Aluminum Intake Manifold

[Brian Oatway]

I'm looking to do some welding on an aluminum intake manifold.

The thing is filthy and I'm not sure the alloy but I'm looking to add some 6061 pieces and I'd obviously like to avoid warpage.


Any suggestions on how to clean the old piece up? Will just some surface grinding be sufficient or could the fuel/oil have pentrated into the material.

Should I preheat the manifold?

Any filler suggestions?

I'll be using a Syncrowave 180....Thanks

[H80N]

ideally.... hot steam cleaning.... followed by vapor degreasing... then baking out in an oven.....

but the real world only affords that thorough a cleaning usually to the places that weld cylinder heads and automotive aluminum every day... a lot of those castings are Very porous and have soaked up a lot of oil over the years... clean it best you can and bake or preheat the best you can... and expect guck to come out of the casting as you attempt to weld... it may take a few stabs at it before it burns out and you get a decent weld.... or maybe you will get lucky and it goes like a breeze..... but try to clean as thoroughly as you can before trying to weld....

hot pressure wash and engine cleaner should get most of the surface crud off...

how about some pics so we can better understand what you may be facing on warpage issues...and general setup as well as welding?? type of welder?? makes a difference... many times with an inverter like a Dynasty you can get in and get out without much heat being put into the surrounding area...

[Suvi]

Hei

Here are my taughts.

You should try to clean all manifold with soap(something that dissolves oli) and hot water. Try to clean it as good as possible inside out. The area you are going to weld clean with acetone. Before welding use stainless steel wire brush and wipe it again with acetone. Wipe the wire also with acetone.

Heating up the manifold will help to avoid little cracks when welding. If the weld cools too quickly, it can crack in the end.

As for wire i would use 4043(AlSi5)
I would also use thoriated (red) or lanthanated (gold) tungsten. That way you can keep the tungsten sharp and these don't contaminate so easily.

These technicues work for me.

Hope it helps

[Brian Oatway]

Thanks all....I'll try to remember to snap some pics this weekend, but what I'm doing will be similar to the picture below.



The manifold is for a supercharged motor but it's a little unusual since the SC sits directly on top of the motor but does not discharge down into the manifold but rather up then through an air-to-air innercooler at the front of the car then back to an inlet at the back of the intake manifold which is pancake style and I'm looking to extend the air charge opening as shown about 6" to make room for a larger plenum on the back of the supercharger just as is shown here. This guys used a mig/spool gun and laid in a ton of weld then cleaned it up but I'm not sure how it will hold up. I'll be using tig on a Syncrowave 180.

This is a "shadetree" type of project so no fancy steam or sonic cleaning unless I hire that stuff out but I've got the surface clean with degreaser, I can certainly get after it a bit more with some acetone or something once I get the cuts made where I'm looking to make changes.

I would like to make these welds without warping the flanges at either the heads or block. I have a parts motor I could bolt this to while welding if that would help it hold it's shape..

[H80N]

what is the make and model of the welder that you plan on using?? it makes a difference...

[Brian Oatway]

I'll be using a Syncrowave 180....Thanks

I'll be using tig on a Syncrowave 180.

Thanks for any help.

[H80N]

Sorry Brian
somehow I missed that... looks to me that you are gonna be pretty light on horsepower with a sync 180 on that much mass of aluminum... even with a bunch of preheat and maybe helium... 180amps is good for 3/16ths aluminum... and it looks like anyplace on that manifold is thicker by a bunch... plus you are probably looking at 15 or so pounds of aluminum heat sink...
am not trying to be a downer but you may be better off finding a buddy with a much larger machine... to tackle this...

free advice is worth what you pay for it...but this is how I see it... other opinions may disagree

[H80N]

you might spend some time reading some old threads on welding aluminum castings.. lots of info there......

Just do a search on "Cast Aluminum" many many threads on the subject...

[Brian Oatway]

I've read alot of those posts...very helpful!!

I've welded up to 3/8" aluminum flanges with my 180 but nothing as large as this manifold which has some areas that are 1/4" thick but most is about 1/8-3/16 and the actual flanges may be as much as 3/8"

Fortunately I have two of them so I can use one as a practice piece. I'm going to use a propane grill to bake it and an electric hot plate to maintain preheat as much as possible. If I can do it I'll be pushing my Sync 180 pretty hard.

We'll see I guess..........

[Brian Oatway]

Made some practice welds on the spare manifold this weekend. I cleaned it up, ground/sanded out the areas to be welded, baked it for an hour and sanded off the crud.

Made a bunch of test welds attaching some scrap pieces in 1/8" and 1/4". No problem with having enough power with my Syncrowave set at 150amps, I did not preheat. I did get a little bit of crud floating on the top of the puddle but not alot so I'm thinking I'll be fine with this setup.

Thanks for talking this through with me.

[H80N]

Brian
here is an article on welding automotive aluminum cylinder heads... there is a lot of similarity between the two..

http://www.enginebuildermag.com/Article/62070/tig_welding_aluminum_heads.aspx

best of luck and please keep us posted...

[Brian Oatway]

I've managed to get the extension welded onto the old intake, went pretty well. No leaks on a 40psi pressure test. I guess we'll see how it holds up.

[H80N]

That is Great!!

could you outline what you did to accomplish this with limited amperage??... preheat.. blankets etc....
Thanks...

[Brian Oatway]

I preheated on my gas grill (don't tell the wife) before making the welds where the new material attached to the casting but I didn't get too crazy the thing may have been 200deg or so. I didn't maintain any heat on it while I was welding other than what the welder was putting in.

The areas I was attaching to were about 1/4" thick with the new material being 1/8" and 1/4" the only places that were thicker where were the old bolt bosses were.

Had the Sycrowave 180 set at about 165a and luckily didn't have any problems except for a couple of really tight inside corners where the arc was jumping all over the place....fortunately where that was happening I was able to get nice clean welds on the opposite side of the joint so no problems.

[H80N]

Brian
thanks!! that will give the guys with smaller machines some food for thought before they tackle aluminum castings...
Frankly... I was concerned about your outcome.... glad you thought your way around the situation.....