Hot day, Hot car

[steve_D]

Did Surrey run today then went to Thorny Island for the car show.
Huge queue resulted in the water temp passing 115C then blowing both ends of the bleed pipe from top of rad to swirl pot.
Nice man from the AA grafted some new pipe at each end.
Remains to be seen if any damage has been done. Bubbles were coming through when refilled but these may just have been trapped air working its way out. He checked the bubbles for hydrocarbons and said it was ok.

So where do I get bigger fans?

Steve

[gtr-gaz]

wow, thats a bugger Steve.

www.pacet.co.uk for fans.

I have the bigger fans, almost twice the cfm as factory spec.

A straight swap.

Gary

[bluesatin]

Steve

Have you got the big rad, what idle do you have and are you using water wetter stuff. Done that and been in 33 degree traffic without problems. Did boil the petrol on the hottest day ever though a few years back!

[steve_D]

Gary
Thanks for the link, do you have the part number so I can just go order them? Cheers.

Guy
Big rad, 1200 idle, no water wetter just antifreeze.

So rad should be OK.

Idle should be OK for this situation but could do with being lower. (It went up when I fitted the wedge under the carb, just not gotten around to winding it back down).

Will water wetter make a difference?
Do others use it?

Steve

[tuxman]

steve i use the water whetter ( 2 bottles ) and touch wood i have had no problems with std-fans ,have you cut the 2- 4" holes in the side of the fan shrouds ? simon

[gtr-gaz]

Steve, the fans I have are Pacet Thinline Profan
part no: KPF1011P.
They came with thermostats etc, which was a bit of a waste. They were also £100 each!
For some reason I got them through Demon Tweeks? Can't remember why. It was 18 months ago!

The spec for you to check up on is: www.pacet.co.uk/profan.htm

Gary

[B1 ECC]

I have the same fans as Gary, I don't use my car on the road a lot. but i was out on Saturday (25 degrees) in second gear traffic, never went over 90.

[eliot]

I dont understand why the factory just dont supply the decent fans in the first place? - Stig discovered the better ones a few years ago. (unless they do now?)

[bluesatin]

steve

Drop the revs to 800 rpm with a bit of water wetter and the problem sould go. I now have a cam that shows no vacuum and idles ( a bit rough) at 800 rpm!

[tjb]

I fitted the Pacet 10" Thinline Profans to my Sports before Le Mans this year. Queuing through Arnage after the race with an outside temp of 38C my water temp never got above 98C. Much better than 2 years ago when I hit 105C in Rouen with an outside temp in low 30's.

I bought them direct from Pacet. Think they were less than £90 each (but can't find the paperwork so don't quote me).

[Crazy of Cookham]

Had similar problem. Follwed factory advice and now all OK. With tickover set at 800rpm. water wetter and standard set-up no overheating even with the extreme temps of Le Mans. Max temp was 95 sitting in traffic.
If you had air in system do not forget to run the car with heater on to make sure you get air blocked air from there.

[gtrclive]

Question ? Why does everybody fitt 10" fans with angle brackets to space them to the centre of the rad ? When an 11" fan of the same make fitts perfectly on the rad ? Just woundering ?
Price difference at Merlin Motorsport is about £5 each when I bought mine...

[gtrclive]

Just as a note I think SPAL are one of the better fan manufactures but they are more expensive...

[menostig]

My water temperature is just fine ~90 until on a long hot-day with traffic (e.g. Le Mans) when the oil temperature stars a prolonged climb from 90 to 110, at this point the water temperature then starts to climb and if it gets close to 105 I switch it off.

Bigger rad fans ?
Oil cooler with thermostat ?
Or extra fan to pull air out from rear clip ?

cheers
Roger

[tjb]

menostig said:

My water temperature is just fine ~90 until on a long hot-day with traffic (e.g. Le Mans) when the oil temperature stars a prolonged climb from 90 to 110, at this point the water temperature then starts to climb and if it gets close to 105 I switch it off. Bigger rad fans ? Oil cooler with thermostat ? Or extra fan to pull air out from rear clip ? cheers Roger

I don't have an oil temp gauge so I don't know what happens to my oil, but I've done a number of things to try and sort out both the water temp and the engine bay temp in my Sports.

- Fitted a thermostically controlled 13 row oil cooler. I know this is smaller than recommended but I'm only running a ZZ4 making about 350bhp. The oil cooler has an oil filter sandwich plate with the thermostat in it, so it can't be used with an accusump.

- Fitted 8" fans inside the side air intakes, to draw air into the engine bay (and also through the oil cooler on one side). These are wired so that they come on when the front fans come on.

- Put two bottles of Water Wetter into the system

- Had the exhaust system ceramic coated as this is supposed to help reduce engine bay temp.

- Panelled in the gaps between the front clip and the radiator.

- Replaced the standard fans with Pacet Thinline Profans

The net result of this is that the water temp seems to be under control (as previously posted). Panelling between the rad and the front clip seems to make a big difference to cooling when the car is moving, and the uprated fans seem to help when stationary. I did these jobs last and with hindsight they should have been first! Particularly the panelling as it costs virtually nothing to do.

Tickover is about 1000rpm, and I'm having problems this year with the engine dying on hot days with the aircon on. It also misfires under hard acceleration when very hot. I think this is either due to fuel vapourisation in the carb, or its running rich, and very hot air just makes the problem worse. Will get the carb looked at professionally. It was last done a couple of years ago and tickover was fine up until this summer.

Next challenge is keeping the driver cool!!!

[BogBeast]

I use Evans NPG+ coolant. Bit expensive on the outlay but it has a very long life and you stop having to worry about the coolant temp quite so much an just make sure you oil temp stays under control (I have a oil cooler mounted in the side pod)

[layada]

Even @800RPM tick-over, I’ve always suffered incipient overheating but *only below* 30MPH when above ~15 degrees C ambient on my (uprated to 460HP) Spider. If stuck in traffic with high ambient temps for more than a few minutes post a good run then I need to switch off quick.

The Ultima Factory recommended that I look for a good aftermarket rad. So on this advice I’ve gone to Pace Products in Haverhill (run by ex lotus engineer) [url] www.paceproducts.co.uk/default.php [/url] supposed specialists in cooling and oil systems to get a new rad cooked up.

New Rad Specs...

Aluminium 3 core
100cm wide as opposed to 80cm
3x profans as opposed to 2x tripacs.

Fitting three fans will require some minor cutting and rewelding to the front box-subframe assembly that holds the rad etc. Interestingly Pace recommended a three row unit rather than the original 4 row or greater. They recanted great success on Nobles (sorry for swearing) and other cars by using less rows (two in the case of Nobles) but who knows…

If that doesn’t cure it for good I've planned a second rad (650mm x 330mm), mounted *horizontally* between the two rear mufflers, suitably heat shrouded and vertically baffled on all sides. A couple of 12 inch fans to do the business pulling it up past the gearbox and out of the top out of specially cut vents. However lets hope it doesnt need to get that far..

Alternatively I'll attach a tow hitch and carry a water bowser!

[davefiddes]

Just to stir things further on the cooling front. I've seen a lot of people say that running more advance at idle (with a vac advance or ECU) can really help cooling. This is because the mixture is more likely to burn inside the cylinder rather than half way out of the exhaust port. With the exhaust port being very well cooled to avoid it melting all of the extra heat goes straight into the water rather than staying in the exhaust gas, going to the oil (irrelevant at idle) or radiating from the block.

Can't vouch for the claim but I do know what happens if you run an Ultima with the timing 20 degrees ATDC...say hello to cherry red headers!

[tjb]

layada said:

If that doesn’t cure it for good I've planned a second rad (650mm x 330mm), mounted *horizontally* between the two rear mufflers, suitably heat shrouded and vertically baffled on all sides. A couple of 12 inch fans to do the business pulling it up past the gearbox and out of the top out of specially cut vents. However lets hope it doesnt need to get that far.. Alternatively I'll attach a tow hitch and carry a water bowser!

ALAN 2 (Alan Mountford) fitted an aluminium rad in one of the side pods of his Sports. I think he has a std rad and std fans up front. Might be worth investigating that option.

>> Edited by tjb on Tuesday 12th July 21:49

[steve_D]

layada said:

.......If that doesn’t cure it for good I've planned a second rad (650mm x 330mm), mounted *horizontally* between the two rear mufflers, suitably heat shrouded and vertically baffled on all sides. A couple of 12 inch fans to do the business pulling it up past the gearbox and out of the top out of specially cut vents. However lets hope it doesnt need to get that far.......

It's been suggested before that a large fan in the rear grill may do the trick. This would lower the engine bay temp making it easier for the cooling system to cope.

Steve