FWF for IO390-EXP119 engine

[Cwood2000]

Anyone see any issues with ordering the RV14 FWF kit and using it on the 8?

[RYOUNG]

I am by no means an expert but I am installing the IO-390A3B6 in my RV-8. Areas you will need to address in the RV-14 FWF kit that might not work or may not be the best choice for the RV-8 are oil cooler mounting, exhaust, control cable lengths, prefab hoses, and battery mounting, to name a few. There are probably others that I have left out. The -119 is a little different than my install so take this for what it’s worth, but for oil cooler mounting consider the RV-10 mount or the Showplanes mount. For exhaust I am planning on Vans IO-360 200hp RV-8 exhaust. Control cables for IO-360 200hp RV-8 with forward prop gov. Hose lengths will all have to be verified. Battery mounting in the aft location for W&B. I will be using the RV-14 baffle kit. Hope this helps.

[scsmith]

Well, the engine mount of course. You should plan to put the battery in the back. Hoses are a complete wildcard.

You will probably want to roll your own firewall mount for the oil cooler. Several ways to do that well--search for previous posts here. My original was similar to the RV-10 oil cooler mount, but with the face angle adjusted to nest into the motor mount tubes better. Recently removed the abrupt transition from scat hose to the box and replaced with a fiberglass diffuser.

On future build I will mount the cooler perpendicular to the firewall, with a fiberglass inlet diffuser and an outlet diffuser. I think this will occupy less firewall real estate AND allow me to better control where the outlet flow goes.

[DanH]

At the fundamental level, a 119 is a 390C with an Airflow Performance FM-200. It bolts up like any angle valve.

I would be unlikely to buy a kit intended for another model, in particular 14 parts for an 8. It's a custom installation, and it will probably require custom parts. Yeah, some stuff will work.

The dual outlet cowl concept has some merit for any A-model. The goal is exit velocity for cooling drag reduction. The dual outlets would move the primary cooling flows outboard, so they are not slowed by the forest of nose gear support tubing. Obviously that particular rationale doesn't exist with conventional gear.

The 8 and 8A incorporate an inset ramp in the bottom of the fuselage. For the A-model, start by removing the "coal shovel" off the belly of the cowl and replace it a flat section flush with the lower skin. Now a decision...size the new dual exits for fixed outlet area (a cruise drag compromise, offset by simplicity) and eliminate the outlet ramp by sheeting it flush with the belly skins....or size the dual outlets smaller, and develop a variable area door feeding the existing exit ramp.

The wildcard is an exhaust system. The Vans crossover is a sure choice, but will it fit in the RV-8 cowl? Can you get one from Vans on a timely basis? Vetterman is making a dual outlet exhaust, but it's not a crossover:

https://vansairforce.net/community/s...94&postcount=7

The new RV-14 setup performs better because the Vans crew did a nice job in integrating a whole bunch of detail changes. It's not just an engine swap.

I'll imagineer a bit, and hope for some opinion slack. If I were to build another RV-8 tailwheel with a 390, and wanted 119-comparable power...

As delivered the, servo mounting flange on the standard horizontal plenum sump has a diameter sized for an RSA-5 servo. The much larger FM200 will bolt on with an adapter, but the small sump inlet is still there, choking the flow. It's possible to re-size that inlet, opening the diameter and moving the studs. I can't prove it (doing so would require before and after dyno runs with the same engine), but I'm pretty sure the C or 119 models make 5 more rated HP simply because the "cold air" manifold's intake flange diameter is sized for an RSA-10 servo...something like 75% more area. I doubt cold air has anything to do with it; the horizontal sump does not flow intake air through the hot oil, and all intake pipes run through the same hot engine compartment.

Ok, so what to pair with an un-choked 390A? The 4-into-1 from AWI will mostly tuck up into the -8"s exit ramp, so frontal area can be reduced by loping off the cowl shovel and replacing it with a simple fixed exit. Any resulting frontal area is probably less than dual outlets, and there is no heating from exhaust crossover tubes. Next I'd switch to a rear alternator and a composite prop, to move the CG rearward.

Simple fixed exits; I flew four in development, the first three shown below. With the caveat that I run a non-stock cowl intake and plenum, all three of these worked. Although smaller than stock, the one on the left was excessive. The middle one would be fine in hot weather. The one on the right was too small for Oshkosh in July, but would be fine in the winter. A fixed exit is less of a compromise if the cowl is modified so area can be changed with the seasons.
.

[Cwood2000]

Originally Posted by RYOUNG

I am by no means an expert but I am installing the IO-390A3B6 in my RV-8. Areas you will need to address in the RV-14 FWF kit that might not work or may not be the best choice for the RV-8 are oil cooler mounting, exhaust, control cable lengths, prefab hoses, and battery mounting, to name a few. There are probably others that I have left out. The -119 is a little different than my install so take this for what it’s worth, but for oil cooler mounting consider the RV-10 mount or the Showplanes mount. For exhaust I am planning on Vans IO-360 200hp RV-8 exhaust. Control cables for IO-360 200hp RV-8 with forward prop gov. Hose lengths will all have to be verified. Battery mounting in the aft location for W&B. I will be using the RV-14 baffle kit. Hope this helps.

Very Helpful,

Mant Thanks

[Cwood2000]

Originally Posted by scsmith

Well, the engine mount of course. You should plan to put the battery in the back. Hoses are a complete wildcard.

You will probably want to roll your own firewall mount for the oil cooler. Several ways to do that well--search for previous posts here. My original was similar to the RV-10 oil cooler mount, but with the face angle adjusted to nest into the motor mount tubes better. Recently removed the abrupt transition from scat hose to the box and replaced with a fiberglass diffuser.

On future build I will mount the cooler perpendicular to the firewall, with a fiberglass inlet diffuser and an outlet diffuser. I think this will occupy less firewall real estate AND allow me to better control where the outlet flow goes.

Thanks Steve,
I was considering the Showplanes mount and probably a EarthX Battery. But not written in stone.

CW

[Cwood2000]

Originally Posted by DanH

At the fundamental level, a 119 is a 390C with an Airflow Performance FM-200. It bolts up like any angle valve.

I would be unlikely to buy a kit intended for another model, in particular 14 parts for an 8. It's a custom installation, and it will probably require custom parts. Yeah, some stuff will work.

The dual outlet cowl concept has some merit for any A-model. The goal is exit velocity for cooling drag reduction. The dual outlets would move the primary cooling flows outboard, so they are not slowed by the forest of nose gear support tubing. Obviously that particular rationale doesn't exist with conventional gear.

The 8 and 8A incorporate an inset ramp in the bottom of the fuselage. For the A-model, start by removing the "coal shovel" off the belly of the cowl and replace it a flat section flush with the lower skin. Now a decision...size the new dual exits for fixed outlet area (a cruise drag compromise, offset by simplicity) and eliminate the outlet ramp by sheeting it flush with the belly skins....or size the dual outlets smaller, and develop a variable area door feeding the existing exit ramp.

The wildcard is an exhaust system. The Vans crossover is a sure choice, but will it fit in the RV-8 cowl? Can you get one from Vans on a timely basis? Vetterman is making a dual outlet exhaust, but it's not a crossover:

https://vansairforce.net/community/s...94&postcount=7

The new RV-14 setup performs better because the Vans crew did a nice job in integrating a whole bunch of detail changes. It's not just an engine swap.

I'll imagineer a bit, and hope for some opinion slack. If I were to build another RV-8 tailwheel with a 390, and wanted 119-comparable power...

As delivered the, servo mounting flange on the standard horizontal plenum sump has a diameter sized for an RSA-5 servo. The much larger FM200 will bolt on with an adapter, but the small sump inlet is still there, choking the flow. It's possible to re-size that inlet, opening the diameter and moving the studs. I can't prove it (doing so would require before and after dyno runs with the same engine), but I'm pretty sure the C or 119 models make 5 more rated HP simply because the "cold air" manifold's intake flange diameter is sized for an RSA-10 servo...something like 75% more area. I doubt cold air has anything to do with it; the horizontal sump does not flow intake air through the hot oil, and all intake pipes run through the same hot engine compartment.

Ok, so what to pair with an un-choked 390A? The 4-into-1 from AWI will mostly tuck up into the -8"s exit ramp, so frontal area can be reduced by loping off the cowl shovel and replacing it with a simple fixed exit. Any resulting frontal area is probably less than dual outlets, and there is no heating from exhaust crossover tubes. Next I'd switch to a rear alternator and a composite prop, to move the CG rearward.

Simple fixed exits; I flew four in development, the first three shown below. With the caveat that I run a non-stock cowl intake and plenum, all three of these worked. Although smaller than stock, the one on the left was excessive. The middle one would be fine in hot weather. The one on the right was too small for Oshkosh in July, but would be fine in the winter. A fixed exit is less of a compromise if the cowl is modified so area can be changed with the seasons.
.

You gave me a lot to chew on, I appreciate it. I have a 390 Thunderbolt in my 14 now and had a -119 in my 14A I just sold. I noticed a significant power difference, both on takeoff and cruise. the -119 definitely has more balls.
I know there is more to it than HP, I had a BA foil on the A and an aerobatic on the 14. Both Hartzell CS 74".
I was wondering if the Shoplane cowl would be a good option, it is a little longer which may help with the FM200, but don't know for sure. I spoke to Rian Johnson in October after waiting for the exhaust system for several months. He assured me that they had worked their bugs out, but some of the issue was tubing was hard to get, Vetterman said the same, but they were only a couple weeks out on their system. Hopefully, supply issues will improve. I do have the 119 on order.

Come to Marianna, Fl. this weekend for lunch

[scsmith]

Originally Posted by DanH

At the fundamental level, a 119 is a 390C with an Airflow Performance FM-200. It bolts up like any angle valve.


I'll imagineer a bit, and hope for some opinion slack. If I were to build another RV-8 tailwheel with a 390, and wanted 119-comparable power...

As delivered the, servo mounting flange on the standard horizontal plenum sump has a diameter sized for an RSA-5 servo. The much larger FM200 will bolt on with an adapter, but the small sump inlet is still there, choking the flow. It's possible to re-size that inlet, opening the diameter and moving the studs. I can't prove it (doing so would require before and after dyno runs with the same engine), but I'm pretty sure the C or 119 models make 5 more rated HP simply because the "cold air" manifold's intake flange diameter is sized for an RSA-10 servo...something like 75% more area. I doubt cold air has anything to do with it; the horizontal sump does not flow intake air through the hot oil, and all intake pipes run through the same hot engine compartment.
.

Dan, are we sure that there is enough 'meat' on the standard IO-390-A1B6 sump to allow relocating the studs and opening the hole to mount an FM-200? IF so, this seems a great way to go.

[DanH]

Originally Posted by scsmith

Dan, are we sure that there is enough 'meat' on the standard IO-390-A1B6 sump to allow relocating the studs and opening the hole to mount an FM-200? IF so, this seems a great way to go.

Apparently some of the engine shops do the mod. Ron Moring has one on his Sportsman. I'm gonna do it if I need to remove the sump. Hopefully that will be about 1000 hours from now.

[N546RV]

Originally Posted by Cwood2000

Vetterman said the same, but they were only a couple weeks out on their system.

Just as a data point re:Vetterman, I ordered a four-pipe exhaust for my -8 in mid-September last year. At the time, Clint told me they were running "about six weeks out." My exhaust shipped last week and arrived yesterday, so that six weeks turned into more like three months.

Didn't bother me - I'm still waiting on my Titan engine that I ordered 14 months ago - but just FYI that the quoted lead time might be optimistic.