Advice required.

taffyjenks

Member
Hi, I have a 1968 series one 2000tc and the exhaust manifold is blowing in as couple of places.In order
to repair it it has to be removed and I need some advice on what gaskets,studs etc I will need to to get
before it goes back on.Can anyone help please?
Regards
Tony Jenkins.
 
The only "difficult" to find items are the 4 copper sealing rings for the exhaust manifold to cylinder head joint. However, these are readily available from i believe all P6 parts suppliers.
You will also need two papper gaskets for the inlet manifold to cylinder head joint, so you can either order them too, or get some gasket paper of the correct thickness, and be creative using the old ones as a pattern. If the old ones are knackered, you can knock them off the inlet manifold face.
While you are at it, have a look at the heater hoses, if they need replacement, this is the time to do it.
Also you will find that with the manifolds and carbs off the engine, the access to the starter motor is fantastic! So again, if you plan an overhaul, you'd better do it now, rather than having a fight later.
 
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The only "difficult" to find items are the 4 copper sealing rings for the exhaust manifold to cylinder head joint. However, these are readily available from i believe all P6 parts suppliers.
You will also need two papper gaskets for the inlet manifold to cylinder head joint, so you can either order them too, or get some gasket paper of the correct thickness, and be creative using the old ones as a pattern. If the old ones are knackered, you can knock them off the inlet manifold face.
While you are at it, have a look at the heater hoses, if they need replacement, this is the time to do it.
Also you will find that with the manifolds and carbs off the engine, the access to the starter motor is fantastic! So again, if you plant an overhaul, you'd better do it now, rather than having a fight later.


Very sound advice
 
The only "difficult" to find items are the 4 copper sealing rings for the exhaust manifold to cylinder head joint. However, these are readily available from i believe all P6 parts suppliers.
You will also need two papper gaskets for the inlet manifold to cylinder head joint, so you can either order them too, or get some gasket paper of the correct thickness, and be creative using the old ones as a pattern. If the old ones are knackered, you can knock them off the inlet manifold face.
While you are at it, have a look at the heater hoses, if they need replacement, this is the time to do it.
Also you will find that with the manifolds and carbs off the engine, the access to the starter motor is fantastic! So again, if you plant an overhaul, you'd better do it now, rather than having a fight later.
Brilliant post Demitris.Just what I needed and I will take on board your advice re the heater hoses.The starter motor has just been reconditioned.
Thanks again
Tony
 
Don't forget to drain the cooling system before removing the inlet manifold.
Welding an exhaust manifold can be problematic as they often crack again. If you're able, it's better to start welding while it's still bolted in place. Do as much as you can then remove it and complete the bits that you couldn't access. Alternatively, bolting it to a spare/scrap cylinder head for welding is the ideal method if you have one to hand.
Before refitting it to the car, make sure that the engine mounts are in good condition (many of us replace them with VW mounts) or it'll crack again. Then, take care to avoid any stress while connecting to the rest of the exhaust. You really need to loosen the next sections and adjust them to fit perfectly to the manifold rather than trying to persuade the manifold to fit the exhaust. It might sound tedious, but it really is worth getting right for the repair to last.
 
Don't forget to drain the cooling system before removing the inlet manifold.
Welding an exhaust manifold can be problematic as they often crack again. If you're able, it's better to start welding while it's still bolted in place. Do as much as you can then remove it and complete the bits that you couldn't access. Alternatively, bolting it to a spare/scrap cylinder head for welding is the ideal method if you have one to hand.
Before refitting it to the car, make sure that the engine mounts are in good condition (many of us replace them with VW mounts) or it'll crack again. Then, take care to avoid any stress while connecting to the rest of the exhaust. You really need to loosen the next sections and adjust them to fit perfectly to the manifold rather than trying to persuade the manifold to fit the exhaust. It might sound tedious, but it really is worth getting right for the repair to last.

Yep, i fully agree.
One last thing i forgot to mention is the throttle actuating shaft that runs under the carbs. Originaly it is supported by a bracket bolted to the steering idler on a rubber bearing. Naturally this rubber gives up after all those years, and usually the replacement is a bodge. I knew that the late Ian Wilson had those rubber bearings remade, so probably now Wins have them in stock. In any case it is worth checking the throttle rods for slack.
 
Yep, i fully agree.
One last thing i forgot to mention is the throttle actuating shaft that runs under the carbs. Originaly it is supported by a bracket bolted to the steering idler on a rubber bearing. Naturally this rubber gives up after all those years, and usually the replacement is a bodge. I knew that the late Ian Wilson had those rubber bearings remade, so probably now Wins have them in stock. In any case it is worth checking the throttle rods for slack.
Thank you very much.All help useful and appreciated.
Regards
Tony
 
The header has such a thick mating plate that welding it off the head (in my experience) never introduces problems. However, just slapping some weld beads on the cracks will be a stop gap repair, and they will soon re-crack. I've had better success by finding a welder who could preheat the entire header to a few hundred degrees before welding the cracks, which in one case has been a permanent repair (so far—20,000 miles before that engine got stored) and in the other lasted several years before re-cracking in one spot.

I've never had any trouble obtaining a new rubber bearing on the throttle linkage, but time flies by and it has been a few years since I've bought one. One thing commonly done with the bearing is to cut a slot in the bracket to allow the bearing to be installed without having to detach the bracket, which makes taking the carbs off a bit simpler.

Yours
Vern
 
The only "difficult" to find items are the 4 copper sealing rings for the exhaust manifold to cylinder head joint. However, these are readily available from i believe all P6 parts suppliers.
You will also need two papper gaskets for the inlet manifold to cylinder head joint, so you can either order them too, or get some gasket paper of the correct thickness, and be creative using the old ones as a pattern. If the old ones are knackered, you can knock them off the inlet manifold face.
While you are at it, have a look at the heater hoses, if they need replacement, this is the time to do it.
Also you will find that with the manifolds and carbs off the engine, the access to the starter motor is fantastic! So again, if you plan an overhaul, you'd better do it now, rather than having a fight later.
I used exhaust header sealing rings from a motorcycle. Went to my local bike spares shop with one of the old ones and sized some up. They cost about £3 for four.
 
The header has such a thick mating plate that welding it off the head (in my experience) never introduces problems.
They are capable of warping though. I had one that was bowed and changed shape when it was bolted down. My solution was to cut it across between 2 ports, bolt it down and then weld up the cut. It then behaved itself. So it's worth checking the face with a straight edge.
 
Yes indeed, i also had a warped one, as the pipe out of the cylinder 4 was pulling for some reason the plate out.
They were indeed a problematic design, but they do give an odd noise signature at idle that can be mistaken for a multi (=more than 4 that is...) cylinder one.
 
I rewelded mine in place with a fire proof blanket to protect the head. I used a lower setting and stitched the weld. Small short welds that join together over time, a bit like welding thin sheet steel. So far it's held up for about 18 months.
 
I used exhaust header sealing rings from a motorcycle. Went to my local bike spares shop with one of the old ones and sized some up. They cost about £3 for four.
Do you have a part number, or model of motorcycle, so I can add it to my spreadsheet of parts crosses?
 
All sorted now.Thanks for all the help.Actually found a mechanic who removed the manifold.Located the cracks and welded them up.Now sounds sweet.
He said he thoroughly enjoyed working on the car although his heart was in his mouth in case he snapped anything .
 
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