Agree taking head of wise as it will act as a heat sink. Is your goal to just fill the hole then re-tap it? There is special welding rod available for welding cast iron.
Not to mention, if an aluminum head were attached to an iron block and both were brought up to suitable temperature for welding either, you’d warp the head past the point of usability.
The special welding rod does not require preheating. I’ve got some, will try to find. I welded the cast iron chase on the letter press with it (not the best looking welds) but the welds are structurally sound even if not pretty.
Just to clarify, afaik this cylinder head (where the problem is) is cast aluminum not iron.
Cylinder block alloy cast iron
Cylinder head alloy aluminium
I’m not too familiar with the Zetec engine family, but I’m also not familiar with any engines where the timing belt tensioner or idler are bolted to the cylinder head. That’s typically a block-mount thing on belt-timed engines. Can you confirm that the head is in fact the target here?
That’s wild. I’ve only ever dealt with head-mount timing tensioners on chain-timed engines. The timing gear is typically a lot smaller on those, so it’s easier to pull off. Funny that.
Yeah man, I say try some ideas at welding it, and depending on what happens, that $50 engine will at least give you the option for spares.
You shouldn’t need to heat treat. However it will be interesting for you. Check up with Jody on welding tips and tricks on YT. He does some cast aluminum welding on a motor bottom end for a boat, I can’t remember the exact name. He goes into the explanations of the challenges associated with it. It you heat treated that head, I’d bet money it would come out warped. Not to mention that you would have to replace all the valves guides. Essentially it would be cheaper to buy a remanufactered Head say from Cylinder heads international.
Would brazing hold up to being retapped for the idler pully?
My gut sense as someone who only welds accidentally is, even as good as aluminum is at dispersing heat, the small size of the affected area needing to be welded should allow you to get a decent weld without getting the head hot first.
That said, the head should be able to hold up to about a 250F heat before anything goes stupid, if some amount of preheating is necessary.
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Preheating is recommended by both Wyatt Swaim and Art’s Automotive
If you heat to the recommended 350F, I’d recommend tearing the head down first so it’s just the bare head casting without any bolts, valvetrain components, or seals installed. That stuff will all get unhappy with the aluminum at that temperature.
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What’s the size of the bolt hole? I can’t imagine it’s any more than 8mm. If it bottoms at 5/8" that’s a pretty small volume to fill.
Bolt is 8mm, hole the previous owner made is at minimum 15mm wide.
Okay but why tho
That $50 cylinder head is sounding a lot more enticing to lazy guys like me.
I don’t know, I guess it’s more fun to at least try to improve your skills at some things lol. Also I did text him, no response yet though
What I’m meant is in the “heat treat” I’d bet money that the head won’t stay true. I would definitely tear the whole head down too.
So if we do a teardown to just the cast aluminum, no additional parts or screws, it should be able to be pre-heated, welded and post-heated without warpage? Assuming I dont weld like a jackass
Basically my gut says that in heat treat the head will warp.
Beforehand I would check flatness. Then again afterwards. That will really tell you.
So just start welding? No heat treating? What are you suggesting?