The Rally Maestro project

[Guest]

Will it help if we remove the thermostat altogether? Any reason why not?

[E_T_V]

Not really. Well it may marginally help the cooling but it will hurt the longevity of the engine as the fuelling will never be right as the engine temp will change a lot during use.

[Chris Y]

Also removing the thermostat lowers the pressure in the system, which in turn lowers the boiling point of the water. Not good! A pressurised cooling system is more efficient.

[G Force]

Will it help if we remove the thermostat altogether? Any reason why not?

Hello Philip.

Removing the thermostat as already said is not a good thing to do. You need the engine to be hot enough to maintain optimum running clearances, to prevent engine wear, avoid oil contamination, avoid distortion of the head and block due to massive local temperature differences & give maximum power etc, etc.

But cool enough to stop the whole lot overheating and melting into a big lump

Selecting the radiator size and thermostat value is going to be a bit hard as we can only guess on what conditions you will encounter, but I think its safe to presume it will be hotter than the UK. The advice of moving to the EFI or turbo larger radiator if you can get them, seems a sensible modification

The inlet manifold may run cooler once you have had the car tuned on the dyno because at the moment it could easily be running too lean. If you take the improvements made to the cylinder head and exhaust will have increased the air flow + the air temp control is no longer fitted giving cooler intake air you will need to add quite a bit more fuel to compensate.

The engine in standard form uses an electric manifold heater system for better initial post start-up fuel vaporization for drivability & to shorten the amount of time the choke is needed, this cuts out once the inlet manifold reaches 50 degrees C. The inlet manifold is also heated by coolant; this improves fuel vaporization, drivability and economy and gives a stable inlet temperature platform for tuning the carburetor and ignition timing settings. In addition the inlet air temperature is controlled to approx 35 degrees C by mixing hot air drawn from around the exhaust manifold and cold air from the front of the car. This further improves fuel vaporization and prevents the carburetor from icing around the throttle butterfly area.

All this intake heat is good for fuel economy, drivability and emissions regulations but directly sacrifices engine power.

Leaving the inlet manifold not heated by coolant and junking the warm air intake control, should increase the potential maximum power output due to cooler denser air reaching the cylinders. It should also help with the high temperatures around the carburetor and improve engine cooling a little. It will just be a question of checking the best way to go on dyno day. The small concern being, if any night driving in much cooler temperatures was needed to be done, would the carburetor ice-up?

HTH, gforce

[E_T_V]

SU's aren't prone to icing and I think it is fair to say that many cars have had manifold coolant bypassed and have broken manifold heaters too. The hot air pipe commonly drops off yet I don't think I've ever heard of an SU icing up. So I think it'll be a very small risk to take. From the pics I think the hot air intake has been junked already.

[Guest]

Some interesting stuff, above, thanks for all that. Will take some photos of the set up and ask ETV to post them up for us in the next day or so, so you can see how its set up. It is due a visit to the dyno. We have a big K&N filter now alongside the SU, and I wonder if losing the pipe across the top of the engine to bring cold air in from the front, as with standard, is something we could restore.
We will lag the inlet manifold with asbestos-tape of the sort used on exhausts, make a heat shield under the carb, and wrap the float-chamber as well.

We need a full-width two-litre radiator, or, a twin-core rad from the turbo, but there are none on ebay it seems at the moment, the ones for sale seem to be the size we already have? Any offers, anyone?

Running the car on the North Circular Road today (some have said its been the hottest day of the year), in jams past the Ace Cafe, the temperature gauge failed to go past the half way mark. So, all is normal in the region where the temperature-gauge sender unit is... the problem is what we detect is very high temperatures around the carb area.

[G Force]

SU's aren't prone to icing and I think it is fair to say that many cars have had manifold coolant bypassed and have broken manifold heaters too. The hot air pipe commonly drops off yet I don't think I've ever heard of an SU icing up. So I think it'll be a very small risk to take. From the pics I think the hot air intake has been junked already.

Back when the cars were new, I had quite a few reports of icing problems with montego's especially, ok by no means an epidemic but enough to raise the point Dan. The Montego in particular was a popular choice for reps & large companys, as such spent a lot of time on motorways at speed in all conditions & sometimes late at night. Symptoms were commonly reports of engines revving above 3000rpm at ends of slip roads, throttles sticking when driving or grinding to a stuttering halt on the hard shoulder.

In all cases the problems would go off after a short stationary period. Back in the workshop you would generally find the thermac switch faulty or simply the vacuum pipes disconnected or hot air ducts missing or broken like you mentioned. Once fixed there were no more issues.

I don't want to just not mention the chance of icing & end up with the girls in a ditch with a sticking throttle. If cold night stages are a possibilty (I have no idea if they are?) it could be worth having a system that could be quickly employed for night driving. Something like a hot air pipe that can be quickly connected when or if needed to a K&N hot air adapter kit, for the K&N filter pictured.

Cheers, Gary

[Guest]

Thanks for that, all this needs some careful planning. In January, anything can be expected. They leave London on Jan lst in the evening, and drive through Kent, once started, the engine ought to keep the carb warm and we need to ensure it does just that - it goes through the night and through the next day, non stop, to a hotel in Beaune, middle of France, after that, its in warmer climes, usually, and once across the Med, it will steadily get hotter as it goes south and icing up is no longer a worry.

There is an oil leak that has developed - well, a low-mileage car needs using, in testing the temperature on the North Circular Road yesterday, its found when returning to the garage there is a bit of a drip that seems to be coming between the gearbox and the block. Is this common - any ideas what needs sorting?

It needs a couple of thousand miles on it between now and the start. A visit to a rolling road will ensure its not running too lean.

[G Force]

Thanks for that, all this needs some careful planning. In January, anything can be expected. They leave London on Jan lst in the evening, and drive through Kent, once started, the engine ought to keep the carb warm and we need to ensure it does just that - it goes through the night and through the next day, non stop, to a hotel in Beaune, middle of France, after that, its in warmer climes, usually, and once across the Med, it will steadily get hotter as it goes south and icing up is no longer a worry.

.

Hi Philip.

It is the cold moist air rushing through the carburetor throat at very high velocity that causes the icing, the radiated and convected heat from the engine is not enough to prevent this. Even with the heating of the inlet manifold if it was left as standard is not guaranteed to be enough to prevent icing because the conducted heat to the carburettor is kept fairly minimal by the isolator block.

For max power there is a good avantage to be had by junking all means of heating of the inlet air. For the coldest parts of the rally I would personaly play safe & use something like the K&N hot air kit, like this one. Just click on the link below to view one.


http://www.ebay.co.uk/itm/ws/eBayISA...m=390325659447


The hot air hose can be quickly detached from the filter end by the service team once you hit warmer climates, and you are back to full power.

Gary

[E_T_V]

I've never experienced carb icing on any of our 1.6's, but I suppose anything is possible. Carb icing is usually associated with partial throttle openings for extended time periods (as this generates the lowest temp in the airstream).

I've had my motorbike carbs ice open before which was a bit unexpected.

[Guest]

Two concerns have cropped up: An oil leak appears to be coming from between the engine and the gearbox, do they all do this, is this a worry?

The fan doesnt come on when it should, it seems the switch on the side of radiator is faulty - any idea where a spare could be found?

.....This might a source of more than half our concerns about hot running .

[E_T_V]

How hot is it getting, The fan usually cuts in about 3/4's the way up the gauge.
If the thermostatic switch is faulty it is a fairly standard part so should be available from the motorfactors.

As for the oil leak, are the breathers clear and set up correctly. It was common for the breathers to clog with gunge pressurising the sump and then oil finding its way out where-ever it could!

[Guest]

The breathers seem to be working but an oil change and filter is on the list of things to do in the coming days.

Fan problem has been diagnosed! Bloody fuse was blown. It runs cooler when the thermostat was removed altogether, (while waiting for new one to arrive).

Lagged the back of the bulkhead with two layers of heat relfective foil backed cloth and this has held back a lot of heat that was getting into the interior.

The original carburettor has been replaced, and running the air intake forward using the original tubing, and filter tub, only because the engine runs sweet as a nut with this, the HS6 SU that came with the head from Peter Burgess has been modded slightly (bit a of re-bore inside, feathered butterfly), but bangs and pops a bit when accelerating, and we suspect the needle is on the lean side which can only add to the overheating issues, it will be fitted when it goes to the rolling road.


We are minded to keep the original tubing and filter box, (is there a decent non-paper filter that fits it? If so from where?) as the big K-N job we tried was just breathing in the hottest air from the enginebay being sited on top of the engine.

The crew turned up today. Girls posed with new t-shirts, alas, the connection of the garden hose to tap was bust, so can not file you wet-shirt look, you will have to make do with "this is a size too small" look instead. (am now sending ETV some shots).

py

[E_T_V]

Pics from Philip,

You can check out the girls, their remarkable challenge of 10,000 miles in 29 days, and the Maestro preparation on their website, www.girlsacrossafrica.com

Standard carb is back on, for now…

Jane Edgington at the wheel…she has competed in over 300 rallies.



Jane and Gill Cotton at Tony Fowkes workshop in Park Royal…

[G Force]

We are minded to keep the original tubing and filter box, (is there a decent non-paper filter that fits it? If so from where?) as the big K-N job we tried was just breathing in the hottest air from the enginebay being sited on top of the engine.

py

The K&N direct replacement filter is part no. E2360. It is listed only for the 2.0l but the 1.6 single carb engine is the same size. You can probably find a local stockist or buy direct from their website.

Heres one on ebay, click the link.

http://www.ebay.co.uk/itm/K-N-Air-Fi...item45f946b504

Regards, Gary