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Cracked cylinder head. Stitching pins and new seats

Garwood

Diamond
Joined
Oct 10, 2009
Location
Oregon
That's likely where my issues with nickel welding parts near their centers of mass- I lack the means to heat large things to 800+ degrees and hold them there.
 

Newman109

Diamond
Joined
Sep 4, 2006
Location
Sacramento County, California, USA California
From the picture it appears that the valves are very close together. Reminds me of the
'56 Cadillac engine design. I put one of those in my former 1941 Ford Convertible. After a while I got coolant out of the exhaust pipe. The head had cracked between the valve seats which were no more than 1/16" apart!
I looked in various wrecking yards for a good one and discovered that the problem was so common that the heads on wrecked Cadillacs would all be missing. I never could find a good one. I finally swapped in a 327 Chevy engine.
If the OP can get a rebuilt head with a guarantee for $1K that is the way that I would go. New 20HP Diesel tractors usually start arouind $30K in my area.
 

john.k

Diamond
Joined
Dec 21, 2012
Location
Brisbane Qld Australia
The first Ford OHV V8s were notorious for cracking between the valve seats,and Ford dealers used to sell a bottle of sealant to fill the cracks.........however as has been said......what works on a gasoline engine wont work on a diesel.
 

Wlhequipment

Plastic
Joined
Oct 22, 2022
Location
Denver, CO
Well, I gave it my all, and it's time to call time of death on this head. I had everything all set up, my grill had the head up at around 500, the Lincoln ran just fine, but this iron is different than my practice pieces. Firstly, I simply cannot get it clean enough to not be porous. Nothing I did made a clean bead. No amount of cleaning, de-greasing, shiny metal and all could make good bead. Not only that, but the head was made out of a possibly different type of iron, because, no matter how low I set the current, the iron just melted away like butter. Fast. It's like it boiled off. I gooped it up, in the hopes of success, but wow, that was just awful. I tried. Can't win em all, I guess.
 

john.k

Diamond
Joined
Dec 21, 2012
Location
Brisbane Qld Australia
if the iron appears to foam ,then its a free graphitic high tensile strength iron ......lots of post 1970 s diesel heads are special high strength irons............ the iron is very fluid when melted (like water) the arc force simply blows it out of the arc melt zone ..........nickle rods have special coating that reduces arc force to zero ........the melted nickle simply drips into the weld zone and solidifies.
 
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Wlhequipment

Plastic
Joined
Oct 22, 2022
Location
Denver, CO
if the iron appears to foam ,then its a free graphitic high tensile strength iron ......lots of post 1970 s diesel heads are special high strength irons............ the iron is very fluid when melted (like water) the arc force simply blows it out of the arc melt zone ..........nickle rods have special coating that reduces arc force to zero ........the melted nickle simply drips into the weld zone and solidifies.
That’s what I have is 99% nickel.
 

Wlhequipment

Plastic
Joined
Oct 22, 2022
Location
Denver, CO
if the iron appears to foam ,then its a free graphitic high tensile strength iron ......lots of post 1970 s diesel heads are special high strength irons............ the iron is very fluid when melted (like water) the arc force simply blows it out of the arc melt zone ..........nickle rods have special coating that reduces arc force to zero ........the melted nickle simply drips into the weld zone and solidifies.
Also, the foaming… that’s exactly what seems to be happening.
 

john.k

Diamond
Joined
Dec 21, 2012
Location
Brisbane Qld Australia
If you are using pure nickle rods,the cast iron should not melt except where the nickle touches it ...there should be no melt pool like with steel.,and almost no penetration.....the nickle should simply drip into the veed preparation and build up........a different technique to steel welding is used ............with nickle filler ,there is no cleaning action,and prep must not smear graphite over the surface......no grinding ....chisel out the vee.
 

johansen

Stainless
Joined
Aug 16, 2014
Location
silverdale wa
Has anyone tried to braze one of these heads with 56% or 45% silver rod?

I'm guessing it won't hold due to the tensile forces involved.
 

john.k

Diamond
Joined
Dec 21, 2012
Location
Brisbane Qld Australia
Ive always used the nickle /bronze rod with high strength iron .....you need to chip not grind,and use the white scaling powder to wet the iron,then go with the pink............nickle bronze (not flux cote ,dont like it) is my go to for any strength repair of cast iron......however ,bronze can soften significantly at quite low temp ,so how it would go in a cylinder head ,I dont know.
 
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john.k

Diamond
Joined
Dec 21, 2012
Location
Brisbane Qld Australia
Nickle bronze can also be built up into a fillet ,its not as fluid as brazing rod......if the head is a mess ,Id cut out the damaged iron ,and use nickle bronze.............certainly never silver solder .....its meant for close fits and small gaps ,not bulk buildup.......edit ...braze should be OK , prewar ohv motorbike heads were made of bronze ,often as a race accessory for the bike .....so bronze will be OK with the heat.
 
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