Those damned heat shields

[maydharm]

Hi all,

Those of you at Brands on Sunday who heard me park up will know what i'm talking about,the car sounds like crap with its heat shield rattling away happily . Anyway i'm replaceing both engine mounts on Sunday and thought while i'm under the car i'd rip the thing off.

My question is is it wise to run without heat shields?

Cheers Jon.

[silverfrost]

Hi Jon,

Yes mate the heat sheilds are there for a reason, the constant heat without them will damage the rubber engine mounts dramatically reducing the mounts life! And as you probably know the mounts are not cheap! Not sure how much the heat sheilds are from lotus but if you look at merlin motorsports website they sell heat sheild material, its light alimium and can be in either two or three layer, then just cut to shape. Its good stuff as i have used it on the v8 conversion for the mounts on my car. Regards danny

[maydharm]

Hi Danny

The car is going in for work on the exhaust on the 16th i think i'll get them to do something with them.

cheers Jon

[act2007]

Hi Jon,

The rattling came from the exhaust manifold heat shields, and I don't think it's wise to run your car without those. You can check & see if your exhaust guy can weld it but it is very very difficult to get to the heat shields while they're in the car. It may be difficult for them to try and weld it.

Alan

[mike_sekinger]

Hi Jon,

Hateful ex. manifold heatshields

The problem is the guage of the sheet used. The constant heat and vibration cause cracks/splits in the shield and hence the awful

[sanj]

I have a new RH heat shield for sale in the US if anyone needs one.

[Jonathan]

If you can get them off - post a picture and lets see where the cracks are.

Failing all that I would look at stiching (with stainless wire) or riviting a thermal blanket onto the heat shield which might stop the problems.

Depending where the cracks are, might highlight the issue - looking at the R&B heat shields they are pressed which might not be ideal, what might be as easy is to make them out of 3 pieces of stainless and use rivited tabs to hold them together, if you're careful with the rivits the metal will be free to move and expand / vibrate without causing cracks.

[Günter]

the cracks come usually directly from the point where the nut & washer holds it on the manifold. Mostly as the is one round hole, and one is larger -to give some way for the different temp-reactions of manifold and heat-shield. If the second one is to tight you loose this ability and it gets hugely stressed of time. Best thing would be longer studs into the manifold and on top of the washer one of the copper 'exhaust-nuts' , but not entirely tightened all down.. .

As I could not get those stuff there was the simplest way by just use an *Dremel*-grinder, and work the cracklines out. reweld the material after the stresses and bend had gone, and add (with weldspots, as you can see..) some other stronger [but softer] steel on the backside.

[maydharm]

Hi all.

It's the r/h shield, with the wheel off I can see the nut is missing & the stud has no thread left.

Hopefully my exhaust guy will figure something out he works with s/steel so it should'nt be too hard for him.

Cheers Jon.

[Günter]

this perfectly illustrates the stresses over all those years: the rust fixed it in position totally, there was no way to go. Therefore a lot of cracks under the big washer, and around that in a circle. The bend shape shows the way it wanted to go there.. .

[act2007]

Jon,

This happened to me not too long ago. Check and see if the stud simply fell off or it broke. In my case the stud fell off so I just got a machine screw & put it in with washers on both sides & it solved the problem.

Alan

Hi all.

It's the r/h shield, with the wheel off I can see the nut is missing & the stud has no thread left.

Hopefully my exhaust guy will figure something out he works with s/steel so it should'nt be too hard for him.

Cheers Jon.

[Jonathan]

IC

If you put longer studs in there (pref stainless) and enlarge the hole you can fit spring / sprung washer on it so that it holds it on firm but not tight so that it cannot move.

If you're nuts come loose drill em sideways and tap a thread in there for a tiny grub screw. Similar to what Gunter says.

They do look a bit fairey, 2 ply would work as well.