Welding v-bands on truck manifolds

[83 Silverado]

Looking to see if anyone has modified a set of truck manifolds from flanges to v-bands. I'm mostly looking for info on the weld of it, and if its something that needs per and post heating like older cast iron manifolds.

[boostedc10]

I have done them with no pre/post heating. The LS manifolds are like a cast steel and actually weld pretty easily.

Way easier than an old cast iron manifold!

I know Wasted Income has also welded some vbands on his. Maybe he will chime in.

[tinydb84]

I read a bunch of threads on LS1tech because I am going to do mine (eventually)

Without pre or post heat it was a mixed bag. Some people had them crack some didn't. Everyone that pre/post heated didn't have them crack. I plan on pre post heating mine when I get around to it.

[softballnrd27]

I pre and post heated, mig-welded and I haven't had any issues.

[Wasted Income]

I preheated mine, and they've been perfect. I agree with boostedC10 that they weld more like steel than iron....it's like GM knew what we'd be doing to these poor engines...lol.

[mister twister]

i cut my flange and rotated it to fit the frame rail on the driver side. Gave it to my buddy to take to work where he could preheat it and weld it with inconel filler. When he gave it back he said he welded it with mild steel and i'm not sure he even had to preheat it. I have been driving the truck for over a month now (heating and cooling) and not had an issue knock on wood!! If that was truely the case i could've done it myself with my MIG..

[Wasted Income]

I was able to weld a stainless elbow to the manifold to avoid the master cylinder, and it's been holding up great, through much abuse.

[83 Silverado]

Thank for the info guys, it's looking like per and post heating is the way to go but what are you using to heat them? If your using a oven I can only imagine the GF's reaction if she fond my cooking car parts lol.

[tinydb84]

Originally Posted by 83 Silverado

Thank for the info guys, it's looking like per and post heating is the way to go but what are you using to heat them? If your using a oven I can only imagine the GF's reaction if she fond my cooking car parts lol.

I plan on using my oven hahah. I have seen people welding cast iron use BBQ's, Fire pits, OA torches, etc. Then either let the fire die down or wrap the part in a welding blanket and cover it in sand.

[LS1Impala]

I MIG welded my manifolds without pre/post heating and they have held up just fine. Ive got over 5k miles on my build now.

[Wasted Income]

My wife gets a little pissy when she comes home to car parts in the oven.

[Jon01]

Originally Posted by Wasted Income

My wife gets a little pissy when she comes home to car parts in the oven.

Yours does that too?
I tell ya...some women!

[BigRed76]

Is there a specific temperature range that the manifolds need to reach for the pre/post heating?

[BR3W CITY]

just take a rosebud torch and heat the general area for 5-10 minutes before welding. I'd say your in the 4-500* range. Most guys I know that do them in the oven set the oven to "clean " which is max or usually 500*.

[BigRed76]

Originally Posted by BR3W CITY

just take a rosebud torch and heat the general area for 5-10 minutes before welding. I'd say your in the 4-500* range. Most guys I know that do them in the oven set the oven to "clean " which is max or usually 500*.

Thanks. I figured they'd probably have to be pretty hot.