New Eddie Myers’s heads question

[Bored&Stroked]

Hmmmm . . . I would next accurately measure the crankshaft stroke.

Something seems weird in that you're running a very "normal" setup --> with a 4.00" Merc crank. I would also measure exactly how high the top of the dome of the piston is above the deck. The heads look about "normal" in the dome areas. Would also like to know the depth of the dome/pocket in the center of the head.

Measure a piston on both sides of the block. Once we know the stroke and the height of the piston dome, then we can figure out what to do next. If the piston locations (to the deck) are consistent on both sides, then maybe the pistons are for a 4 1/8" stroke compression height. This would result in the piston being .0625 further down than it should be. If the piston was .0625 higher, then things would be a lot closer to how they should be (squish). The piston definitely should not be "down in the hole" as it is.

Also, while the engine will run - I would surely want the piston/squish situation to be "fixed" if it was mine. It will be a "dog" as it is currently configured.

Companies make mistakes - maybe the pistons were manufactured or boxed incorrectly?

[Tim Ayers]

Originally Posted by Bored&Stroked

Hmmmm . . . I would next accurately measure the crankshaft stroke.

Something seems weird in that you're running a very "normal" setup --> with a 4.00" Merc crank. I would also measure exactly how high the top of the dome of the piston is above the deck. The heads look about "normal" in the dome areas. Would also like to know the depth of the dome/pocket in the center of the head.

Measure a piston on both sides of the block. Once we know the stroke and the height of the piston dome, then we can figure out what to do next. If the piston locations (to the deck) are consistent on both sides, then maybe the pistons are for a 4 1/8" stroke compression height. This would result in the piston being .0625 further down than it should be. If the piston was .0625 higher, then things would be a lot closer to how they should be (squish). The piston definitely should not be "down in the hole" as it is.

Also, while the engine will run - I would surely want the piston/squish situation to be "fixed" if it was mine. It will be a "dog" as it is currently configured.

Companies make mistakes - maybe the pistons were manufactured or boxed incorrectly?

I'm kind of thinking the same, Dale. It seems to me like it's got the wrong pistons in it.

[Bored&Stroked]

Yeah Tim - that is my guess as well.

[V8COOPMAN]

.

More of John's pics that he sent this morning.

Coop

[Tim Ayers]

That piston position looks fine to me. Something is amiss here. Are you sure you measured correctly?

[Bored&Stroked]

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Yeah, from the picks, looks like the piston is above the deck to me? I wonder how tall the dome is - should be about .187 above the deck. I'd also measure the heads - they should have the same dome shape and almost the same depth. Then, with a .050 or so head gasket, the squish should come in at about .050 . . . with a bit of milling, you can then tune it.

[Ronnieroadster]

Piston looks fine no issues there from the picture. Would be nice to see the thickness of the putty when its cut in the center and then measured with the vernier. The Orosco heads may be domed at a radius different than the Ross pistons. Older cast pistons such as Jahns as an example were definitely a different dome radius than today forgings.
Ronnieroadster

[flatjack9]

Originally Posted by Bored&Stroked

Yeah, from the picks, looks like the piston is above the deck to me? I wonder how tall the dome is - should be about .187 above the deck. I'd also measure the heads - they should have the same dome shape and almost the same depth. Then, with a .050 or so head gasket, the squish should come in at about .050 . . . with a bit of milling, you can then tune it.

The block has been relieved.

[Tim Ayers]

Originally Posted by flatjack9

The block has been relieved.

Jack,

Judging by the chatter marks and the straight shot, it appears to me to be a factory relieved block.

[Ronnieroadster]

Originally Posted by Tim Ayers

Jack,

Judging by the chatter marks and the straight shot, it appears to me to be a factory relieved block.

Your right Tim its certainly a factory relieved block.