Splitting Exhaust Manifold Questions

[Andydodge]

For those that have had their exhaust manifold cut & split what sort of welding rods were used to repair the manifold?......I am thinking about using the front half of a front dump manifold and just have the hole where it would join to the heat riser in the centre welded up and do the same to the rear half of the stock exhaust manifold where it also joins to the heat riser, effectively giving me a pipe that drops between # 5 & 6 cylinder and another pipe that drops between # 1 & 2 cylinder......it seems that this will be the only way I can run a dual or split exhaust on a RHD 1941 Plymouth........the problem being that on the RHD side of the engine block not only does oil and fuel pumps live, but a steering box lives between both of them and to make matters worse the clutch pedal pivots thru where a rear dump exhaust would lie and also there is a clutch linkage and brake master cylinder living there too........anyway back to the exhaust manifold welding question........has anyone had it done and how is it holding up regarding cracks, etc......thanks, andyd

[Andydodge]

Oh....and I forgot to add that I will be running an Offy twin carb intake with Oz single barrel Strombergs......so the stock heat riser with attached intake manifold would be tossed..........andyd

[hkestes41]

Andy, maybe you could have Moose fab up one of his long runner intakes that goes up and over the top of the head but instead of an intake, make it a header. Should have all kinds of room on the other side.

[Tony WestOZ]

Andy, what model strombergs are you using on your car?

I have 3 or 4 here to sort through to set up twin carbs on my 251.

With the twin exhaust set up, there is not a lot of room there to play with on a RHD, and I`m lucky I have a truck.

When I weld up mine I will be using oxy with cast iron filler rod. There are some good iron -nickel rods I have used before for welding cast iron using arc welding I can find the numbers I your interested.

[dezeldoc]

If arc welding use ni-rod 99x, make sure to pre heat it before welding it, and clean it real good to get rid of as much of the old carbon as possible. also make sure it cools down very slow.

Edited June 24, 2009 by dezeldoc

[greg g]

I have had several cracks welded and welded up the holes fo my heat riser axle using mig. The area to be welded should be heated up before welding begins and while the process is goin on. My guy used his rose bud tip to get the area nice and red, and then usd it a couple times more during the process to keep the whole area around the weld nice and hot. and we did grind the snot out of it before beginning.

[wayfarer]

Not everone has a rosebud and they can be expensive, so I use a weed burner on a propane tank. This works very well and since it has a large orifice it produces a very generous flame.

.

[Andydodge]

Thanks for the info guys, I will probably get the local ehngineering shop to do it but was curious whether it was a do it yourself thing, I can oxy/arc weld sounds like something for the experts......Tony, I'm using late model Strombergs, with the larger cast iron lower base, same bolt pattern as the Offy intake, I think they are from HK-HQ Holdens........for you US guys, these are a single barrel stromberg carby that was used on the GM Holden cars from 1948 to about 1975, the 6 cylinder engine they were used on went from 138/149/161/173/179/186 & 202 cubes and are the standard multi carb carby over in Oz much like the Stromberg 97 is in the USA......andyd

[Olddaddy]

Well, at the risk of seeming old fashioned...........I braze them. I've never had a failure in nearly thirty years. Cleanliness is next to Godliness as others have stated. Preheating and slow cooling doesn't hurt either.

[moose]

Ummmm, O...K...

Andy, maybe you could have Moose fab up one of his long runner intakes that goes up and over the top of the head but instead of an intake, make it a header. Should have all kinds of room on the other side.

[Andydodge]

Moose........you don't seem so enthusiastic.........lol......one of the few joys about a RHD early mopar is that we have a very simple accelerator linkage and have never had the joy of a foot starter......however on the other hand we, of RHD mopars have the sheer bliss of looking at not only the intake,exhaust,oil & fuel pumps on the "passenger" side of the car but also have the pleasure of seeing the steering box,brake & clutch pedals also living on this side as well...........lol........nah, I don't think you'd appreciate doing a rhd exhaust.........eventually I'm gunna have to bite the bullet and fab something up myself but am not looking forward to this.......lol.........andyd

[blueskies]

Andy-

I don't have any info for you on welding cast iron, but here's a couple of examples done by Mike Yoder. From what I've heard, Mike no longer does this kind of work, but he did a very nice job on my manifolds.

The first one is a manifold he had on hand, that I had him split so that I could keep my original for a spare in case someone wanted to put it back to stock someday. At the time, I didn't know that there were two types, and the manifold that he had was the rear dump, which does not fit on my '50.

So I returned the rear dump version, and he split my original. Both of them were very nicely done, with ground welds and clean appearance. They looked like they were factory made.

I later sold this split manifold and used Langdon's headers, a choice that I now regret somewhat...

Pete

[Andydodge]

Pete, had you thought about using a front dump manifold?.......cut the rear dump from your heat riser and cut the front dump manifold from its heat riser and voila!!....a pair of 3 port cast iron exhaust manifolds......thats what I'll probably aim for.........andyd