Overheating Tiger

JAYANDSHEL · Post by **JAYANDSHEL** » Sat Jun 13, 2009 4:01 pm

Today had our first experience of a overheated tiger

Noticed the temp climbing slowly everytime we got into a little traffic once moving again the temp stopped climbing but did not go down this happened a few times untill the the rad cap said enough and it spat its dummy out along with a few pints of water, up untill now our car had not been getting hot and I thought the horror stories about Tigers getting hot was a bit over stated but now we know its true. On the positive side we have standard 4 blade fan no shroud around fan original rad (no ally rad)very old electric and a std bonnet (no LAT bonnet) so lots of things to change.

Is there one single thing of the above that makes the most diference ie what to buy first, would like all of the above but funds do not allow.

Jay

Tomaselli · Post by **Tomaselli** » Sat Jun 13, 2009 6:44 pm

We have all been there

In order, bearing in mind associated costs, I would certainly consider;

1) Check fuel/air mixture/timing, a rich mixture will certainly cause overheating.
2) Check Thermo, a closed thermo will cause probs and they are pennies to replace
3) Flush out the rad with hosepipe and lots of water, Tiger rads are prone to collect dirt
4) Water pump doing its job?
5) Make sure you are using antifreeze/Water wetter and not just neat undiluted water
6) Fit higher pressure rad cap - 13lb+

now it gets expensive

7) Fit fan shroud makes a huge difference, but £150+ on eBay

8} Fit larger electric fans, £80 (approx) for the kit
9} Alloy rad, £400+
10) LAT hood, personal preference but still £200 plus fitting/painting

Only other cheap option, is when in slow moving traffic just pop the bonnet open, that gets the air flowing through the engine bay but you'll have to stop and close the bonnet when on the move again - which can be a bit of a chore

Sure there will other bits/suggestions I've missed and somebody will chime in too, let us know how you get on.

tigerman7347 · Post by **tigerman7347** » Sat Jun 13, 2009 7:50 pm

Sounds like a blocked radiator.open the screw at the bottom of the rad and see what colour the water is when you drain it. If it`s rusty you have a blockage. Other than that , a 6 bladed fan and 13inch electric fan on a thermostat.

V Mad · Post by **V Mad** » Sat Jun 13, 2009 8:14 pm

I have always had marginal cooling on my Tiger, although I am impressed that it has never popped its cork. I just had my radiator uprated (3-row S-type core) and cooling seems to be better now. Today I had many fast runs up Brooklands Test Hill in warm weather, and did not even need to use my electric fan.

The Tiger rad is a cross flow type, and the bottom rows of tubes are below the outlet, so sediment usually collects at the bottom and blocks it (mine had). If the sediment has been there for ages you will never shift it by flushing so a recore is the only viable answer.

The standard fan is OK, but IMO running your car with no fan shroud is asking for trouble. But if you can't get a shroud you will need a good electric fan instead. Mine has a shroud, but like some other owners I have fitted a Flex-a-Lite fan because it cools the engine well without wasting horsepower or making noise like the original fan.

As Tomaselli says, check the Thermostat , but I cannot agree on increasing the system pressure above 13lbs. This will not help cooling (although will delay boiling), and may blow your heater matirix, which is not very strong.

garyv8tiger · Post by **garyv8tiger** » Sat Jun 13, 2009 10:04 pm

i have ,ally rad 6 bladed fan .i also have an electric fan on a switch,not had to use electric fan as the 6 blade fan and ally rad seems to cope ok

Tomaselli · Post by **Tomaselli** » Sat Jun 13, 2009 10:55 pm

V Mad wrote:Flex-a-Lite fan because it cools the engine well without wasting horsepower

Agree, these are great as they give you loads of air flow without loss of any performance as the blades fold away when the revs build up, great design well worth the money

garyv8tiger · Post by **garyv8tiger** » Sun Jun 14, 2009 10:54 am

do u not get overheating probs ,the speed u drive looks like u are always in a tailback,recomend using uprated crocs they have more surface area

H, Sunny 65 · Post by **H, Sunny 65** » Sun Jun 14, 2009 10:44 pm

Hi I also have no fan shroud, been looking for a while, very hard to find an original. Any way by far the best & prob cheapest way for cooling in traffic, is to fit the latest kenlowe fan in front of rad, if you go to there web site, & contact them, they know what s needed for tiger. I fitted one & have had no probs at all since, cost was about £70.00. allso in one of your other posts, you said about condensor prob, if your timing has changed, to far retarded,this can cause overheating. Hope this helps. Harry.

V Mad · Post by **V Mad** » Mon Jun 15, 2009 2:06 pm

Yes, fan shrouds are rare. If you dont have one its probably best to fit an electric fan.

I test my uprated rad (3-row S type core), yesterday, warm day in heavy traffic etc and I didnt need to switch on the elctric fan once. I just have the flex-a-lite fan with shroud.

JAYANDSHEL · Post by **JAYANDSHEL** » Mon Jun 15, 2009 5:37 pm

Hi all, great response to this one seems like a lot of people have suffered this and have tried many things so this is what I have checked this evening 15/06/09

1 Mixture is correct at idle
2 Timing is set at 6 degrees advance it was at 8 degrees advance
3 Running a dual point dist points are at 31 degrees total dwell
4 Undid small drain plug bottom of Rad, water flowed out very nicely and was very clean
5 Have already fittewd new 13 lbs cap (Was first thing I tried)
6 Themostat is working ok

So looks like 6 blade flexifan is the next on list but will this work without shroud

Has any used a repro one that Brian lists seems reasonable price if second hand 150 and can not say I have seen one on ebay

Do LAT bonnets very in quality seen some and they look rough or is that down to the paint shop

Thanks again
Jay

V Mad · Post by **V Mad** » Mon Jun 15, 2009 7:13 pm

Jay, the flex-a-lite fan will not really improve cooling it just saves power.

Get your rad tested at a proper rad shop, and you will probably find you need a recore; you may want to go for an uprated (3-row) core or try one of the Tiger suppliers. Should be less than £200 (about £175).

Tomaselli · Post by **Tomaselli** » Mon Jun 15, 2009 8:51 pm

Agree with Chris, radiator is the one that will make a huge difference. That with electric fans will do the job am sure, I have an 8 inch single electric fan and will shortly be fitting a much bigger version. I'm afraid you need it today with so much traffic on the roads, hopefully you'll get it sorted before the Spa trip in September

I forgot to mention before there is an article on the web well worth reading, see the following link;

http://www.teae.org/cooling/cooling_article.html

Keep us posted

PS, will you be able to make Brooklands on Sunday

odl21 · Post by **odl21** » Thu Jun 25, 2009 8:46 am

sorry to disagree but if the car doesn't overheat at speed, i very much doubt the radiator is at fault. first check your gauge reads right. a mechanical gauge is much better than the stock electrical one which requires a working regulator. an infrared thermometer pointed at the top of the radiator can help calibrate and check.

most real overheating at idle is caused by recirculating air. believe me - i've studied this in detail.

assuming the radiator is not blocked, the easiest fixes are blocking the horn holes and sealing the top and bottom of the radiator with foam strip and tape.

mine runs fine in weather upto about 20C with no fans at idle for any period of time. over 20C i use a 13" 6 blade flex fan on the water pump which has never caused issues even upto 37C ambient temp which you'll never get in the UK. these flex fans are low on parasitic power and work very well. the stainless blades flex a lot though and can fracture after a couple of years so replace every couple of years to be sure.

and thermostatic electric fan in place of the mechanical fan is also fine unless you have a monster engine which needs the extra airflow of a clear radiator at speed (e.g. over 350hp).

if you still have issues and you don't have a fan shroud, this can help a lot if the fan is spaced correctly in it.

V Mad · Post by **V Mad** » Fri Jun 26, 2009 7:42 pm

I don't think we can assume they dont have a problem at high speed, they may not yet have encountered the conditions that cause it.

Mine didnt get too hot until I did a track day in hot weather.

I experimented with closing off the horn holes, blocking in the gap below the rad, and fitting the flex-a-lite fan but nothing really helped until I had the rad recored/uprated.

JAYANDSHEL · Post by **JAYANDSHEL** » Fri Jul 03, 2009 7:41 pm

03/07/09

Been out hot weather testing today, as I have now got the cooling system back together after a few hick ups.
first problem was bolt snapped off in manifold thermo stat housing while trying to change stat.
Then easyout snapped in bolt so had to redrill and put in time sert in manifold.
302 inlet manifold gaskets dont fit a 260 so had to order them.
Rad drain would not seal and so it seemed to go on.
However I now have a few things working well.

1. flushed out rad (although seemed clean)

2. Installed a Flexi engine fan

3. Installed repro fan shroud (very happy with quality of this item cheers Brian

4. Refurbed header tank (found a small pin hole not allowing sytem to pressurize correctly)

5. New thermostat 82 degree

6. New hoses all round

7. New heater valve

8. Oil change

Electric fan is still suspect beleived to be a puller and not a pusher though today was very warm around 26 degrees I did not need to put it on but must admit traffic was not to heavy

So first signs are good with still a few things left to do.

Jay