46 replies to this topic

[yukonphil]

As a small update, I went to fit my new Mini lower radiator hose, as this is around 25mm ID and the copper pipe currently fitted is 19mm ID I thought this would be very worthwhile. But when I removed the bottom rubber piece and checked the outlet of the rad with my finger it appears my cheap rad isn't going to be able to flow anything like the capacity of the hoses that connect it. Not pleased. Will have to contact Minispares or someone reputable?

[nicklouse]

Trying to get my head around what is going where.

 

do you have just one radiator element in the system?

 

some of those pipes and hoses go way too high.

 

none of the cooling system really want to be above the fill level on the rad.

[yukonphil]

Understandable! The highest point is the filler on the auxiliary radiator which is smaller but side mounted right in the airflow. Before fitting the additional radiator it would just keep overheating, with the additional radiator, and it's own small fan running and the extra pipework it will now run around 90-95 degrees without any issue, any period of time stationary and I switch on the electric fan and that keeps it cool. In a way there's no problem but I know Minor's run nearer 80 degrees. I'm aware my radiator is half the size and I have much less coolant but my engine and pipework are exposed to cooling. Viewed directly from the front of the trike you can't see the main radiator at all so it can't be getting that much air through and the discovery that the outlet is really badly formed and causing a restriction makes me think a decent rad and a mechanical fan could have it running at a much lower temp all day long.

[cal844]

You may well be best off going to a radiator specialist and seeing what they can come up with.

Not ideal as not an off the shelf unit BUT it'll cool the engine as it needs and fit as it should (can be custom for the bike).

[Earwax]

As a small update, I went to fit my new Mini lower radiator hose, as this is around 25mm ID and the copper pipe currently fitted is 19mm ID I thought this would be very worthwhile. But when I removed the bottom rubber piece and checked the outlet of the rad with my finger it appears my cheap rad isn't going to be able to flow anything like the capacity of the hoses that connect it. Not pleased. Will have to contact Minispares or someone reputable?

Hi

 

Just some thoughts for you to mull over / throw away or reconsider/

 

Is the bottom outlet from the radiator Not 1 inch ( standard) or can you feel that the core is getting in the way?.  Why wont the radiator flow the volume ?

 

Is the electric fan on the frame blowing into the radiator or sucking ? If sucking then the headwind is working against it, if blowing then actually dispelling warmed air towards the engine

 

Is it a possibilty to remove the thermo fan from the primary radiator and mount it on the side radiator ( and still fit?) The placement of the primary one is terrific for air cooling- but atm the thermo fan blocks most of the wind  ( I know it is the idle that is causing heating issues but maybe the secondary rad if fitted with fan could handle it better?

 

( I cant really tell the directionality of the cooling system - so this may be another silly question)  Can you direct the hottest water towards the other ( i am presuming side mounted rad) first or vice versa to see which way handles heat dispersion better.

 

Some of the aftermarket ( cheap alum radiators ) do a great job. ( I don't have problems with the standard minispares types either The things i have found to look for on the alloys  ( on a mini mounted towards under the wheel arch) 

 

Total overall width less than 58 mm :

the angle of the top doesn't effect your set up):

core width 50 mm  ( a number are only 40 mm but look identical ) 

 

Love the beastie, good luck with solving this issue

[yukonphil]

Thanks for the suggestions. A custom rad is a possibility but I believe at this stage it's sortable with off the shelf stuff, fingers crossed. The extra rad is just the equivalent of putting the heater on in a Mini when you're really getting nervous in traffic, the bigger fan would be overkill, especially as it's being fed with 15mm pipe. I'm thinking of getting hold of a secondhand copper rad and trying that to begin with, it wouldn't surprise me if that just about cures the problem. Will post up any conclusion though.

[yukonphil]

Mmmm, more fuel to the fire to get a standard copper one as a starting point, only 40mm.

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[Shooter63]

If you don't mind can I ask a couple of questions,

What thermostat are you running ?( degree wise )
Is the trike a complete custom built frame or is it a front half of a bike frame with a trike section welded to the rear, if the latter, what was the doner bike?

Shooter

[Spider]

If you are considering a new radiator, I'll suggest in the strongest terms to go to a Copper / Brass unit, definitely give an Aluminum one a wide birth.

Copper / Brass transfers heat for the same thickness of material, around twice the rate as Aluminum does, further, because of the poor fatigue strength of Aluminum and that they need to be welded together vs soldering for Copper / Brass, the material used is thicker, so there simply do not move the heat of of them anything like that of a Copper / Brass unit.

Then there's the issue of dissimilar metals and the damage that does. Aluminum is so highly reactive, much more than any other part of the cooling system. Yes our thermostat housings and water pumps are an Alloy, but not Aluminum, these parts are designed to be Sacrificial Anodes, meaning that these are purposely made from specific materials, alloyed together so they 'dissolve';while preserving the cast ion of the block and head. I have an engine in the workshop presently where the owner (against advice) fitted an aluminum radiator about 5 or 6 years ago. The head is a write off, the block after some $800 of chemical treatment, I have managed to 'save', though it won't have much life in it and t will be prone to getting hot more easily than it should, the Thermostat Housing is like new - except for the huge rust stain inside it - yes, rust from the block and head. These engines were never designed to run with Aluminum radiators. BL, with all their resources thought they could, first back in the early 80's with the first Metros, but in less than 18 months went back to Copper with their tail between their legs, then Rover again in the late 90's with the MPi, which they also had issues with that were biting them on the backside right up to 5 years after they ceased production. Respectfully, how the guy at home thinks he can do better here,,, well,,,,,

[yukonphil]

Spider, I think I might have had a stroke of luck, I went to see a friend who has a few Mini's as I took out my aluminium radiator and found it has a bottom outlet of 17mm ID due to very shoddy welding. I wanted to measure the outlet of a standard radiator but during the conversation he mentioned he had a brand new 4 core brass rad for sale, £50. Needless to say it's now hanging from the front of my trike, much heavier and thus more efficient I hope and around 25mm wider core. I've ordered my Morris Minor fan and now have standard Mini hoses connecting the rad so I'm quietly confident this will drop the temp significantly, mebees to the point of only needing one rad even? Time will tell.

[yukonphil]

Shooter, it's an 82 degree thermostat and the frame is GS1000 front into custom rear.

[Ethel]

Let us know how it goes. The inlet on the water pump won't be that much bigger than 17mm I bet, but a mm in diameter is a lot in cross sectional area at those dimensions.

[yukonphil]

Yeah, with the new rad and standard hoses I've got much, much more flow potential

[m1n1]

Hi, i might be wrong as i cant quite see but is the heater outlet going back into the bottom hose heater take off? that is just recirculating hot water back into the engine without being cooled.  

[Shooter63]

Shooter, it's an 82 degree thermostat and the frame is GS1000 front into custom rear.

The reason I asked is why didn't you use a bike rad, they tend to be tall and thin, fitting in front of the down tubes, but obviously the GS1000 was an air cooled bike, but a couple of brackets welded on would soon sort that out.

Shooter