Motorway cooling

[richardthestag]

Stag truly is a paradox, you would have thought that 70mph or air forced through the front grill would be enough to keep the engine cool at 3k rpm but no way Hose.

I have been messing with this for years now and nothing really has fixed it.

So the car is standard has a supergill rad fitted, viscous fan and is in excellent running order as Giles will testify

typically on a motorway the temp will creep from 85 to 95 and settle then creep again to 100 and then maybe after 30mins of fast running it might be up to 105. None of this should really cause concern except that if I come to an exit of a jam the temp briefly soars onto the red before slowly setting back. After maybe 3 miles of a road normal driving the temp is back to 90 again.

So last weekend I did a flow test on the rad, seemed to empty pretty quick and there was no fluid left in either tank (either side of the matrix) after the 5 second rapid drain. Next I laid the rad flat and filled it with hot water and checked the temp (with IR temp gauge) across the matrix and it was consistent. Rad seems ok then.

One suggestion out there is to block up the gaps either side of the rad, I did this using basic car door draft excluder

http://www.ebay.co.uk/itm/321170364910?_trksid=p2057872.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT

This sealed one edge completely and the other partially.

Next I have heard about LDPart secret spoiler. cheap and easy to fit it went in in seconds

Fast M40 run from HW to Thame and then back home again on A roads with ambient at around 23 didn't see the temp go over 90 until I stopped on the motorway exit, it climbed to 95 but then after 2 miles of A road was back to 85 where it stayed most of the a road home.

Ready for a round trip to Le Mans next month now I reckon

Edited to add

And yes I have an 82 thermostat with foot fitted into a mk2 manifold
Yes I have a HT but with the top - feed pipe blocked off it is more of a high level ET

[tractorjames]

Before I fettled my stag engine up, it used to run hotter on the motorway than stop start. Being in the lake district there is a lot of hard uphill pulls on our stretch of motorway. Just cruising 60-70mph not a problem, but a mixture of hills and getting it to hold 90mph ish soon made the temp rise, not good if you get off the motorway and straight into some red traffic lights. Didn't really modify and of the cooling system to fix this, just removed 40 years worth of crud from the block.
James

[new to this]

what do you think made the biggest difference, the spoiler or the door seal round the rad

Dave

[richardthestag]

door seal was a lot cheaper

Having fitted the secret spoiler I can fully understand how logically it might work

[Motorsport Micky]

"you would have thought that 70mph or air forced through the front grill"

If only that was the case. If the front bumper is fitted, along with that and the front number plate plinth and plate it obstructs the air flow and loads of the front displaced air refuses to enter the openings in the front panel behind the bumper.
Interesting that the touted "expert" from F1 in charge of the "For love of cars" program Stag being tested on a rolling road for cooling foibles didn't insist the car was tested in a "road ready" condition, he thought the Stag without bumper fitted cools ok...it does. The LD "secret spoiler" channels the air into the openings and then through the radiator which is why your experiment worked enhancing the road use cooling. Also every modification you can do that forces the air through the rad (cowling etc) instead of allowing it to turbulate and stall the airflow helps greatly, do what you can to close those gaps,

Micky

[HersnotHis]

After 20 mile plus 70 mph blast down A14/M11to Duxford a couple of weeks ago on a warm day temp guage stayed below half way. Then joined 1 mile very slow moving queue of classic/specialist cars waiting to get in. Temp Guage did then rise to just over half way.
(Mk1.5 with Mk2 radiator with Stagwebber fan cowl). After journey back used IR temp guage to measure temp on black surfaces - highest was 85 deg. No Idea what thermostat is fitted.
H

[wilf]

H, you didn't speak to a chap with a yellow Stag at Duxford by any chance?

[HersnotHis]

H, you didn't speak to a chap with a yellow Stag at Duxford by any chance?

Most certainly did! AFAIK we were the only Stags there! I did move my Stag from the "independants" area after our chat as discovered that local "all types " classic car club ( I am a member) had an area just beyond the refurbed American hall.

There was another Stag owner at the event but he went with his Chrysler Crossfire! ( Interesting car actually really a Merc in US clothes but made by Karman in Germany!)

H

[flying farmer]

I actually got as far as buying one of LD parts secret spoiler for the project Stag, but in the end decided to go the TR6 spoiler route and the secret spoiler is still sitting at the back of the garage.
The theory behind it seems good, hence the reason for getting it, but I knew the TR6 spoiler will cool the Stag on ram effect alone regardless of speed even without the crank driven fan and only an original 3 row radiator.
Some people don't like the look of it, but I really don't like the way the fan shroud pokes below the front panel.

If Triumph had dipped into their parts bin and fitted the TR6 spoiler as a standard part it would have gone some way to easing the Stags reputation for overheating.

Neil

[Motorcycle mad]

Hi Wilf
I didn’t see you, or H but I saw “buttercup”, I didn’t have my Stag, but was in my Crossfire.
Ken
DSCN7007 (1024x768).jpgDSCN7008 (1024x768).jpg

[mike@thenook]

I actually got as far as buying one of LD parts secret spoiler for the project Stag, but in the end decided to go the TR6 spoiler route and the secret spoiler is still sitting at the back of the garage.
The theory behind it seems good, hence the reason for getting it, but I knew the TR6 spoiler will cool the Stag on ram effect alone regardless of speed even without the crank driven fan and only an original 3 row radiator.
Some people don't like the look of it, but I really don't like the way the fan shroud pokes below the front panel.

If Triumph had dipped into their parts bin and fitted the TR6 spoiler as a standard part it would have gone some way to easing the Stags reputation for overheating.

Neil

+1 on this Neil and to add a little extra I've trimmed the number plate down top and bottom so that I gain about an extra 1" of clear air way via the spoiler- it works for me.

[mjheathcote]

Its funny never had a cooling problem with mine, even when ragging it on the motorway.
I swapped the temp gauge for a capillary gauge so you really know the temperature.
Standard 4 row rad, standard viscous fan, 12 vane water pump.
Only mod the header tank....and the other mod, removing all the 'free' casting sand out of the block 20 odd years ago!

[Staggard]

I bought a LD secret spoiler never worked for me made no difference whatsoever, perhaps the temperatures are too high here. I gave it away and fitted a TR6 spoiler when I had the re spray. That made a big difference up till now the 16" kenlow I fitted replacing the twin Lucas fans has not come on.

[Ian F]

+1 for TR6 spoiler, also makes the front end more "planted" at 70 mph (and above).

Only downside (with mine) is that the heater does not seem as effective, not necessarily the heat but noticeably a reduction in the ram effect without the blower.

Ian F

[Stagsongas]

+1 for TR6 spoiler, also makes the front end more "planted" at 70 mph (and above).

Only downside (with mine) is that the heater does not seem as effective, not necessarily the heat but noticeably a reduction in the ram effect without the blower.

Ian F

That's intersting Ian, exactly the reverse of what you'd expect at first glance, but there again the heater air does't come from under the Bonnet, the supply is via the under screen grille.

Most likely the spolier also affects the airflow/ pressure in that area, and that might also have great bearing on the perceived improvement in straight line stability which I definately do get.

Regards

Steve