“I can’t envision what 12 measly degrees will mean to your driving experience. Can’t you simply slow down on that hill and accomplish the same thing?”
Bill[/QUOTE]
Bill,
I am no expert ...just someone who drives his Model A's a fair amount. To help you envision what 12 degrees means to my driving experience, I respectfully offer the following:
I have a stock '28 pickup with an open system that I rarely drive over 55 mph. It works fine. On the days it gets over 100 degrees, I do just as you suggest on the long hills. I slow down.
IMO: If you have a stock engine you do not need a sealed system.
I also have a '29 Phaeton with a fully inserted touring engine, mildly ported, touring cam, 5.9 Brumfield head and a few other modifications to produce a little more power. With more power comes more heat. I often drive this car on a freeway in the slow lane. To be safe on a freeway, in my opinion, I need to be moving close to the speed of the traffic. An open system will not work as I choose to drive when the outdoor temps are approaching 100 degrees. I know as I tried it with an open system. I have driven this car with a sealed 4# system for over 90k miles and the cooling system has never boiled over or even needed coolant added during long road trips. Bill, During the summer of 2013, we traveled from east of Albuquerque (where you are from) to Needles, Calif. and when we arrived at Needles at 11:00 am, it was 118 degrees when parked on the blacktop of the motel. My wife and I both overheated that day but our car did not.
I am currently building and testing a '31 Slant Windshield Town Sedan for long trip touring. I plan to pull a camper designed to look like an era correct teardrop. I have installed a Ken Davis air conditioning system (AC) in this car because my wife is on a medication that makes her ill if the air temps are over 90 degrees. I also chose to use an overhead valve head that puts out more horsepower (and heat). With the AC load and outdoor temps over 100, a standard system will not work in this car. I ran it this past summer with a zero pressure cap and we needed to avoid driving when it was much over 90 degrees. When I was doing early testing, the 4# cap allowed the car to operate in 100 degree temps.
Yes, I could choose to slow down on that hill, stay off the freeways and avoid driving when it is over 90 degrees and accomplish the same thing but I choose not to.
I know this site is dedicated to maintaining the originality of our cars and therefor many passionately consider straying from original as disrespectful or wrong. I get it and respect that opinion. Off this site it’s a hobby and we all get to choose what we do with our cars. Don asked the question and some of us tried to address his question without regard for whether it should have or should not have been asked on this forum.
I should add a couple comments: No Model A's were harmed in building my two modified "A's"! Every part I replaced with a modified one was saved in the event that the next owner of my current cars wanted to return them to stock condition. I have two organized collections of parts ready to be passed on.
I build engines for myself and others. I am often asked to build an engine with a little more power than stock. My dabbling in performance engines for myself is a means of testing engine modifications before I offer them to customers. What is most important to me when building and using these engines is durability and performance.
Good Day!
Dave Gerold
www.durableperformance.net