what kind of compression ratio would that yeild? im looking to build an efficient/budget turbo motor.

thanks.

 

i think in the realm of 8.5 which is perfect for a turbo motor
but dont quote me

 

I think it's closer to 9.1:1, but I would love to be shown some math saying exactly what it is.

 

What vehicle is this going in?

A full 6.0 long block might be easier to do (and make more power).

Anyway, 6.0 heads drop an LS1 to 9.6, and the drop would be a little bigger for a 5.3 because those combustion chambers are 5cc's smaller than LS1 heads (a 10cc difference going to the 6.0's).

Tell me the stock compression ratio of a 5.3 (I don't know it off hand) and I can figure it out for you.

 

stock on the 5.3 is 9.5. its all going in an S10. i was looking at the 5.3 because they are floating around very cheap. i think it will make plenty of power with two turbos

 

I'm gonna give you a bump since I would like to know as well.

 

*drumroll*

And the compression of a 5.3 motor with 6.0 heads is...

--- 8.56 ---

Thank you! Thank you!

*bows*

A set of forged pistons and rod bolts and you should be set.

How strong are the rods on 5.3's?

And yes, S10's are dirt cheap and great for a project.

Also, you should try looking at 6.0's, it wouldn't be much more money and you'd make enough power to be worth it.

And you'll have to change pistons to make any real power and keep it alive, so you can get your compression drop from your new pistons...

Oh well, just things to think about.

 

and the winner is me haha i called 8.5

 

How did you come up with that? I'm not saying you're wrong, I just want to know for myself how to come up with those numbers.

 

i think 15 psi or so on a stock 5.3 shortblock with worked 6.0 heads, ls6 intake, cam, and enough fuel, should make 500 to the wheels and live a full healthy life. id like to test the limits of the stock 5.3 bottom end....you know....for science!

 

Would the CR have anything to do with the size of the bore/stroke? I was thinking that would have to be plugged into the equation as well.

 

Yes it does. It's basically (chamber volume + displacement/8)/chamber volume. But you have to include the volume from stuff like gasket thickness, valve reliefs, and the small area above the piston rings in the chamber volume if you use that formula.

 

just how accurate is that calculation? did you account for the dish in the 5.3 piston? if its right, how many cc's of unshrouding would be needed for 8:1 compression?

 

Mmmm....that would be nice for a blower car....I wonder how many horses you could make on a blown 5.3...