replacing exhaust downpipe to manifold studs 3.5 V8

Andrew T. uttered summat worrerz funny about:

I've had some luck using mole grips on the unthreaded part.. they are actually fitted in to the manifold. It's much simpler to take the manifold off and do it that way. Refit using gaskets on the block to manifold face.

On an old rangie I had I just took the manifold to the local none franchised and they replaced them for about£10,, application of heat then mole grips. That was before I was brave enough to have a go myself.

Lee

Mmm, I thought about taking the manifolds off, but the state of the bolt heads make me wary! I might just wait until I change the gearboxes, when I can drop the engine fairly easily.

Andrew

You may find that even tho they look rusted in the come out quite easily.

I've just done the same job on one of my V8's, the studs were knackerd so I drilled them out and replaced them with bolts.

Oh no, I make a decision to wait until I drop the engine, and now you suggest it might be quite easy :-) .... I hate indecision, but I might just take a closer look at the manifold bolts.

Andrew

On or around Tue, 23 Jan 2007 10:38:21 -0000, "Dr_D" enlightened us thusly:

much much much

why? I've never noticed a problem in fitting them without as Rover did. I guess if you're bothered a smear of loctite or other sealer suitable for high temperatures (high temp silicon would do) on the face before fitting would seal it better. The transit turbo exhaust is done like that, no gasket and sealer used on assembly, but AFAIK the V8 ones are just bolted up clean and dry. There's not much pressure in an exhaust, normally.

back to the original thing - it's almost inevitable that one will shear off, and then you've got to get the manifold off anyway.

It's possible to drill the old one out and retap with 10mm thread, then make a special stud with 10mm one end and 8mm the other.

On or around 23 Jan 2007 03:03:00 -0800, "Andrew T." enlightened us thusly:

the bolts usually come undone quite easily, IME. use a single-hex socket of the right size though. They should be 9/16" AF, if they're well-eroded you could use a 14mm instead which is a bit tighter.

I'm sure you're right, it is inevitable that one will shear or something. Its bugging me so much having the exhaust leaking from this joint that I may start dismantling it tonight.

Andrew

If you are planning to pull the engine then you may as well wait, no point in doing the job twice.

Like Austin says, the manifold to head bolts will come out no probs. Don't worry about shearing the downpipe to manifold studs, just drill 'em out on the bench. If you have access to oxy-acetylene (or oxy-propane) then heat the casting around the studs to a dull red and they'll unscrew no probs at all. Badger.

I snapped one, trying to seal a leak, on my V8 110 and fully intended to take the manifold off the following weekend. As a temporary fix I tightened the other two and ran a jubilee clip through the manifold and round the triangular clamping plate, using an old bolt in the hole to stop it sliding off. It's still there ;-).

This will probably need to be fixed for the MOT but I also need a new windscreen by then if anybody has a serviceable one? I could also do with a bumper to play with to see if I can manage to fit the Ramsey electric winch I have had in my garage since I acquired it (ex but un issued dennis fire engine).

AJH

You've all convinced me now to get it done, last night was thwarted by a last minute panic at work, but I also need to order a set of studs and manifold to head bolts from Beamends before I start.

By the way Badger, the V8 still sounds very sweet since you replaced the cam a while back - I ended up keeping the 110, no one wanted to buy it for the money it is worth to me!

So once again thanks for all the support.

Andrew Acharacle, W Highlands.

I hope the downpipe studs are cheaper than those for the 300TDi. You might want to price them up before buying more than you actually need.

At almost £8 a piece the sensible course of action is soon ruled out.

Glad to hear it mate. Got the new workshop built mid 2005, what a godsend! No more rummaging around in my mate's cold draughty midden, hahaha. Got yet another P38 in at the moment, yet another cracked block to be cured!! Was over towards your neck of the woods last weekend, had to get the Lochaline ferry over to Mull and back, nice part of the world.

Badger.

Thats good to hear, the old shed was a bit rough, I seem the remember the floor was inches deep in water in places!, I've now also got some sort of covered "garage" 7 x 4m made from 3m lengths of uncut spruce covered with a polytunnel plastic roof, (great for light) and timber sidings as cladding, just got to make some doors. But its so nice to get shelter from the rain which we get alot of round here (but snow this morning).

Aye, its quite nice around here, just pay for it with the rain and midges and tourists.. :-)

Andrew