Problem with good set Iron Heads

GTGeorge · 05-03-2001, 01:55 PM

I have a great flowing set of ported iron Street Heat heads That I just took to the engine machine shop to have them freshend and they discovered a small crack in almost all the chambers the cracks are running from the valve seat area to the spark plug hole, I have not had any trouble with these heads and the machine shop said to just run them the way they are. I am a little uneasy about that. he said that welding them changes the metal and it might be worse, he is a major engine builder in the racing arena (dirt) and does good work, but I am still wondering if there is not a way to fix them. Has anyone had similar problems and had there cast iron heads welded? I hate to scrap them because these are really killer heads.
any help?

------------------
93GT 398" 14:1,1080 Barry Grant Carb, nitrous fogger, c-4, Street Heats, 2" RCI long tubes, more.
79 notch 306, 5speed, carb, small plate nitrous.
88 turbo coupe 5 speed stock
91GT conv. 5.0 5speed, 3.73, and the normal bolt on stuff, just added to herd a sweet 86,SVO,5speed,306,msd,650dp,bbk,autometer,ect.
91 f-150 4x4 tow truck

Unit 5302 · 05-03-2001, 06:19 PM

Cast iron is very difficult to weld. The welder doing it needs to be very experianced.

They CAN be welded, I know a shop around here in Rogers, MN that does it, but do to the slow expansion rate of cast iron, the heads should be baked in an oven to heat them up before the welding is done, otherwise the welds will crack right down the middle, or right on the sides. This happens because the cast iron doesn't contract as much as the welding material as it cools. It literally tears the weld apart.

All the extra pain involved in welding iron heads usually comes out of the pocketbook.

I cannot advise you on any performance, or reliability issues on this, sorry.

GTGeorge · 05-04-2001, 12:39 PM

Unit 5302 thanks for the reply, I think I am going to try to find someone to weld them but I still am not sure, someone else told me Indy cyl heads does weld them, I am going to give them a call.

------------------
93GT 398" 14:1,1080 Barry Grant Carb, nitrous fogger, c-4, Street Heats, 2" RCI long tubes, more.
79 notch 306, 5speed, carb, small plate nitrous.
88 turbo coupe 5 speed stock
91GT conv. 5.0 5speed, 3.73, and the normal bolt on stuff, just added to herd a sweet 86,SVO,5speed,306,msd,650dp,bbk,autometer,ect.
91 f-150 4x4 tow truck

05-03-2001, 01:55 PM	#1
GTGeorge Registered Member Join Date: Apr 2001 Location: Harrisburg,Pa Posts: 11	Problem with good set Iron Heads I have a great flowing set of ported iron Street Heat heads That I just took to the engine machine shop to have them freshend and they discovered a small crack in almost all the chambers the cracks are running from the valve seat area to the spark plug hole, I have not had any trouble with these heads and the machine shop said to just run them the way they are. I am a little uneasy about that. he said that welding them changes the metal and it might be worse, he is a major engine builder in the racing arena (dirt) and does good work, but I am still wondering if there is not a way to fix them. Has anyone had similar problems and had there cast iron heads welded? I hate to scrap them because these are really killer heads. any help? ------------------ 93GT 398" 14:1,1080 Barry Grant Carb, nitrous fogger, c-4, Street Heats, 2" RCI long tubes, more. 79 notch 306, 5speed, carb, small plate nitrous. 88 turbo coupe 5 speed stock 91GT conv. 5.0 5speed, 3.73, and the normal bolt on stuff, just added to herd a sweet 86,SVO,5speed,306,msd,650dp,bbk,autometer,ect. 91 f-150 4x4 tow truck

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05-03-2001, 06:19 PM	#2
Unit 5302 Registered Member Join Date: May 1999 Posts: 5,246	Cast iron is very difficult to weld. The welder doing it needs to be very experianced. They CAN be welded, I know a shop around here in Rogers, MN that does it, but do to the slow expansion rate of cast iron, the heads should be baked in an oven to heat them up before the welding is done, otherwise the welds will crack right down the middle, or right on the sides. This happens because the cast iron doesn't contract as much as the welding material as it cools. It literally tears the weld apart. All the extra pain involved in welding iron heads usually comes out of the pocketbook. I cannot advise you on any performance, or reliability issues on this, sorry.

05-04-2001, 12:39 PM	#3
GTGeorge Registered Member Join Date: Apr 2001 Location: Harrisburg,Pa Posts: 11	Unit 5302 thanks for the reply, I think I am going to try to find someone to weld them but I still am not sure, someone else told me Indy cyl heads does weld them, I am going to give them a call. ------------------ 93GT 398" 14:1,1080 Barry Grant Carb, nitrous fogger, c-4, Street Heats, 2" RCI long tubes, more. 79 notch 306, 5speed, carb, small plate nitrous. 88 turbo coupe 5 speed stock 91GT conv. 5.0 5speed, 3.73, and the normal bolt on stuff, just added to herd a sweet 86,SVO,5speed,306,msd,650dp,bbk,autometer,ect. 91 f-150 4x4 tow truck