Machine shop said as bad as it is, and due to some uneven thicknesses, they want me to pull the camshaft and bring it back so they can check the top. They have a theory that it's so far warped, it's prolly eating the cam and causing a friction weld to form (which may be what dragged the engine down rather than a little water getting in there).
It's really hard to do while the valves and springs are installed- it takes quite a bit of force to counteract the push of the valve springs. You can likely do it with two hands wrapped around the cam gear.
Trying to remove the cam, which way does it come out do you know? It wont pull out past the front seal without knocking it out I think, maybe the timing pulley comes off and it'll slide out the distributer hole? I tried getting that pulley off, there's flats on the cam to put a wrench on to hold it, but I couldn't get the bolt out off even tapping the wrench with a hammer...
That aside, this head on eBay is only $195 + $34 shipping and includes everything:
Think I should just buy the rebuilt head for this $~500 car rather than spend ~$100 getting the head machined (assuming it's salvageable)? I'd still need a gasket kit ($60-150) and a timing belt and tensioner ($60-80), and the car is free if I can fix it and drive it off the property...
I would worry about a head that warped, because if you get it machined the cam bearings could be misaligned and eventually it would break the camshaft.
Not real experienced with Mazdas but it would happen on Nissans. You had to resurface both sides of the head (removeable cam towers on the L series engines), then shim the cam towers to keep the timing chain tight enough.
Maybe used if it checked out OK, and the savings was considerable. I would at least use the factory head gasket.
Take my words with a grain of salt, my friend. I had to guarantee my work for a year with no mileage limitation. If the customer wanted cheap then he risked the failure rate.
Free car, how much do you put in it? We always told the customer to let us look the whole car over to get an idea of what the total cost would be to keep it on the road long enough to justify the expense.
Also consider the fact that a head that warped was probably caused by overheating. Probably the radiator is almost plugged up. They don't usually warp that bad without getting really hot.
Also the possibility the it got hot enough to crystallize the rings, in which case you get the head on and she hold coolant but the oil consumption is atrocious.
It's a tough call from the perspective of treating you as I did my old customers, but it kept me from being summoned to court for 30 years and people who understood the real situation appreciated the candor, instead of feeding the repairs one at a time and really draining their wallet on a car that did not justify the expense.
used engine that looks good inside
rebuilt head and new radiator, possible thermostat and or water pump.
How are the belts, brakes, clutch, shocks, body rust, interior. Do a serious condition appraisal, and get and idea of what it will take to get two more years out of the car before you start.
It needs brake work, and maybe a wheel bearing. Clutch seemed ok. Shocks may need replacement in the future, they were tolerable for now. I have a friend with a dead one I can get 4 new tires off of. No cancer, but a couple huge dents and the interior is dirty. Belts appeared ok.
No idea if it was overheated, but it had antifreeze in it. But considering that a previous mechanic had obviously changed the gasket before, and it was obviously not properly installed, he probably torqued the head wrong and warped it... I guess there's no way to check the rings, but the cylinder walls were really nice looking, and I was told it didn't smoke before it quit running.