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New SS Exhaust

PostPosted: Wed Sep 07, 2016 8:55 am
by Galwaylotus
Just received my new SS exhaust manifold. Hope to get it fit this week.

Re: New SS Exhaust

PostPosted: Wed Sep 07, 2016 8:58 am
by William2
Did you get yours from Sue Miller? Good luck fitting it as it's a fiddly old job. Having sought advice myself, I would take the precaution of assembling the Y piece with some Holts FireGum.

Re: New SS Exhaust

PostPosted: Wed Sep 07, 2016 9:41 am
by Galwaylotus
William2 wrote:Did you get yours from Sue Miller? Good luck fitting it as it's a fiddly old job. Having sought advice myself, I would take the precaution of assembling the Y piece with some Holts FireGum.

No. SJ Sporscars. I'm taking it to an exhaust centre in town as I don't have the facilities to fit it outside my home! I'll take your advice on the sealer. Thanks.

Re: New SS Exhaust

PostPosted: Wed Sep 07, 2016 10:55 am
by Grizzly
Some thing else to bare in mind..... if they remove the exhaust side engine mount and raise the engine the other engine mounts must be loosened or you will end up needing new mounts in the very near future (as i found out)

Also not sure if you have any sort of heat shielding but i found on my +2 the stainless manifold put out allot more radiant heat than the Mild steel one it replaced, it was bad enough on a long run it was uncomfortably hot in the passenger foot well, so i fitted some NimbusG2 and Zircoflex III around the area which helped allot. On my 2 seater i got a ceramic coated manifold on top of the heat shielding simply because with the reduced space in that area i was worried a stainless manifold would start damaging things like the Alternator and Clutch etc.

Re: New SS Exhaust

PostPosted: Wed Sep 07, 2016 3:16 pm
by prezoom
Since the manifold is new, have it ceramic coated both inside and out. This will reduce radiated heat significantly.

Re: New SS Exhaust

PostPosted: Wed Sep 07, 2016 4:06 pm
by Galwaylotus
prezoom wrote:Since the manifold is new, have it ceramic coated both inside and out. This will reduce radiated heat significantly.

Easy in So Cal. Not so easy on the west coast of Ireland!! :roll:

Re: New SS Exhaust

PostPosted: Wed Sep 07, 2016 5:42 pm
by JJDraper
Last time I got a quote from Zircoflex (near Oxford), they wanted around 300 of our finest British pounds for the job. It is Pukka though, and not the same as some things sold as ceramic coatings, but which are high temperature coatings and do not function as an insulating barrier in the same way.

no connection to company etc etc, but a TVR owning friend had the work done with remarkable results to reduce under bonnet temperatures (and you think its a problem with Loti). I just couldn't stretch to that amount at the time

Jeremy

Re: New SS Exhaust

PostPosted: Wed Sep 07, 2016 6:31 pm
by Grizzly
Jeremy do you mean zircotec? I was fortunate to get mine already coated but yes i believe ?2-300 is about the going rate.

If you do get it ceramic coated don't get performance white :( (Shows marks badly) but i't made a huge difference to the temp of ancillaries around it.

Re: New SS Exhaust

PostPosted: Wed Sep 07, 2016 6:37 pm
by Galwaylotus
Just to clarify, I will not be getting my new manifold ceramic coated. Underbonnet temperatures have not been a problem for me except when I inadvertently had my timing WAY out due to a second set of notches on the crankshaft pulley! I've spent enough on this upgrade and will save funds for something more productive (for my car).

Re: New SS Exhaust

PostPosted: Wed Sep 07, 2016 7:55 pm
by Grizzly
Are you replacing a Mild steel manifold ? you may be surprised how much difference in radiant heat you get between SS and MS.

Don't blame you not getting Ceramic coating (it's expensive) but if you don't have heat shields it may be worth looking into especially round the clutch slave cylinder.

Re: New SS Exhaust

PostPosted: Wed Sep 07, 2016 9:04 pm
by JJDraper
..yes I did mean Zircotec. Brain fade - I was thinking about the sheet material I used in the footwell adjacent to the exhaust. Same company, different product.

I believe they do a faux rusty finish that would make it look authentic..

yes, expensive, but it is F1 tech.

Re: New SS Exhaust

PostPosted: Wed Sep 07, 2016 9:34 pm
by TroonSprint
I had a 2-seater Elan exhaust coated by Zircotec last year and it cost me ?528 including shipping and VAT. :( Ok it is a good product, but at that price I doubt I would do it again. I wrapped my V8 MGB's exhausts (twice the area compared to the Elan) with bandage from Demon Tweeks for about one twentieth of that price. And it works - I can actually touch the bandage when the engine is hot - not for more than a microsecond but without the bandage I would have left skin behind.

Mike

Re: New SS Exhaust

PostPosted: Thu Sep 08, 2016 8:20 am
by Galwaylotus
Grizzly wrote:Are you replacing a Mild steel manifold ? you may be surprised how much difference in radiant heat you get between SS and MS.

Don't blame you not getting Ceramic coating (it's expensive) but if you don't have heat shields it may be worth looking into especially round the clutch slave cylinder.


From an engineering materials standpoint that doesn't make sense. The thermal conductivity of mild steel, k, is in the 26.0 - 37.5 range while stainless steel is (304) 8.09 or (430) 8.11. The emissivity of heavily rusted (mild steel) surfaces is 0.95 while smooth SS 316 repeatedly heated is 0.57 - 0.66 and 304 42 hr @520?C is 0.62 - 0.73 so from a conductive or radiant heat perspective ss should let out less heat. What am I missing?

Re: New SS Exhaust

PostPosted: Thu Sep 08, 2016 4:18 pm
by UAB807F
Galwaylotus wrote:What am I missing?


I'm not sure myself on that one. If it's any consolation I've got a very similar looking set-up on my Elan, bought back in the days when Chris Neil were the go-to guys for parts not available at Lotus. It's no longer shiny but other than that I can't say I've noticed anything melting nearby. I wouldn't want to touch it after a run but otherwise it's just stayed there doing it's job..

Possibly controversial, but I don't get why you'd want to insulate one. The heat output from the engine is just the same if you've got a cast iron manifold or mild steel thing and it's got to escape from somewhere. AFAIK Lotus didn't insulate them from new ?

I'd have thought that you insulate the pipe effectively you're relying on all the heat escaping through the exhaust itself and consequently raising the actual running temperatures of the steel over a non-insulated one ? I don't know if that's good or bad but it might be interesting to know the wall temperatures before & after insulating.

Brian

Re: New SS Exhaust

PostPosted: Thu Sep 08, 2016 5:46 pm
by Grizzly
Hell it's way above my knowledge all i can say is i've done it and had issues with my Clutch and Alternator, i added heat shields and it went away........

My Rx7 race car is probably a better example of radiant heat issues even though it's much more hard core, i ran a MS manifold for years and had no issues, i swapped to a Tubular stainless and it started melting plastic master cylinder reservoirs 16" away even though my EGT's were exactly the same. I can't explain it but thats my first hand experience.

Even if it was a mild steel manifold i would be fitting heat shields, when rebuilding my 2 seater i had to cut quite a large section of foot well out and re-glass it because the Resin had just turned to dust thanks to the exhaust heat on a 30,000 mile elan.