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RE: [ihc] Intake manifolds



Steve and I talked about timing on my '80 Traveler when he was here.  I'm
running 80BTDC and it normally doesn't ping, but it did on several occasions
on the trip to Detroit pulling the car and trailer.  One thing that Steve,
Hofs, and I all have that I don't think you do, Ed, is we're all fuel
injected with the Holley system.  When I ping I'm in the closed loop mode.
I unplugged the O2 sensor forcing the ECM to go into open loop and it made
it rich enough to make the pinging to away.

My engine is also probably different than the others in that I have a 392
non-improved cooling with 345 heads on it so I'm running a bit more
compression than others are.  FWIW, there was a lot of 91 octane premium on
the trip that I fed the Scout (as opposed to our 89 octane 10% ethanol here)
and I could tell no difference at all in the  amount of pinging.  What I
REALLY need is a recurve of the distributor with a more aggressive vacuum
advance and less total mechanical advance, either that or lock the whole
thing down and let an ignition control have at it through a MAP sensor.
What I'll probably end up doing is limit the total advance on the mechanical
side  so I don't lose my initial advance (and the unbelievable throttle
response I have now with the FI) and play with some vacuum cans to see what
I can come up with.

If you have your intake heat tube hooked up, make sure your door is opening
all the way when the engine is warmed up.  Hot intake air can aggravate
pinging quite a bit.  Another thought is to block the exhaust heat crossover
in the manifold, but I'd be hesitant to do that unless you want to run FI to
compensate with a richer mixture till it warms up in the winter.

John Stricker

----- Original Message -----
From: "ihc-digest" <owner-ihc-digest@domain.elided>
To: <ihc-digest@domain.elided>
Sent: Tuesday, November 04, 2003 6:36 PM
Subject: ihc-digest V7 #187


> Date: Tue, 4 Nov 2003 12:09:13 -0600
> From: "Ed Sohm" <idaemes@domain.elided>
> Subject: RE: [ihc] Intake manifolds
>
> I was hoping not to have to run premium at an additional $.12 and 8mpg.
>
> I'll try it though.
>
> Thanks,
>
> Ed
>
>
> - -----Original Message-----
> From: owner-ihc@domain.elided [mailto:owner-ihc@domain.elided] On Behalf Of
> Steven Stegmann
> Sent: Tuesday, November 04, 2003 11:57 AM
> To: John Hofstetter; Ed Sohm; ihc-digest
> Subject: Re: [ihc] Intake manifolds
>
>
> I set mine at 15 deg BTDC and run premiun gas.  Amazing difference in
> the character of the engine.
>
> Steve
>
> You probably already know this, but the pinging is a function of a
> whole lot of factors. Elevation is one of these factors.
>
> When Steve S. talked about running his engine on premium, he wouldn't
> have to use premium if he lived at 7000 feet.
>
> I have the variable timing control on my Terra and in the CA Central
> Valley, I have to run the engine at about 0 degrees advance. I run it
> at about 13 degrees early above 3000 feet, and here at home at 2000
> feet, I run it at about 6 degrees early.
>
> And, my Terra is a pinger. Probably the worst we've ever talked about
> on the digest. EFI didn't change that, Mallory ignition didn't change
> that, but going with the Autolite 85 plugs and the Magnacor plug
> wires seemed to help the pinging and a number of other ignition
> problems that I was having, the most noticeable of which was the
> kicking back against the starter when trying to start the engine.
>
> Joel B. told me it didn't take a rocket scientist to figure out that
> I was getting cross firing, but he was wrong, in this case it did
> take a rocket scientist. <g>
>
> John Hofstetter
> t
>
> ------------------------------
>
> Date: Tue, 4 Nov 2003 13:37:58 -0600
> From: "Ed Sohm" <idaemes@domain.elided>
> Subject: RE: [ihc] Intake manifolds
>
> Yep, I understand elevation's effect on pinging.  I live at about 1100'
> I guess I'll dial it up and see, especially since I am running a little
> rich.  Does your Terra have a 392 or 345? I would love to have a timing
> control so I could really "dial" it up and down.
>
> Thanks,
>
> Ed


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