2.9V6 Exhaust manifold gaskets - anything to beware of?

[Top Gear TVR]

I have one 'puffing' a bit - anything to watch our for? any particular type or brand recommended?

[Barkychoc]

Biggest danger is snapping a stud off in the head when you try to undo the nuts

[Top Gear TVR]

yeh - looking forward to that - warm, cold, hot or not. I'll try cold ish and perhaps a bit warm if thats no good!

[phillpot]

Barkychoc said:

Biggest danger is snapping a stud off in the head when you try to undo the nuts

I believe Ford used studs 'n nuts but TVR went for bolts (space issues maybe)?


New bolts and plenty of "copper Grease" when you put them back in. Could go for stainless but downside is would be a real pain to drill out if one snaps at a later date?


Manifold faces tend to corrode/distort so ideally take manifolds right off and draw file the gasket faces to see how flat they are.

Brand wise you want good quality, genuine Ford if you can find them or "Gaskets for Classics" do some with a "flame ring" rather than cheapo ones just stamped out of gasket material.

Edited by phillpot on Monday 12th November 15:41

[glenrobbo]

Hi Steve,
I recommend soaking each nut/stud daily with PlusGas for a few days before attempting to undo any of them. Get an old long socket or similar that will fit over the stud and butt against the nut, and give it a good "crack" with a Mk I knockometer to shock the threads & help penetration.
Using a good quality surface drive socket, try undoing the nut. If it starts to move, great! Apply more Plusgas & "work" the nut back & forth until it's undone.
If it doesn't move, don't shear it off. Give it another soak, another crack, & move on to the next one.

I succeeded on all of mine (25 years old). It's just a case of patience & persistance & lots of brews.

Be careful seperating the manifolds from the heads, if yours are cast iron, they are prone to cracking.

When refitting, ensure the mating faces are nice & flat & not eroded.
Use graphite based grease on the studs.
The best gaskets are the composite with flame ring, the alternative are all-metal with embossed ring.
Assemble using a little exhaust assembly paste.
After tightening, run the engine at low revs for a few minutes to warm up, then retighten.

Hope I'm not teaching how to suck eggs here!
Best of luck,
Glen

[phillpot]

glenrobbo said:

Hi Steve,
Using a good quality surface drive socket, try undoing the nut.

Unfortunately with the tubular manifolds TVR made for the 2.9 engine getting a ring spanner on some of the lower bolts is difficult. socket no chance

[glenrobbo]

phillpot said:

glenrobbo said:

Hi Steve,
Using a good quality surface drive socket, try undoing the nut.

Unfortunately with the tubular manifolds TVR made for the 2.9 engine getting a ring spanner on some of the lower bolts is difficult. socket no chance

OK, surface drive ring spanner then. Main point being, you don't want to round off the nut/bolt with a poor quality tool.

[tvrgit]

Article with photos on this excellent web site!

http://www.tvrgit.com/exhausts.html

also shows phillpot's point about some of the bolts being bleeding inaccessible...

[phillpot]

Some spanners like these make access to the lower bolts a lot easier.....




All Top Quality

[Barkychoc]

You'll also need a collection of swear words and bleeding knuckles are compulsory.

[Top Gear TVR]

hmm - i have a straight set and no cigarettes for 4 months. i am am sure i will get them out, even if it involves a nuke

[phillpot]

Top Gear TVR said:

I am am sure I will get them out

that's the easy bit


What comes out has to go back in .....best 12 quid you'll ever spend (well nearly)

Or less than two packets of fags

Edited by phillpot on Monday 12th November 21:26

[Top Gear TVR]

i have to say that i found B&H a bit like wd40 for my brain. without it i frequently seize up and let go in an uncontrolled manner, bent spanners or not

[mep12345]

Even with my heads off the car one set came out really easily but the other side had 4 snap. Used plusgas, oil bath impact stud remover and then went for drill with final 3. The good news is there is room if you bugger it all up to drill the head mating face to a clearance hole and fit a nut to the back with lock washer. Makes doing up even harder for access but I've had to do this on one of mine where thread was so corroded it just stripped. Fortunately it was the top one on cylinder 5 so easy access.

[S2Mike]

You are better at this job than me, my nuts were mostly rounded off, or siezed. Took my local garage several hours and heads off, gas torch, drilling out, re cutting threads, lots of hammering swearing etc, thankfully they did me a deal, but could have been frighteningly expensive. Hope all goes well for you!

[glenrobbo]

Perhaps I'm just lucky in having an S1, but it's definitely not a good time to give up smoking. I came so close even after 8 years without a fag, but tea & biccies saved the day. It's all about perseverance, stiff upper lip, & knowing when it's best to just go down the pub & trying again tomorrow.

It worked for me anyway

[Top Gear TVR]

This is the 2nd time I have had 'weird bolt head size syndrome'

Brake callipers ended up using 23 / 32 or something odd and today the exhaust manifold bolts have a range of sizes.

I do not understand this .......... so what is a bit like 1/4AF, smaller than 13mm, but a bit smaller and not 12mm and nearly 7/16AF.

If you see what i mean!

Nothing in my box!

Joy.

[mep12345]

Top Gear TVR said:

........ so what is a bit like 1/4AF, smaller than 13mm, but a bit smaller and not 12mm and nearly 7/16AF.

A corroded 13mm I suspect that's what mine were

[Top Gear TVR]

i get the suspicion - but i also fear that there are such marked differences that some were 'howlfords nasties'

by the magic of many spanner sockets and banana spanners (as above) we now have;