Sealing the primaries to the collector

[Lardy]

I've heard high temp flexible motorbike sealant does the trick. Any different ideas or recomendations???

 

 

Thanks

[Stationary M25 Traveller]

I used to use a very thin smear of normal clear silicone sealant - which helped lubricate the joint. Not enough that it got inside and on to the cat though !

 

However, when I got the new 4-2-1 collector from PowerSpeed, they advised they don't use any sealant, just a reasonable fit, as the primaries get hotter than the collector, thus expand more - to make a tight seal. Seems to be fine. I do have both front and rear mounts in use for the 7" dia silencer now though.

 

You can buy a cheap tool to expand the bore of the primaries if needed for fine tuning.

 

 

 

Edited by - Stationary M25 Traveller on 22 Apr 2009 17:24:18

[Tonycaterham]

Hi

 

i've used this quite successfully on mine Valco silicone

 

 

 

 

Tony

 

L7 EVL

 

 

 

Edited by - Tony7 on 22 Apr 2009 15:25:13

[MusCat]

I use silicone flue sealant like this stuff here. It's red so you have to do a neat job but it is resistant up to 300degC unlike normal silicone sealant, and remains flexible unlike proprietary exhaust sealants which go hard, crumble and fall out.

[Dickie Normuss]

What happens of you use this and want to seperate the collector from the primaries at a later date?

 

VX HPC - Loud and proud here

Adding power makes you faster on the straights. Subtracting weight makes you faster everywhere

[MusCat]

It's no stronger than ordinary silicone - a combination of sealant remover and brute force tends to do the job

[kenny.]

EEEK, I've never ever sealed them 😳

[paulyb]

Ditto: Never sealed mine. Fit is pretty tight and no evident blowing

[millsn]

If you're using a lambda sensor at the collector do you need to seal. I've always been told not to seal after I took the car to James Whitings's to seperate the collector from the manifold (it was pretty much jammed on with exhaust sealant) but I am concerned that pulling in air though an unsealed joint would invalidate the results somewhat

[Rich N]

I'm about to use Fire Gum on mine because I've tried normal silicone and apart from smoking quite nicely for a while, it now blows again. I realise Fire Gum can cause "it's stuck" issues.. but has anybody used it and managed to seperate the parts afterwards?

 

..or do B&Q/Homebase/Halfords sell something like hi-temp silicone someone could recomend for Lardy and I instead?

 

--=[Oxford7s.net]=--

[blade_runner]

I use this here the red high temp version, i use the black for a dry sump gasket on the blade and many other things... I got it from a local motor factors.

 

'Pinky Pics' here

[Dickie Normuss]

Unless it's really bad I'd avoid sticking these together. You'll have to remove the collector from the primaries in one go as they'll still be on the car and that's quite a large surface area to glue.

 

VX HPC - Loud and proud here

Adding power makes you faster on the straights. Subtracting weight makes you faster everywhere

[djg]

Yes I have used Holts fire gum on the primaries, works a treat. It's works well on my Oil boiler flue too.

 

Removal from my first attempt required a little persuasion, but nothing too serious and a wire bruch cleaned up the mating surfaces for next time.

 

Having done it a couple of times now, engine out recently, put the gum on the collector, this then means as you push it on the gum goes away from the join you can see and you don't end up with fire gum all over your primaries.

 

I also put the collector on 'dry' just to get a feel of which way all the primaries needed to be persuaded to fit into the collector.

 

Doug

 

Edited by - DJG on 23 Apr 2009 16:38:30

[CageyH]

I seem to recall this being recommended by Oily. It's what I used anyway...

 

Only dead fish go with the flow....!

[Myles]

I'm about to use Fire Gum on mine because

 

Oh, please NO!

 

It doesn't work because:

 

i) It dries hard and crumbles

ii) You'll find it a bugger to remove the primaries later.

 

Beer-can fillets and decent 350deg-C silicone works for a goodly-while and can be easily undone.

 

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Alcester Racing

7s Ecosse™

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Alcester-Racing-Sevens.com

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[Jason Plato]

get a pipe expander and rematch the primaries and collector. Then add an additional support brace on the rear of the silencer to prevent vibration and flex. The primaries go oval from the flex of the silencer. Anything else is only covering over the basic problem

 

dj

 

here is my Duratec R .... C7 TOP

Taffia joint AO with Al