Over Heating or Rad Cap?

T

Tucker

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Greetings Gentlemen from Vancouver B.C. !

I am recently a new club member as well as a tiger owner….a 1966 MK 1A …and quickly learning about all the little nuances associated with the Tiger ☺ I have a question I hope some of you may assist me with. Yesterday, while enjoying an afternoon drive (sun was shining and 85 degrees) I got stuck in traffic …start…stop …stop and my temp started to rise quickly (205). Once back on the go things settled back down to 190. However, as I got closer to home, I again got stuck in traffic and the temp quickly started to rise and this time stayed there (210). By the time I pulled into my garage the temp was approaching 220. When I turned off the engine she emptied the expansion tank on my garage floor ☹. I am unsure if the car overheated or perhaps my rad cap is faulty or insufficient. I check my cap and it states 7 LBS. Is this sufficient or does the system require a higher pressure release cap? If so, what cap (lbs) is appropriate? Any feedback would be greatly appreciated.
 
The stock heater core won't take much more pressure than that before the ends start bulging. I run a 15 lb cap without the heater core...the rest of the system is fine with a 15 lb cap.
 
Formula

Please feel free to correct the high school auto shop memory here but, for every pound of pressure of cap add 3 degrees to boiling temp.

Trying a 16 lb cap may indeed blow the sides out of the heater core which adds good cooling area to the system if you turn it on when it is getting too hot. I think most bulge as result of a 16 lb cap and being plugged.

I think I have a 7 lb or so and a rod cleaned 3 row radiator and heater core Gano filter. Got my horn holes blocked stock fan shroud and do not see the problem. I would like to shoot it with a whiz bang Infared or whatever temp gauge rather than believing the stock gauge or my pocket gague . I must drive like the little ol lady from Pasadena with exception of a squealing corner or two
 
RE hot Tiger

I've been through the hot Tiger syndrome to some extent and agree with not over pressurizing the system with a heavy cap. Lots of good info on keeping Tigers cool out there but I found my gauge to be off a tad. A digital thermometer will help determine that your gauge is reading close to true. If I put a tad too much water/coolant in my overflow tank it will pee some out after a drive. Level seems to prefer being kept just below the add coolant level shown in tank. Once it does blow the excess out it won't generally do it again. My car (67 MKII with 289 stock engine) will hit about 210F under similar circumstances to yours. Installing a stock 6 blade LAT fan brought my temps down about 5-7 degrees overall and pretty much puts my car in the safe zone at least for the way I drive it. Mine tends to see pretty light useage however and I usually avoid serious traffic!

Dave Gilmore
Leawood, Ks
 
At best these cars ran a bit hot right out of the box new and age is not a good friend either. You might tell us more about your car and what has been done to it that you know about. You might first check your timing since a retarded motor will run HOT and you should have 32/33 degrees total timing

I can tell you what I did to make my car run cool all of the time and it was no small feat or cheap. The first thing I did was removed the stock radiator and replaced it with a new Griffin 4 row aluminum radiator and that made a huge difference but I still had a stock fan and water pump along with an unknown
289. I found that the 289 had been bored .040" over when it was rebuilt which was the kiss of death for that motor. These thin wall block should never
be bored more than .030 since the cylindar wall gets to thin and you get an increased heat transfer. A poorly maintained cooling system will have a ton of rust which will also give you the same result as a reduced cylinder wall thickness. I my case I built a new 302 motor using a clean std bore block
going only .020" overbore. I used the new Edelbrock high volume water pump
with the stock shroud and blade. The heater core was rebuilt and static tested
at 14 lbs along with the overflow tank. I use a 14lb cap and have thrown away my horn gap covers in favor of a vented hood. The car now runs at 180 no matter what the outsde temperature.....as you might guess there is no easy answer to overheating with these cars....

Moondoggie
 
First, do no harm !

If you haven't already done this: Pull the lower hose and drain the coolant. While the motor is cool, add 2 gallons of white vinegar and top it off. Drive a few miles until warm and then drop the big chunks out of the system. You may see some ugly brown and black sludge flush out that has been hiding for years. This is the poor man's method for clearing a marginal sysyem. Sometimes once is not enough (she said). Then you can pursue other options if the malady continues.
 
TIGER INCONTINENCE

AS A POINT OF REFERENCE: GO TO TIGERS /ALPINES EAST WEBSITE FOR TIGER TOM AND OTHERS STUDIES ON COOLING HOT TIGERS.
Tiger cooling is lacking in airflow department especilly in stop and go traffic. When you turn the engine off heat and pressure elevates and the little bugger pees antifreeze all over your driveway. My Tiger's incontenence prroblem was resolved with an electric pusher fan with themostat ( from JEGGs $50 bucks).
 
chirodoc said:
AS A POINT OF REFERENCE: GO TO TIGERS /ALPINES EAST WEBSITE FOR TIGER TOM AND OTHERS STUDIES ON COOLING HOT TIGERS.
Tiger cooling is lacking in airflow department especilly in stop and go traffic. When you turn the engine off heat and pressure elevates and the little bugger pees antifreeze all over your driveway. My Tiger's incontenence prroblem was resolved with an electric pusher fan with themostat ( from JEGGs $50 bucks).
Click to expand...

At least give the poor guy a fighting chance with a link...

http://teae.org/cooling-the-tiger/

good article but there is no one simple fix it really depends on what you have
that makes up your system

Moondoggie
 
knowledge in key.......

Thanks guys for all your input! The Tiger/ Alpine East - Cooling the Tiger article is very informative! Additionally, I did not think to check the accuracy of the temp gauge. I will get an infrared temp gun tomorrow…..
Moondoggie – sorry, I should have given a little more background….My tiger has a crate 302, newer aluminum rad, horn holes still open, no shroud, 13-inch fan, LAT hood and I believe the original water pump. Given what I have just read in the aforementioned article…..I have much room for improvement!
One of Five – I was contemplating flushing the system. Never thought of Vinegar! Will give it a go and see what’s been lurking in the system. I currently do not have a coolant filter inline….is it necessary to have one prior to performing the vinegar flush?

Many thanks !
Tucker
 
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