Mini Cooper Cooling Testing
Mini Cooper Cooling Testing
(OP)
This thread is for the original Mini that was discontinued in 2001. The early Mini's used a side mounted radiator that fit in the left side wheel well. Air enters through the front of the car , takes a 90 degree turn and is pushed through the wheel well by an engine driven fan.The Mini has always been known for a poor cooling system. What series of tests can I perform to pinpoint the problem with this car's cooling system? Also, what is the best way to measure a pressure drop across a radiator?





RE: Mini Cooper Cooling Testing
2) A water tube manometer
Paging evelrod
Cheers
Greg Locock
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.
RE: Mini Cooper Cooling Testing
Good luck!!
RE: Mini Cooper Cooling Testing
I use a "Two Core" rad sold by MiniMania, stock replacement with the stock fan shroud. Fan is the 11 bladed yellow plastic fan---I once tried the OEM "tropical" fan and it seemed to work almost as well, but it's metal and heavy. I switched to the "high output" water pump with stock diameter pulleys. I have routed the heater outlet at the back of the cylinder head to the radiator tank via a 3/8" hose (to aid in cooling the #4 exhaust valve). I alternate between a 180f degree thermostat and a "blanking sleeve" to slow the water return to the rad and help prevent pump cavitation.
I use a 19 row (too big for street use) oil cooler with a remote mounted racing oil filter and a 3 qt. oil accumulator for a total oil capacity of 10 qts. (this is in no small way responsible for added cooling capacity). All this works for me, but is obviously not totally suitable for street use.
For my brief time with a street Mini, I used a "four core" radiator (hot setup at the time) that did NOT work all that well---"Two Core" along with the OEM 'tropical fan' was much superior in cooling. I did use a smallish ex-Sprite oil cooler---seemed ok on the streets and freeways of Southern California in the summer where temps in my area are often 110f and more.
When I hear of major overheating problems with Minis (all too often it seems) I first question the quality and condition of the radiator. You cannot use one indefinitely without service to clean out deposits, etc. Properly cared for, many older rads will work "forever" (My 30 Ford rad is still going strong), but many of the newer replacement parts are inferior in quality and construction, thereby limiting their ability to cool sufficiently, IMO. Stick with the basics, quality parts from trusted vendors and you will usually be ok.
Two additionl comments---Always use a fan, the bigger the better, IMO. The side mounted rad needs the fan to get the airflow pointed in the proper direction. It has been proven in racing Minis that a "remote filler tank" in the cooling system will prevent coolant loss and thus prevent overheating from that cause. Mine is mounted on the fender inner panel and is connected to the rad by the standard overflow hose. I use a 7 lb. cap on the rad and a 15 lb. cap on the remote tank. The overflow from the remote tank goes to a one qt. plastic bottle via a small dia plastic tube (no coolant has ever made it that far, at least not yet)!
www.miniamania.com www.minispares.com www,calverst.com
www.pegasusautoracing.com www.mincompracing.com
www.heritagegarage.com
Some vendors offer aluminium radiators, I haven't tried one yet, but the guys that use them swear by them. Kinda pricey but I want to try one if my situation ever changes. Like I said before, "don't fix it if it ain't broke"!
Rod
RE: Mini Cooper Cooling Testing
RE: Mini Cooper Cooling Testing
Rod
PS: Honda? Is that one of them thar Japanese cars?
RE: Mini Cooper Cooling Testing
I expect BMC at the time tested here and developed "tropical" or heavy duty parts before release.
We have quite a hot climate in most areas.
Once again, Rod Is Right. I would take serious heed of his advice.
Regards
eng-tips, by professional engineers for professional engineers
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RE: Mini Cooper Cooling Testing
RE: Mini Cooper Cooling Testing
To the cooling challenge..
One other point is the Mini vents the readiator air into the LHS wheel well which can allow a build up of road debris to coat the radiator thus reducing heat transfer.
I have to agree with the comments by patprimer above...well maintained Minis here rarely had any oveheating problems.
Author David Vizard's book "How to modify your Mini" holds a lot of information on this subject and is well worth seeking.
Cheers,Pete.
RE: Mini Cooper Cooling Testing
i used to employ an agressive cooling system cleaner once a year to get lost of the blockage and also used a pressure cap with a somewhat higher setting. that cured most of the problems, but not the original design deficiencies...
one additional item might be the fitting of an electric driven high capacity fan. my mini usually overheated not when driving at high speed, but when idling for prolonged periods of time after a fast drive. under those circumstances the engine driven fan does not give enough airflow through the radiator and heat may build up. a thermostatically driven fan that becomes active under those conditions made a big improvement.
RE: Mini Cooper Cooling Testing
Show me a car that WON'T overheat under those conditions!
carockwell.
It gets hot in Newport Beach? The folks up in Costa Mesa around Heritage Motors and Mincomp seem to manage the "heat" without undue stress!
Rod
RE: Mini Cooper Cooling Testing
RE: Mini Cooper Cooling Testing
Cheers
Greg Locock
Please see FAQ731-376: Eng-Tips.com Forum Policies for tips on how to make the best use of Eng-Tips.
RE: Mini Cooper Cooling Testing
I've only spoken to Don R. once in 2003 at Las Vegas where we were racing each other and my crew was helping fix his car's overheat problems due to a broken fan belt pulley (temps were in the low 100's). We got him on track, but, during the flag race, I saw him off course "steaming". I did not get a chance to determine his problem as they had loaded up and left the track before the end of the race. I suspect it was the pulley again (toothed belt type).
As to airflow, I'm in agreement that the side mounted rad is in probably the worst place that I could think to put it...then again, considering all the extra room in the engine compartment <grin>, where else could you put it?
When I was tinkering with airflow underhood, I blocked the grill to see what would happen...airflow was from under the front valence up across the front of the engine to the bonnet and then it would "spread out in a flower like pattern" missing the rad altogether...thus the "11 bladed fan". Of course I did not leave the grill opening closed, but it did give me some insight into what I needed to do to properly duct in my radiator (left wheel well) and oil cooler(right wheel well). As I said before, so far no problems, even with summer track temps at California Speedway and Willow Springs in the low 100's. My water hangs in around 200f and oil at about 190f on those days. I'd like to see the water a little cooler, hence the desire to one day try one of the aluminium radaitors.
I'm not sure how comparing a Honda to a Mini is valid. One is a modern thin wall casting design of the 1980's and the other is an antique design of the 1950's (actually the engine design goes back to pre war era)...apples and oranges.
I'm not trying to "pick a fight" here, but I see your quest for info as simply an academic exercise. Am I correct?
Rod
RE: Mini Cooper Cooling Testing
You did include in your question that
If you make a statement as a presumption that it is the cause of a problem, and others have evidence to the contrary, then correcting your inaccurate presumption is an appropriate answer.
and
There are 2 pressure drops across a radiator. One person took the trouble to accurately answer one possible meaning.
Re the guy at Heritage, just maybe he gave you good advice, you did not understand or heed, so he decided that in your case, there would always be an overheating problem, so he gave an answer appropriate to you.
Regards
eng-tips, by professional engineers for professional engineers
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