I've got to agree with Joe here whole heartedly.
Don't forget, your present engine is stressed simply
by having to 'suck' air in. This reversal (pushing/pulling air)
of inertia on all the moving parts, thus stressing the
bearings etc.
On a mildly blown engine, the pressure in the intake
can actually keep a positive pressure on the pistons
at all times, eliminating much of these 'reciprocating' stress.
Blowing the engine, and simply removing the work
load the engine needs to perform just to 'inhale' an
F/A mixture, dramatically increases the efficiency
of an engine and 'removes' some stresses already inherent
in an internal combustion engine. This simple premise
(removal of the 'inhale' work) was the design premise of the
supercharger back in what...1939?? .
Most engines use anywhere between 12% to as
much as 30% of their power, just trying to 'suck' in air.
So if you blow an engine and keep it within reason,
you can actually get a more efficient engine with
better power, AND better gas mileage.
Ahhh... yes. But what fun is mild. Plus the trade off in
price vs. performance. When just a little bit extra boost
will cost nearly nothing compared to what you've already
spent.... it's hard not to go a little overboard.
:-)
Paul Tegler ptegler@gouldfo.com www.teglerizer.com
----- Original Message -----
From: "Joe Curry" <spitlist@gte.net>
To: <BillDentin@aol.com>
Cc: <spitfires@autox.team.net>; <fot@autox.team.net>
Sent: Wednesday, June 13, 2001 10:56 PM
Subject: Re: 1500 head needed
I think most Supercharger additions actually are done after the owner has
already increased the compression and is not satisfied with the results.
Sometimes one has to take steps backwards in order to move forward.
Yes, The term "Modified Engine" is the operative case here. However, I believe
Judson intended the usage to actually mean "An engine that has
increased Compression" over stock. So you put increased compression on top of
increased compression and that is where the troubles lie. But if you
modify the engine to lower the baseline compression and tune the cam timing to
better handle the boost, you can (or should be able to) add power
without overstressing the engine.
Also, as Kas points out, controlling timing and fuel flow while the boost
increases, helps keep detonation and running the engine lean in check.
Hopefully, as I consider these things, I don't miss any details.
Joe (C)
BillDentin@aol.com wrote:
>
> In a message dated 6/13/01 7:02:31 PM Central Daylight Time, spitlist@gte.net
> writes:
>
> << I fully intend to make you eat your words! I am going to build a complete
> engine specifically engineered to handle the Supercharger. It will have
> decreased compression, forged pistons, a cam ground specifically for the
> supercharger and the best rods we can find for the price. >>
>
> Good for you, Joe. I hope I get to eat my words. I had a 1959 TR3A with a
> Judson Supercharger. I broke the crank and cracked the block warming up for
> an autocross at an early NATC in Illinois. The bottom end of the Triumph
> engine appears to be a weak link. The Judson directions said something o the
> effect of, "Do not use on a modified engine." At least when I did it, they
> were right. I hope you find a path that works.
>
> Bill Dentinger
>
> Bill Dentinger
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