Exhaust manifold gaskets....

[B-Reight]

for a 390se.

Are they the regular off the shelf rover v8 items or do the require slightly larger port sizes?

After an afternoon with a length of garden hose stuck to my ear,the smell of burning flesh and some perculiar looks from passers by, it looks like ports 2 & 8 are blowing. Sods law they are the most difficult bolts to get to!

I've got a couple of spare gaskets with a port size of 22.25mm X 33.5mm, will these do?

[GRIFFONMARK]

I met a chap the other day who said use composite gaskets rather than the shiny metallic ones, but I've never seen any. My brother used to work at TVR and he reckons they used to smear screen sealant (black stuff which apparently had a very high temp rating) on the gaskets when customers complained and this shut them up permanently. yet to try it on mine though. Regards

Mark

[Campbell]

If you have a look at ACT Products they stock the correct gaskets, the porting on the 390 will be bigger than the standard ports.

Campbell

[Trickie Dickie]

B-Reight said:

for a 390se.

Are they the regular off the shelf rover v8 items or do the require slightly larger port sizes?

After an afternoon with a length of garden hose stuck to my ear,the smell of burning flesh and some perculiar looks from passers by, it looks like ports 2 & 8 are blowing. Sods law they are the most difficult bolts to get to!

I've got a couple of spare gaskets with a port size of 22.25mm X 33.5mm, will these do?

Big coincidence Ben

Mine started blowing on my 400SE yesterday
Started with like a ticking noise that I thought was
something like a bearing on the alternator
then smoke started coming out from under the bonnet
then the noise got louder until I could tell what it was

Let me know how you get on and I will do likewise

Best of luck
Richard

PS Noticed your profile - where in Yorkshire are you?
I am in Thackley on the outskirts of Bradford

[TVRleigh_BBWR]

I've found the biggest problem,
Is they way they made the manifolds, that most of them was not flat, and some even had parts missing.

once I took mine off and filled the holed with weld and grinded them flat. they was fine after.

RPI also do the compersit gaskets that cover 2 ports.

[adam quantrill]

Just nipping up the bolts cures it 8 times out of 10.

[B-Reight]

Well, what a bugger of a job, you need the patience of a saint and the hands of Jeremy Beadle to get to all those bolts! Just got one bolt left that refuses to budge, i have a horrible feeling that it may well shear so its soaking in lashings of WD40 at the moment before i attack it again tommorow.


As for the composite gaskets a few of you have mentioned, are these the ones with a central layer of black material sandwiched between two pieces of dimple embossed metal?

Adam, tried nipping the bolts up to no avail unfortunatley.

Mark, cheers i've been advised to use some high temp silicone sealant, i guess the black screen sealant would be the same stuff or a polyurethane based sealant.

Richard, will keep you posted on my progress. I didn't get any smoke from under the bonnet, just a slight ticking which was only audible with the roof on. I'd definitely try Adams suggestion of nipping up the bolts first as a couple of mine had worked their way loose (not on the ports that were blowing though). Im just up the road in Ilkley btw.

Edited by B-Reight on Monday 22 September 22:51

[TVRleigh_BBWR]

Be careful of just nipping them up, as they have quite a low torque setting, and a lot of the problems are caused by people over tightening them, and stripping the threads, they are never going to give a good seal after that.

I cant remember where I got it from, but once I got some copper based silicone sealant, this was rated to about 350oC remember the manifolds can get very very hot.

Also if you undo the engine mounts and jack the engine up you can get much better access.

Also ARP do special stainless bolts with extra small heads, so its easier to get a spanner on them.

[convert]

I agree these gaskets are real buggers to fit.

I had one bolt that seemed to have partially stripped the thread in the head. I went for a stud kit from Rimmers. I used this along with some thread lock, and the studs managed to grap into enough of the thread to lock OK. The thread in the head is usually a little bit longer than the standard bolts.

The stud kit also made fitting the gaskets, and getting them alinged a lot easier.

Took about 4.5 hours to remove both manifolds, and about 5.5 to refit them...

[adam quantrill]

I'm getting an old hand at this, and can do the manifold in about 2 hours.

I too had a stripped thread on the 400SX, and tapped it out to M10, then used a long M10 bolt as a stud, plus an M10 nut on to tighten it up. Quite cheap, all in all.

When I say 'nipping up' this should usually be done by hand, and only take the slack out of the loose ones.

[TVRleigh_BBWR]

You can also heli-coil the thread's if they get stripped, this also makes it a lot stronger,

you would be surprised and what different people this nipping up is.

A well know TVR dealer nipped mine up do to a blow. it but came back very quickly, and after checking 2 or 3 threads was stripped. not sure if was them or not, but if not they should have noticed. unless they managed to strip themselves after.

Also as said in previous post.
Remove the engine mounts you can then more the engine about on a jack to get better access.

[convert]

I also removed the starter motor, disconnected the battery, the brake servo pipe and the king lead to gain enough access to take my manifolds off. Plus you need the car up on stands to get the manifolds out.

[matt-man]

Hey there,

Sorry for being so slow to reply to this!

The manifold gaskets do need to be bigger as the standard ones dont work! I bought some from a local auto factors for a landrover and after removing the manifold on the drivers side (worst one!!) and undoing all the bolts to change both sides gaskets, the standard ones were great for about 30 miles and 1 hour!!

My language needed a little censoring when that happened!!

So i got the right ones from TVR car parts and went through the whole ordeal again with no problems...

I put some very high temp instant gasket on both sides to fill any holes i couldnt reach and thats worked and lasted months so far...

Its a crappy job but well worthwhile!!

Good luck!!

Edited by matt-man on Wednesday 24th September 13:03

[Trickie Dickie]

Turns out mine is not an exhaust manifold gasket
BUT THE CYLINDER HEAD GASKET AROUND NO 3 CYLINDER

A friend who runs a garage has taken both heads off
and sent for crack testing and scimming before replacing

On the bright side using this oppurtunity to get my rocker covers
and plenum polished up to look nicer while the car is in bits

On the bad side expecting large amounts of money to disappear
from my bank account into the black hole under the bonnet

Richard