Problem with new build.

[FurryOnTheInside]

A ring could have been cracked during the assembly. I don't think it would be noticed the way these are thrown together, or if it was noticed it would be ignored.

The tolerances are also very poor, and mismatched parts could be combined, the shortest rod produced that month with the longest cylinder etc.. but I doubt that alone could account for only 55psi cranking pressure.
1.35 mm extra piston-head clearance increases the combustion chamber volume by 1cc so it is worth checking but there is almost certainly more to it than that.

Edit : that was wrong. I think it's 1mm too much clearance = 1.75cc extra combustion chamber volume. But I don't even trust myself now lol.

 

[gary55]

1.73mm = 1cc on 47mm bores. 23.5 sq X 3.14 div. 1000 = 1.73. I agree if he knows his gauge is correct at 55psi it's almost certain he either has a warped or crackedhead, blown head gasket, or cylinder damage. On the same note if you have a mis matched jug that is 1mm to tall for the engine IE A type jug on a B type engine That 1mm will cost you 40+ psi

 

[FurryOnTheInside]

1.73mm = 1cc on 47mm bores. 23.5 sq X 3.14 div. 1000 = 1.73. I agree if he knows his gauge is correct at 55psi it's almost certain he either has a warped or crackedhead, blown head gasket, or cylinder damage. On the same note if you have a mis matched jug that is 1mm to tall for the engine IE A type jug on a B type engine That 1mm will cost you 40+ psi

I definitely did the calculation incorrectly.
So I did it again but now I think we both did it wrong. I think 1mm is 1.75cc! But maybe I did it wrong twice lol.
2.35 x 2.35 x 3.142 x 0.1=1.74993

 

[gary55]

I definitely did the calculation incorrectly.
So I did it again but now I think we both did it wrong. I think 1mm is 1.75cc! But maybe I did it wrong twice lol.
2.35 x 2.35 x 3.142 x 0.1=1.74993

It's so goofy it's funny. Iv'e done it twice your way now using 23.5 sq. x3.142 x .001 rather than div. by 1000 (same same) and get 1.7351695. With just 3.14 I get 1.734065. I think since the earth rotates from west to east you're getting the numbers sooner than I am, and they're shrinking a little bit by the time they get here.

 

[Spare_Parts]

It's so goofy it's funny. Iv'e done it twice your way now using 23.5 sq. x3.142 x .001 rather than div. by 1000 (same same) and get 1.7351695. With just 3.14 I get 1.734065. I think since the earth rotates from west to east you're getting the numbers sooner than I am, and they're shrinking a little bit by the time they get here.

Some of the s**t you say cracks me up!

 

[gary55]

Some of the sh*t you say cracks me up!

That's cause I am a wild and crazy guy. Anybody seen my chicken?

 

[FurryOnTheInside]

This is a family friendly forum. Nobody wants to see your "chicken".

 

[gary55]

My chicken brings all the girls to the yard
And they're like, it's better than yours

 

[Spare_Parts]

LMFAO!

I thought you choked it to death?

 

[Mcdonns]