Anyone pull one of these? (longish)

[Andy B]

I thought I share a story and perhaps you can have a laugh on me.
It started about a month after I bought the Seven, after a stop at lights etc. the car was venting steam through the hood louvres. It took a few tries of pulling over and quickly removing the hood but eventually I noticed the plastic coolant recovery tank had finally given way to the heat from the headers and and a small hole had burned through just above the hot coolant mark. When I stopped quickly it would squirt through the hole onto the headers and vaporize quickly. BTW this car runs a zero pressure coolant recovery system employing Propylene Glycol.
Simple fix, buy a universal plastic tank and install it complete with a heat proof wrap.
All was well for about a week until I attempted a 4 hour highway drive (Prescot/Manotic area Wayne). I was 3 hours into the return trip when at 5.30 pm on a busy Friday afternoon in the passing lane those hood louvres worked overtime for about ten seconds spraying the windshield with thickish red propylene glycol which at first I thought was oil. Another good reason not to have Broolands type wind shields. I managed to get safely to the right lane shoulder to discover the short top rad hose had split. After getting the car home on a flatbed (it's self another story) I proceeded to find a hose and install it.
The very next drive saw one end of the hose come adrift. Gees I obviously did not tighten it sufficiently so I double clamped it. For another 2 weeks I drove the car but was puzzled as to why the level in the recovery tank never seemed to move, I was getting a fizzing sound and the hoses appeared "bloated" when the engine was hot. Although it always remained around the 70 to 75 c range.
I asked several people and they all suggested I might have a faulty head gasket, not what I wanted to hear. Also why would a zero pressure system that vents to the atmosphere become pressurized?
I removed the small dia. hoses running to and from the recovery system and bypass but none were either kinked or collapsed. I had already checked the hose on the tank when I replaced it. The last item to check was the dryer. A small copper tube that is supposed to remove the dreaded H2o from the cooling system. Propylene Glycol is used non-diluted.
Perhaps it was blocked, no it was not blocked but some silly notion had me blow down the hose leading to the NEW recovery tank. Blocked solid ... but I had already check the hose. Well it appears on a new recovery tank they don't drill the in/out spout all the way through to the inner tank so when I installed it I had basically sealed my system.
10 seconds with a 5/16 drill and my baby was fixed.:thumbup:
All's well that ends well and the blush has just about left my face:blushing:

[USAndretti42]

Pardon my ignorance but why do you not want water in your cooling system?

[Andy B]

Although it was not my initial choice, the car was already running the Non-Aqueous Propylene Glycol when I made the purchase.
Having said that it does have 2 maybe 3 advantages over a conventional system.
1. Containing no water it is just about corrosion free and good for life. (It's been in the Twi Cam since 93.)
2. It has a heat range of -41 f to +375 f at ZERO pressure and no I don't want my engine running at 375 f.
3. Puppies and infants can drink it or so the story goes.:thumbup:

Cons
You have to use a special flush if converting from a conventional system to clean out any water and coolant.
It cost close to $40 a gallon in Canada.

It's primary use has been in racing engines.

[WayneB]

Hmmm, I have never used that stuff in any of the racing cars I work on (all pre 1982), and in fact just use straight distilled water (sometimes bung in some Redline water wetter)

A common codge years ago was to fill the cooling system of a car (that had a blown head gasket) with thin oil (leaving the cap backed off so the system doesnt pressurise), any oil that gets into the cylinders is just burnt, enabling you to carry on driving the car until it blows up!:lol:

Apparently after WWII in Canada, ethlene glycol was in short supply and mega expensive so people would use stove oil as an anti-freeze in the winter.

As for newer cars, Texaco Dex Cool is the new accepted cooling medium, but its not advisable to use it on older stuff with copper radiators or heater matrixes as ingredients in it react with the solder that holds them together and causes leaks.

As for your Propylene Glycol system, it sounds interesting (but expensive).

Maybe Trever Knowles (US Andretti 42)can fill us in on its use in Modern Racing Cars, and its pros/cons?:huh:

[Andy B]

Here's a link (http://www.evanscooling.com/index2.html) for those interested. Click on any of the NPG areas.

[WayneB]

Thanks for the link Andy, I had heard of Evans , but hadnt really gone into it before.

What temp does your 7 normally run at using this stuff Andy?

Are you still using a thermostat?

[Andy B]

According to the previous owner yes it does have a thermostat.
Generally it runs at 70-75 c but in heavy traffic on a hot day it will hit 80+ c.
The rad has been upgraded although it does have an oil cooler in front of it.
The electric fan fills the rad top to bottom and out to the sides, it also has the manual over ride switch.

[USAndretti42]

As for your Propylene Glycol system, it sounds interesting (but expensive).

Maybe Trever Knowles (US Andretti 42)can fill us in on its use in Modern Racing Cars, and its pros/cons?:huh:

Every engine I have worked on has used water with maybe a lubricant or corrosion inhibitor. That includes F1, Touring Cars, CART, IRL, ALMS and NASCAR. Water has a few advantages. It's practical. If you fly your cars overseas you don't need to ship a load of coolant. It has a very high latent heat of vaporization. So, if it boils, it takes a lot of heat out of the system. Thus you can let the water boil near, say, an exhaust valve seat and condense it once it's moved away. For that to work you need a pressurized cooling system. Too much boiling and you get an insulating layer of steam next to whatever's hot and that would not be good. Even without boiling it has a high specific heat which helps to remove heat.

For racing it also has the advantage that it is easy to clean up after an accident. That is why anti-freeze is not used as it's so greasy. It would be like oiling down the track.

[WayneB]

Thanks Trev, thats the same as I'm doing up here ATM.

I am a bit concerned that Andy is overcooling his 7, I have always tried to keep coolant temps at a constant 90 degree c (195 /200 degree farenheight), so as not to overcool the engine (not allowing all the clearances to fully expand , and getting the thermall efficiency where it needs to be) Having a cold running engine would mean a richer jet setting or longer injector pulse leading to more fuel consumption and possibly oil dilution /increased wear (bore wash?)

I would be blanking part of the rad at least to get it running a bit hotter.

Any other thoughts on this?:huh: