wheel arch holes for improved cooling

[rocket]

My plus 2 is a bit warm inside in hot weather,i see that some elans have mesh covered vents in wheel arch to allow some engine heat to escape.Anyone done this mod on a 2?

Ian.

[bcmc33]

My question has always been - why on one side only? Would it not be better on both sides?

I recall seeing an Elan some years ago with a chrome grille in the centre of the bonnet parallel with the plenum grille and thinking how good it looked. For this to work, of course, there would be the need for some means of preventing rain water flooding the plug recesses.

[rocket]

I wondered why only one side myself Brian,maybe to keep water away from the coil etc? I agree with you about bonnet grills looking good but i dont want to change the appearance of my car.Im also wondering if cutting holes in my glass wheel arch would weaken it in any way?

Ian.

[hatman]

I wondered why only one side myself

The much hotter manifold side?

[rocket]

Yes hatman that crossed my mind but id expect the air under the bonnet to be mixed around so as to even out temperature on either side..im probably wrong..


Ian.

[msd1107]

The wheel well is a low pressure area.

Under the hood is a high pressure area - the air from the intake has no where to go.

So I might think that the low pressure area in the wheel wells will help exhaust the hot air under the hood, no matter on what side they are.

There have been people who have installed the exhausts on both sides. Some have drilled two or more holes. Usually install some screen or mesh to keep the worst of the crud from the engine bay.

Any other theories?

David
1968 36/7988

[bcmc33]

The much hotter manifold side?

Again, that did cross my mind but I didn't think that was a good enough reason. The flow of air through the engine bay has always been an issue with the Elan, and a lot of concerns always seem to be regarding the possible blockage of air flow through the front grille. It seems obvious to me that if there is an easier way out, the flow through the radiator will be that much greater.

It so happens that I've drilled two holes on the RH side in an attempt to improve things, but have to admit not knowing if it has. I'm working on the basis that there has to be some degree of improvement. I don't see why that theory should not apply to the +2.

BTW, it was my intention to buy a side grille from Matty to cover the new holes on one of the few sunny days a couple of Saturday's ago, but got there after the spares counter had closed. In a straight line Matty is only 20 miles from me, but intoxicated by the sun's rays and the knowledge of so many country lanes of Warwickshire and Worcestershire, the long way round took more time than I'd allowed - 70 miles worth to be precise.

[rocket]

How big were the holes you drilled Brian?

[bcmc33]

They are 2.5" diameter - the same as the original holes.

[Carlos A]

Do any of you guys have pictures of these holes on the Elan and the Elan +2?

Carlos

[69S4]

I did this mod on my S4 about 20 yrs ago after reading somewhere (Club Lotus magazine maybe?) that it would improve cooling. I started with a 2" hole on the exhaust side but eventually it ended up about 4" diameter as the smaller one seemed too small to be functional.

If it made any difference at all I'm not aware of it. A couple of times, out of curiosity, I've covered it with tape to see if the temperature goes up but nothing seems to change.

My other worry, that floods of wheel spray would come the other way also doesn't seem to have happened. The mesh covering the hole is "fine grained" and would clog easily with road dirt but that hasn't happened either so I'm guessing that there is airflow into the wheelarch which is keeping it clean, but it's just not enough to make any difference to engine temp.

No pics at present but when I get the car back on its wheels later today I'll dig the camera out.

The grill in the bonnet idea is interesting. On several occasions when I've been stuck in traffic for long periods and started to squirm as the temperature climbed towards the bending the needle point, popping the bonnet open has brought it down again.

Stuart

[rocket]

I dont have an engine temp issue Stuart.I am trying to find a way to reduce in car temperature on a hot day..we did have one a while ago didnt we??? I am working on the theory that removing hot air from the engine compartment will reduce the heat transfer into the car..

Ian.

[john.p.clegg]

Before I get the hole cutter out,isn't there a big hole underneath the engine bay that the sump dangles through??


John

[69S4]

I dont have an engine temp issue Stuart.I am trying to find a way to reduce in car temperature on a hot day..we did have one a while ago didnt we??? I am working on the theory that removing hot air from the engine compartment will reduce the heat transfer into the car..

Ian.

I accept that but I thought the hole in the wing idea was originally touted as being something to help with engine cooling. If you're looking at keeping the interior cool the only thing I've tried that made a difference to this was to wrap the manifold with insulating tape down as far as the y piece. It definitely makes a difference on the passenger side (UK car). Doesn't do much for manifold longevity but does reduce interior temp.

I'm probably a few steps away from having this as a major concern. Like a dog walking on it's hind legs, the miracle with my car is not that it goes well but that it goes at all. I've grown to accept as normal that I boil on a hot day with the heater on trying to keep the engine cool and that I allow a bit of time for carb icing stops on winter trips. Spring and Autumn are ok though!

Stuart

[rocket]

Its not a major concern really Stuart,its just something im trying to improve.Its not cooking us just a little sweaty if its hot and raining and windows need to be up.Im not keen on wrapping the manifold as my engine performs well and i dont want to change this at all.I guess im lucky at the mo that this is my major problem of the year..

Ian.