Overheating Tiger

Sownman · Post by **Sownman** » Fri Jul 03, 2009 9:31 pm

One other solution is to make pieces (heavy low flex rubber or sheet metal)that cover the excess opening space around the horn openings. They allow a lot of air to enter the engine compartment without passing through the radiator. This builds up air pressure in the compartment which further inhibits air from entering through the radiator so it can cool.

Steve R

JAYANDSHEL · Post by **JAYANDSHEL** » Fri Jul 03, 2009 10:05 pm

Great minds steve

Have already made cardboard templates

Jay

gtsmrt · Post by **gtsmrt** » Sat Jul 04, 2009 9:14 am

Hi Jay,

Sometimes things just don't go our way with our Tiger's as I found out earlier this week, but that's another story

. I think you are taking the right steps with your Tiger. Once you have sorted out all of the obvious causes, then go on to the modifications as described by the other members. You may find that you don't need to worry. What temperatures have you been experiencing up there?

Regards, Robin.

JAYANDSHEL · Post by **JAYANDSHEL** » Sun Jul 05, 2009 1:47 pm

Hi Robin

Air temp aound 25 26 degrees cars gauge says about 190 running around 75mph
Came back from Goodwood festival of speed last night and pulled car half way in garage and with electric fan on for about 10 mins the temp stayed at 200 it would not go down, no water came out and when I turned car off again no water came out but I could here bubling water in rad and header tank.

Jay

V Mad · Post by **V Mad** » Mon Jul 06, 2009 10:55 pm

Jay, 200F is not too bad (about 93C), well below boiling point; even without the 13lb pressure boost, the coolant should not boil. The noises are probably just gurgling as the water moves around.

Mine runs at just under 90C most times now, although it went to just over 90C after a 'very fast' run on Sunday. If I use the electric fan, it drops a few degress further within minutes.

If you are still unsure which way your fan blows you really need to get that sorted, as it is easy and only takes a few seconds to check.

gtsmrt · Post by **gtsmrt** » Tue Jul 07, 2009 9:21 am

Hi Jay,

The easiest test to check your electrical is to hold a sheet of paper in front of it. It will soon tell you which way it blows. A lot ot the electric fans are also reversible by reversing the polarity of the motor (swap the two wires over).

Regards, Robin.

JAYANDSHEL · Post by **JAYANDSHEL** » Tue Jul 07, 2009 4:41 pm

The electric fan is a puller that the previous owner wired back to front to give the impression that it was blowing through the rad, just reversing the polarity is not enough the pitch of the blades needs to be correct. I know some fans can have the blades reversred to be either puller or pusher but this can not.
Have sorced a pusher fan but means have to take out rad again and make up more brackets for the replacement fan

Will have a go this Sunday.

JAYANDSHEL · Post by **JAYANDSHEL** » Fri Jul 24, 2009 2:01 pm

Update 24/07/09
Decided that while I was going to take rad out again to make new fan brackets, I might as wel get the rad recored. Had thought about ally rad but did not want to block it with rust from a 40 year old engine.
Have just come back from a fast run with my new refurbed cooling system.
Early CONCULSIONS

1 The temp gauge has been lieing to me the whole time. Believe it is nearly reading 30 degress F under what the water actually is, hence the bubling header tank at 200 was in fact more like 230, temp gauge now reads 145 even under spirited driving conditions

2 If you want your tiger to stay cool every thing in the cooling system needs to be in first class order, any part that starts to wear will put it over the edge.

This was only my first run out and further testing will be done (autosolo at north weald on Sunday) but signs are looking good

gtsmrt · Post by **gtsmrt** » Sun Jul 26, 2009 1:02 am

Hi Jay,

You are absolutely correct. As we all know, in our Tiger's there is a great big lump of V8 iron in a very little space with little ventilation. As you found out, everything is the cooling system has to be top notch or they will overheat. Great to hear that you have sorted out the issue and you did not spend money for no reason.

Regards, Robin.

STEWART · Post by **STEWART** » Wed Aug 12, 2009 10:06 pm

After carrying out a total engine rebuild last year I decided to upgrade the cooling system. I Have fitted an aluminium radiator and header tank, a thermostat controlled 16" Pacet (blower) electric fan with override switch and warning light (just in case) and have removed the mechanical fan. The temperature gauge reads between 90/95 degrees all the time regardless of speed or ambient temperature. The fan cuts in and out as required.
Thought this might add another perspective on this subject.

Stewart.

gtsmrt · Post by **gtsmrt** » Thu Aug 13, 2009 12:15 pm

Hi Stewart,

How did you fit a 16" fan in that space?

. Did you block the horn holes, etc?

Regards, Robin.

STEWART · Post by **STEWART** » Thu Aug 13, 2009 9:07 pm

Hi Robin, I fitted the fan up to the top of the inner front panel, I cut back the starting handle channel and removed the bottom bar its fitted to. I dropped the fan through the gap, it just fits and covers the radiator's height. I fabricated the brackets and fitted them to the 4 spare tapped bosses in the front panel, these are adjacent to the radiator fixing bosses.
I have not covered the horn apertures, the results are fine so will not bother,

Stewart.

JAYANDSHEL · Post by **JAYANDSHEL** » Tue Sep 15, 2009 6:32 pm

Just thought I would update this thread a little.

Took the car to the national assoc street clubs (Hot Rods and Customs) weekend event in suffolk over the Bank Holiday weekend in August. One of the organized events is a cruise that takes place on Saturday afternoon.
This cruise involves some 600 cars driving out of a show ground at 12 o clock then crawl down to a round a bout nose to tail at 5 mph for 2 miles then get onto the A 14 drive at 100mph surrounded by v8 Hot Rods with open header exhausts for 5 miles then crawl again nose to tail for 3 to 4 miles to line the said 600 cars along the prom down at felixstowe sea front. Saturday was a nice hot day as well and the Tiger was able to handle this with no problems what so ever.

Conclusions I have drawn from our over heating experience are:

1 If the entire cooling system is A1 Tigers do not overheat

2 Check and recheck other peoples work it can lead you astray

3As ODL21 says temp gauges can give you misleading info causing you to chase the wrong things use an external temp gauge of known quantity

4 In our case and only this set of circumstances the biggest contributing factor IMO was, the Radiator was in need of a recore (should have taken note of Vmad as this was his diag)

So all in all at very satisfactory outcome

Hope this tread may help someone in the future to cure their overheating woes

Jay

Tomaselli · Post by **Tomaselli** » Tue Sep 15, 2009 10:09 pm

Anything you can do to keep Tigers cool helps and have never thought of blanking the horn apertures before but that clearly makes sense as you try to "funnel" air through the radiator.

These have appeared on eBay on look a neat way of blanking them aperture openings on the front panel.