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IO390 EXO 119 Cowl Mods

YellaDawg

Well Known Member
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Couldn't find a thread on this. I have an old cowling and have ordered a IO390 EXP119 engine. Has anyone modified an older lower cowl? If so, is it possible to get a description of what was done. Or is it better to just order a new lower from Van's? Thanks!
 
I did not modify my cowl for the EXP engine however did modify it for Vettermans dual exhaust. I would't think it would be terribly difficult if your half decent with fibreglass. I never worked with glass prior and was able to do it.

Additional things to consider is price, shipping, and current availability of the new cowl. Will timing hold you up? If so you could alway give the modification a try. Not much to loose.
 
Thanks Glenn, I'd like to see a cowl to see what mods need to be made. No problem working with glass.
 
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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, 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 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.
 
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...

Are you planning to use the exhaust intended for the 119 version of the 14, and install a variable area exit?
 
Update …

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.

My friend said that he did have to modify the INSIDE of the cowl for clearance to handle the fact that the prop governor is now forward top.
 
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.
 
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.

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.
 

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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.
 
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.

Here variable area is a functional description. Implementation may take the form of a conventional cowl flap hinged at the leading edge, or some other manifestation.

For any given addition of exit area, the best design is arguably the one which results in the lowest external drag when open.
 
IO-390 IN A -8 THAT HAD A IO-360

Hello guys,
I didn’t want to get ahead of myself and post anything until I Had flown 332RT after the installation. Flew Her 05/18/22. I have some pics I will post and a full recap. For now I will post the cowl stuff I had to do. I needed no modifications to the lower cowl, I did have to cut and make a ‘pocket” that was bonded to the ramp just above the prop governor. I used the -14 air intake with extensive mods. Flew the intake up to Don @ Airflow, he flow tested it and gave me his approval the 4 into 1 was very aggravating and took 2 tries to get the fit right. Second time was the charm though. Scott
 

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Thanks for the feed back, sure looks nice. I'd be interested is seeing your temps and air speeds.
 
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.

Thanks for the pictures, as always, excellent workmanship.
 
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