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MG Midget and Sprite Technical - Running slightly hot

Zetec Migdet mk3 is currently running slighly hot. It ran fine beforehand - no issues at all cooling wise and yes I know it is warm out. However, since bashing the front end - accident on the drive don't ask - and thus writing off and subsequently removing the front assembly panel which sits in front of the radiator, I think I have also removed some the ducting effect that panel did in directing much of the air to the radiator. Note the bonnet is a GRP Ashley so not standard by any means. I think if I simply fashion a sheet of ply/thin guage SS or similar either side of the radiator upright to the sides of the air intake it should improve matters...what say you?
Oggers

yep
I find the 1.5mm clear plastic from the garden shop is great for making ducts and it's flexy enough to bend and mould where you want it to go
William Revit

I made a fan duct once (not for a car - a big AC unit) from a cheap plastic bucket. Once you cut off the base and the rim the rest can be moulded easily with a hot air gun type paint stripper. Any colour you like!
Greybeard

The main benefit of radiator ducting isn't so much in directing air to the radiator as blanking off the areas to the side of the radiator to stop air from spilling around it. The so-called splash panels on standard cars are really there to serve this function.
GuyW

Guy - I have free space of around 16 inches from the front of the rad to the intake in the bonnet. The thinking is to create some sort of ducting/funnel call it what you will to direct as much cool and flowing air as possible from the intake to the rad - instead of it swirling about and escaping somewhere else. From above it will form a VEE shape splaying outwards to the extremeties of the intake. Thinking of also blanking off underneath this. It will in essence do as you say.
Oggers

Yes Oggers. Good idea. I am sure that will improve air flow through the rad.
GuyW

I am still amazed that the standard rad manages! Beforehand the temp gauge was on 70 deg when running, hotter now admittedly. Not much thermal lag in there though for the engine when stationary. Electric fan defintely required, may even buy a larger one. I do have a larger Westfield rad, but a bit tight up front to get it to fit.

Car is a blast though and handles beautifully. Headlining of the hardtop to do - then basically finished, well for the moment anyways....
Oggers

Did your other car sell then?
GuyW

Yes I did - 6100....No idea if that is good or bad.
Oggers

Sounds pretty good, but it was a nicely spec'd car. I suspect your location limits interest a bit and maybe knocks around 10% off what you might have expected down south.
GuyW

Oggers

My assumption has always been that the best arrangement would be to have a large entry funnelling the air down to the radiator.

I think it was David Stapleton talking about reducing drag in a recent thread who got me thinking. I decided to try to restrict the air being collected by the Sprite's wide front opening. I made a couple of panels out of clear acrylic. These sit behind the grille, blocking the side sections and then duct air collected from the central area direct to the radiator. I haven't noticed any difference in performance or in the cooling, though the gauge did actually go as high as N on its last outing on a very hot weekend! The benefit is probably purely psychological, but I enjoyed the exercise.

The main reason for posting, however, is that I thought you might be interested in this article by Willem Todt: http://www.linkedin.com/pulse/air-ducts-down-earth-guide-motorsport-applications-willem-toet

Contrary to what I had assumed, it seems a divergent duct may be more effective and, if your Ashley grille opening is as I think it is, it might lend itself well to a diffusing duct.

Hope it provides a bit of food for thought.

Colin
C Mee

Guy - Indeed so. Living within the Tundra does come with disadvantages. Miles away from large populations and thus a potential market is very restricting. Mind that said, the buyer resided in Kent - about as far away as you can get!- and had it collected for, I think, a very reasonable 300. It also has distinct advantages, for in this glorious weather, the roads and scenery are sublime, and literally nothing on them save the odd pheasant/deer/sheep/buzzard/kite/lost tourist.

Colin - very interesting. Thanks. The grille is about 8 inches wider than the rad, so I do feel some form of angled side panel each side would help - a funnel if you will. - This would make use of the otherwise spilled/wasted air to increase the volumetric flow of air through the rad, and thus make it more effective at cooling the engine.
Oggers

Oggers, no need to "sell" Scotland to me :-) (I am in Fife as I type this) Best Spridget roads in the UK! Shame the tourism marketing folk took it on themselves to promote the NW500 though. I hear those fabulous roads are now clogged with convoys of creeping campervans

And not a surprise that someone genuinely interested would travel from Kent. But the number of potential buyers is still somewhat reduced. But you only need one of course!
GuyW

Colin,
does this David Stapleton also do books? :)
Nigel Atkins

Guy

NW500 is indeed clogged - as is Skye for the same reason. I guess tourism is rapidly becoming more important for Scotland - hence the marketing drive. Not as bad as the Lakes on a sunny Easter weekend just yet though!
Oggers

Just fabbed up from some ply and tested - a good 5 deg cooler on the gauge under simalar external conditions - result I feel...
Oggers

This thread was discussed between 31/07/2018 and 03/08/2018

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