Talk Morgan Forums Morgan Sports Cars Morgan Three Wheeler & Super 3 Necessary Modification of the Urban-cooler ?

Part I
Sorry for a long story

Rule number 1 :
The best maintenance for these air-cooled V-twins is COOLING.
Do you want to extend the life of this X-Wedge, work on your cooling first.

I have seen a lot of strange design-features on the MMC M3W, but the following beats everything.

The Urban-cooler is an extra option made by MMC for solving cooling problems when driving slow.
It is a very well discussed item on TM.

We have encountered several problems with it during our recent trips in the Pyrenees.

It seems the Fan is actually always ‘ON” in the mountains but the Urban-cooling as it is working has in that case a serious negative result.
The engine gets even only more hot.
You have no speed, the engine is on full power, so it becomes very hot, with a result that the cooler-fan goes on.
The actual natural air-cooling is pressed back forward which creates a standstill of air in between the cylinders.
Result : No cooling at all.
When the wind is from the back – half your time in the mountains because of the hairpins - it is even worse because the sides of the engine with wind from the back are not cooled enough either.

We are working on an oil cooler because the best cooling is by the lube-oil, but that’s another story.
Modifying the MMC Urban cooler we solved already a huge part of that hot-lube-oil problem.

Looking at the Urban-cooler your first impression is that it is a little bit strange designed by MMC.
The Fan brings air from nothing - the closed Fake-Grill - to the front direction which seems odd.
You really try to understand why it is designed like this.
Blowing air from the front to the fake-grill will give problems and building a kind of air-back-pressure. But that is simply solved and that simple solution will give also some advantages.

The biggest problem with this MMC designed Urban-cooler is that it directs already very warm air mainly via the back of the cylinders to the out-side of each cylinder.
AND . . . . only partially through the middle in between the two cylinders, which should be the main task.
The place which needs cooling is not the outside , it will nearly always cool, even when standstill. As already mentioned only wind from the aft at slow speed gives here a problem.

And here you find the biggest problem of the Urban-cooler design.
It does not do what you think it does.
It does not blow air in between the cylinders, because it is blocked by the Fan-support-shrouds.
And made in that way that 80% or more of the air goes aside, where it is not necessary.
This system will even warm up the Fan itself because it has to work hard without getting rid of the air.
Even worse (sorry, again) :
By blowing that little amount of air in between the cylinders you trap the cooling wind from the front, so the air stands still. It has no way to go.
With the result that in between the cylinders the engine gets hotter and hotter.
Recently we got an oil-temperature of > 300 oC when climbing. That’s dangerous stuff.
I thanked my new dash for telling me so much. In time. A lot of my M3W friends will never see it.

The Fan is – as they inform us - ECU-controlled .
I could not find any information in the manuals how the ‘Protune controlled S&S-ECU’ regulates the Urban cooling Fan, but in the Urban-cooler-installation manual it says that it is controlled by speed – low speed of less than 15km/hr and temperature above 100 oC , but how it works in the ECU is not made clear. You probably need a programable Protune II S&S-ECU to find out. I do not have this info – although I studied the manual - but I am interested to know.
On my Emerald-Ecu I could only find that it is controlled by Temperature on output 6. No speed-control.
In the Emerald program Events-Page ( F2 ) there is a ‘tab’ where you can arrange the fan keeps turning after you turned the ignition key off. When I switch that tab into ‘ON’ then it blows the fuse I installed from the Batt+ supply to my newly installed timer-relay.
With or without that fuse the Fan dyed within 2 seconds even with the cylinders on high temperatures.
So the ECU-output signal to the dedicated relay clearly empties only a capacitor in or around the Emerald-ECU.
From the ‘sub-Loom diagram’ in the Urban-cooler-manual it looks the power is directly connected to the battery, which explains the ( very short ) delay even after ignition power is already off.
Two seconds is not enough. Sad because it would be better when the Fan stops after it drops down to 80 oC after you stopped driving . A little bit warm engine after a pub-stop is always better than a cold engine.
Now I have to guess how long it needs to cool. Say under 80 oC.
I hope this is better organized in the Protune S&S ECU.

A Led : Knowing when the Fan is working.
Do not assume the Fan is only blowing at > 100 oC or with a speed less than 15 km/hr.
I made a little red led on the cover. And it showed that the Fan was working too at 50 and 60 km/hr.
Maybe with a Protune S&S ECU it works on speed but not with the Emerald.
Nevertheless, my advice : Install that led and check yourselves.

But that Ecu-controlled thing is not really important.
When the fan blows with vehicle speed of more than 15km/hr , it makes the problem even worse :
The air can also not escape because of that nice top-cover with “Hot Engine” and now my red Led on it.
That is making a pretty but dangerous closed box of it.
It is really an air trap. Especially when the Fan is on and you think it is not.

It is in between the cylinders the engine needs a lot of cooling.
That’s the place where the engine gets far more hot than outside.
And here the damage - done to your precious cylinders - is far more often found and worse than at the outside of the cylinders.
But the MMC Urban-cooler with its big Fan does not cool when we you really need it.
This MMC design will not save, but rather ruin your engine especially in the mountains.
It blocks the air the inside nearly totally. ( See pictures ).


A SOLUTION
I hope I found a solution.
The results after 300 km in the mountains are so impressive that I like to share it with you.
I read too the discussions and wise comments in TM, but I guarantee :
It is absolutely necessary you modify the urban cooler when you want to extend the life of our X-Wedge.
Or take the cooler away and find something else to cool your engine. Everything better than this design.

Open the Fan-support-shoulders so air can flow.[/size]

1. Cut that ridiculous MMC barrier
The most important part of the solution is to cut that ridiculous MMC barrier so the air gets a better direction inside the cylinders.
A ½ hour job, easily done. ( See pictures ).
The plastic material of the Urban cooler is quite strong, so you can take a reasonable amount of it away.
And the extra mounting construction of the Fan it-selves will keep everything nice in place.
And BTW the heat-temperature - which is discussed on T - is not a problem for this plastic, neither for the Fan.
It will : When you blow your engine.

2. Change the air direction .
When you have done this modification, why not give the fan a cooling direction from the front to the aft?
Which is absolutely more logic.
Even that is simple, because the choice MMC made for the Urban-cooling-Fan is a simple one and as a result of that we have a not a really electronically complicated DC fan.
Changing the wind direction of the Fan is easily done by changing the wires.

What about the air-back-pressure ? Will be the next question.

There is a big problem with the temperature of the lube-oil of the M3W.
Mainly caused because the oil-tank cannot be cooled.
Which is indirectly one of the reasons M3W- owners do have problems with their batteries.
Wrong battery-place : Too hot.

Under the bonnet it should be cool as possible.

3. An air-duct in the grill’s bulkhead.
So why not making a nice air-duct in the grills-bulkhead.
Not really complicated. You only have to take care that rain-water will not come in.
The air from the engine will always be far cooler than the oil in the tank.
By making the air duct you solve the problem of the air-barrier.
I made a duct with a 140 cm2 surface . From the outside you cannot even see it.
The working surface of the Fan is 233 cm2 , so that 140 cm2 is enough.
I made the duct in a way that rain cannot come under the bonnet.
And when the air is coming out of the duct it immediately will first cool the oil-tank and the battery too.

A day work - at no costs - which will save our X-Wedge.

PART II

Extra wish.
Keep the cooling fan on when the ignition is off.

The following is less important for some of us, especially when you have the possibility to keep the Fan on – by means of the ECU - when the ignition is off. And when that option works of course.
As written : On an Emerald-Ecu it does not work.
All normal cars, even my nearly 40 years old VW-T3, keep the Cooling Fan and cooling water-pump and even a bypass water-pump on when necessary even after you have taken the key out of the ignition.
Strange but the M3W lets you standard stay with a very hot engine which cannot cool anymore even with the Urban-cooler-kit option installed.

We all know :
Never stop the engine at the high-way for fuelling.
Let it first idle for a couple of minutes. Turbo-owners now this trick. It safes your turbo and engine.
It needs cooling especially after the work is done. Stand-still after use will makes the engine even hotter for a while.

Timing relay.
I spend some design-time and money on another option I wanted.
In case the ECU did not keep the Fan running or as long as needed.

I bought a simple timing-relay on amazon.fr for € 30 which keeps the Fan on as long as I want.
I programmed – that’s a guess - 15 minutes after the engine is cut off by the ignition key.
I needed an extra simple ‘40A relay’ of € 5 to inverse the signal-input on the timer relay.
See the design drawing attached for how to install it.

Conclusion
We were Flabbergasted.
The results are impressive and even far better than my expectations.
Before we even installed our Oil-cooler, this modified Urban-cooler makes already that my engine will hopefully last longer even when driving weekly in the mountains.

The CHT ( Cylinder Head Temperature ) lowered with nearly 50%.
Before the modification we read on the gauges a road-standard of around 175 oC and 200 oC or even more in the mountains.
Now it went to 80 oC till 120 oC in the mountain.
BTW we are very pleased we can control our CHT on this air-cooled engine.
Every pilot will tell you how important those CHT-gauges are to keep your engine healthy.
For small-plane pilots even more because it gives them valuable information about the engine when climbing and descending. And they can – when wanted – change the AFR-levels.

Interesting side-effect :
( With the Emarald-ECU I can switch the AFR too, but that’s another project )
My AFR [ Air Fuel Ratio / mixture ] changed because of the cooler-modification and became far more stable.
Possibly reason : The fuel gets cooler at the injectors in that closed box.
[ I still have a slight AFR problem but that’s due to a leak in the exhaust , which is there from the beginning ]

Cool fuel is very important.
In the “Standard MMC-Urban-Cooler” situation, the petrol did nearly change material-phase from liquid to gas in that closed space.
<< At atmospheric pressure, gasoline has an initial boiling point of 95 °F (35 °C) and a final boiling point of 395 °F (200 °C). >>


Have fun, Life is short :
Please do cool our X-Wedge

Hello Herrie!

I'm confused.... why is your Urban Cooling fan running all the time? Is it because the software of the Emerald ECU? It shouldn't! You know it's commanded by a thermostat and the speedo. If your engine is hot, and your car runs below 16 km/h, then the fan switches on. If it's cold and/or you drive faster than this, the fan automatically stops.

I know your car is an earlier model and the Urban Cooling kit must be a later add-on. Are you sure it's because of the Emerald ECU? Maybe there is some sensor wrong or the system works differently (manual switch?).

Best regards

However, this is a very nice and interesting post. Totally agree that cooling is a must.

I too am curious why your fan runs all the time, I live at 2,590m elevation on very steep switchback mountain roads with ambient temperatures around 27+C in the summer and have no heating issues the fan only comes on when stopping or stopped, I also have an override switch with a timer so I can run the fan after turning the engine off. Even going up Pikes Peak at 4302m did not cause the fan to come on whilst moving, often drive well over 3,300m on hot days (we are classified as high mountain desert) and have never experienced what you describe.

P.S. I have a thermostat controlled oil cooler but the engine has to get really hot (which it needs to) to activate.

See also Phil bleazey's answer.

Hi Javier, Bruce and PaulV

The article of Phil was send me a while ago by Phil to me when I discussed my hot engine situation with him.
It confirmed my thought and was an inspiration to find a modest solution.

It is a very good and important point to ask about why the Fan seems so often ON.
I was not sure when the Fan was ON or OFF and expected – by the specs - that it was speed and temperature regulated.
When driving you cannot really hear it.
But I did not trusted the specs. Not really a bad idea with a MMC product.
For me that was actually the beginning of the analyse trajectory.
That is the reason I do advise to install that little LED.
The LED gave me an answer to my ON-OFF question.
In my case it was clear that it had nothing to do with speed but only with Temperature.
When the temperature is lower than programmed in the ECU the Fan is OFF.

After that I went in the Emerald Program and found only one switch that regulates the Fan.
And that switch is only Temperature depended ( the F2 page ).
So that’s the reason too I am interested in somebodies opinion who know how it is programmed in Protune.

Still that whole ECU issue is of less importance.
The main problem is that the shrouds and the direction of the Fan is wrong designed and that should be changed.
And also the Lube oil tank – and with it the Battery - under the bonnet should be cooled.

Herrie- interesting post and thank you for the detail. It’s a shame that the cooling kit was so poorly designed.

I have always assumed it’s best not to mess with the flow of air through an air-cooled engine. Fluid dynamics being what they are, I think you want as much unobstructed space as possible.

The issue of under bonnet temp is of more interest as this seems to be a design weakness as there is no flow to keep heat from building. No brainer to have a fan moving air through the bonnet and no harm to have it always running. Easy fix.

Brining oil to some decent temp before staring off is an important thing to think about in terms of keeping the X-Wedge happy. Proper oil change intervals as well. Modern synthetics do a great job if they are changed often enough. Small change to pay.

I too have a light for the fan so I know when the fan is running and it does not run unless going slow or stopped. I would politely suggest that the engine temperatures you posted after the fix are rather low for the X Wedge Engine which is designed to run hot.

Hi Britmog

Thanks for your polite suggestion.
I think this is a Fahrenheit vs Celsius issue.

page 13 on my Sands S&S Manual
< Quote >
BREAK-IN AND OIL RECOMMENDATIONS
As with any air-cooled engine, heat is the major enemy you can encounter. Engine cooling is based on air flow over the cooling fins.
Your engine cools as air flows past the cylinder fins and the oil circulates.
Sitting still for extended periods of time — at a crowded bike rally in traffic — will prevent air from flowing past the engine.
Situations like this should be avoided anytime possible — but especially during the break-in period.
S&S suggests maintaining oil temperatures of 180F ( = 82 degrC ) -250F (= 121 degrC )
< End Quote >

Which is exactly what my situation is now.

warm regards