Mustang MonthlyHow To Tech Qa
Correct-Looking Aluminum and more Vintage Mustang Tech Questions and Answers
Beyond the Basics
For years I have been searching for a really good coating for protecting aluminum intake manifolds, and I think I have finally found one that doesn’t look like the intake has been coated. Spray paint aluminum looks awful, clear powder and sprays look awful right after the engine has heat cycled, and powdercoats are often too bright and stand out way too much.
As you know, aluminum is very porous, and the first time you touch it with a greasy finger you are done. Likewise, gas drips stain and saturate the metal and do not come off. There used to be clear sealers, but they needed refurbishing every couple of years.
I recently visited Pro-Kote Indy [(317) 872-0001; prokoteindy.com] and finally found a bare aluminum powder that looks like, well, bare aluminum—not a bicycle reflector. It is a proprietary color used in the aerospace industry so they can’t give out the code (or so they say), but it really is the closest I have come to real replication of aluminum intakes. It is an epoxy hybrid powder, which means it has higher-temp resistance, and it has a slightly coarse finish that actually replicates the as-cast look. The hybrid powder also allows for better color over straight epoxies. I have seen major suppliers’ “aluminum” powders, and they don’t get it right; they look like the manifold has been painted. This one gets it right. I could see this being used for all manner of aluminum engine and drivetrain parts for that as-new and correct finish for your restoration. Another great tech tip from your Uncle Dave.
Just What Is This?
What is this thing hanging out of the driver side of my 1970 Mustang? It looks like a big transistor. Photo attached to show what I’m talking about.
Robert & Travis E.
San Antonio, Texas
That is a temperature sensor, and it is used on 1970-1971 Mustangs as part of the Distributor Modulator system. It was used on 250 inline-sixes, 302s, and 351s. Remember 351s didn’t have a smog pump, and this may be one of the reasons. The temperature sensor is mounted to the outside to measure ambient temperature to switch on and off the control circuits to the modulator, which is mounted up and under your dash by the fuse box and the e-brake. When the ambient temperature gets to about 58 degrees, the switch closes and turns on the box. There are two vacuum hoses connected to the box—one runs to venturi vacuum (that controls your distributor advance) and one runs to the advance itself. When you reduce the timing advance, the burn is much hotter and this burns more hydrocarbons and provides a cleaner exhaust. There is a third component, which is a speed monitor that is inline with the speedometer cable. This is used to signal the modulator to work at speeds above 23 mph. The Modulator controls were also used on some cars that came with throttle modulation.