Best way to detach a head gasket from a block and head?

[mr-asa]

I’m trying to pull the head off the block on my QD-15. The head gasket just doesn’t want to let go. I am thinking about driving a putty knife between the block and the head. Is there a better method?

[beerman57]

Are you sure nothing else is holding it? A light tap should make it move. Broken head bolts make them hard to remove.

[mr-asa]

There’s some corrosion on the left over shanks, but I’m treating that with some heat (to aid in capillary action) and a can of WD. I can see the oil getting sucked in next to the bolts.

[wedgie]

I would start first with an exact or razor blade to get it started. use A good light and a magnifying glass to find a likely spot to start, and trim out the exposed gasket on the edge a bit to create a clean entry for driving a thin blade putty knife in.

If you just have at it, there is a good likelihood of damaging the mating surfaces.

[mr-asa]

Thanks Wedgie. Good, solid plan. I was thinking about trying to split the gasket in half with the blade of whatever I’m going to use but I’m unsure if there is metal in the gasket or not.

I wasn’t planning on whacking it apart, I know it’s not cast iron like my car’s engine.

[wedgie]

Most of the time they will pop off with a good whack with a hard rubber mallet, but the corrosion around the bolts will make that more difficult. Maybe try a soft wood dowel about and inch in diameter and work your way around the perimeter, using the dowel on the cover at an angle to drive away from the block. Yeah, not as rugged as cast iron.

You probably already know this .Once you get it off, chuck both halves in a lathe and resurface them . Mumbles has done this for me in the past. If you don’t have easy access to a lathe you can lap them with a sheet of emery paper on a flat surface.

[mr-asa]

I’ve got a lathe available to me, however my shop is starting to crack down on using personal projects. I might be able to find something else nearby, though. I might be able to borrow a friend’s though. I could also wait until we’re done with our current projects as they’ll relax then.

I assume I only need to take off enough to clean the surface and no more?
The mill might be easier for the block.

[wedgie]

Yeah, if you take too much off you’ll have to double up on the gaskets 😀 . Take off only enough to true up both surfaces. Hey , you’ll have higher compression for a zippier ride 😆 I’m no machinist, but I assume a milling machine would be even better than a lathe 🙄 .

[mr-asa]

I’m no machinist, but I assume a milling machine would be even better than a lathe 🙄 .

I’m just a budding engineer (ha) but that’s what I’d think as well. Which makes me confused considering how many people I know that have shops and small CNCs that will use their lathe for single or twin cylinder heads and cylinders.
The head might be interesting to mount on a mill, I’d have to double check to see if there are any surfaces on there that are level enough to hold onto.

[david-bartlett]

Evan,

There should be a thin band of copper around each cylinder on the gasket, but that should not stick things together. It is the paper/fiber part of the gasket that is giving you grief.

Patience and time.

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