Thread: exhaust manifold

There is no soot around it so I presume it isn't leaking; however; because it is cracked it will only get worse, so a good second-hand one is a good idea.

If you can't get a replacement, it can be welded by: chasing the crack with a grinder; drilling a hole at the end of it; and pre-heating it to a dull-red before welding; followed by post-heating and very slow cooling,

Cheers Charlie

thanks Charlie.

No soot might be because it has been in molasses for a week and then scrubbed down before examining it! Who knows how much soot may have been there. Note to self: examine components before thoroughly cleaning them to get an idea what their operating condition might reveal!

Anyway, as I have a new gasket and as there is no hurry, I will hold off reinstalling it until I see if I can obtain a better specimen.

Are you interested in extractors or do you want to keep it original?

I got extractors for DaOot delivered the same day for about $320 from a supplier in one of the stickies in this forum.

Just be a little careful with replacement after market exhausts, some products sold as extractors are only headers with poor flow dynamics and many that don't have mandril bends so you get a reduction of flow caused by the waisting in the bends. On the inside some even have the pipes assembled in a design better suited to the oposite flow.

Make sure you have a look at the headers/extractors before you buy.

Originally Posted by Lotz-A-Landies

Just be a little careful with replacement after market exhausts, some products sold as extractors are only headers with poor flow dynamics and many that don't have mandril bends so you get a reduction of flow caused by the waisting in the bends. On the inside some even have the pipes assembled in a design better suited to the oposite flow.

Make sure you have a look at the headers/extractors before you buy.

well i'm glad i got the ones you linked to in your aftermarket generic parts thread. :P

they seem pretty good to me

They had two different types when I bought mine, so I don't know which ones you got or even if they were the same. But when a mechanic mate had a look at them recently he started pointing out all the deficiencies. At the end of the discussion he did state, that no matter how bad they were they still flow better than the original manifold.

(He is currently doing some performance work on a customer's 2 1/4 litre. One smart cookey, I love looking over his shoulder to see his latest creations.)

Originally Posted by Cannon

Are you interested in extractors or do you want to keep it original?

I got extractors for DaOot delivered the same day for about $320 from a supplier in one of the stickies in this forum.

Prefer to keep original if possible; though I know extractors would provide a performance improvement. I've got a second manifold here that looks to be in better shape - that is, I have one good inlet manifold and one good exhaust manifold, so I think they are about to get married.

Right! Set screw that holds the counterweight to the spindle. Trying to be firm, but gentle, but managed to break it off!



The 'hot-spot' mechanism is a mystery to me. I mean I read in the manual that the bimetal spring opens as the exhaust gases heat up, causing the flap to close. I sort of get WHAT it does, but have no idea WHY it does it.

Anyway, the spring seems ok, but the whole assembly is a bit loose, causing the adjusting plate to slip off the stop pin and just turn freely. So I was trying to tidy it up.

How serious a problem is this, considering that I doubt it has been working properly for a very long time?

Thanks for the help,

Garry