Hello,

can someone help me out with the math here?
i am looking at a set of piston for my 351m and
i need the size of the dish in cc in order to get
a ballpark of my final compression ratio but here goes,
the manufacturer gives the actual size of the dish
in inch instead of in cc. manufacturer's specs says
2.6' dia. head recess .068 deep with 2 angled vavle reliefs.
compression height 1.921 pin dia. .9752 offset.
any help appreciated.

Thank you.

 

I get a little over 23 cc.

 

23cc ?? are you absolutely sure ? because i think my stock piston has something around 13cc right ? stock 351m 1975.
23cc is huge i was hoping for something in the 15-16 cc range.
that will change my compresion ratio figure enough i think that'2 10 cc more than stock what formula have you used to calculate it ????

Thank you.

Werk

 

Nope I'm not absolutely sure. I calculated the volume of a cylinder 2.6" in diameter X .068" deep. It came out to 1.44 cubic inches. Converted to cc's that's a little over 23 cc. Short of using a burette and measuring exactly how much water that dish would hold I don't know of any other way to do it. Maybe someone else on the board has a better way to do it or you could try contacting the manufacturer of the piston.

 

That is the way to calculate it. I have not figured out your math tho. You also have to add in some volume for the valve reliefs.

I get the dish volume to be:

(1.3)*2 x 3.14159 x .068 = .36 cubic inches = 5.9cc

 

What is the manufacture and the part number of the piston you are looking at?

 

I think you're right Eric. I found another calculator on the web that comes up with the same numbers you did. I guess I'll have to change that bookmark.

Hopefully Tim will come up with the right answer based on the manufacturer name & PN.

 

Bill, you can find all kinds of calculators and converters here http://www.motionnet.com/ but no volume calculators that I know of.

 

hi again,

the pistons are silvolite 1167
or clevite tc-2001 think they're the same.
advertised compression height is 1.921
while my hp book say 1.947 does this means
the piston will be .026 lower in the bore ??
if so, stock .016 + .026 i'm looking at .042 total deck clearance



any ideas?

Thank you for your help