Hi Gents
Trying to figure out the best way to do this. I have a 63 Chevy II and an doing a single turbo TC 78 set up. On the drivers side, I am able to make a truck manifold work if I cut the flange of and weld a 45 and a 1 inch piece of 2 inch pipe and then a band clamp on. On the passenger side, I need to cut the flange off the mainifold and rework the last 2 inches before the flange. This can be done with a short piece of 2 inch pipe and then a weld el which would be part of the merge pipe, Can I make these completely out of 304 stainless or should it be steel pipe? Should I go steel to band clamps and then go stainless? I have found where many people have welded 304 directly to the manifolds and it welded sweet but I do know if the welds broke, cracked, etc over time. The postings show sweet welds but I don't know if they lasted. I have welded the cast steel manifolds to 304 using 309 TIG filler rod and it welds sweet but don't know if it lasts. Please let me know past experience doing this.

Mike

 

Either steel or stainless flanges will work... use 309L filler rod for welding the flanges to the manifolds.

 

Im about to weld some to, gotta clean mu cuts a little first

 

I welded a piece of 304 to some manifolds using 309 rod, stress relieving as I went and then slowly cooled it down. I then heat cycled it with a torch several time and beat the crap out of it with a 5 lb sledge and no cracks at all. It just bent the 304 tubing all to hell and back. Seemed to work pretty well.

 

I have done several just the way you describe without any issues. Hell even welding them with a crappy mig with mild penetration never had a problem or heard of any problems so far. I do use an oven to pre and post heat though.

 

I have tried all ways possable. I come to find that it really does not matter...at all! lol I think heating and post heating are pointless. I had warped vbands I had cut off and lying around in my scrap bin, so i welded it both ways then tested it to comfirm.

The first manifold I did a full preheat in a powder coat oven to 300 degrees. I then welded it with a root pass of 309l, then welded with a secondary pass with ER70s favoring the manifold side, then followed with a pass of 308L on the v-band side and then another final pass with the 309L to cap all 3 filler rods. After the HOT manifold "but not over heated" was done and banded i threw it in a bucket of black sand blast sand and let cool fully then welded a 2ft piece of tube to the vband with small welds for the "test".

The second manifold was NOT heat preped and at room temp. I welded it with a single pass of 309L. I tacked all 4 sides with a quater inch weld then staggered every other weld connecting all four welds with a good fill walking the cup. I finished the manifold off by welding a 2ft piece of tube to the end with small welds also.

After the two manifolds were done and cooled I bolted them to a piece of 2''x2'' tube and slapped them in the vice. I took the first manifold with the pre heat treatment and put my welding gloves over the piece of tube i welded to the end, sat on it and started heating the manifold with my weight "200lbs" on the end......well after my *** got hot enough and nothing happened I decided to throw it a few times, smack the living **** out of it with a hammer, then threw the hot as **** manifold under water...still nothing!

I went on to the other manifold that was just welded....plain ol' welded. I did the exact same thing to this one. I straight up heated and beat the **** out of it also. NOTHING! Not a thing happened. I then heated them again with the torch and kept smacking them with a ball peen hammer. I was able to get both manifolds to crack in the center two primarys, but nothing at the welded spots.

IMO....just weld the damn things!....mig will work too!

 

Yup, the heat cycling with the torch was just to simulate a couple drive cycles....got that sucker RED hot. People tried to say that the heat cycling would cause the weld to crack....I did not find that to be the case. It was once round tube, lol. Beat it square.

 

I welded standard ex pipe to a truck manifold, I just pre heated it and welded it with a standard wire welder. You can't get the manifold hot enough to make it weld good without burning a hole throw the pipe. Turbos has been hanging on it for a year now with no problems.

 

I made this heat sink tool to help w/ split flange warping...Overkill, maybe. But, it works.
A pic of a flange that was welded w/ the sink, but had to have a short part done w/o the sink. Note the heat signature where it was welded w/o.
Made from 1/2" alum plate stock.
FWIW, I've tried both the paste and the purge methods to prevent "sugaring".
Didn't see much difference in them. Both work.
It also sets the overlap depth [1/8" for easier assembly of the flanges. Once 1 side is welded, I use that side to set the relief in the second flange, so they mate tight, and square.

Works for me.

 

Good news on all counts!

 

any other tips?

 

Cracking is caused when two different metals cool at a different rate, usually they have to be very different..... like cast iron vs steel or stainless. These manifolds are not cast "iron". Also you can sometimes get cracks when welding disimilar metals if you weld a thinner peice to a really thick peice, the cooling times will be so different because of the heat retention in the thicker one. Like others have said... you dont need to do any of that with these manifolds.... just weld them. Heating them up is just a sign that you really have no idea what you are doing...lol.

 

Would black iron pipe welded with 7018 rods work? I've only got access to mig and stick welders.

 

Thanks for all the advise. I ended up TIG welding a short piece of pipe on one side and a steel weld el on the other. I used 309 filler and did nothing special. Seemed to weld sweet. The steel pipe I welded on would be very similar to the black pipe. I think that 7018 and black pipe would work ok. I would try welding some scrap black pipe to what ever you cut off the manifold.

 

I went through a lot of trouble when I did mine. Pre-heat, post-heat and used 309 rod. They turned out great. Having said that, too many people are having success just Mig'ing these things cold to go through all the fuss I did. The next set I do I'm going to just blast them with the Mig and call it a day. These manifolds weld like mild steel.

 

There was a fellow here that was machining a v-band flange to the manifold - real trick and the way to go. If we can only find him!

 

Chuck,Dennis here from tb.com
I have a ??? ,i just bought a mig and a guy i work with told me that i can tig with my mig,i just need to get the tri-gas and tig wire and i am all set....is this true??

 

Read something similiar recently. What I read was you switch polarity around and change the gun out for a tig torch. Then just get argon and filler rods........I could be wrong.

 

tag! good thread so far with some good info

 

So basically just clean them, maybe heat them a little then just blast them with the MIG ? mild or stainless wire ?