Gap between head & cylinder on a 305

roachcliff1 · Post by **roachcliff1** » Tue Sep 07, 2010 1:49 pm

I pulled this motor apart, because it was frozen. I'm wondering if the gap shown in the pic is normal? The pic shows the head sitting on the cylinder. There is no other light showing where the head meets the cylinder at the pistons, only where the cam chain runes in the middle. It looks like a big gap, that will get bigger, once the head gasket is installed?

teazer · Post by **teazer** » Tue Sep 07, 2010 7:41 pm

What is it sitting on? Are the corner stud dowels not pressed in far enough or are they too long? Is it safe to assume that you did not have thicker than stock O rings on the two front studs, or was there anything else that could have been hanging it up?

Of course rocker arms in the wrong position can cause the head to hang on the studs but usually that stops the head fitting over the studs at all.

Remove the head and dwols and O rings or anything else and ensure that the head fits down properly. If the dowels are too long, either deepen the counterbore or shorten them by a couple of mm.

roachcliff1 · Post by **roachcliff1** » Tue Sep 07, 2010 8:38 pm

well thats the thing that freaks me out. it is completely flush where the head meets the cylinders. There is no light that passes thru in those areas. The only light shining thru is in the center where the cam chain goes. I would think if the dowels were too long, light would show between the head & cylinder, where the pistons go. I'll remove the dowels anyway, and give it another shot.
thx

kirbb9 · Post by **kirbb9** » Tue Sep 07, 2010 9:29 pm

Check both mating surfaces with a straight edge for warpage. Although I can't imagine it being warped as bad as the
picture shows. My guess would be the dowels holding the head up. Take the dowels out and try the fit without
them.

Brady

ricksd · Post by **ricksd** » Tue Sep 07, 2010 10:34 pm

Are the liners 'sitting up' from the top surface of the cylinder?

teazer · Post by **teazer** » Tue Sep 07, 2010 11:51 pm

I had thought from the earlier post that the pistons were in the bores. I realize now that it's not the case.

If that shot is with no pistons and no gasket, the liners must be raised or something else is seriously wrong.

Check head and barrels with a straight edge and let's see a sharp picture please of the two mating surfaces - preferably from an angle.