I installed the EXP119 on my 14 with a new cowl, what I have been trying to find out are the mods on a RV8, not a 14. I have an older RV8 QB kit I am starting on and just ordered the engine etc. Nothing on FB pertaining to the 8.
I installed the EXP119 on my 14 with a new cowl, what I have been trying to find out are the mods on a RV8...
I have a friend who is changing his IO360 to the 390 in his RV8.
So far, he has NOT modified his cowl but the air intake is being replaced with one that required some special work. His is using AFP fuel injection.
He is also having to have work done on his exhaust (4 into 1).
I will leave it up to him to comment further if he gets around to seeing this. Or, send me a not offline and I MIGHT be able to chat with you in person in Tallahassee one day during the holidays.
Are you planning to use the exhaust intended for the 119 version of the 14, and install a variable area exit?
Yes, the exhaust and cowl flap were my areas of concern along with the prop governor. That is going to be a lot of cutting. I’ll call Van’s today and inquire as to what they have, if anything. I can use anti splat’s cowl flap, because of the 8 more narrow fuselage, not sure how the exhaust will workout.
Are you planning to use the exhaust intended for the 119 version of the 14, and install a variable area exit?
Dan, not sure what a variable exit means, but it looks like the 8 cowl I have will work with some mods. I’ll probable want to add a cowl flap as well.
I've been flying a forward governor IO-390 eleven years now. Mine has much revised cooling air intakes, one of which incorporates a molded rubber seal for the governor. Plan B might be the cutout in the upper cowl's intake ramp, like the 14's, although it cold be done more artfully.
I think the issue with bolting a 119 on the -8 will revolve around exhaust system fit, notably clearance for the cyl 1 and 2 headpipes. The tailpipe end appears to be well inboard, and the composites work for the cowl outlets is straightforward.
Note a lot of the 119/RV-14's speed improvement is based in drag reduction, not the HP increase, so drag work is important if this project is to be worthwhile. I'd lop off the entire stock "coal shovel" outlet, replacing it with a flat panel flush with the belly skin. The resulting fixed exit at the belly recess slot would be roughly 13 x 2-5/8, IIRC. Given good baffling, the aircraft would probably cool fine with the combined area of the three exits (two at the pipes and one at the slot), and there would be some reduction of frontal area.
Splat's cowl flap hinges at the front, and is thus pretty draggy. A center-hinged door is less draggy when open and easier to actuate. If a variable area exit is desired, I'd put it in the new flat area just forward of the slot exit.