DeTomaso Mailing List: June 2001, Message #140

Adam Goldman brought his Dayton motor to the HB Concours to give to me to
evaluate. He had been unable to get it to fit in his car. I was also
interested in it's possible use for the windows. I tinkered with it a bit
last night. Here's what I found.

First, I was interested in it's torque: is it stronger than the stock motor
(especially when stalled)? The short answer is maybe a little. My
measurement system is a little crude. I clamped a 10" crescent wrench to
the flat on the shaft and added weight to the end until the motor wouldn't
turn it over. By that test, the Dayton was maybe 10-20% stronger. Remember
this is a new motor vs a 30+ year old motor. The Dayton was also smoother.
The original motor had a coggy feel, perhaps because of worn brushes or
armature, but maybe not as the permanent magnates give it a coggy feel even
with no power applied. This is only important when the motor is stalled and
trying to overcome the initial friction. If your headlights or windows are
working right this shouldn't matter. Also, the Dayton seemed to use much
less power. It's rated at 3.75 amps. I didn't measure the original motor,
but it's considerably more than this. Finally, the Dayton is considerably
noisier (I didn't think that was possible!) at least when running full
speed. It had a louder and higher pitched wine. Not a problem for
headlights, but might be for the windows.

As previously reported, it's much larger in diameter: 3.25" vs about 2" but
a little shorter. Also, not reported, the shaft is 1/4" vs about 5/16"
(probably 8mm), and somewhat longer. Adam had gotten a coupler with it, but
it's not at all clear how it would be used. The stock coupler is a rubber
unit that matches the shafts on the motor and gear box. This was solid
steel with a set screw for the motor and two prongs sticking out the other
end. I suppose if you had a matching piece for the gear box, they would
interlock and form a crude universal. If I were to use it. I'd get some
5/16" OD thin walled tubing (hobby shops sell this stuff and you can
probably find it at Home Depot, etc.) and epoxy it to the shaft, cut the
shaft to length, and file to extend the flat if needed so that it fits the
stock coupler. Also not previously mentioned is that the motor is not
sealed. The stock motor has some form of plastic overcoat. I'd think, but
don't know, that this might be important, at least for the headlight motor.

Next, I tried to fit it in the headlight motor position. The mounting studs
are about 1/16" wider, but that's probably not a problem. The 3.25"
diameter is. There is a hole in the bulkhead between the radiator area and
the headlight area where the motor is meant to fit. It doesn't stick all
the way through, but part of it does. I don't have my headlight motor
assembly bracket installed yet, but when I placed the motor in the
approximate position, it was clear that it would not fit in my car without
enlarging the hole by at least 1/2", probably more. This could probably be
done with ViceGrips fairly easily, but it wouldn't be pretty. An
alternative might be to have the motor mounted at a slight angle. I can't
see this working with the standard coupler, but might work with a pair of
the solid couplers. The solid coupler however had a shaft hole larger than
the shaft so when attached to the motor would be off center. The gear box
has a smaller shaft and would be even more off center if the same coupler
were used on it. I can't see this working well, especially if missaligned.
Bottom line, I would not recommend mounting the motor in a tilted position.

I looked briefly to see how the motor would fit for window use. My original
units are already installed so I just eyeballed it. Again, the
coupler/shaft would have the same problems and you might want to seal it.
Other than that, it looked like the needed extra 5/8" clearance around the
motor is available, so it should fit. My guess is that it would work about
the same as a 30 year old stock motor. It might go a little faster and
would probably be noisier.

Bottom line. This motor can certainly be made to work and the price (about
$25) is certainly right. I would adapt it to the stock coupler, not use the
solid coupler. I don't need or plan to use it now, but will keep it in mind
for the future. It appears not to be made for automotive applications and I
have questions about it's durability in a car, but it appears to be working
for Jim Demick, at least for 4 years.

Richard Barkley