Y piece to Manifold jointing.. what's best?

[TVR Beaver]

Have used exhaust past before but it goes hard and comes away... I know some silicons will take a high temp but not sure this high... My system is drawing air on these joints at the moment so needs fixing... anyone suggest what can be used here to fill the gaps?... Cheers...

[LordGrover]

A blob of Hylomar does the trick. I'm sure there are others though...

[Pupp]

Silicone RTV will work on exhausts, but be aware that some reckon it can damage lambda probes. I've used it in that application and would do again.

[TVR Beaver]

Hylormar or RTV it is then.... didn't think they would put up with the temp?... anyway, better than the exhaust seal if it get's in... and into the cat... Cheers...

[michielp]

I used this a week ago. put some of it underneath the big clamps and then joined them together.
Just do not put too much on it. It's safe up to 1000 degrees celcius.
Works great, my system is now completely air tight.

Holts FireGum

.

•Stops leaks and withstands heat and vibration.
•Lubricates for fast, easy exhaust assembly.
•Ideal for making gas-tight seals in exhaust joints

[lotusandy]

I used some of this:-

PERMATEX Ultra Copper Maximum Temperature RTV Silicone Gasket Maker - PER89101
Ultra Copper: The most advanced high-temp RTV silicone gasket available.Sensor-safe,low odour non-corrosive, superior adhesion. Three times more oil resistant than conventional silicones, eight times more flexible than cut gasket. Temperature range -75 F to 700 F intermittent.

I put it on the Y pieces over 6 months ago, & they have not leaked since, the advantage over firegum & similar is that it does not go brittle, it is also lambda probe safe..

Just do a google search on the part number to find a stockist..

Andy

[HRG.]

Clean the joint properly first, lightly dress with a file if necessary so that it's flat then use a luggage strap to pull them nice and tight while the Firegum sets.

[michielp]

HRG. said:

Clean the joint properly first, lightly dress with a file if necessary so that it's flat then use a luggage strap to pull them nice and tight while the Firegum sets.

exactly how i did it, works great

[haircutmike]

I used nothing to seal, a strap wrench to pullit together and one of those carpenters quick clamps to hold together until bolted up!

No leaks!

Peter.

[TVR Beaver]

Mmm.. It was removed by V8D when they did the cam... and not 100% sealed since... so I'll re-do it... I used the straps before and a bit of fire gum (not sure if it was actualy needed or not)... and it worked fine... but did notice over the summer period bit's of 'sand' type stuff around the clamp so assumed if was drying out and coming away a bit... Will try the RTV.... like that idea... Cheers....

[ruaricoles]

Mine are blowing a little but the flanges on the manifolds are a little too far apart (perhaps 5mm or so?) so I struggle to get a proper seal on both sides at the same time - are you guys saying you use straps to pull the manifolds together, and if so how much can you do so before you risk cracking etc? (I've got standard manifolds but no precats)

Ta

Ruari

[HRG.]

I'd say 5mm is nothing to worry about whatsoever, mine are probably worse than that when loosely assembled.

The ratchet luggage strap and cramps technique works a treat

[TVR Beaver]

Got some of this that Andy said was good:- PERMATEX Ultra Copper Maximum Temperature RTV Silicone Gasket Maker - PER89101.....
But also been advised to use PTFE tape with it??... looking at the temps PTFE tape goes to, it's much less than this stuff....
anyone know what temps are seen at what points on the exhaust?... Y flanges and lower joint for example??.. Will probably use it on it's own... but just interested??.. cheers

[GreenV8S]

TVR Beaver said:

anyone know what temps are seen at what points on the exhaust?

Occasionally they'll get hot enough to start a dull glow, which would be around 1000C. Usually they'll be less than 600C though. The hottest points will probably be the cats, and the outside of the corners coming away from the heads.

[TVR Beaver]

Peter... have seen this before I did have a Porca turbo once and if i gave it a thrashind and looked under the bonnet they were red....
As you say. header bends and small pipes... I have no pre-cat's... but would think at the Y joints they will be less than say 500F?.....
Pre-cat removal does make a huge diff to under bonnet temps... but allows the heat to creap forward into areas further down....
Will do it tonight see how we go... Cheers