Dude...i've run the stock Mopar roller lifters to 6000rpm without issues
9and I'm definitely not the only one) - they're smoking something.
Now as for the harmonics that the injectors can cause in a fuel rail -
yes...if you look at more modern rails, they're now oval or rectangular.
This is to help absorb the injector "shocks" (or pulsations) that do happen.
But not to the extent that this article is claiming.
- Bernd
-----Original Message-----
From: Ray Block [mailto:BPracing@wowway.com]
Sent: Monday, August 04, 2008 4:20 PM
To: dakota-truck@dakota-truck.net
Subject: DML: RE: Magnum engine "design flaw"
Well Jon, not only am I not an engineer, I haven't even stayed at a Holiday
Inn Express. ;-) However, I (and others I will mention) do have real
world experience with these engines under extreme conditions.
First of all, let me say that I agree with your perception of how the fuel
rail is pressurized and what little effect the firing of an injector has on
the system. While I can imagine a situation where someone may have a
large enough engine and large enough injectors to tax a stock system's
capabilities (fuel rail or pump), I can't imagine it being very common or of
any concern to the vast majority of us.
Since you mentioned Mopar Muscle as the source of this story, I will add
that there is a thread on a Mopar forum questioning the validity of another
Mopar Muscle article that proclaims the stock hydraulic roller lifters in
Magnum engines are too heavy and prone to failure at rpms above 5400. For
those interested, look here:
http://board.moparts.org/ubbthreads/showflat.php?Cat=0&Number=4594789&an=0&p
age=1#Post4594789
Now, for examples of why I agree with you on this fuel rail issue, and
disagree with Mopar Muscle on the lifter issue, let me just say that my Dak
has totally stock fuel rails, injectors and lifters....as does an
acquaintance of mine, Bruce Flodin, a Stock Eliminator, 318 Dakota, racer
from BC. He shifts at 7000 rpm while I shift at 5800-6100....depending
upon conditions. I run 12.90's in the quarter, while Bruce runs high
11's. Here's a qualifying run of his at a NHRA Division race:
(Bruce Flodin, Abbotsford, B.C., CT/SA '95 Dodge, 11.989)
Basically, I don't put a whole lot of stock in much of anything the Mopar
rags write about. When it defies common sense or my experience, I just
call BS on the whole thing and move on. LOL
Ray
http://www.dragtruk.com/ENTRIES/20KM1FD2KWBP.html
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