ok im going to build my own engine and i want it to have 10.5:1 compression. it will be a 350 bored .030" over and have dart 220 heads. the piston style and rod length determine CR right? does anyone have advice or pointers? it will be naturally aspirated with ram air. anything else needed, let me know. thanks!

 

The first thing I would do is get rid of those heads. They are one of the worst possible fits for your project. You would have to be spinning this engine to nearly 8k to use those heads, not to mention the horrible loss of bottom end. Get some better heads. Sell those to someone building a big cubic inch smallblock, or a circle track car.

Then start over. Pick a head, then decide on piston. If possible a slightly dished piston would be best, with the block decked to suit. This is honestly the best way to go about it for quench purposes. iron heads, dont try to go higher than that 10.5:1 mark. Use good gas, and make sure you know how to set it up. thats pushing it.

 

Displacement and combustion space volume determine CR. Rod length has nothing to do with it.

 

ok cool thanks for the advice. so can u recommend better heads? its gunna be a daily driver but i dont drive far (small town) and i treat every light like a drag strip kinda. i wanna be able to toast anyone else who pulls up to me in their modded daily driver. especially all the *****s around here who think their car can do mach 5! all noise and no guts to back em up! anyways... so?
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ok, ok... imports. sorry.