David Stribling
February 17, 2014

Rim Blow Wheel Differences

I’m putting the finishing touches on my ’69 Mach 1 restoration. I purchased a used Mustang three-spoke steering wheel with rim blow horn but I’m having trouble identifying what piece(s) I’m missing for the turn signal cancel mechanism. I took the three-spoke rim blow steering wheel off of my ’69 Shelby, hoping I would be able to determine what I needed, but the two are different. See the photos I supplied. What piece(s) do I need for the Mach 1 and any ideas as to where to get them? I have looked at a few different Mustang parts on-line catalogs without success.

1. Steering column of Mach 1: note position of horn blow copper connectors compared to the Shelby and there is a collar around the shaft with a small pin (at the 4:30 position in the photo).
2. Steering column of Shelby
3. Steering wheels; the one on the left is from the Shelby. Signal cancelation and horn work correctly.

Thanks for your help.

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Eddie Sandboe
Grande Prairie, Alberta, Canada

You should have everything you need. One of the problems is your ’69 Shelby has a factory tilt column, which used a different turn signal switch and an external cam to cancel out the turn signal. If you look closely at the picture of your Mach I non-tilt, that small ring around the shaft that you noted is not on the tilt column (arrows). This, along with the plastic groove between the two horn contact rings cancels out your turn signal. Because of the tilt mechanism, Ford needed to rearrange the switch a bit and add the external cam. You should be able to put your steering wheel on and the turn signal system should work correctly. I just went and confirmed it on my Mach I. Good luck!

Getting’ Chilly With It

I’m a long-time reader of MM&F and absolutely love the mag. I have a heating/cooling question that I hope you can answer for me. I drive a ’79 F-100 that I installed an ’87 Mustang 5.0L HO engine and Tremec 3550 five-speed into. The combo consists of an iron block and heads, a mild Trick Flow roller cam, an Edelbrock aluminum intake with a 600-cfm Holley carb, full length headers with 3-inch exhaust and Flowmaster mufflers, and an MSD ignition. I have a 9-inch rear with a Detroit Truetrac and 4.11 gears. It uses a factory (old style) water pump, new molded cooling hoses and a 190-degree thermostat. The radiator is the factory heavy-duty unit (3-row core) for air conditioning (which my truck has). My problem isn’t with it staying cool, but rather it won’t get up to normal operating temps when the ambient temp is below 40, so the heater doesn’t work well.

I live in St. Louis, so the heater is important. The heater core and hoses are all new, as is the electric fan and thermostat, and there are no obstacles that would block normal flow through the core. My question is, could I have too much radiator? The cooling fan never comes on during these winter temps. I currently have cardboard completely blocking the radiator and it still doesn’t help. Will a regular duty radiator (two-row core) help and will I have overheating problems in the summer with the air on? My truck is an absolute blast to drive, if you dress warm enough!

Joe Clinton
St. Louis, Mo.

Thanks for the kind words on the magazine. As far as your cooling problem—it is possible to overcool an engine. However, before you go downgrading your radiator, we need to check some things first. The two likely culprits are a stuck thermostat and running the mixture in the carburetor too rich. Both will cool the engine. Where the thermostat may open and stay open during real hot days, in the cooler seasons it may be opening and closing depending on engine load and rpm. If it is stuck open all the time, and not closing it is not allowing the engine to heat up after that initial shock of cool water from the radiator when it does open. Check these items first:

1. With the engine dead cold, remove the radiator cap (if you can—’79 should be a top fill) and start the engine and see if you see coolant flow when the engine first fires. If you see coolant flow your thermostat is stuck open all the time. Change it.
2. Put an actual temp gauge on the engine and see if it is even getting up to 190. They can be purchased fairly cheap at any auto parts store. Watch as it reaches 190 and see if the thermostat is opening too soon. Once it does open up, watch what the temperature does—is it fluctuating and eventually settling around 205-210? That’s where you want it to be.
3. There is still a possibility that the engine temp is fine, and you have an air pocket in the engine preventing coolant from passing through the heater core. If you can place your hand on the valve cover and keep it there, the engine is not getting up to temperature. If you can’t, you have a blockage in the engine somewhere preventing the full flow of coolant to the heater core.
4. A rich running engine can cause it to run cooler. I doubt this is your problem, but you may want to double check your mixture on the Holley.
5. I assume your ’79 was originally a 302 small-block and not a 460 big-block? In that case, yeah, you may want to reduce the size of your radiator.
6. I’d go ahead and put a 195-degree thermostat in it, since it is carbureted.

I have had brand-new thermostats fail out of the box before. Normally, they fail in the closed position, but it does happen that they fail in the open position. If it is working properly, it should be opening and closing until the engine and radiator have evened themselves up, then stay open. Check those out and get back with us.

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