Brian already had this IO-390 Lyc from Aerosport that he had purchased for an RV-8 project. We would be the first ones to mount the angled valve engine on the factory QB Patrol kit.
So the original plan was to put it on the Patrol as it would make the plane an amazing performer off the water, let alone what it would be like on wheels. As it weighs 30 Ibs more than a parallel valve engine, I had started to make compensations for it like putting the battery behind the baggage compartment. I knew it was going to be a tight fit for cowling but wouldn’t know for sure how much until it went on the plane. I figured the nosebowl was probably not going to fit as well. It is hard to show in the pictures but a few things were going to present a problem. We would need a bigger nosebowl, in width, in frontal area mainly from the splitline down, and also much larger intakes. American Champion was willing to sell us the nosebowl from their new Denali Scout. The side cowls would have to angle out more from the firewall, especially to clear #4 cyl. The cowls would also have to be wider and deeper to clear the exhaust pipes and the straighter running intake pipes of the 390. Then we would have to custom make the rear exhausts as I don’t think there is anything available that would fit. We have the exhaust for the RV-8 but the rear pipes hit the engine mount and the front of the tunnel.
So this was going to drastically change the whole look of the Patrol’s front end. It would be doable but was going to be allot more work. If we were scratch building the fit would be easier as you could make the firewall wider, but it would still change the shape quite a bit. So we made the decision to scrap the whole plan of the 390. The consensus now, after discussing this with Mark, is that an angled valve engine is not suited to fit the factory QB kits.
We have a new IO-375 M1S (195hp) coming from Aerosport. It is the same dimension and weight as the 360 so now we are back to a known quantity and won’t have to worry so much about the W&B of having the 390 up front.
aeroliteflight 