Autolite 3923 + 4.7

From: Stlaurent Mr Steven (STLAURENTS@mctssa.usmc.mil)
Date: Tue May 15 2001 - 10:23:09 EDT


Unless we have a metallurgist here on the DML, I would have to disagree with
the comment. I used them for more than 15000 miles and find them much
better than the copper. Before totally the truck, I even tried the cooler
version 4416 and they were quite impressive.

If you look at the design of the 4.7 heads and Bosch Plus 4, they would be
compatible. You want a blow-down spark not across the head. This will
increase the usage of all mixture (air/fuel) in the cylinder area, while I
had doubts with a standard plug. Unless someone can prove that the
coil-over has failed on there truck, I would whole-heartily disagree with
the tech.

I even tried them on the Suzuki 1.3, which duplicate the Dodge hemi head
design on there heads but in that case, to much RPM (8000) and not enough
spark. So, yes, in a way there is some fault in the design but great at
lesser RPM factor.

Bosch could design an all-cooper design plus 4 if there is enough demand for
them.

--------------------------------------
Steven St.Laurent
System Engineer (IOW/IOS-NT)
PSD, MCTSSA
MARCORSYSCOM, USMC
(Work) 760-725-2506 (DSN: 365)
(Work) mailto:stlaurents@mctssa.usmc.mil
(Home) mailto:saint1958@home.com
"In fact, my work has already proven
itself to be correct. People such
as you just haven't gotten it yet.
(unknown author)

-----Original Message-----
From: WOT or waiting at a Red [mailto:dakatack@home.com]
Sent: Sunday, May 13, 2001 9:26 AM
To: dakota-truck@buffnet.net
Subject: DML: Re: Autolite 3923 + 4.7

William

I would be interested in learning more about your experience with this plug
swap.
I have been using the 3921 because they are a cooler temperature range plug
than the one that came with the Dakota. They seem to work fine and after 10K
or so, looked much better than the stock plugs that came with the 4.7L.

The concern I have with the +4 4417's is that they are a platinum plug.
According to the good folks I contacted at the DC technical service center,
the platinum plugs have a thin core of platinum that can't carry away heat
as fast as the coppers can. The concern is that the temperature of the COP
(coil on plug) will get too hot and fail.

Is the construction of the core of the +4 4417's different than a typical
platinum? I know that the grounding electrode, all 4 of them, are different
and from any other plug. I also know the spark will only go to 1 of the 4
grounds at any one time. This leads me to wonder if the 4 grounds are a
gimmick to sell plugs or is there something that I have not considered here.
The question that I have not gotten a good answer for is whether the
temperature the plug conducts to the coil will damage the coil like a
standard platinum plug is supposed to do.

I would appreciate any thoughts you or anyone else might have on this
matter. In particular, can you quantify the difference in performance that
you have experienced with these plugs.

Thanks

Patrick O'Day
2000 Dakota 4x4, 4.7L, CC
Profile at www.dakota-truck.net/profiles/dakota/Cy9WFjn1QtCYw/profile.htm

----- Original Message -----
From: "William H. Hiatt III" <william@hiatt.net>
To: <dakota-truck@buffnet.net>
Sent: Saturday, May 12, 2001 10:07 AM
Subject: DML: Autolite 3923 + 4.7

> Ok, last time I'll aska question. I put some 3923's in today, gapped at
> .040, and it doesn't rev nearly as quick as it did with the +4 4417's.
> Maybe it's just me and I'm crazy, and it's in my head, but does that make
> a difference? Thanks alot
>
> william
>



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