I've been slowly building my RV-8 with 13BT engine for about 14 years...!

On June 13th 2013 it received the coveted Airworthiness Certificate. That same day I detonated my engine due to the trailing spark plug holes being machined oversize in an attempt to improve the single spark plug power, should the leading plug ignition fail. This, and possibly advanced ignition, and possibly over-boost detonated my engine on it's first high power taxi test. That took about 2.5 seconds.

Now I've rebuilt the engine with new unmodified rotor housings, and it runs better than ever. I've re-marked the timing marks on the pulley, and reset the timing, though not to 4000 RPM yet. today I checked it. At 3000 RPM my hat and hearing protection blew off. 11 degrees BTDC, and 16" manifold pressure.

I've been taxiing around at modest RPM, it's great. I've consistently been idling at about 1600 RPM, (730 prop RPM) and sometimes as low as 1490, (680 Prop RPM) smoothly. That is slow enough to keep the brakes from getting too hot.

I've done run ups and brief bursts of power to 4200 Engine RPM, (1917 Prop RPM) which is about 32" manifold pressure, and seen 37" manifold pressure briefly. I know this is not enough power to take off, although I have done a Pre-take off to 50 MPH with this power before powering down with roll out to the end of the runway.  I suppose it would fly off and maybe clear the trees at this power. I've lifted the tail, and rocked the wings with the ailerons. It steers well and the brakes work.

The water level in the engine stays up between flights as does the oil, and the water temp today was consistent 163 F oil  about 173 with the highest observed 183F. I did about 4 pre-take off passes with taxi back, with excellent temperature control and throttle response.

A couple of oil fitting were tightened looking for an oil seep.

7.3 hours engine running time on the EM2, about 2 hours since the engine overhaul.

I don't think I'm at all ready to fly this thing. I'm missing something, so offer up some advice, I'm all ears!

One thought, not directly related to making max power: on the Lyc powered RV's I've flown (I've owned a couple; flown several more), an idle rpm above about 700-800 rpm with a fixed-pitch prop will result in a strong aversion to landing ( the plane wants to float forever). 600 prop rpm is much better, if you can achieve it.

For a 'sanity check' on prop rpm:  With the 2.19 reduction gearing, you're going to be limited  to about 6000 rpm max, right? (~2700 prop rpm) This is typical max rpm for a Lyc.  With fixed pitch Lycs & props in the 68" to 72" dia range, full throttle static rpm needs to be somewhere between 2100  & 2300 to have enough low speed thrust and still have enough thrust at speed to continue out of ground effect and into flight. Of course, this assumes that the prop maker cut the prop for RV requirements & simply reversed the rotation (which makes sense to me).

Charlie
Oh yeah, one more thing: doing high speed taxi tests with the tail up with no intent to fly while trying to regulate speed with the throttle scares the living daylights out of me. If you're actually doing that, I hope you're a much better pilot than me... :-)