# How much compression should a small block 350 have?

## How much compression should a small block 350 have?

It’s likely that you have somewhere in the range of 150-170 psi.

What octane is needed for 9.5 to 1 compression?

The standard recommendation for street engines running on pump gas has always been to shoot for a 9.0:1 to perhaps 9.5:1 compression ratio. This is in order for the engine to safely work with pump gas, which for much of the country, is limited to 91-octane.

What is the compression ratio for 93 octane?

We are being told by most piston manufacturers that 9.5:1 is the most you should run in an engine with cast iron heads on 93 octane pump gas. Because aluminum conducts (dissipates to the cooling system) heat much faster than cast iron does, you can run 10.5:1 with aluminum heads on 93 octane.

### What compression ratio is a 350 Chevy?

11.0:1
It was a higher performance version of the base 350 cu in (5.7 L) V8 with casting number 186 2.02 / 1.6 in (51.3 / 40.6 mm) valve heads and had an 11.0:1 compression ratio requiring high octane gas and produced 350 hp (261 kW)(SAE GROSS POWER).

What is the compression ratio for a 383 Chevy small block?

Compression Ratio Calculator. This 383ci small block Chevy is being built to run on 87 octane, which with aluminum heads will limit our safe compression ratio to 9.7:1. We now start inputting compression related information into our dyno software.

What is compression ratio?

Compression ratio is the ratio of the volume of the cylinder (called swept volume), plus all the volume that is left once the piston is at top dead center called combustion volume, divided by the combustion volume.

#### What affects static compression ratio?

Static compression ratio is affected by multiple variables including crankshaft stroke, piston-to-head clearance, head gasket thickness, and piston valve reliefs (if present) or the presence of a dish or dome in the piston. Here’s an example of a 350 with a 10.1:1 compression ratio:

What is the compression ratio of a Ford 350?

Here’s an example of a 350 with a 10.1:1 compression ratio: 4.030-inch bore and 3.48-inch stroke Heads with a 64cc combustion chamber Flat top pistons with 6cc of valve relief that sits 0.005-inch below the deck