manifolds question

[classicswede]

As Derek has said all the manifolds are one peice other than the fuel injection and the early twin carb manifolds with an alloy inlet.

I have never seen an exhaust manifold rust through but they can crack.

When I replaced the exhaust on my 145 I just made stainless pipes that followed how the original ones went with the S bends. The system is 2.25 inch and it does go better for it. I did not bother doing a 4 branch as for the small power gain over cost I just did not see it worth it on this car.


If your manifold is dead then just replace like for like but by the sound of things it is more likely teh downpipe.

Do not buy an off the shelf 4 brach manifold as it will not fit without chopping it about at which pont you will have lost the gain in flow it was going to provide

[Billy Smalls]

I'm very grateful to you both for explaining things, cheers. However, unless I'm being really daft, I may have opened a strange tin of worms! Pictures tell it best so gonna upload some tomorrow

It's weird but the two manifolds are definitely separate and it's a May 1970 144 DL with single Stromberg B20A engine

Unless I bought a Frankenvolvo 5 years ago??!!!

[Billy Smalls]

Hi again, so here are some photos to illustrate what I'm talking about. You can see the crack!! but strangely there's no soot around it???

http://s713.photobucket.com/user/Wil...0.jpg.html?o=0

http://s713.photobucket.com/user/Wil...8.jpg.html?o=1

http://s713.photobucket.com/user/Wil...4.jpg.html?o=2

http://s713.photobucket.com/user/Wil...0.jpg.html?o=3

http://s713.photobucket.com/user/Wil...9.jpg.html?o=4

what do you think?

[classicswede]

The inlet and exhaust are all in one. This is just the nroaml standard B20 single carb manifold.

The exhaust side has clearly cracked and that is your blow.

Your best bet will be to just replace like for like. I do have some if you are wanting one

[Derek UK]

None of those pictures prove your case that the 2 parts are separate. The join is in the centre where the inlet and exhaust cross over. The exhaust ports for cylinders 2&3 are combined into a larger part of the casting and the inlet joins onto the top of that. It is deliberate as this heats the incoming fuel mix a little to help with cold running. The area of the join is quite small. As I said, a sort of Siamese twin type join. The surface character of the metal looks different because the inlet runs cold and the exhaust runs hot. The hot one tends to rust and the cold one doesn't. This should show you the layout.
http://www.ebay.co.uk/itm/like/28215...0865095&crdt=0
This one should come up well after a good bead blasting.
It looks as if when you had the head removed the manifold was left attached to the downpipe. You can barely see the join, whereas if they were separated you should see signs that a new gasket was fitted. By the look of the stud and brass nut the whole lot is going to come off so that you can separate the manifold from the pipe so in this case it might be a good idea to source another manifold that you can restud and tidy up for a quicker swap over. As I said, I will check out the front pipe section to see if you can use it. From the picture it might work. If your stainless exhaust company is still open and willing to swap it in that may be the best idea.

[Billy Smalls]

Originally Posted by classicswede

The inlet and exhaust are all in one. This is just the nroaml standard B20 single carb manifold.

The exhaust side has clearly cracked and that is your blow.

Your best bet will be to just replace like for like. I do have some if you are wanting one

Thanks mate - I guess I'm just looking at it from the wrong angle - as it looks like two separate pieces of metal to me, I just can't see how they are joined - I guess I'm wrong though....EDIT EDIT - Derek's ebay posting link shows me now!!

Yes, that crack is quite bad - so maybe pm me what you have, thanks very much

[Billy Smalls]

Originally Posted by Derek UK

None of those pictures prove your case that the 2 parts are separate. The join is in the centre where the inlet and exhaust cross over. The exhaust ports for cylinders 2&3 are combined into a larger part of the casting and the inlet joins onto the top of that. It is deliberate as this heats the incoming fuel mix a little to help with cold running. The area of the join is quite small. As I said, a sort of Siamese twin type join. The surface character of the metal looks different because the inlet runs cold and the exhaust runs hot. The hot one tends to rust and the cold one doesn't. This should show you the layout.
http://www.ebay.co.uk/itm/like/28215...0865095&crdt=0
This one should come up well after a good bead blasting.
It looks as if when you had the head removed the manifold was left attached to the downpipe. You can barely see the join, whereas if they were separated you should see signs that a new gasket was fitted. By the look of the stud and brass nut the whole lot is going to come off so that you can separate the manifold from the pipe so in this case it might be a good idea to source another manifold that you can restud and tidy up for a quicker swap over. As I said, I will check out the front pipe section to see if you can use it. From the picture it might work. If your stainless exhaust company is still open and willing to swap it in that may be the best idea.

Thanks Derek - consider my tail firmly between my legs!!! yes, the exhaust company is still there - to be fair the garage who did my head kept the labour costs down by taking manifolds off with exhaust pipe attached. Thanks again, and sorry for doubting you guys!!

[Derek UK]

This is the front piece of the pipe mentioned. If you think it might be useful, perhaps with one of Dai's manifolds or the eBay one, let me know. It's a 2" outlet. The exhaust people should be able to knock you up a joining piece if needed.

[Billy Smalls]

Originally Posted by Derek UK

This is the front piece of the pipe mentioned. If you think it might be useful, perhaps with one of Dai's manifolds or the eBay one, let me know. It's a 2" outlet. The exhaust people should be able to knock you up a joining piece if needed.

Thanks alot Derek; I'm in the process of getting a manifold from Dai, so will take a look once I get it and get back to you - really grateful for your help

cheers mate