To Suck Or Blow

[stevedohc2b]

Hi To suck or blow is the question? I have my rad fan mounted in front of the rad and at the moment it is blowing air through the rad in to the engine bay,and at me the driver.I sat in a jam on monday and I nearly cooked. I do not have any bonnet vents all the heat seamed to be comming around foot well. So if The fan sucked the hot air away from me would this work ok for engine. I did have it ticking over when first fitted with the fan sucking and did seam ok.

So is a blow job best or a good suck!!??

 

 

Any view would help

Thanks

Steve DOHC2B Altwasser

[Guest Steve Allen]

Hi Steve

I would say you have it the right way. If you turned it around you would cause the air that natuarally comes into the nose cone (Whilst Moving of coarse) To fight each other. Should the fan kick in whilst your moving. I did this and it caused me to over heat. At least the way you have it both push the air in the same direction.

Fit some side vents would be the answer.

Ps off for second SVA today so what do i know.

Hope this helps

Steve

[Guest Ant]

Most of the heat reaching the driver is coming from the exhaust manifold, particularly if you've got a 4 into 1 whish has more surface area than the twin pipe setup. The air is coming in through the radiator, being heated further by the manifold, and then hitting the drivers legs. Ever sat on the passenger side? It's much cooler that side.

 

So ... a good first step to reduce the problem is to prevent heat escaping from the manifold. Either use exhaust wrap, or ceramic paint (I went for this option), or even both. Bonnet vents will help too, but keeping the heat in the exhaist gas in the first place is a good idea, and it is claimed to give a couple of extra horses of power too!

 

Ant

[Big Jim]

You can do what ever you want with the exhaust etc. the only way to stop yourself getting cooked, is to stop the heat coming into the passenger cockpit. that means paneling in completely over the pedals, getting the firewall to actually seal with the bonnet would also be a good step, because it's miles off on a 2B!

Bonnet vents etc. will help the engine run better as the hot air gets away much faster, thus cooler air for the carb.

[stevedohc2b]

Thanks for the replys I have the dohc car so the exhaust is on the passenger side.

Have not cooked a passenger yet. the fan cuts in a quite a high temp 98c I think on this engine so the chance of it cutting in while moving is quite remote.

Dose this happen on the pinto cars ie do you cook in a jam.

Also can heat affect the cluch as I had a problem getting in to rev at stoneligh the other week.( mt 75 box)

thanks

Stephen Altwasser

[Les Welsher]

Ant,

Steve has a DOHC engine so the exhaust is on the passenger side.

oops, got there before me.

 

Steve,

As Jim says, make sure the firewall has a good seal with the bonnet (I had to make mine over 2" higher to reach the bonnet)

 

Put some nice big bonnet vents in to let the hot air escape, I have the alligator vented bonnet and have had no problems in hot weather.

 

There was a thread about this

Do a search for 'MY LEGS ARE HOT'

 

Les.

[Swan Jnr]

Dose this happen on the pinto cars ie do you cook in a jam.

 

Our Pinto had the standard viscose fan, sierra heater matrix, and bonnet vents and never cooked itself once, despite occasionally being stuck in hot weather in traffic.

 

the only problem was that when the car was built it didnt have a shut off valve to the heater matrix which meant that the passenger tended to get nicely roasted legs, because even without the fan on the air was still being forced through. After a while though this heat would gradually drift across to the drivers side. One day driving in shorts it got so hot that the petrol key dangling from the ignition burnt my knee!

 

fingers crossed that with the new electric fan, and valve all should be solved.

 

Paul

 

counting the days....

[Big Jim]

Swan Jnr, Read the original post properly!

It wasn't about the engine cooking, but the driver. So basically you've got the same problems.

 

for bonnet vents, I recommend the ones on here, and if you look, they also do the other type as well.

[stevedohc2b]

THANKS JIM I WILL ORDER THEM ASAP.Do they only stick out or do they go in a bit. thinking about servo etc.

re heater I also have the heater on all the time and will have to look at that one as well?

 

Stephen Altwasser

[Big Jim]

They go inside the bonnet space by about 20mm 'ish

[stevedohc2b]

Jim Have placed an order.Whats the best way to cut holes. I have a nibbler.aviation snips. jig saw. angle grinder.?? I think i need to get this done before Le Mans.

 

Ps what happened about the Le Mans menu?

 

Thanks

Stephen Altwasser

[Guest mickmellors]

Le Mans Menu and order forms will now be handed out at Le Mans to be filled in and returned immediately - then we place the block booking.

[Guest daveg]

All

 

You could have a switch that reverses the rad fan....if you are stationary, set it to suck, if you are moving set it to blow

 

Dave

[Peter Bell]

I used a jig saw to cut the holes from the inside, IT IS VERY NOISY! mark it out with masking tape. Be careful about positioning, too far back and they will clash with the pedal box. On that side anyway, (sorry this is a monocoque I am thinking of)

Peter

[Big Jim]

I personally plaster masking tape where the vents are going (check either side that they won't touch anything, as they do stick through a bit) draw round the part that goes through, make sure that it's level with the edge of the bonnet, then i would cut using a disc grinder, with a cutting disc on. I don't like jig saws. they always snatch when I use them :angry:

grind up to the lines and that should be it. I use a bit of silicone behind the flange just to make it neat.