Teknohund

Quick question. I have a 355 in my car, with stock bore and stroke, and I was looking at different heads, and what compression would I get if I went with 74cc heads or 68cc heads, or even 64cc heads. I was looking at AFR 190 or 195's to be exact.
Thanks
Chris

mod313

You need to give more info. Like chamber cc's you have now, what pistons are in it, etc.

Teknohund

Here are all the engine specs that I know:
4-bolt main block bored .030 over, decked .010
.010R and .010M cast crank
ARP rod bolts, rods resized
TRW forged flat-top pistons
MOLY rings
Michigan bearings
LT-1 heads (old-net reverse cooled)
Manely Valves 2.02-1.6
Hardened exhaust seats
Z-28 valve springs
New pushrods
Elgin rollar tip rockers
Speed pro Hyd. Cam-
302 degrees, 536 lift int, 536 lift Ex
Performer RPM intake

hope that helps
Chris

Z_Ghost

Here is a good place to calculate what it will be.
http://www.smokemup.com/auto_math/compression_ratio.php

Their is a lot of stuff that you need to know to get it really close to what it will be.

Here is what all you need to know.

Bore
(Inches)
Stroke
(Inches)
Connecting Rod Length
(Inches)
Cylinder Head Volume
(cc)
Deck Height
(Inches)
Head Gasket Bore
(Inches)
Head Gasket Thickness
(Inches)
Piston to Cylinder Wall Clearance
(Inches)
Top Ring Land Height
(Inches)
Piston Dish Volume
(cc)

Teknohund

which chamber size would you guys recommend? the 78,74,68,or 64cc ones?
Chris

Stephen 87 IROC

Although a smaller chamber will bump up compression it also shrouds the valves. As long as the heads can flow enough to feed the engine, use whatever chamber size gives you the best compression ratio that you want to use. Using 58cc 305 heads may sound like a good way to increase compression but if you're trying to feed a 383 or 406, the heads won't flow enough to provide the engine with it's best performance.

If you're building from scratch, use an open chamber design 76cc head and install dome pistons to increase the compression.

Determining what compression ratio is best depends on a lot of factors. Type of fuel used and if a power adder will be used or not. High compression builds torque.

Teknohund

thanks for all the help. I think i understand it now.
Chris