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Exhaust Manifold Heat Shield

PostPosted: Mon Jul 10, 2017 5:51 pm
by William2
Just by chance after a good run out, I lifted the bonnet and was rather alarmed at how hot the car bodywork was adjacent to the exhaust manifold. I had read that stainless manifolds throw out more heat as well. I decided to fabricate a simple heat shield from aluminium sheet and angle so that I could fit it from above the footwell as drilling the mounting holes would be a lot easier. I also made sure there was a small air gap between the plate and the grp panel. Hopefully this will make a big difference.

Re: Exhaust Manifold Heat Shield

PostPosted: Mon Jul 10, 2017 6:27 pm
by Grizzly
When i rebuilt my Elan the end of the footwell's GRP had totally dried out and had turned to dust in a 3"x6" section, when i was reassembling the car i put Zircoflex self adhesive heat protection around the area and bought a Ceramic coated manifold which made a massive difference to under-bonnet temps (not cheap though)

Sorry not the best pic but you get the idea, since that pic i've added some to the front face, made a heat shield for the engine mount and Clutch slave.
p1030719.jpg and


You can see why i'm such an advocate for putting heat protection on the inside of the bonnet too, i've seen cars with discoloured paint above the Manifold so it can't be doing the GRP any good.

I'm sure i've said this before but i had a Stainless manifold fitted to my +2 and it would go through engine mounts on a monthly basis, for some reason it didn't click the mount was getting hot until one day the cover on the alternator melted so i refitted the Mild Steel manifold and the problem went away.

Re: Exhaust Manifold Heat Shield

PostPosted: Tue Jul 11, 2017 1:49 am
by prezoom
Last evening, I started the engine in my Zetec Plus2 conversion for the first time. The entire exhaust from the head to the muffler was ceramic coated. Based upon my initial running of the engine, the coating was well worth while.

Re: Exhaust Manifold Heat Shield

PostPosted: Wed Jul 12, 2017 1:40 am
by cbguerrajr
interesting...I was about to start making a very similar heat shield for the foot-well, except planning to use a sheet of Teflon, about .060" thick and aluminum angle to hold it at the top. the Teflon sheet could be right up against the FRP because it is a good insulator.
plan to use the same materials to make a heat shield under the clutch slave cylinder and also another shield on the rear side of the motor mount.
the underside of the hood/bonnet has been reinforced with layers epoxy/fiberglass, which is much more heat resistant than FRP and also the additional thickness reduces the temperature of the shiny side.
unfortunately, not adding lightness!
Carlos

Re: Exhaust Manifold Heat Shield

PostPosted: Wed Jul 12, 2017 5:33 am
by john.p.clegg

Re: Exhaust Manifold Heat Shield

PostPosted: Wed Jul 12, 2017 4:44 pm
by alan.barker
On my Elan Sprint there is a thin sheet of alloy that is riveted to the grp to protect from exhaust manifold heat.
Alan

Re: Exhaust Manifold Heat Shield

PostPosted: Wed Jul 12, 2017 5:55 pm
by pharriso
alan.barker wrote:On my Elan Sprint there is a thin sheet of alloy that is riveted to the grp to protect from exhaust manifold heat.
Alan


I don't think it was there when the car left the factory.

Re: Exhaust Manifold Heat Shield

PostPosted: Wed Jul 12, 2017 8:59 pm
by Grizzly
I have to agree with prezoom, the Ceramic coat may be expensive but in my opinion is worth every penny. Heat shields are good but they don't deal with the root of the problem so won't help your under bonnet temps.

Re: Exhaust Manifold Heat Shield

PostPosted: Thu Jul 13, 2017 9:27 am
by alan.barker
pharriso wrote:
alan.barker wrote:On my Elan Sprint there is a thin sheet of alloy that is riveted to the grp to protect from exhaust manifold heat.
Alan


I don't think it was there when the car left the factory.


Maybe the alloy sheet was riveted in place when it was buit up from a kit at TollGate Engineering Rye by Terry Tozer and used as a demonstrator for 2 years.

2nd owner was a women for 23 years and always serviced by Miles Wilkins including a Chassis change Lotus Galvanised August 1985 ?3,119.89 . I don't know if Miles added it when doing the Chassis change.

3rd owner for 2 years never did anything to it, he had no money.

4th owner me since 1999 i didn't add the alloy heat shield.
So another Lotus mistery :roll:
Alan