How To Pull a Stuck Flathead Cylinder Head

This was inspired by a thread Elrod did a few years ago on a banger.
http://www.jalopyjournal.com/forum/showthread.php?t=218487

Mine is the same concept, just taken a bit further.
I put a lot of basic info in here (lay out, drilling, tapping) that experienced fabricatrors will find elementary; I just figured some younger guys can get some use out of what has worked for me.
First, I found a piece of steel plate. This is about 3/8"; 1/2" would probably be better, but I already had this.

I laid a spare head on the plate and got out the trusty transfer punches. If you don't have a set of these, get some. They are invaluable for fabrication. They are in 1/32 increments, so they fit squarely in the hole and find the perfect(within a few thou.) center. I punched out the two outer spark plug holes:



An then head stud holes on each corner:





You can see the nicely centered mark the transfer punch leaves behind(the soapstone circles are just to point out the marks, I didn't trace them from the heads).


If you don't have a spare head laying around, you can fake it with a gasket.
I may even cut around it and grind the edges smooth!


Now to the drill press. I drilled a 5/8" clearance hole for the 9/16 fine thread bolts to go in the spark plug holes. Notice I use plenty of cutting oil, and a brush to clear away chips. These are my good USA bits, I keep them stashed away from my ham-fisted buddies who are to lazy to use cutting oil; I keep cheap China bits out for them to fuck up!
Next, size "U" for the 7/16-14 all-thread.


Now, tapping the 7/16-14 holes. I start the tap with the drill press immediatly after drilling each hole, so it's still lined up. Don't do this under power! Good way to break a tap. Hand turn it, using the chuck key for a little added grip. Use oil. Every half turn, I turn the tap back a quarter turn, to break the chip.

After you get it going good and straight, finish it up with a tap handle. Don't forget the oil.

 

Using the tool:
First, lay the plate over the head, and screw the 9/16 bolts into the spark plug holes, which will pull up on the head. I bought extra long bolts, before I started on the project. They would be easier to use if much shorter. I'll get shorter bolts and post the length later.

Before screwing in the corner bolts(allthread), here's a trick to cleaning up the ends after cutting them with the bandsaw. Chuck them up in a drill, and spin it against the running bench grinder, rounding the ends off.


Now screw in the corner bolts, which will push down on the studs(don't forget to take off the nuts!). I'll cut off the excess plate before I do the other side, and take more pictures, it'll be more clear how this works if you can see what's going on under the plate. Refer to Elrod's thread listed above for reference.

Tighten each corner a little at a time, and BAM, the head is loose. I finshed the job with a prybar; when I get shorter bolts, I can pull the head all the way with the tool.

I don't think the bolts I used in the spark plug holes were the right size, I was afraid of stripping the threads, so I only screwed them in a few threads. It was enough to break the head loose, but they pulled out. I wasn't too worried, as I am replacing these heads with 59 B A heads. I will find the correct size and length bolts to match the spark plug holes for the other side. But the tool did work, just needs a bit of fine tuning to work perfectly.

Success! I think I spent more time last night pounding, prying, and cursing than I did making this tool!

 

I don't have a flathead handy but I thought they had 14mm threads

 

Richard why are you working on one of them junky flatheads?<?xml:namespace prefix = o ns = "urn:schemas-microsoft-comfficeffice" /><o></o>

 

Coarse, fine, or only one size for 14mm?

 

I like to make myself suffer. I seem to remember you had one of those old underpowered, overheating bastards in your car, I'll haul it off for ya, I got a small block Chevy I'll make you a screamin' deal on...

 

Could you maybe take a couple sparkplugs, knock the centers out use a steel eyelet welded into the plug body. Then screw one in each end of the plug holes in the head, put a chain on them and hang the engine a couple inches off the floor over something soft, 2x4's or? Then put penetrating oil around the studs and wait for the engine weight to do it for you? Just an idea anyway. I got a model A head off that way using Coca-Cola. Lippy

 

Another way, probably not as effective as yours, is to get a couple of old spark plugs and break out all of the ceramic. Then weld in a couple of T-handles. You screw those in and get busy pulling.

The other technique I like if the engine will turn is too put all the plugs in with all of the bolts or stud nuts off and turn it over. Let the compression do the work of loosening the head.

 

The steel plate works great, just need the right size bolt for the spark plug holes. I don't want to dick around with welding old spark plugs, etc.

 

Yep. and thinking about building one more. 4" Merc motor.

 

Since I can't find the right size bolts, I'll do this:

 

I learned a simple way on the flathead forum,using plastic leveling wedges. The hardware store sells small wedges,about 2"X1" made of plastic. They are for leveling cabinets. Just pound them into the gasket edge,between the studs. Use 4 or 5 spaced equally around the head, and go slow , pounding them in about 1/8" at a time. Keep going around the head,alternating corner to corner. I was amazed at how well these Mickey Mouse wedges work. I popped off 3 or 4 sets of heads this way.