The Stovebolt Site Forums The Shop Area Engine Shop Manifold disaster

After cleaning up and installing new studs I was bolting the intake to the exhaust to take it into the shop for facing and the exhaust cracked on the left front bolt. IT looked so nice too. Into the scrap pile it will go.
I was being really careful and torquing with an X pattern too. It was a used one I picked up for $30 and it may have already had a crack in it because it seemed to break so easy. Anyhow, now I am in the hunt for another one. If I can't find one, I might just put headers on it. Not that I want to really go that route with my two ton and I just got a new exhaust pipe made too.

Hy Super55, why don't you have it repaired, either by brazing, or cast iron spray welding as TClederman did recently, Happy New Year.

Inline manifolds are very prone to warping and then break when you tighten them. I always check them with a straight edge and true them on a belt sander if they are warped.

Hey Bobb, What the heck its spary welding... That sounds interesting. I have another manifold with teeny hairline cracks just barely showing. I need more info. I sent a PM to TClederman for some help. It would be great if I could just use that one.

Here is my PM reply to Super55:

3B's memory is better than mine. I thought that I had posted the spray-welding information on the oldGMCtrucks.com website - if you are a member, you can read it.

However, 3Bs post caused me to remember that I had made a photo album of the spray welding). I should mention that the manifold cracked in another location when I installed it after making the repair (after assembling the three pieces on the engine and then having the surfaces planed at a machine shop).

Tim, was the base metal preheated when you guys repaired the Venturi box?

Thats a very interesting looking outfit, and looked like it does a good job.

Joe

Joe,

Yes, the cast-iron part was preheated with the same torch used for spraying the powder.

Here is a link found in the text under one of the photos:
http://www.aa1car.com/library/ar497c.htm

Tim,
Thanks for all of the information. I went to the TCW web page and checked out the info. I emailed them and asked for pricing and tech info.

Your photo gallery is excellent. My manifold cracked just like yours did, but I thought I had flattened the surfaces before bolting them together, but I just used a sanding block. I was totally shocked when it broke.
Thanks again,
Paul Stanley
Maple Ridge, BC

the manifold on my 40 didnt apprear to be cracked prior to sand blasting. after blasting i saw the crack. i took it to the same place that fixed a casting on the fire pump for the Ashton. the process is he used was spray welding. neither jobs showed signs of repair, thats how nice they came out and both are still in service. its sort of pricey but well worth it.

Thanks for the feed back. I am going to try and find someone in the Vancouver area that does spray welding. I wouldn't mind learning it myself, but I think there may be a curve involved. Also, I wonder how large an acetylene tank you would need to have the flow rate for the spray weld torch. It would come in handy to know spray welding, I would think. I bet almost every 235 manifold has some sort of crack on it, no matter how small. I have another manifold that I could use that may have tiny cracks, but I would guess a magnaflux would show it for sure.

Another thought about manifold repair. Has anyone ever used Muggy weld silver solder or rods for repair? Here is a link. http://www.muggyweld.com/index2.html
It is a lot cheaper than investing almost $600 into a spray welder set up.

With a good procedure (mild preheat, short beads peened vigorously between each, slow cool in a blanket/sand, and the right rod and an experienced welder can make this ridiculously easy with the stick method and if pounded properly while warm will blend right in to the casting. After that stand the manifold assembly on the head side on a flat surface and see if it rocks. Use feeler gauges to determine the amount of reface required for cleanup and be aware the depth of the alignment ring counterbore will be reduced after.

http://www.alruqee.net/ind_mkt/RIM-CD&WEB/welding_consumable-files/utp/265-85fn.pdf

Looked at the .pdf for that rod Curt, first time I've ever seen a .pdf that wouldn't print.
dg

Denny,
Go to file in your menu bar, then select "create PDF", use the selection icon that comes up and it will make a printable PDF