My Diesel Build (evil laugh here :D) - Page 20 - Mazdatruckin.com Truck Forum and Tech Site

EmJay · #**286** (**permalink**) 02-08-2010, 02:56 AM

well guys I grew a pair and now I am welding cast. I know that I should be heating it up to 500 before welding it but I just don't have the means to do it this way. I figure this will get me by on start-up until I am ready to make a header to mount a turbo to. It's not complete yet, I have welded them together where I want them but these are the only pictures that I have taken as of yet. More to come

dealwithit · #**287** (**permalink**) 02-08-2010, 05:34 AM

lol im glad you grew a pair hahaha.

just gonna put a plate over the hole then weld the flange on the middle somewhere?

briankmizell · #**288** (**permalink**) 02-08-2010, 07:19 AM

Quote:

Originally Posted by dealwithit

lol I'm glad you grew a pair hahaha.

just gonna put a plate over the hole then weld the flange on the middle somewhere?

Its always nice to have a pair......lol

I was thinking the same thing about the plate and welding in the center.

briankmizell · #**289** (**permalink**) 02-08-2010, 07:20 AM

Couldnt you use a small propane torch to heat it up before you weld it. That may not get it 500 degrees but it would help I am sure.

EmJay · #**290** (**permalink**) 02-08-2010, 07:50 AM

eh, i'm a little tight on the funds to get a propane tank to do that. I didn't have any steel thick enough to use as a plate, so I just welded that hole shut

I have plenty of welding wire left and my tank should have enough for the aluminum job as well. The Mig setup does get pretty hot and running a grinder over it makes it hot as well. Definitely not the 500 degree hot, but hot enough to burn a finger really quickly. I'm confident that if someone mickey moused the intake together using rubber hose over the exhaust manifold, then I should be safe with a welded manifold without boost. After all, it IS getting a custom header made when I do turbo it. Note that I still need to sand it down some and make it clean enough to run it over with high temp fireplace paint and to smooth out the interior manifold welds. Will be shown in later pics, but I welded the flange both interior and exterior, to help create a smoother channel for exhaust flow. Overall, the manifold already survived the sledgehammer test without incident, so the welds ARE nice and strong

briankmizell · #**291** (**permalink**) 02-08-2010, 09:10 AM

D@amn! that was a lot of welding to fill a hole like that.

Just wondering what you used to cut the hole in the center of the manifold before you welding the exit for the pipe on it.

Did it splatter a lot when you welded it? Just curious if it was like welding galvenized metal or not.

briankmizell · #**292** (**permalink**) 02-08-2010, 09:12 AM

If it survived the sledge hammer test it will probably be ok. If its going to break anywhere it will break right next to the weld.

EmJay · #**293** (**permalink**) 02-08-2010, 02:32 PM

That's the beauty of using MIG with pure argon. There was no splatter. From my point of view, it welded just like regular steel, just thicker and took more time is all. I used my angle grinder and a diamond blade to cut the center as my air compressor tank is much too small to use a pneumatic cutoff wheel for cast. I originaly cut a square hole then made diagonal cuts. Then I tapered the flange to help it slide in easily. It went on really clean, I just had gaps to fill. I purposely made a larger weld around the flange and tried to meld the weld with as much of the cast as possible to make it stronger. It only took me about 20 minutes to fill that hole. First do a ring around the border, grind it down, then reweld untill the hole was closed. After that it was a matter of making it smooth and clean like on any other steel. Just time, patience and a lot of repetition.

EmJay · #**294** (**permalink**) 02-09-2010, 03:27 AM

Well I believe that I am finished with the exhaust manifold. I will need to modify the piece that I made earlier on that connects the manifold to the rest of the exhaust, as I designed that to attach to the manifold when the flange was pointing straight down. That should be easy though with a torch, a vice, and a bar. I also managed to get my heat shield to work with the relocated flange, it's only minus one bolt and completely protects the intake. Another thing that me and K6 were discussing, I'm going to need to create a shield to protect the starter as well. Probably going to go to a JY and take one off of any plain ole vehicle and mount it directly to the block.

As it sits with the intake.

Another shot with the heat shield flange point of view

and with the paint drying. This is 1200 degree grill paint, it should be sufficient for a NA diesel.

dealwithit · #**295** (**permalink**) 02-09-2010, 06:15 AM

hmmmmm strait argon you say? you won't get much penetration with strait argon, should at least have some co2 in the mix to get it to stick nice.

looks pretty good otherwise, aren't you glad i said just weld it? lol

EmJay · #**296** (**permalink**) 02-09-2010, 02:17 PM

lol, yeah. It seems to be stuck on there pretty nicely though.

EmJay · #**297** (**permalink**) 02-11-2010, 12:36 AM

Well, I don't know if this proves anything, or did anything or not. I had a night where the little lady was not in so I decided to throw the manifold in the oven. It sat at 550F for about an hour then I cooled it down in 75 degree incriments, leaving it sit at 300 between 2-7am, at 200 between 7-9, 150 at 9 then off at 9:45. What I did notice was my fresh welds inside the manifold had turned to an auralescent blue, the rest of the exterior was painted. (the main reason was that I wanted to see if the paint would fall off or not with some moderate heat, and I know that the exhaust will be hotter than 550.)
The good news is that there were no visible cracks and all the old soot inside the manifold successfully buned off. The bad news is that the whole house still stinks and I'm in trouble

Any thoughts as to if this proves good welds or if it was just a wasted effort? Or if I successfully did anything beneficial doing the heating post welding?

dealwithit · #**298** (**permalink**) 02-11-2010, 01:58 AM

im pretty sure all you did was cure your paint and get in trouble lol. the reason for heating the metal is so that when the weld is applied the metal is already expanded, and when it is all cooled together there are minimal stresses.

EmJay · #**299** (**permalink**) 02-11-2010, 02:00 AM

lol, yeah I thought as much.
now next is getting the motor back and getting the argon tank refilled/aluminum feed kit installed so I can redo the intake. Oh joy

dealwithit · #**300** (**permalink**) 02-11-2010, 03:47 AM

just beware with the aluminum, it won't go nearly as easy as the cast steel did.