engine overhaul and prop change

[oaklandaviator]

Looks like it's time to pull down the o-320 e2d on our rv-3. We had a70x79 Sensenich but looking to go with a Catto (probably 3 blade). Before they start building the prop we need to know the approximate horsepower of the engine. Anyone know what changes are required to get the most power from the e2d? If we put in 10+ to 1 pistons with new cylinders, what carburetion changes are necessary and how much power for planning purposes?

Thanks for any help!

[BobRv4]

if you put in H series pistons about 165hp.
As told to me by local engine shop.

[jrs14855]

I have an 0 320 with 10-1 pistons, balanced, no other mods. Bendix mags and stock Marvel carb. I have a Sterba 70 x 82 prop that was intended for a 0 360 RV4. It is way too much prop. Full throttle at 4500' I am only turning about 2500 r/m. The airplane is not an RV. I am truing about 205 statute at 2500 so the airplane is pretty clean aerodynamically.
The carb is just slightly on the lean side at low altitude.
I estimate the horsepower is only around 150 at 2500 r/m.
I need a prop that will turn at least 2700 full throttle at altitude and maybe even 28-2900.
The best you can expect from an 0 320 is 170-175 hp, unless you want to go above 10-1 compression.

[oaklandaviator]

Thanks for the replies. Are there any carburetor changes that need to be done to get the mixture right or is everyone just changing the pistons and pins and calling it done?

[jrs14855]

Carburetor changes seem to be more related to cowling/baffling efficiency than to horsepower. Drilling the main jet one or two number drill sizes larger is quite common, even on stock engines.
I chose a different route, I have a very efficient baffling system and a cowl flap. Cools adequately up to 120 degrees surface temperature. I do climb at 130 knots until I am in cooler air.