Micatherm or composite exhaust gaskets?

[Discopotatoes]

I've been plagued with exhaust gaskets blowing since turboing the car, so thought of going micatherm, anyone have first hand experience? Can they handle the extra heat?

[Pupp]

If the flanges and head mating faces are in pretty good order, could be worth trying no gaskets and a smear of high temp silicone... I know it's not rated for anything like the temperatures it'll encounter there but we used to use it exactly like that on a drag bike. The silicone used to 'carbonise' (least that's how it looked) and expand whilst still having some body. Certainly read of folk sealing turbo flanges like that with success too.

[Discopotatoes]

Agreed the best gasket is no gasket but I don't fancy pulling the heads off to get it machined.
Might be worth a go though

[SILICONEKID346HP]

This is the stuff you want ,difficult to get hold of but is the best .


"OEM specified. For high operating temperatures common in 4-cylinder, turbocharged or high-performance engines. The most advanced, high temp RTV silicone gasket available. Sensor-safe, low odor, noncorrosive. Superior adhesion. Three times more oil resistant than conventional silicones; eight times more flexible than cut gaskets. Temperature range -65°F to 700°F (-54°C to 371°C) intermittent; resists auto and shop fluids and vibration - See more at: http://www.permatex.com/products-2/product-categor...

http://www.permatex.com/products-2/product-categor...

[Discopotatoes]

SILICONEKID346HP said:

This is the stuff you want ,difficult to get hold of but is the best .

http://www.permatex.com/products-2/product-categor...

Cheers ill get some

[Mr Supercharged]

Do you have ported heads? If so you might not have the area coverage for a sensible gasket. Some of the ported head designed gaskets only seem to give 1 to 2mm width coverage on the head right next to where the cylinder head bolt boring / spot facing leaves a scallop shape if you know what I mean?

[Hoofa]

bewarned that stuff makes a right mess of the manifold if you have had them coated as it get everywhere. Mine looks two tone colours

[Discopotatoes]

Yes they're ported, and I know exactly what you mean!
The problem area is cylinders 1 and 7. I believe the arp bolts are working loose then I'm getting blow by which destroys the centre of the composit gasket.
I have drilled the bolt heads for wire locking but I think it will look tatty, I'm thinking of going to studs and using aero tight nuts

[Hoofa]

Tried using nordlocks washers ?. Never had a problem with mine, if you havnt I have some washers spare I could send you

[Discopotatoes]

Hoofa said:

Tried using nordlocks washers ?. Never had a problem with mine, if you havnt I have some washers spare I could send you

They don't seem to work for me and do still come loose

[ChimpOnGas]

The answer to loosening manifold bolts may already be here.



http://taylorvertex.com/vibe-lock/


And Remflex gaskets have a good reputation in the States.



http://catalog.remflex.com/LAND_ROVER_EXHAUST_GASK...

I'd say they'll be the standard port size though.

[Discopotatoes]

I've done some research into those remflex gaskets and they seem to be very brittle lots of people having dramas after a short time

[carsy]

Theres also these Stage 8 locking fasteners from Summit Racing.

http://www.youtube.com/watch?v=U15OxrX_NBc

[ChimpOnGas]

Discopotatoes said:

I've done some research into those remflex gaskets and they seem to be very brittle lots of people having dramas after a short time

Possibly because people can't resist the temptation to over tighten, they are a graphite compression gasket after all so you can easily go too far.

That seems to be another advantage of the Vibe-Lock bolts, unlike the Nordlocks that only seem to lock when you cram them up, you can tighten the Vibe-Locks to the correct torque then lock them off with the central alen grub screw.

At the end of the day I'd put money on a good percentage of Chimaera manifold gasket failures being down to loose bolts, not the quality of gaskets; once you've got a hot jet of escaping exhaust gas acting on the edge of the gasket it's life will be very short indeed.

Obviously just re-tightening the bolts isn't going to fix a blown gasket, replacement is your only option, that's why I'd say a bolt that doesn't wind itself out in the first place is exactly what we all need.

I'm sure if those Vibe-Lock bolts really do work as advertised the big port metallised gaskets we all use would be just fine.

Vibe-Locks certainly look like they're well worth a try to me.

[carsy]

Ye they do look like a good idea. Come on who`s gonna jump in and try some.

I`m currently running these gaskets. Seem good quality, metal faced on both sides.

http://www.ebay.co.uk/itm/ROVER-V8-BIG-BORE-EXHAUS...

[ChimpOnGas]

carsy said:

Ye they do look like a good idea. Come on who`s gonna jump in and try some.

I`m currently running these gaskets. Seem good quality, metal faced on both sides.

http://www.ebay.co.uk/itm/ROVER-V8-BIG-BORE-EXHAUS...

They are the metallised ones I have, they are fine & compress a bit to take up a very small amount of warping/pitting but I also used a thin smear of Permatex Ultra Copper on mine which will tolerate 700ºF of intermittent heat.





I think most of us use those metallised gaskets & they're fine as long as your manifold & head faces are in reasonably good shape and you respect they're not reusable.

For me, better bolts that don't wind themselves out is where the real solution is at.

The ARP bolts are good for a number of reasons but they still wind themselves out, it seems the Nordlocks I've used aren't the complete solution either so I may just resort the old PTFE tape trick.

Actually although you'd think it would never survive on the threads of manifold bolts, PTFE tape works quite well and of course its a very cheap solution.

Edited by ChimpOnGas on Sunday 12th January 19:40

[Discopotatoes]

I think your right Dave if I can keep the bolts from undoing that's half the battle.
So no one has tried the micatherm gaskets then? Maybe ill be the guinea pig!

[Pupp]

ChimpOnGas said:

you can tighten the Vibe-Locks to the correct torque then lock them off with the central alen grub screw.

And HTF do you propose to get a torque wrench anywhere near them? Just asking