Horsepower Estimate...............

[fred cook]

I am planning a rebuild on my 1980 SC 3.0 litre engine. The configuration that I am considering will be:
98 mm Pistons and Cylinders 10.5:1 compression (3.2 short stroke)
"S" or 20/21 cams
Twin plug heads with direct fire ignition (no distributor)
PMO 46 mm carbs

Given these factors, approximately what HP should I expect the engine to develop?

Also, how much HP would the same engine make using 3.2 or early SC heads with the larger ports?

Last question: Name of a shop that does the twin plug conversion in the Atlanta, South Georgia or North Florida area?

Thanks,

[cstreit]

Probably 245HP I would guess... (give or take 10HP) your exhaust choice will also impact this.

Why would you stay with a 20/21 cam if you are replacing the pistons and using carbs? The only reason for a 20/21 cam is because of the compromise required with the CIS system.

A GE40 cam or similar profile would make sense for this engine (street) or GE60 (track) and take better advantage of your investment.

[fred cook]

Thanks for the camshaft suggestion. What about the "S" cams? I have read that they will provide good power and with 3.2 ltrs of displacement not exhibit the peakiness exhibited in a 2.0 or 2.2 ltr engine.

Thanks,

[cstreit]

S cams are a good cam, but there may be some that are better. I'd talk to John at DR Camshafts (pelican member) or WebCams about your specific application.

[Eagledriver]

With a proper exhaust system and a 7300 RPM redline you should be able to get 270HP or so. A GE40 "mod S" cam would be nice.

-Andy