Daniel & Greg,
Thanks to both of your for your input. The chances of me ever throwing the
Red Rat Bastard on a rolling road or engine dyno are about as good as
betting that monkey's will be flying out of my ass. (Not impossible, but
highly unlikely...)
I have no idea what kind of HP it makes... it's a 948, I'm running 12.7:1,
on a head that I'd always thought was an ancient Comptune head.. (but Dave
Tabor looked at it and said it wasn't anything his father had done based on
the numbers stamped in it) with ARP studs. Flat top AE Heppolite pistons
(also suitable for refrigerators according to the documentation), stock rods
that were reconditioned and shot peened. The crank was Nitrided years ago...
(each time the machinist and I debate whether we can get by with a
polish...). The block has a center main strap, a rear oil seal kit, running
a stock clutch and a stock (not even straight cut gears) ribcase. The cam is
an Elgin grind (with a vernier gear) that I chose based on the power band,
and my attempt to get the torque in the most usable RPM range for maximum
exit speed based on a 7500 rev limit. It turned out to be a great choice...
I can supply the number for anyone of you if you'd like). As I said earlier,
the distributor is stock. The carbs are a spare set Jim "Elmo Mancini"
Donato had in his parts tub.
I may go 2 years without adjusting the mixture on the carb, checking the
points, plugs, or timing.
The problem I had as Mosport... a high end miss, was definately "weak spark"
related, as we weren't getting enough juice from the utility pole with 20
racers all plugged in at the same time to get a good charge out of the
battery charger.
I don't think Tom Colby ran an alternator on his stinkingly fast 1380cc
Speedwell beast. He also used a garden tractor battery. I know he wasn't
spending the $9k per motor that Dr. J does (150HP), but I'm sure he was
revving it pretty good. This is a pretty interesting subject.
Since monkey's are not likely to fly out of my ass real soon, maybe in the
spring I'll try some tests with and without an alternator, and time the car
between markers at Road America. Thanks to "Dr. Dreadful, I've got a little
two timer stopwatch on the dash that should allow me to set up some timed
runs.
WST
Flounder
Team Thicko
----- Original Message -----
From: <Daniel1312@aol.com>
To: <mikeg@vicnet.net.au>; <wsthompson@thicko.com>;
<team-thicko@autox.team.net>; <spridgets@autox.team.net>
Sent: Wednesday, October 06, 1999 1:59 PM
Subject: Re: What I've been up to...
> I'm with Mike on this one and there are two points here.
>
> Firstly the total current draw from either an alternator or dynamo is
getting
> on for 2 horsepower and I know DV's book says something else but I checked
> this point with Lucas some time ago.
>
> Without a charging system the engine MAY/CAN produce less power because
the
> ignition system produces a weaker spark.
>
> It is possible that the loss in spark energy and thus power can more than
> offset the gain in not running any kind of generator.
>
> For my own car I had problem (in fact lots) with a highish rpm misfire
that
> was worse under load - turned out this part of the problem was due to the
> alternator lead coming unplugged.
>
> Finally I would not argue with anyone who is running with lots of power
and
> no misfire (ignition systems can vary in demand, as can batteries). I have
> seen 150+bhp A-Series engines on the dyno with my own eyes and four people
> sitting/pushing on the car to prevent wheelspin on the rollers and NO
> alternator or dynamo. What I would say is: Have you done back to back
tests
> on the dyno to see if you get MORE power with an alternator/dynamo fitted.
>
> Last point running an alternator unplugged can permanently damage it, so
it
> would need to be removed from the engine for the testing.
>
>
> Daniel1312
>
>
>
> In a message dated 06/10/99 03:47:41 GMT Daylight Time,
mikeg@vicnet.net.au
> writes:
>
> << Well, all I can report is that I got the same story from everyone,
> including
> one race engine builder in Sydney who said that he has had a car on the
> rolling road and it dropped > 5HP just by pulling off the alternator lead
> and
> popped straight back up when reconnected. this was at 7200 rpm.
>
> Compared to when it was running smoothly, the engine felt fluffy and down
> on power at high revs. It wasn't like an audible misfire.
>
> Over here, no-one runs without an alternator. If the current drain isn't
> big, the
> losses are very small.
>
> My old engine builder also gave me the same advice independently. he said
> it was a sure way to lose HP.
>
> Anyhow, when this engine gets fixed, I'm back on the rolling road. I'll
do
> the experiment myself and report the results!!!! We'll then know if it is
a
> folk tale
> or real.
>
>
> Mike
> >>
>
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