Big gap between pistons?

[Wicked_306]

What would cause a gap between the pistons and the piston wall. It is at the front of each piston. It looks like the pistons are not square in the cylnder. What would cause this? Thanks

 

[Rick 91GT]

Are you looking at an assembled shortblock?

 

[wht93gtEd]

What would cause a gap between the pistons and the piston wall. It is at the front of each piston. It looks like the pistons are not square in the cylnder. What would cause this? Thanks

i thought pistons were round .

















haha, j/k

sorry, but I couldn't help on this one; so I figured that a smart a$$ remark was best

 

[rd]

If you are looking at the engine with the heads off, there is a fair bit of movement available to the pistons. It is normal, especially on the pin axis, not quite so noticable on the rod bearing axis, but still enough to be visible. Should not be a problem.

 

[ECU5.0]

i think what he is talking about is the cylinder being out of round. thats what it sounds like to me at any rate

 

[vristang]

If you are looking at the engine with the heads off, there is a fair bit of movement available to the pistons. It is normal, especially on the pin axis, not quite so noticable on the rod bearing axis, but still enough to be visible. Should not be a problem.

The pistons are not round. This is due to the expansion characteristics of the piston material and the thickness of the material. Thicker material will expand more. In a round bore it will look bad, but it is fine. I was aware of this when I put my motor together, but had to double check all the dims before I felt safe putting it together.

 

[giddyup306]

Pistons are "cam" ground. The Skirts will not change while the other parts will expand .001-.003" to allow for heat expantion.