Bonnet insulation / sound deadening pad?

[Grizzly]

I was just wondering what every one does with the Bonnet's felt pad?

I was going to leave it off but it had one one before and with the amount of heat generated from the engine on grp i didn't want any air bubbles expanding thus causing issues with the paint. I did think the padding may help with engine to bonnet impacts but after spending a bit of time checking clearances i don't think i'll have that issue any time soon.

Sounds easy enough just put a new Felt pad on but no its not quite that simple, every Elan i've seen about with the original type pads on have had the felt separate so it goes saggy or areas start to come off and i'd like to avoid this plus you get lots of bits of felt all over the engine bay after a while. I spent allot of time removing all the old paint from the bonnet and epoxy primed inside/out over bare grp so i know the paint is not going to come off which is one issue down.

So i'm thinking about buying some universal bonnet insulation of ebay and giving that a go but i thought i'd ask what others have tried first.

[elj221c]

Threw mine away as soon as I got my car home. It was sagging badly.

Just adds to the potential for fire, in my opinion.

Who needs soundproofing in an Elan anyway. They aren't the quietest of cars!

It would have also got in the way when I put the tall block engine in.....

Didn't paint the underside as that would have covered over the matching unit number....

[Grizzly]

I agree it looks bad / tatty But!! at the same time it does a job, it keeps the heat from the engine off the GRP bonnet (Grp doesn't like heat). Its a bit of a miscomprehension that its there for engine noise, i've just got the paint on my Elan how i want it so taking precautions to keep it that way

[mbell]

Have you thought about the reflective type materials?

The type a lot of people use down near the footwells. Far from original or orginal looking but it should protect the GRP well, last a long time, no issues with water and expect it is very light.

[Grizzly]

Have you thought about the reflective type materials?

The type a lot of people use down near the footwells. Far from original or orginal looking but it should protect the GRP well, last a long time, no issues with water and expect it is very light.

I have been to a car Audio shop this morning to see if they have anything they could suggest and the only thing they have for this sort of job is Dynamat DYNAMI 11905, they didn't have any in stock but i believe its self adhesive approximately 1/2" thick and has an Aluminium appearance over a foam core. So i've ordered some of that and we'll see how it goes should be ok just as long as its not covered in Dynamat logo's

http://www.jegs.com/i/Dynamat/327/11905 ... tId=763881

[pharriso]

Surely the elan did not come with any hood (bonnet) insulation?

I know... Don't call me Shirley!

[richardcox_lotus]

That's what I thought. The underside of my Sprint bonnet had some form of gritty substance to act as a sound barrier. Now gone as part of the re spray.

[saildrive2001]

No insulation on the bonnet in my car.

[mbell]

Interested to here your thoughts on the dyna mat material.

Come on guy's (and Shirley ) this is Lotus it is never going to be consistent or predictable. I could see that the later SE models or +2S might be meant to have it but whether it got fitted or not probably is more dependent on how much Dave had to drink the night before than anything else. If a car did get it it probably fell or or got removed a long time ago.

[Grizzly]

I am a car painter by trade and i've done allot of work on GRP cars so as far as i'm aware all grp cars require good heat protection or the bubbles in the laying process expand and the GRP resin dries out (makes it very easy to cause stress cracks) the first time you try and Bake a grp panel in a low bake oven it becomes very clear that they dont like heat

I also have the advantage of having a one owner Elan that i know the Felt matting is original because it was one of the things that drove him mad about the car, he complained about it saying he was going to rip it off but thought it was padding to stop the engine making contact with the bonnet so he left it on, when i took it off it was only just on and the glue had pulled the black paint off in area's and in other area's the felt had separated so had rubbed the paint off the cam cover (looked a mess) it was the same felt type material that is used between the body and the chassis.

[rgh0]

My 68 S4 certainly had the felt matting on the underside of the bonnet when I first got it. It was soaked in oil and dirt and falling off so if removed it soon after I go the car. I use material like listed below on the bonnet section directly above the exhaust these days which is the only area that gets significantly hot. I glue it on using the high temperature silicone gasket forming material ( the red or copper coloured ones) as this sticks it on well but it is easy to remove if you want to renew the heat shield. I use the same material on the side of the foot well and on the section of firewall behind the exhaust.

http://www.thermotec.com/products/16850 ... rrier.html

cheers
Rohan

[reb53]

I got my Sprint when it was 5 years old and it had nothing, maybe the PO binned it.
Since re-painting it 23 years ago I've had nothing, and no problems.
If I was going to do anything I'd probably just glue some nice shiny aluminium foil on there to reflect the heat.
Or you could do what Gordon Murray did in the McLaren F1, line it with 24K gold foil.....

Ralph.

[69S4]

Same as Ralf - I've had my S4 since it was new enough to still have some original parts and never knew there was supposed to be a bonnet liner. I've often wondered whether exhaust heat would damage the paint or the structure of the glass fibre - particularly when I've been stuck in traffic for an hour or two, but to date it hasn't happened.

Now that I know there was supposed to be something there it'll go on the list of winter / spring projects. Anyone got a picture of what it's supposed to look like.

[reb53]

If it isn't broken Stuart, why are you planning on "fixing" it ?

Ralph.

[richardcox_lotus]

Yes a picture would be helpful