14 replies to this topic

[johnnysti]

Hi all
Ive recently brought the love of my life and am using it now and then to commute to work.
The problem is that the other day it cut out a couple of times in the Oxford traffic jams and i put it down to the amount of heat under the engine saturating the air into the filter.
Right or wrong, i want to do something about the heat under the bonnet. I cant believe how hot it gets under there. So ive ordered a super 2 core rad with an uprated four(or two) blade fan that is ment to keep it cool in that department. There other thing i thought of doing is wrapping the manifold with exhaust heat tape.
Please could someone tell me if its a tricky job to get the manifold off of a mini?
Im not after a performance gain, just looking to keep it as cool as poss under the bonnet.
Also just to let you know that its had quite a bit of engine modifications if that helps. The work was carried out by Somerford minis which is just down the road from me.
Thanks for reading!!
Johnny

http://img.photobuck...nyst1/baby2.jpg

[dklawson]

I can't comment on how hard it is to remove the standard iron manifold. My car has the early Cooper-S exhaust which is not easily removed with the engine in place.

Regardless of how easy (or not) it is to remove your manifold, be sure to wrap the "downpipe" also. You want to continue the wrap down from the head to where the exhaust turns towards the back of the car. I wrapped mine last time I had the exhaust out and it does help. However, most people report that the wrap will shorten the life of the standard, mild steel pipes. It becomes a trade off... lower under bonnet temperatures vs. shorter life of the downpipe. If you find you like the results, you may want to source a replacement pipe in the near future and have it ceramic coated. This will give the same thermal results w/o reducing the life.

[johnnysti]

Thanks for the reply DK

Its a performance system so i believe so at a guess it think it is stainless steel. Should this last longer than the standard iron one? I was going to wrap the complete manifold to the bottom of the branch where it goes into a single pipe. I just wanted to see if it was a pain to remove really. I wrapped the down pipe on my impreza turbo and that really wasnt easy but worth it in the end. I just dont trust any garages round my way to do it properly.

Johnny

[Dan]

Bear in mind that all this stuff does is move the heat somewhere else, further down the pipe. It means the pipe that runs under the passenger compartment will be a lot hotter (and I mean a lot, I speak from experience) which will heat up the cabin floor and so the cabin. It also means that more heat is conducted into the mountings, which are made of rubber and so will fail sooner. I ripped the stuff out of my car when I couldn't take it anymore. Great for racers, not ideal for road cars. So long as you have carb heat sheilds it shouldn't be a problem, even turbo's don't use this stuff much.

[johnnysti]

I havent got a carb heat shield!!!
This may be a problem.
Where can i get one from?

Johnny

[Dan]

Aha! You should really use one on a tuned engine with a tubular manifold. Most of the Mini specialists should sell the part, it'll probably be listed as part of a pair for twin carbs. Or if you're using an HIF carb you'll need the one for a turbo.

[Jackman]

Can you make a heat shield for the hs4? If so what can you use?

[dklawson]

You can use almost any metal to make a heat shield as its job is to block radiant heat. The factory ones (on early cars at least) were regular carbon steel. Aftermarket ones are available in stainless steel. (You could even use aluminum... but it would probably fatigue and break over time AND it may carry some additional heat into the manifold. The best choice would be light gauge stainless steel). A buddy of mine made some for his Triumph using heavy gauge, lazer cut stainless. That was gorgeous.

Dan's experience with extra heat getting into the car from a wrapped manifold/header isn't the same as mine. However, I think it's all relative. It's so beastly hot here in the summers that I don't drive the Mini a lot on supper hot days. With sliding windows ventilation is at a minimum... making the car uncomfortable at best (with or without a wrapped header). SO, if he says wrapping the header makes the car uncomfortable, I accept his comment and I'd take it under consideration when making your decision. On the other hand, if you lived where I do and drive an early sliding window car, I doubt you'd feel the difference.

[johnnysti]

Thanks for all the help.
Ive got a single carb so what will i need to look for as per heat shield. Im not sure on what all the "HIF carb" and "hs4" things mean? Sorry to be such a spaz!!

Johnny

[johnnysti]

Is this the carb heat shield i need? My car is a pre 92 though and i cant find a heat shield for that.

http://www.minispare....aspx?pid=34097

[Guess-Works.com]

HS4's don't have heat shields ( unless in a pair ) HIF's have a small square plate which is sandwiched between the carb and the inlet manifold. Nothing like what you have there..

Also I've never found exhaust heat to be a problem on a normally aspirated road car, but maybe that's just me.

[Teapot]

Hi johnnysti -- I'll keep an eye out for your car -- pretty eyecatching so I shouldn't miss it! :grin:
My MG Metro engine, which I was told tends to overheat, has a two-core supercool rad. For a while the needle hardly ever got off the C (too cold in fact). But it was running rich and when the krypton tuner was plugged in the mixture was leaned off, and going to the Nurburgring and back the needle sat on N or near, so I'm happy.

[johnnysti]

Thanks teapot!! There are a few nice ones round our way.

Its my bday next week and am getting the two core rad and uprated water pum from mini spares along with a new manifold aswell.

Im guessing at the under bonnet heat problem being the reason why it kept cutting out in traffic the other week. It was hot outside and thick traffic(OXFORD!!) and it cut out twice and didnt want to start back up to the extent that i was just about to get out and push it off the road!! It was fine before that and after i left the traffic so i just put heat soak down to cause of it

Teapot, who did you use to krypton tune your car?

Thanks all

Johnny

[Teapot]

Teapot, who did you use to krypton tune your car?

PM on the way when I can find the details

[minimadandproudofit]

I think your initial diagnosis about heat being the problem may be wrong. I have had many minis, many have run in very hot weather, none have cut out due to overheating. Methinks you might have a different problem....my carpet caught fire after I put exhaust wrap on my car....this was both worrying, unpleasant and smelly....and it makes your feet hot :saywhat: