Talk Morgan Forums Morgan Sports Cars Morgan Three Wheeler & Super 3 under the bonnet cooler

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I enjoyed the read. If you want to get into an oil war, go on a v-twin site and just mention oil change or synthetic vs Dino oil. Grab some popcorn and watch the posts. These v-twins run hot. It is the nature of the beast and it doesn't surprise the engineers that designed them. However, sitting in traffic they get upset with heat and start doing all kinds of fun things! With that being said, I am only concerned about traffic situations. I know that if I.am going to do a toy run or parade ride, I take a bike with a radiator! I have read somewhere, about oil viscosity break down and the temperature where that occurs. It has been some time ago but I am thinking that doesn't start to occur until 275 degrees and up, and that was with regular Dino oil not this new synthetic oil on the market. Most of these big displacement v-twins come with oil coolers installed on the bikes now, if there is no water cooling. I guess I said all that to say this, I just want some cooling happening when I am stuck where I can't get air across the engine. Are you saying that the fan blowing on the cylinders is sufficient for cooling in stop and go city driving? I am just trying to figure it out since I do not have a temp gauge on the car
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Yes, the Urban fan is for Urban driving and only comes on if M3W is below 12mph or stopped and yes it does cool the back of the jugs as it pulls air in from the sides.

it pushes air from between the fan and pushes it onto the cylinder heads and through into the air intake. The intake is then sucking hot air where cool air is the mantra for good running engines. What is the fan direction was reversed and air was sucked through the heads from the front where the cool air is coming from?

Pretty much...the cooling for the cylinders is by heat transfer from the metal of the fins to the air so keeping a supply of air moving across the fins will keep the heat transfer going. If you were to have a fan behind the cylinders trying to suck air through the fins you would need to fit really well sealed ducting or the air would be drawn by the easiest route to the fan rather than through the fins; basically its easy to direct a jet of air blowing into nooks and crannies but damn near impossible to choose where air is being drawn from once you're a very short distance from the air inlet face.
Way back, Suzuki had a family of oil cooled engines which had oil jackets similar to the water jackets that all water cooled engines have and enormous oil coolers that were often supplemented by additional coolers on tuned engines. Our engines don't have anything like those jackets, most if not all of the oil just goes through the push rod tubes so is effectively external to the cylinders.
In a hot climate and with lots of stop start, crawling traffic, a small fan cooled oil cooler with a really quite high temperature thermostat on it may well be beneficial but I don't believe that the large oil coolers mounted in the breeze with no fan assist do much good at all. The engines cool adequately when at speed and you need quite high temperatures in the oil to keep it in good condition.
Where I live, high temperatures and crawling traffic aren't a problem!

You make sense to me. Thanks for your perspective. Sometimes I can be guilty of over engineering. Some of the mods are really good where there is a mechanical fix to a nagging issue. Bevel Box brace, compensator fix, fuel pump fix, etc. I will do these for sure.

Hogzilla is right about the "oil wars".... the other urban myth is that you cannot run synthetic oil in engines that have wet clutchs.

and then there is the air in or the exhaust out debate.

It all gets rather exhausting!

The two times I worry about heat is 1: sitting in traffic, and the urban fan has prevented the engine from ever going into split fire, but the heads still get darn hot. and 2: Cruising up the winding mountain roads nearby as I rarely get out of 3rd and I am running at generally high RPMS

If you have the Urban Cooling Kit fitted and the ECU programme that controls it, the engine will never go into Skip Fire as that feature is removed from the ECU. Only pre-urban cooling kit cars had skip fire.....and you certainly knew if it went into skip fire mod. The urban cooling kit is a big improvement and does a lot to keep temperatures within reasonable limits. Oil cooler are not needed in the UK, according to my oil pressure and temp gauge, never been over 120c even on hot days in traffic.

My one in 8 years and 40000 miles never went into skip fire even though I don't have the urban cooling kit.
Of course now I have a completely different ECU and have no idea if it even has anything resembling skip fire.

some photos just to add fuel to the fire ................ of this hot topic !!!!!!!


<a href='https://www.casimages.com/i/201110051258847534.jpg.html' title='Mon image'>Lien vers mon image</a>
<a href='https://www.casimages.com/i/201110051238395698.jpg.html' title='Mon image'>Lien vers mon image</a>
<a href='https://www.casimages.com/i/201110051611916273.jpg.html' title='Mon image'>Lien vers mon image</a>

perhaps these links are better

How is that ECU working out? Anything that needs tweaking yet?

Bilymog, what is that cooler? Twin fans should keep it cool in bumper to bumper traffic.