Post 22 got it. Thanks 33IMP.
Not sure I am understanding this.....
"Calculate the volume of the cylinder as if it were a flattop with no reliefs, then cc your cylinder as if it were a cyl head, and compare volumes."
My H655CP pistons are below the deck. So I would drop them in cylinder to x depth, fill with fluid, measure and calculate volume. Does it matter that my pistons are dished? How does that factor?
Piston Head Volume (cc):
+11.23cc
View attachment 1715769144
If those are your pistons pictured, with no reliefs out to the edge, there is no need to cc them in the cylinder. You can just use a plate with a hole in it, seal it to the top of the piston with some grease, and cc the dish just as you would a cyl head chamber.
The cc-ing of a cylinder is usually used to find cc of a domed piston, or one with a dish that has valve reliefs to the edge that cant be sealed with a plate.
Now, that will get you dish volume, but that is only a SMALL part of determining actual compression ratio!
If those are your pistons, and you know the dish volume, (and you believe the numbers) you dont need to cc the cylinder. But accurate measurements need to be done if you want an accurate comp.ratio.Not sure I am understanding this.....
"Calculate the volume of the cylinder as if it were a flattop with no reliefs, then cc your cylinder as if it were a cyl head, and compare volumes."
My H655CP pistons are below the deck. So I would drop them in cylinder to x depth, fill with fluid, measure and calculate volume. Does it matter that my pistons are dished? How does that factor?
Piston Head Volume (cc):
+11.23cc
View attachment 1715769144
Agreed! But i thought he was trying to get the volume of his dish. Rereading his post, he already knows that. Now he just has to measure, and calculate, to get his c.r.He needs to know how far down the hole they are as well though.
Thanks. I hindsight I wish I went with some better pistons for closer to 10:1 but didn't have the scratch to balance. It's a magnum and piston choices are limited but it is a street performance engine and should be fun. The cam will help.
No sir I wouldn't dream of it nor do I have that kind of expertise.Thanks. Here's my cam spec from Oregon but we should not turn this into a cam selection discussion. I already Hi-jacked this enough. Hahaha
View attachment 1715769221