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Sealing exhaust collector?
TrophyJem - 1/7/14 at 08:21 PM

Having just run my new engine for the first time, I notice that I have some exhaust gases escaping where the collector and manifold pipes join.
Is there a method to seal these?


DIY Si - 1/7/14 at 08:24 PM

How fussed about it are you? There isn't any need to actually seal those joints as they lie outside the car's floorplan.


TrophyJem - 1/7/14 at 08:28 PM

quote:
Originally posted by DIY Si
How fussed about it are you? There isn't any need to actually seal those joints as they lie outside the car's floorplan.


I was more worried about when it goes to be mapped next week that the lambda reading in the exhaust will be wrong


dave_424 - 1/7/14 at 08:52 PM

Could you use a motorcycle exhaust gasket ring in each of the holes in the collector to seal it? not sure that the spring would have enough force to crush the end of the primary pipes into the gasket though


DIY Si - 1/7/14 at 08:54 PM

I'd be tempted with a smear of exhaust paste on all 4 header pipes before sliding the collectors on. I doubt it'll need much.


gingerprince - 1/7/14 at 09:01 PM

I got bored trying to seal mine with putty, paste, high temp silicone, Stella gasket etc, all shook or blew out pretty quickly. In the end I got the bloody thing welded together! To be fair it was a poor loose interference fit so too big a gap to fill. It's mild steel too not stainless. There is a teeny weeny hole in mine still where it's not possible to get the welder into but it'll ruddy do


madteg - 1/7/14 at 09:15 PM

I would be tempted to fit two more springs on the pipes missing them. This would stop the two loose pipes from moving and also put more tension on all four pipes.


theconrodkid - 1/7/14 at 09:48 PM

clear silicone bath sealant,never goes hard and seems to hold up on manifolds joints as well....and it,s cheap


19sac65 - 2/7/14 at 03:25 AM

+1 for cheap clear silicon
The collector should seal itself once hot but they can also develop an annoying rattle
Silicon cures it and stops them corroding together


TrophyJem - 2/7/14 at 06:40 AM

When you say cheap clear silicon do you mean don't buy the expensive stuff like rtv?


Andy B - 2/7/14 at 07:03 AM

What the guys said - the cheapest CLEAR silicon sealant you can buy - seals, withstands the temps and also allows the joint to slide apart in the future - been using it for years and its one of the nice ones where it really must be the cheapest variant


TrophyJem - 2/7/14 at 07:43 AM

Thanks I'll give it a try


Paul Turner - 2/7/14 at 09:29 AM

Be very careful using bathroom silicone. It can damage Lambda sensors. Would not make you popular with the RR chappy.

Over the 25 years my sevens have been on the road most of the time have managed quite happily with no sealant. However, whenever I refit the pipes I use the orange exhaust silicone which lasts quite a while but eventually fails.

On mine (which is a 4 into 1) the joints are after the sensor boss thus no chance of any leaks affecting the lambda readings.


britishtrident - 2/7/14 at 11:17 AM

I have started to use stainless steel-graphite anti-seize paste on exhaust joints it seems to work pretty well for exhaust where you don't want a permanent join.