RITA ignition in Combat engine

Hi Group,

I had advise from a few sources that my RITA ignition is not well suited for a high compression engine due to the advance going full at 2500rpms....to fast. I just check Dyno Dave's website again for the curve below. This shows full advance at 2500 distributor rpms. Does that mean camshaft so that crankshaft rpm is 5000 at full advance. If so why would the RITA not be suited to my combat?

Rita curve is very close to the ancient accepted and appreciated fast straight slope rise of mechanical AAU and should work a better treat in a Combat than lower compression set ups. Denser charges my be harder to ignite but once lit flashes off rather faster so fast rise in adv is generally a good thing for response in hi CR engines, as long as the octane allows the max torque pressure w/o any bing bang boom. My Combats loved the points response but I try keep in mind what octane I last topped off with for how fast I sanp throttle, but even so have not heard/felt/sensed any pings on 87 octane when forgetting to take it easier on 87.

DynoDave's site curves did not open up for me today but you may find the curves to settle your nerves on this. Just be alert not to exceed the 28* max adv - by very much. Last I checked my AAU Combat adv. during current record 100+ F heat wave it showed 29*. During this heat wave I had the two fastest hardest harshest WOT ride tests in Mt climbs with sport bikes than I'll ever risk again but no issue with detonation on mixture of 87-91 no booze gasoline.

Follows my thinking. Will keep the RITA and look for a combat camshaft this winter. The Norris RX isn't working out for me.

Ugh, another Commando hobby mood swing. Can't help raise the mood much as its possible to have similar performance with the 2S if some mystery still lurking.

I ran a RITA on my 920 Commando engine with 10.5 CR for several years with no problems, until I mounted the box without the rubber vibration isolators, and it died. Very important to have it rubber mounted.

Ken

My options were change the ignition and use the standard camshaft or keep the RITA and use a combat camshaft. Both costs were about the same, but I hate to give up a perfectly good RITA. The rubber mounts are in great shape!

I have the head off fixing a leaky head gasket...oil spraying. While it's off thought I would check the Norris camshaft timing again from the cam followers. Exhaust spec is 54d degrees BBDC at .020" lift on the rocker. Rocker ratio is 1.13:1 so follower lift should be 0.0177" (0.020/1.13) at 54 degrees BBDC from the lifter...right?