TheHaflinger.com

Lurch went to the Durch Treffen without any real trouble,although on the return journey he developed a strange noise. Drove perfectly well with only the occasional backfire, so we kept driving till we got home.
Just been out to have a look see what was wrong and discovered that the right hand side (as you look from the back), pre heat pipe has broken at the joint to the carb.

This obviously means the manifold has to come off. Has anyone else had this issue and how did you solve it?

Won't be able to do anything till the weekend, so have time to ponder the problem before tackling it!

John

Isn't it amazing how things like this break after lots of use - I guess the pipe was slightly the wrong shape and when tighened down at the other end, the stress point was where it finally fatigued and has cracked. I have had the same thing happen at the end where it bolts to the exhaust but that was rust related.

My pipes are brazed into the housing under the carb and if possible I suggest you tack braze the pipe back on where it is now. Then remove the entire inlet manifold (a pain) and braze up the crack - by doing it in its current position it should not be stressed when it all goes back in.

Good luck with it

Garry

Biggest issue is that the break is right at the manifold joint so there is the issue of the section between the two pipes which you can't get at to braze other than by heating everything to get he braze to "run" down between the two pipe and seal that way. Problem with that is getting everything clean there so you get a good bond!

John

A good quality muffler putty works in there great. My new inlet/carby heat manifold came with a couple of small holes in that spot where the sun don't shine and I filled the space between with muffler putty and it worked fine. As I don't have the butterfly for the engine governor, I also filled the little hole for it with muffler putty and it also worked great.

Garry

Lurch had a small hole in there somewhere when purchased, filled like you said with putty and a jubilee clip to hold it in place, but it has now rusted, cracked, stress fractured etc all teh way round the pipe right on the joint, so it will have to come off. Hopefully, I can get that one piece of pipe either removed or at least cleaned up so that I can just heat it and add a section of pipe. then put the manifold back in place, cut the old existing pipe to match against the end of the new bit of pipe. tack weld the two bits of pipe together to get the angles correct. Take the manifold off, and weld the pipes together properly.

That way everything should line up correctly.

Don't really fancy heating the whole butterfly section and taking all four bit of pipe out, cleaning and then trying to get them all back in the correct position seeing as it would be unwise to try brazing them all in whilst it was still on the engine!

John

You might be able to braze it in by cleaning the area well (sandblast to white), and then bash out a support plate of sheet metal, and braze that in. I did that for a few rotten sections on one of my manifolds, they're holding up fine. So far.

make a jig to bolt it to .
so every thing is in the correct alignment

kerry

I agree making a jig would be the best way to do the job except it looks like the four pipe mounting points are not all on the same plane, so can't just use a flat sheet of metal and drill holes to put bolts through. Would also need to work out how to hold the Carb mounting plate.

I don't think I will go to the effort of making a jig to line up all the pipe manifold mountings, when I only need to repair one. I can do that by taking the manifold off, brazing a straight piece of pipe into the Carb mounting plate, then put it back on the engine. Line up the broken pipe and cut to length. Fix the broken bit of pipe to existing pipe joint. Tack weld the two bits of pipe together, take it off and weld them properly.

Picture below of the broken bit(s) showing my temporary fix - an aluminium blanking plate and a cork!
If I was going to do all four or make lots of new Carb manifolds, then it would be worth while making a jig.
I'll try to take some picture as I do the repair, but it's not going to happen in the very near future as I have spent the last 3 weekends away and have various things I need to catch up on.

John

Having asked the question of a near by Haflinger owner regarding the use of his oxy/acetylene kit and being told that it would be available over this weekend, I bit the bullet and removed the carb manifold. Cleaned up the bit of old broken pipe on the Carb mounting block and cut a piece of 25mm steel pipe to braze in.
All shiny ready to be brazed in.

Sunday saw me turn up and after a while playing with braze I had this to show for it.
Only when it had cooled down and I could trial fit it did I find out it had moved! Having been a bit over enthusiastic about adding the braze I didn't think it would be very easy to get it to line up again with out applying a lot more heat which might mean the other pipe might move. So I set about about addign another section of pipe at an angle to get it all line up. As the gap between the to pipes was now very narrow I could not weld on that side of the pipe. Solution was to cut a big enough hole to allow welding on the inside of the pipe. (picture shows the access hole).
One of many trial fits.

Other than having run out of argon gas, so I can't finish all the welds off, it all lines up but we'll see if it works correctly when I put the governor system back on. It uses that pipe as a stop and now that it is at an angle, I might have to reset things.

More photos when I get more gas and can finish the welding.

John

Why did the designers have to put the Oval pipe manifolds on so the hole is UNDER the pipe? Makes it a real pain to get a bolt in there and then tighten it up... would have been so much easier to have put them so they were right angles to where they are now. Socket on an extension and done!

Another nail I want to put in the coffin!

John

heinkeljb wrote:Why did the designers have to put the Oval pipe manifolds on so the hole is UNDER the pipe? Makes it a real pain to get a bolt in there and then tighten it up... would have been so much easier to have put them so they were right angles to where they are now. Socket on an extension and done!

Another nail I want to put in the coffin!

John

Yep been there and done that a few times - as we have discussed there are a few design items on this vehicle that are bizarre.

I modified a spanner to get in there but is still a very slow process to tighten up.

Garry

Really don't fancy buying a 13mm ratchet spanner to cut in half just to be able to fit 1 bolt and 1 nut! So I will continue with my stubby spanner set.

Lurch should be back on the road this weekend when I get some more gas and the gaskets.

John

I couldn't get a rachet in there - used a couple of cheap open ended spanners and cut them down and bent them - I guess there are a few ways to do it but it the flange was located 90 degrees on the heater pipe and the exhaust it would make life a lot easier. the first time I did it there was a lot of choice words and knashing of teeth but process is now pretty down pat - I have had mine off about 6 times now but is still frustrating.

Garry

Hey John, I posted some comments in regards your manifold repairs as I have been doing the same repairs on mine for the last couple of days, but my post has disappeared somewhere, and hasn't shown up anywhere that I can find on the forum. This morning I hear on the news that a couple of local fishermen saw a UFO and I wonder if the pilots of said UFO grabbed my post as it went passed. I only thought of this because I don't think the fishermen would have been drinking while wetting a line . Or would they?
Regards Rick

from memory .
a 13 mm crowsfoot spanner is the go

kerry

Hi John - I haven't experienced the broken pipe that you have (you have my sympathies!), however it was something that I was concerned about some time ago.

There's some weight in the carb/airfilter housing and the whole lot is supported cantilevered in mid-air just by the two manifold pipes and the two preheat pipes - my concern was that travelling over bumpy ground that the loadings from this mass would cause fatiguing and pipe fracture.

What I did as a preventative measure was to provide an extra support from one of the bellhousing studs up to one one of the boltholes for the governor housing; this is a much more direct path for support of the carb and pipes and will serve to steady that whole assembly.

Here's a photo - you can just see the support in the middle of the picture - apologies for the poor quality.

Cheers,

john

That jubilee clip is more or less where I had a small hole for some time which I filled with putty and wrapped with a piece of thin steel metal wrapped round and held in place with a jubilee clip. Have to say mine was right up against the carb manifold mounting block.

I will certainly look at adding another support like yours as that does seem like a good idea as it will stop the Carb from bouncing up and down even a tiny bit which could well have contributed to the pipes failure.

My biggest problem is I have run out of Argon Gas and the place I buy it from is shut on the Saturday before a Bank holiday Monday which is what we have this weekend! So no gas until next weekend! I also haven't received the gaskets I ordered, but they might arrive tomorrow morning.

John

John,

Machine mart and Halfrauds both stock it, if you use the disposable bottles.

I tend to get mine in larger bottles from Telford group where I also got my Turbo set 200 oxy set from.

That's the problem, I use a 200psi 3/4 metre high bottle with a separate regulator. So don't have any set-up to use the small disposable bottles, although it might be worth get that set up for 1 off use.

I'll look into the costs, but I still need gaskets so even if I finish the welding. Putting it together again will be an issue!

Thanks for the suggestions though.

John

John - if you want to use the oxy-acetyln again, feel free. I am around for much of the (long) weekend.