I agree with Barney's statements concerning cruise controls with
4 bangers (vacuum limitatons) except for the statement concerning
not using the magnets. According to most instruction sheets, yes this
is possible, but not advisable with a clutch. Any slippage would result in
the
cruise control erraticly trying to control speed, possibly surging or
completely
dropping out. Using the magnets on the driveshaft, picks
up a much more consistant speed sense, and eliminates the extra wiring
and circuits (inside the cruise control) that would add an electrical load
to the
to the coil circuit. In some cases it's also been known to interfer with
proper tachometer
operation.
The magnets are easy to mount, and the trans. rear mount is a perfect plale
to mount the
brakets, placing the sensor safely just ahead of the driveshaft u-joint.
I guess that's another photo worth placing on my web site. (The controls on
the
turn signal lever and the magnet and sensor mounts.)
Paul Tegler
Twin 73' MGB GTs YB and OB
YB born 8/72 (Primrose Yellow) Yellow BGT
OB born 1/73 (Blaze Red) Orange BGT
email: wizardz@amdyne.net
http://www.amdyne.net/~ptegler/mgmain.htm
-----Original Message-----
From: Barney Gaylord <barneymg@ntsource.com>
To: Rick Roberts <rrobertsmg@hotmail.com>
Cc: mgs@autox.team.net <mgs@autox.team.net>
Date: Friday, March 05, 1999 12:11 PM
Subject: Re: Cruise Control
>At 10:07 AM 3/5/99 EST, Rick Roberts wrote:
>
>>A few months back some folks were talking about successful ventures with
>certain types of cruise controls. (prop shaft magnet types) Might anyone
>recall the types recommended? I remember maybe AudioVox form PEP BOYS or
>JC Whitney's??
>
>The cheap generic cruise controls work. And you don't need the magnets.
>If you have a manual transmission the speed pickup can be one wire to the
>ignition coil.
>
>One word of warning though. Most of the aftermarket cruise controls these
>days are vacuum operated with electronic controls. The vacuum diaphrams
>are rather small and have some difficulty working properly with four
>cylinder engines under moderate to heavy load conditions. At more than
>half throttle there's insufficient vacuum to operate the servo.
>Recommendation is to include a vacuum reservoir about the size of a
>grapefruit to get the thing through short intervals of hill pulling. If
>you're going to be doing long hauls up mountains, all bets are off.
>
>OTOH, someone now makes an all electric cruise control with a stepper motor
>for the servo. These are somewhat more expensive, but should work well
>with small engines. At the moment I have no clue as to where you might buy
>one, haven't been looking lately. If you go that route, ley me know how it
>works out.
>
>Regards,
>
>Barney Gaylord
>1958 MGA with an attitude
> http://www.ntsource.com/~barneymg
>
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