Tunnel insulation.

Tunnel insulation.

Author
Discussion

notaping

253 posts

70 months

Thursday 18th February 2021
quotequote all
It's more about the heat than the noise. A previous owner of my car obviously had a missing panel from the original insulation and this is what I found next to the cat on the drivers side (also melted carpet between drivers chair and tunnel)



Anyway - I like the noise. It's part of what makes the Cerb such a rush :-)

Mr Cerbera

5,031 posts

229 months

Friday 19th February 2021
quotequote all
TwinKam said:
Thanks Paul,
....
Do you have more pics/ a link to Simon's build?
Cheers,
Rik
Rik,
Simon is a contributor to the FB Cerbera Page

Here are the rest of my pics of his from April 2013.







HTH thumbup

Ummm, when yiou say "plastic tie raps"
Do you mean "plastic" or "tie raps"
Coz they come in Stainless too

Edited by Mr Cerbera on Friday 19th February 10:06


Edited by Mr Cerbera on Friday 19th February 10:23

NuddyRap

218 posts

102 months

Friday 19th February 2021
quotequote all
I gave quite a lot of thought to this when doing my body off, and didn't want to compromise on cost grounds alone given that the difference between doing a pretty good job and doing a better job is less than the cost of a tank of fuel.

TVR pop riveted little triangles of insulation to the tunnel, which was crude, and pretty ineffective. When I fetched my body off, most of my triangle bags were just fibreglass fluff with a bit of tape left, and it was quite clear that they would never have been that good to begin with. The chassis would also catch a fair bit of heat which as we all know affects the powder coat.

I decided to put insulation around the tunnel rather than on the chassis after asking around. This meant I used some acoustic heat shielding along the tunnel like this:
https://www.woolies-trim.co.uk/product/1938/acoust...

With then a roll of the thin insulation that was pop riveted to the inner wings and upper tunnel being bought from Powers for those areas too.

Additionally, I bought some silver 3M tape for the chassis rails themselves to protect the powder coat.

I then also picked up quite a lot of reflective heat shield sleeve to protect vulnerable wires such as the crank sensor etc, and the fuel lines as they passed along the top of the engine where they would be vulnerable to heat degradation.

Although the insulation I used down the tunnel had an adhesive backing, I decided not to trust this on its own and also pop riveted it to the tunnel, with penny washers around the rivets to spread the stress of the rivet location having noticed that the rivets on the remnants of insulation left on my car had just walked back through the insulation itself over time because of point loading.

I then took the approach of gluing and riveting the rest of the thinner inner wing insulation in place, with foil tape to neaten off the edges. I went over some of it again after this picture was taken.

|https://thumbsnap.com/JnMir7ba[/url]

The above picture is from when I just aligned the body with the chassis by loosely resting it near before going for the drop.

As a word of advice, ignore the tales of tipping the car at odd angles in odd ways to lower the body. Lower it straight down, rear first. The tunnel opens up when you drop it because the chassis diverges towards the front, so it just plops over. You have about 900kg of body weight working in your favour, which is safer and more sympathetic to everything involved than tipping it as 30 degrees and trying to waggle it down with perhaps 90kg of human power on the end of a crowbar, all whilst trying to avoid damaging your new chassis.

It didn't snag my insulation doing it that way either and it was really easy. The whole drop once I had the body hanging from the cranes at either end probably didn't take 10 minutes. I set aside a whole day to do the drop, and was done before I knew it.

Edited by NuddyRap on Friday 19th February 22:31

Classic Chim

12,424 posts

148 months

Friday 19th February 2021
quotequote all
NuddyRap said:
I gave quite a lot of thought to this when doing my body off, and didn't want to compromise on cost grounds alone given that the difference between doing a pretty good job and doing a better job is less than the cost of a tank of fuel.

TVR pop riveted little triangles of insulation to the tunnel, which was crude, and pretty ineffective. When I fetched my body off, most of my triangle bags were just fibreglass fluff with a bit of tape left, and it was quite clear that they would never have been that good to begin with. The chassis would also catch a fair bit of heat which as we all know affects the powder coat.

I decided to put insulation around the tunnel rather than on the chassis after asking around. This meant I used some acoustic heat shielding along the tunnel like this:
https://www.woolies-trim.co.uk/product/1938/acoust...

With then a roll of the thin insulation that was pop riveted to the inner wings and upper tunnel being bought from Powers for those areas too.

Additionally, I bought some silver 3M tape for the chassis rails themselves to protect the powder coat.

I then also picked up quite a lot of reflective heat shield sleeve to protect vulnerable wires such as the crank sensor etc, and the fuel lines as they passed along the top of the engine where they would be vulnerable to heat degradation.

Although the insulation I used down the tunnel had an adhesive backing, I decided not to trust this on its own and also pop riveted it to the tunnel, with penny washers around the rivets to spread the stress of the rivet location having noticed that the rivets on the remnants of insulation left on my car had just walked back through the insulation itself over time because of point loading.

I then took the approach of gluing and riveting the rest of the thinner inner wing insulation in place, with foil tape to neaten off the edges. I went over some of it again after this picture was taken.

|https://thumbsnap.com/JnMir7ba[/url]

The above picture is from when I just aligned the body with the chassis by loosely resting it near before going for the drop.

As a word of advice, ignore the tales of tipping the car at odd angles in odd ways to lower the body. Lower it straight down, rear first. The tunnel opens up when you drop it because the chassis diverges towards the front, so it just plops over. You have about 900kg of body weight working in your favour, which is safer and more sympathetic to everything involved than tipping it as 30 degrees and trying to waggle it down with perhaps 90kg of human power on the end of a crowbar, all whilst trying to avoid damaging your new chassis.

It didn't snag my insulation doing it that way either and it was really easy. The whole drop once I had the body hanging from the cranes at either end probably didn't take 10 minutes. I set aside a whole day to do the drop, and was done before I knew it.

Edited by NuddyRap on Friday 19th February 22:31
That’s a very comprehensive job. thumbup
I’m using Demontweeks insulation tape on chassis rails on my Chim in a similar way.
Has that tape held overtime.
How many miles have you done and does it take heavy weather ok. .
I’m just trying to decide if using this self adhesive tape is a good idea or not.
Thanks in advance.

TwinKam

Original Poster:

2,937 posts

94 months

Saturday 20th February 2021
quotequote all
Mr Cerbera said:
Rik,
Simon is a contributor to the FB Cerbera Page
That's a shame, I'll have to rely on you to copy and paste for me then, Paul!

Mr Cerbera said:
Ummm, when you say "plastic tie raps"
Do you mean "plastic" or "tie raps"
Coz they come in Stainless
Wraps even wink
I just think they scream, "I'm a kit car".
Sure, they have their uses, but IMHO they look awful on a chassis, so I'm exploring alternatives.

phazed

21,844 posts

203 months

Saturday 20th February 2021
quotequote all
We still haven’t heard from people who say that additional aftermarket heat insulallation makes a noticeable difference.

?

notaping

253 posts

70 months

Saturday 20th February 2021
quotequote all
Made a huge difference in my case. My left leg no longer gets cooked :-)

TIIVRS

78 posts

68 months

Saturday 20th February 2021
quotequote all
I used DEI floor and tunnel shield too, it’s slimline has a glass fibre backing and an aluminium top layer so should be super durable... works pretty well. If you go this route buy it from summit in the USA it’s soooo much cheaper.

TwinKam

Original Poster:

2,937 posts

94 months

Saturday 20th February 2021
quotequote all
TIIVRS said:
I used DEI floor and tunnel shield too, it’s slimline has a glass fibre backing and an aluminium top layer so should be super durable... works pretty well. If you go this route buy it from summit in the USA it’s soooo much cheaper.
Lovely job!

Mr Cerbera

5,031 posts

229 months

Wednesday 24th February 2021
quotequote all
As many of you know, I have bee 'doing a bit' on BlackBeauty© over the last few months so the time came to start her up and, after a few
initial teething probs, she now starts reasonably.

There are 2 'little' worrying things:-

The first is a god-awful graunching noise at start-up.
It sounds like an old starter drive crunching on the flywheel teeth
BUT
As you know, I am a numptie, so any of your wonderfully superior experiences would be welcome.
(Here's a YouTube Vid to show it (approx) 22 seconds in)

The second prob is the proximity of the engie bay insulation to the chassis member.
I remember seeing, on Wheeler Dealers' Cerb, that the body had to be cocked at an angle in order to squeeze it past the 'pinch' in the chassis top-tubes.
Well, now that the exhaust heat (and time) have destroyed the layer of my shielding closest to it, I am getting some smoke from the strands of what's left of the middle layer of shielding (approx 2:50 into the above Vid).
I have tried to remove the destroyed foil and heat resistant mat but I am stopped by the pinch at the chassis tube.

I originally panicked, thinking "the whole thing's gonna catch fire"
but after a coupla cups of Tetley's finest, coffee
I now think
"as long as I protect the remaining foil layer, still stuck to the engine bay wall, then the job should be a good un'.

In the longer term I intend to remove the Exhaust Manifolds and dead shielding
and then resurface the bay walls in a similar manner to you Stars above
BUT
I'm starting to miss the slipper-down feeling and am longing to just get her moving.

What're thoughts, chaps ?
AND
more importantly, as I'm just testin' atm, how hot can I let the current layer, stuck to the bay wall, get before I should worry ?

I know it's a bit vague
BUT
I hope it will prompt some lively discussion

Thanks chaps thumbupcoffee

phazed

21,844 posts

203 months

Wednesday 24th February 2021
quotequote all
Sounds like the starter solenoid is not throwing the starter pinion in to mesh securely before it cranks over.

TIIVRS

78 posts

68 months

Wednesday 24th February 2021
quotequote all
I had perished heat matting like before I replaced it and it hadn’t burned any of the fibreglass beneath so it’s possibly o.k as is. I use fibreglass matting like this behind a blowtorch when plumbing and it can take that kind of heat.

If you want to protect against the radiant heat soaking through to the footwell a reflective surface should help, Perhaps attach some aluminium heat shield with the help of a couple of rivets and/or stainless cable ties around the chassis rail, it’s pretty flexible stuff so is easy to mould and it also holds form.

https://www.carbuilder.com/uk/embossed-aluminium-h...

Otherwise perhaps some exhaust wrap?


Edited by TIIVRS on Wednesday 24th February 22:25

Byker28i

58,831 posts

216 months

Thursday 25th February 2021
quotequote all
phazed said:
We still haven’t heard from people who say that additional aftermarket heat insulallation makes a noticeable difference.

?
Honestly, noise wise I doubt it, but mines reasonably quiet anyway. Heat wise possibly a little in the cabin, but the main reason I did it was for more protection. The original was frayed and tatty so was replaced, and when the engine was out, I added more as the chassis rails had started to discolour near the exhaust in the engine bay

Robscim

792 posts

255 months

Thursday 25th February 2021
quotequote all
Hi Paul,

This probably doesn't help at all(!!!) but every once in a while, mine makes that noise when trying to start the car. However, it doesn't turn the car over. The solution is to stop, and have another go!!!

Sometimes it can take 3 attempts (rarely) but it usually goes when tried again.

I was advised by the garage when I bought the car that when it became a problem, they'd change the starter to fix it. That was almost 16 years ago and it's still on the original starter!! In fact, the starter has lasted longer than the garage (thankfully!!!). shootbandit

There, I told you it wouldn't help!! hehe

Cheers

Rob
P.S. Lux was always hot and humid in the summer when I used to go there for work - or maybe it was just the bars we visited!!! beer

TIIVRS

78 posts

68 months

Thursday 25th February 2021
quotequote all
It made a HUGE difference to mine, cabin temperatures were dramatically reduced, as well as the DEI on the tub I also protected by the chassis rails - took a leaf out of the book from later tvr’s by using some ally shielding where the manifold goes down, so I effectively have a double layer where it gets really hot.

Thankfully the noise doesn’t seem to have been affected at all!

Mr Cerbera

5,031 posts

229 months

Thursday 25th February 2021
quotequote all
Hi Y'All,

Firstly, thanks to Peter and Chris for your advices and Link thumbup .

Thanks Rob for that little bit of history laugh

Well, the thick plottens....

When I was listening to the soul-splitting noise, the motor fair flung round
but now that I've taken her off the jacks the noise has disappeared
BUT
the laboured starting problem has returned...

So I am starting(sic) to think that there must be summat wrong with how the Starter Motor is mounted.

I've had it off (Oerrr, Mrs) several times in the past when dealing with Clutch Probs so now think that I replaced it incorrectly.

I remember, in the distant past, that Peeps mentioned extra washers to be mounted between the SM body and the Engine to resolve spacing/throw probs.

Has anyone done this and resolved SM problems ?

Many Thanks (AGAIN),

PJ

p.s. Took some temp readings after a short run of the motor and manifold temps at the exhaust ports were approx 75° whereas at the heder pipe junctions they were 140°.
I was surpised at the difference yikes

Temporarily jammed some ex-underbonnet shielding between the exhaust and bodywork and smoking stopped so it was just the exposed fibres of the shielding that were smoking thumbup



Edited by Mr Cerbera on Thursday 25th February 09:05

TwinKam

Original Poster:

2,937 posts

94 months

Thursday 25th February 2021
quotequote all
Hi Paul.
Rather than washers there is a shim plate available that many have fitted to 'lift' the starter and thereby give a tad more clearance in the meshing of the pinion and the ring gear.
When this was being discussed a while (years) back I made the mistake of buying one from the specialist starter motor place mentioned on here, and I was shocked at the rubbish quality; it looked as though it had been cut out by a gorilla with a gas-axe. I've subsequently bought one of Peter Esslings, which is as neat as a pin. If he doesn't have any ready, and you're in a rush, I could pop one in an envelope for you... just say.
Best,
Rik
Best pic I can do atm, they're in the 4th crate down!
Pete's is the one behind.



Edited by TwinKam on Thursday 25th February 10:10

ukkid35

6,138 posts

172 months

Thursday 25th February 2021
quotequote all
TwinKam said:
Hi Paul.
Rather than washers there is a shim plate available that many have fitted to 'lift' the starter and thereby give a tad more clearance in the meshing of the pinion and the ring gear.
What is the best way to hold the shim in place when fitting the starter motor?

I haven't found a way that doesn't involve several attempts and lots of swearing

TwinKam

Original Poster:

2,937 posts

94 months

Thursday 25th February 2021
quotequote all
Don't know, I've not fitted one yet Paul!
But 'trade tips'... Superglue or grease it to bellhousing....? Elastic band it to the starter, snip and pull band out once both bolts are started...?
Rik

Mr Cerbera

5,031 posts

229 months

Thursday 25th February 2021
quotequote all
TwinKam said:
Hi Paul.
Rather than washers there is a shim plate available that many have fitted to 'lift' the starter and thereby give a tad more clearance in the meshing of the pinion and the ring gear.....
Hi Rik,

Many thanks for that description. thumbup
I will investigate more thoroughly laugh


YHM

PJ