Trouble fitting new exhaust, Mk2 3.8

Hi, I wonder if I have done something stupid here. Fitting a new Bell exhaust from barratts to my 62 Mk2, 3.8.

Using new aluminium crush gaskets which came with the Barratts exhaust fitting kit. They slide over the ends of the downpipe no problem, but when slid up to the exhaust manifold, and the flange plates offered up, none of the manifold studs protrude far enough through the flange plate to start the brass nuts.

I am using the original studs from the car. I know these are crush gaskets but the nuts needs to at least start on the threads to crush the seal.

Any suggestions please?

Thanks
Morro

Some manifolds do not use the crush type of gaskets , they use flat ones , check on the manifold to see if there is a recess for the crush gasket to fit !

Yes I see. Pipes and manifold both look like they have recesses… certainly no flat mounting surfaces…

thanks

The ring crush gaskets can be a pita to fit if they are fatter than the groove.

I hate the damn things. One option might be to seat them into the manifolds off the car first.

Yes, I guess that might work. Means taking the manifolds off. Bugger! I am looking to see if I can source a motor cycle type seal that may be thinner than the jag ones… but I cant see how this can be such a PITA given almost every mark 2 in existence must have changed exhausts in the last 50 years… anyway… thanks… onwards and upwards…

and of course longer manifold studs would work… but again a PITA to change!

Just had a horrible thought!! What if the original donuts are still inside the manifold? I threw the old exhaust away some time ago. Dont recall if the gaskets came out with the exhaust or not? Hmm. That might explain it. Is it common for these to stay inside the manifold? cheers

I do not know if it is common or not but it did happened to me. I was puzzled an hour how to get new ones in until realized that old ones were still in there. After removing them it was easy.
Köpi

Pretty easy and gives you the chance to clean them up and paint them. Plus chase the threads on the studs.

Just make sure that you haven’t been stiffed with the wrong gaskets. It’s happened to me before: ordered E type gaskets (C18405/1) and received XJ6 gaskets (C33487). The XJ6 units are too big. E type and Mk2 have same part. Paul.

well I pulled off a manifold. Doesnt look like the old donuts are still there. Looks like cast iron to me. But there is no way in a million years that the new donuts can enter this manifold. The holes in the manifold are only slightly larger than the pipes on the exhaust. So, if there are donuts for this, they would need to be way smaller. I will take a look at Paul’s comments and see. Otherwise I have some other weird combination of parts… cheers

One further question please. Do the donuts squash face to face with the manifold or should they fit inside before squashing? I cant see for the life of me how they would fit inside. cheers


Hi Morro. I am unfamiliar with the mark 2 manifolds but would think they have a similar system as the 3.8 e type manifold pictured here. There is a sizeable space for the donut. If yours are not like this then possibly you have manifolds without the recess as Ian said. Try taking a wire wheel to the area to clean it up well and then post a good quality picture.

Thanks Geoff (and all others too), Attached are some pics of what I am trying to make fit. Is it possible I need the other style of donut? C33487? I reckon these ones are C18405’s Cant find any reference to anything else. If I were to use the flat square gaskets (Listed for XK,120, 140 and 150 ) I would need a different exhaust (not too hard), but I cant find any reference in part numbers for Mark 2 manifolds any different to what I have here… I think??

Phew, I hate these websites… wont let me upload pics… says “Discourse:Invalid Action”. Is there a size limit or similar?
Totally useless error message…

Here we go… smaller pic. will do some more…



so pic one is the bottom of the manifold, pic 2 is the manifold, donut and pipe fitting… note the donut doesn’t enter the manifold at all really and the studs don’t clear the plate and pics 3 and 4 are the relative sizes… the id of the hole in the manifold is 52.88mm (2.08 inch), the od of the exhaust pipe is 50.47mm (1.99 inch) (the donut is a nice fit on this), and the od of the donut is 59.66mm. (2.35 inches).

Does this help? I cant tell if the other style of donut will fit because I cant find its specs anywhere. Given there are some 90,000 of these cars somewhere I cant believe I have to go custom. I must have screwed up somewhere… sigh…

Here is a pic of the other type of donut. I think this is the etype one… listed for S1 and S3… interestings not S2! Hmm…

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Ok, at this point I would get after this with a wire wheel and clean it up very well and then gently with a wood chisel tap around the areas where the arrow is pointing. You should be able to determine if the whole thing is cast iron or if there is the remnants if a donut in there. If it is solid cast iron I expect you will have to use the flat gaskets instead of donuts or else get manifolds with a recess. Once again I have never even looked at a Mark 2 up close so now is the time for Mark 2 guys to render an opinion. Good luck.

Thanks. Will give it ago

These seals are a generic part. If you took yours to Midas I bet they’d have something that would fit and seal.

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May have to that Andrew… but I cant see what is supposed to work… oh well, its never stopped me before form doing something else that works. cheers