We made a decision to add a Surefly ignition to replace the left mag on a F1 Rocket. The engine is a IO540 with 9.5 pistons and a Raven CAI. The process took a bit longer than expected due to weather and time to get the install done. Initial installation with professional assistance went smoothly with really the hardest part adding the dedicated 12 volt since our battery and master are in the tail. We tapped manifold pressure off the primer port.
Initial test flight to 9500 feet was perfect. Partner took the aircraft from NC to Marco Island. First leg was fine. After the fuel stop he experienced a rough running engine above 6000. Install was double checked but this continued on the return so he came back low. The Surefly was set up with base timing at 23 degrees and advance activated. Numbers on the first leg were really good with excellent FFís. At this point performance below 6000 was excellent.
We contacted Surefly and I can only state their customer service was beyond outstanding. They worked with us on troubleshooting and several test flights were flown. The aircraft would start and run perfect but on every flight at almost exactly 6000 feet the engine would get rough. No abnormal CHTís or EGTís were noted. 6000 corresponded to where the Surefly should start advancing the ignition. MAP in the climb was about 24.5 at that point. After several test flights the problem worsened and continued below 6000 feet on the return and for the first time could be duplicated on a mag check on the ground. Strangely if the aircraft was restarted after cooling everything ran perfect.
At this point Surefly elected to send us a new Mag. Swap out was quick and easy and after 6 flights everything is running perfect. We returned the first unit to Surefly and they should get it midweek for bench testing.
Now for the good news, performance is excellent and we seemed to gain 6 to 8 knots LOP with the advance. Engine starts are excellent both hot and cold. I will add some inflight pics. We need to work a bit on injector balance but the engine runs well LOP. Despite the issues with the first mag we are very happy with the unit. Again I canít over emphasize how good the customer service from Surefly was, they went above and beyond. When I hear if they found something wrong on bench testing the first unit I will add a update. We still donít understand the first two flights being normal and then the follow on issues. Pics to follow.
Nearing top of climb. Takeoff roll started at 1400:30 and climb was done at 100 knots to see how advance would effect CHT’s. Engine leaned for best power in the climb. Airport was 400 feet MSL. Temps were very good however OAT was 42F on the ground. Summer will be different.
Last edited by sailvi767 : 12-20-2020 at 08:35 AM.
The cruise photo makes for an interesting comparison. Photo on right is my -8, last fall. Same altitude, pretty much the same TAS, a little less fuel burn for the 390. Need more MP and RPM to match the 540, no surprise. In the context of this thread, note the angle valve doesn't need or want much advance (here 23 fixed) cruising at peak EGT. The Surefly allows a full range of fixed or variable timing, so it will work fine on either parallel or angle valve.
__________________ Dan Horton RV-8 SS Barrett IO-390