realize you are destroying your bearings.
You could also retard your timing or richen the carbs to prevent pinging under severe load on whatever octane gas
you desire. But again, this will mask the bearing damage you are doing. It also moves the threshold of that "sweet
spot" downward. Now you will not have pinging under sever load, but you will also not have complete combustion
under normal conditions (such as cruising), and that can lead to poor fuel economy and excessive carbon deposits.
In a nutshell, the engine should ping if properly adjusted, under low RPM, severe load conditions. Next, you should
use your transmission to avoid those conditions.
--
Larry Piekarski
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
That is utter bullshit... if that were true, every engine would be pinging.. and that just ain't happening!! Sorry... I don't know this
guys credentials, but I'd love to meet him.
Gnarls.
Re: Weber 32/36DGV verses the Weber 38DGES
what do you think's BS?
a lot of it makes sense to me, granted it's just some random post online (do you have any idea how hard it is to find good info on
anything these days on the web? everyone's tryin' to sell you crap)
especially the parts about bangin' away on your bearings if you're pinging under load. I don't know that I buy his claim that pinging
doesn't hurt anything, but the info I found interesting was the causes for pinging and what to do about repairing it.
Re: Weber 32/36DGV verses the Weber 38DGES
Quote:
what do you think's BS?
a lot of it makes sense to me, granted it's just some random post online (do you have any idea how hard it is to find
good info on anything these days on the web? everyone's tryin' to sell you crap)
especially the parts about bangin' away on your bearings if you're pinging under load. I don't know that I buy his
claim that pinging doesn't hurt anything, but the info I found interesting was the causes for pinging and what to do
about repairing it.
Scott, I'll agree that it's interesting reading, but I'll compare it to the post about the acetone and the link that was posted as
"gospel". The link on the acetone was bogus. There was absolutely NO data to support the claims. And, the link you posted is the
same.... absolutely NO data to support the comments. If engines were supposed to "ping" they'd all be pinging... and they are
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