Heat under bonnet

[Pembroke Pat]

I have been told that I should either put in a heat shield above the manifold or I should wrap the exhaust as there is a danger of over heating the bonnet.  Is this true?  Should I do it anyway as for performance reasons?  ( Oh forgot to mention I have a 2l zetec with Westfield exhaust ( just don't go there . I have the exhaust and it is in)).

Thanks

Pat

[fordy]

You can put exhaust wrap on the manifold - but ive heard that this pushes the heat further down the pipe and can sometimes cause the welds between pipe and silence to crack prematurely - my yellow bonnet goes a little darker during running above the exhaust, but there is no cracking or anything, and has done 7K miles like that.  unless your manifold is less than a couple of inches away from your bonnet, i dont see how you could overheat your bonnet.

[Pembroke Pat]

I am also rather concerned by the proximity of the starter motor and cables to the manifold.  

I might try compromising and wrapping near the starter to prevent excessive heat there as well as wrapping at the top of the manifold to partially shift the heat away from the lid.

p.s. I am virtually finished and am putting in the engine management loom at the moment ( hopefully in a week or two I will be able to start her up for the first time).

[Westfieldman]

My 1800 Zetec and Westfield manifold has been fine unwrapped I would say leave it as it is.

I shortened the wires but for weight [every little helps] as much as a fire risk.

Paul.

[Barry Ashcroft]

What about a V8? Any idvice as I could hardly touch my side panels as they where that hot! Sure they will melt after a hard blast.

[Pembroke Pat]

I will reserve judgement until after I have started up the engine for the first time ( next week maybe.....)

[Julian N]

I am also rather concerned by the proximity of the starter motor and cables to the manifold.  

You could just put bodge a piece of aluminium sheet around the starter to protect it.

[neilwillis]

Bodge? what can you mean?

Do you mean engineer to exacting tolerances?

   

[neilwillis]

I read somewhere else here a warning about the danger of metal foil heat insulation and starter motor terminals.....

The two don't get on well together - far from reducing heat, you'd get lots - and flames, smoke, sparks galore.......

[Mike]

i once seen a westfield with a 2L VX engine, who put some type of heat reflective material on the underneath of the bonnet instead of on the engine ( manifold etc). dont know how much difference it makes.

mike

[Turbowestie.co.uk]

If your that concerned why not fit a V8 bonnet, or add some vents to your bonnet? Heat proof material on the under side of the bonnet will help protect the local areas for sure, but ultimatly as hot air rises it has to go somewhere?

I dont know about nat asps in Westfields but when i come to a stand still in mine the heat haze pours out of the bonnet vents even on a slowish run.

[neilwillis]

Stop it TurboWestie, you're making me drool!!!

Do you get flames from the exhaust on overrun too?

[Turbowestie.co.uk]

LOL yeah i do on over boost, the first time i noticed it was at night time, i see red flashes in my left rear view mirror and thought oh s**t the old bill, (some northants cop cars have blue and red lights) slowed down then realised it was unburnt fuel on the boost limit..hehe, was just glad i didnt get a speeding ticket errrr not that i was speeding officer

[neilwillis]

       

I'm just getting mine ready for SVA, and the carbs need a little attention.   I get lovely long blue flames spitting out of the trumpets, and it pops and farts beautifully.

Do you reckon i can get em tuned and keep the bad tempered exhaust noise?

       

[Pembroke Pat]

I think that venting the bonnet will happen although I was planning to do this post SVA.

Metal shielding the starter sounds like a really bad idea.  

I still think that wrapping the exhaust is the best solution.  If I get cracks in the exhaust then I can get it rewelded fairly easily.  Also I can allow additional give by slackening the clamp from the collector to the silencer.