I refitted my cylinder head yesterday and the car was delightfully fume free.
After driving to work and back I smell fumes. Is it possible I should re-torque the head after this heat cycle?

Thanks!

Wouldn't harm, though I suspect the manifold nuts ought to be checked, the gaskets must be in good order, as well as the exhaust clamp joints. I use adhesive foil tape (heatproof) to make a 'wrap around' into which I put firegum or an equivalent, wrap the whole aroung the joints before fitting the clamps. Exhaust paste on its own can harden and crumble, could be a source of escaping fumes.

I just use exhaust paste. I was so fed up with the clamps that I bought Burton ones. Very robust. look for soot around the clamps. I think you tend to get chuffing but no smell if the clamps are not sealing.

Did you clean the mating surfaces of barrel and head?

Another possibility is the pipe in the heat exchanger may be perforated.

Thanks guys.

I just had a guy put in new studs for the exhaust manifold attachment. Refitted everything very carefully but the studs on one side are not torquing very well really. I think I need to get him back. (I gave up helicoiling them myself.)

I have those Burton clamps, they are awesome aren't they. Everything is buttoned up nicely so my thoughts were either cylinder head retorquing or getting him back for stronger helicoiling. Darn..

The only other thing I wonder is that this cylinder head is a replacement due to me mullering the previous exhaust stud holes. It could need lapping I guess. I've never done that. And wonder about how it's done given the pushrod tubes being there.

Oh I should add the heat exchangers are good (replaced) and I did indeed clean the surfaces between barrel and head. Only with cloth and Wd40 though.

before you tighten the cilinder head you should tighten the manifold so the the gaskets are sealed. tightening the head firts tghere will be a lot of tension at the manifold and the seals wont be closed..

Perhaps lapping in then if you've done all that! Get the helicoils checked out as well.

I've not read back, but when you fitted the head, did you tighten it a bit to pull it back, then fit the manifold to make sure the head was pointing the right way for the faces to mate, and then torque everything?

Edit

Snap

"Burton" Clamps were standard on the 50s 2cvs (but smaller) and yes they work well. The others can work well too if you bend one side of the u-shape, were the bolt is passing through, so that it can fit into the u-shape of the other half. So you can tighten them further.

I love the Burton clamps. I just use grease to fit those, with the connections being nice and clean. They work really well and probably cheaper in the long run.

Yes I tightened the manifold before tightening the head, but actually since the other side of the engine didn't get disturbed, I didn't loosen that cylinder head before I tightened the manifold. Darn, maybe you're onto it there. (That's the side that blows a little.)