How to separate Al head from an Fe block...

Seriously I've never seen this happen, an aluminum head that WILL NOT separate from an iron block. I picked up a free 1300 X1/9 motor and I began tearing it down to get the head off to see what I had. I finally gave up after I had removed the entire botom end thinking I'd work at it from the bottom (can't get the pistons out through the bottom). It looks as though this car blew a HG, the pistons were seized, but some penetrating oil and time and they freed up, all the bearings were rusted or pitted and several of the oil passages had closed up so the bottom end was garbage, but I may make this into a coffee table.

Anyone have some really clever tricks to free the head? I've gone so far as to wack it with a deadblow tried to get a scraper in on the block side under the HG, and nothing, it's superglued in place...

EDIT: So it turns out the studs bind and stick the head to the block, I guess I'll try getting some nuts and torque them together and try to back out the studs, of course there's barely any room to work given the recesses, stupid engine...

If the bottom end is apart, all you need is a 2X4 and a BFH. The dowel pins are probably froze in place. Drive it off.

Pry bar in one of the ports.

Many moons ago, we would use the engine crane to lift it off if the engine was still bolted into the car. I've seen 128's with the front wheels lifted off the ground.

Try to pull the studs. Thats what is holding the head down.

does the starter work?

Thread some rope down into one of the cylinders, turn engine over. That should pop the head off with something reasonably soft.

alfadriver wrote: does the starter work? Thread some rope down into one of the cylinders, turn engine over. That should pop the head off with something reasonably soft.

Except the engine is all apart...

If it were me I would cease deadblows from the side, the studs and dowels will laugh at you. I also would not knock the pistons from the underside into the chamber - unless you're throwing the pistons away. Since you can't get the pistons out, you can't get in behind it.

I would get a good chisel and drive it in where the gasket is in a few different areas. Your idea of double nutting the studs is also a good one.

Not sure I agree with you there, tuna.

With respect to splitting motorcycle engine/gearbox cases, the phrase I've heard used is "if you could potentially be tempted to use it as a prybar, lend it to your brother-in-law before attempting to split your cases". Prying doesn't do nice things to aluminum.

If the head is a throw-away, pry away.

My $0.02, take it at face value.

For your next fun adventure, stop by an outboard motor shop and ask them to let you seperate the unit to replace the water pump impeller. Preferably a big one that's seen saltwater duty.

There has got to be an improved design for that.

Remove the plugs, bring a piston all the way up on the compression stroke, or if engine is stuck, find a piston closest to the top with the valves closed. Get one of those anti-fouling spark plug doo-hickeys and thread a 1/4 PT grease zerk into it as best you can. Install it into the cylinder and attach your grease gun. Pump the gun until the head pops off.

Oh yeah, you will have to put the crank back in or somehow keep the piston from blowing out the bottom, as even a hand held grease gun can generate up tp 5000psi.

Heat and Kroil (or acetone/ATF, if you're in that camp) down the studs to wick into the holes. Then more heat, and a big deadblow hammer.

Then, you need to input a lot of force, sharply. Can you fasten a couple bars/angles/plates across the head casting by existing bolt holes? Do so, then with help, drop the head/block assembly on stacked masonry cribbing - ie. cinderblocks - so it lands on the these supports and the block is falling away from the head - it's own mass is the hammer. Try for the blocking to be not much higher than the height of the block so it doesn't have far to fall. and put a bunch of plies of cardboard or old carpet down to cushion where it'll fall.

Don't laugh and dismiss it. Sometimes a good solution takes some time for the setup, and seconds for the execution. Vs. the more popular methods of simply applying lots of ineffective force for a long, tiring time.

I didn't see the part that the engine was so far apart.

Buy a Yugo, and use it's engine.

tuna55 wrote:

alfadriver wrote: does the starter work? Thread some rope down into one of the cylinders, turn engine over. That should pop the head off with something reasonably soft.

Except the engine is all apart... If it were me I would cease deadblows from the side, the studs and dowels will laugh at you. I also would not knock the pistons from the underside into the chamber - unless you're throwing the pistons away. Since you can't get the pistons out, you can't get in behind it. I would get a good chisel and drive it in where the gasket is in a few different areas. Your idea of double nutting the studs is also a good one.

Basically sums up all the things I looked at except I didn't want to destroy the pistons, or head, so I just stopped for the night and left the pistons in and the head on, I got one stud out, 4 to go, good lord these studs are the dumbest idea given the tight spacing/recesses on the head...

exhaust studs are holding the head on. They go in too far and lock the block to the head