firewall at bulkhead

[SteveJB]

Just taken the engine out and the firewall have been burning away with the heat and needs replaced before the car goes back together.

Any idea where is the best place to get a replacement, any alternatives(seeing as no Craig for advice) or does anyone have something lying in the garage that would do the trick?

cheers

Steven

[Ferg]

Maybe start with looking at nimbus.

[SteveJB]

http://www.trophyelisebuild.com/page17.htm

thanks for the tip. Noticed it being used here which is good to know

[robin]

Hi,

You used to be able to get these from Lotus - I've replaced one on my old S1.

In your shoes I would be tempted to go down the Nimbus route, though, because it will allow you to get a better heat shield for the exhaust put together at the same time.

The reason the heat shield on the bulk head fails is usually a combination of the original heat shield falling apart & the abuse the firewall gets during manifold fitting/removal.

It is well worth switching to the S2 manifold and downpipe because you can fit the S2 heat shield to it - this is pre-formed Nimbus-like material that bolts to the manifold (rather than the bulkhead) and is easy to replace when it falls apart. As a side effect the downpipe is easier to replace and the Lambda sensor is better placed for access also.

Cheers,
Robin

[Ferg]

Pretty sure Steve has a 421 (twas the shugmobile in a former life). I would imagine this makes fitting a heat sheild a bit more of a challenge? A previous owner had a shot on mine and while functional, it's not pretty. Does the exhaust heat shield need to be fitted to the engine so it moves with it or can it be something that is connected to the bulkhead?

[woody]

S2 heat shield is a definate improvement. MG TF uses the same one too, plus they both have small additional heat shields.

[robin]

Hi Ferg,

It doesn't really matter where the heat shield is mounted from a heat perspective.

You do need a shield mounted to the block between the exhaust and the alternator - without this you will toast successive alternators.

For a standard pattern manifold, the S2 solution is neater, but it too disintegrates over time (heat & vibration - eventually the material fails around the mounting eyes).

Your other option is to heat wrap the exhaust. This is a horrible job as the material is some sort of glass fibre, but it is good for keeping the heat off everything.

Cheers,
Robin

[Shug]

Hi,
It is well worth switching to the S2 manifold and downpipe because you can fit the S2 heat shield to it - this is pre-formed Nimbus-like material that bolts to the manifold (rather than the bulkhead) and is easy to replace when it falls apart. As a side effect the downpipe is easier to replace and the Lambda sensor is better placed for access also.

Robin - this is the old Shugmobile, it's got a 4-2-1 manifold, so an S2 bag of bananas would be a pretty retrograde step

[woody]

Hi,
It is well worth switching to the S2 manifold and downpipe because you can fit the S2 heat shield to it - this is pre-formed Nimbus-like material that bolts to the manifold (rather than the bulkhead) and is easy to replace when it falls apart. As a side effect the downpipe is easier to replace and the Lambda sensor is better placed for access also.

Robin - this is the old Shugmobile, it's got a 4-2-1 manifold, so an S2 bag of bananas would be a pretty retrograde step

tip; the S2 heatshield works on a 4-2-1.

Robin, never wrapped an exhaust, but generally hear poor things about it in the longer term?

[robin]

Yes, but the longer term is better than the life expectancy of the standard S1 furry cardboard box I would rather re-wrap the manifold every 3 years than battle to refit that stupid heat shield.

Shug - didn't realise this was your old shed - I am sure your 4:2:1 manifold is awesome and adding 100's of BHP - so best not swap it for the S2 manifold I agree.

Cheers,
Robin

[Corranga]

tip; the S2 heatshield works on a 4-2-1.

Robin, never wrapped an exhaust, but generally hear poor things about it in the longer term?

This. I have a 4-2-1 with an S2 heat shield. I think one of the mount holes is missed, but mine has been happily in there for 5 or 6 yeas with no issues (and removed and refitted recently, and still looking in good condition.

I think there have been reports of exhaust / manifold cracking with heat shielding, but this comment should be treated only as a hint to do some research as I'm just repeating stuff I've read and have no evidence of

[robin]

I have cracked an S1 standard manifold by heat wrapping it when I was trying to work around a missing heat shield. On inspection, though, where it cracked the metal was very corroded so probably was "going to fail soon". You can get a "pulley" effect if you go overboard on pulling the wrap, I agree.

Cheers,
Robin

[SteveJB]

Thanks for the ideas. Wrapping the manifold looks a goer but using the nimbus to repair the damage (hopefully the pic works) sounds a bit expensive/fiddly. Is the S2 a similar size so can be used easily? MMC couldnt tell me a size or advise.

[Dominic]

With regards to the nimbus, most garages will likely have a bit kicking about in their scrap bin,... if you are on good terms with a garage, that would be my starting point.

[woody]

The S2 set up bolts to the manifold itself. There's a tab, or 2 on the manifold you'll need to make (it's welded on IIRC) but straightforward from there. Worth noting I only used the tip portion as i'd other heat shielding that provided a better solution for the lower portion sitting.