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RV6A with 200HP

Gyrodoug

Well Known Member
Folks,

Can anyone talk about any concerns, issues, worries, whatever, regarding swapping an O360 180hp already on the a/c with an IO360 200hp....

All input is welcome. Thank you!!!
 
Steve Barnard did it back in the 1990s or so, tight fit in the cowl and cooling issues caused him to rework the cowl quite a bit.

As I recall, the design is now sold by James.
 
Steve Barnard did it back in the 1990s or so, tight fit in the cowl and cooling issues caused him to rework the cowl quite a bit.

As I recall, the design is now sold by James.



James??? Company or person???

Thanks for your quick response.

Doug
 
Thank you. Me and an A&P buddy have a future in an RV6A, soon! We are selling our Stinson 108 and going, Faaaaster.

We are located in Dayton, OH. Pretty excited to become an RV owner.
 
Talk to Lycon in Visalia California. I am going to take the stock 0-360 and put 10:1 pistons and port/polish. Won?t be 200hp but close and wihout having to rework anything else.
Just a thought
 
The IO360 is a FAA certified motor at 200hp. Does this help clarify?

Thank you.

As soon as a "certified" engine is mounted on an experimental aircraft, the engine comes "experimental" as well.

A minor but important point, if the engine is ever to go back on a "certified" airframe. This typically means a complete overhaul to TC configuration.

One last thing, and I have to add this because I always catch it with my engine and airframe combination, Van's does not recommend the angle valve IO-360 for the RV-6(A) or the RV-4 for that matter.
 
Just add injection to your O 360. My 2 cents. My Fuel injected add on O 360 feels plenty of power at 180 HP.
 
Personally I think higher compression and porting is possibly a good fix.

The old Franklins had a 335cu in 150hp motor and the later version 350cu in motor puts out 235hp.

Primary difference is the 150hp has low compression pistons.

Sure the TBO is 1500 but....
 
My buddy just bought an rv6 airframe with an rv7 tail and angle valve 360 currently installed. The seller is keeping the engine and prop, but i get to fly it home before removal. I am really curious how it will perform.

5-B77-B601-7885-476-E-8134-B68887726-CF7.jpg
 
I have a new O-360 that I installed EFII fuel injection and electronic ignition. Supposed to put out 195 hp. Will let you know in 6 months.
 
Folks,

Can anyone talk about any concerns, issues, worries, whatever, regarding swapping an O360 180hp already on the a/c with an IO360 200hp....

All input is welcome. Thank you!!!

Issues with doing it to a 6 have already been posted, HOWEVER you said a 6A and there is an item to address.

Vans specifies a maximum weight limit for the nose gear. On my 7A with a lighter engine than you propose, I am close but within limit in all W&B scenarios.

I recommend obtaining that specification from Vans for the RV6A, redo the W&B based on your own scale measurements, make an estimate of new W&B with new engine, calculate nose gear load and then make your decision.

If you are new to RV's, search here for nose gear failures to aid in a decision to go outside recommended loading.
 
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I'm not disputing this AT ALL, as I'm no mechanic. Just curious, where in the world does this weight come from? From O360 180 vs IO 360 (CIC) ?

Thanks again!

The IO-360 that is rated at 200 HP is a totally different engine than the O-360 (carb.) and IO-360 (injected) engines that are rated at 180 HP.

The 200 HP version is referred to as an angle valve engine. The others are parallel valve engines.

The angle valve engine has a different case, crank shaft, cyl., etc. As a result it is quite a bit heavier and a bit bigger. It will not fit in a standard side by side RV-6 cowl.

It is officially not recommended for an RV-6 for these (and other) reasons.
 
The added weight might preclude aerobatic use of the plane. I've also read on this site that high horsepower engines can damage the trailing edge of your rudder on 6's due to air pulses from the prop. (Your plane may have an upgraded rudder with thicker skin.) John
 
200HP?

If the true goal is increased HP, do FI, EI and 10:1 on a 180HP PV. You will easily get better results with less aggravation from it.

I've done a 200HP IO-360 AV and it was not worth all the effort. I did FI and higher compression pistons on a 160HP O-320 PV and got nearly 180HP.

After all of the cowl and engine compartment work, you will still have cooling issues on the 200HP AV. I did the James Cowl and Plenum, larger oil cooler, relocated oil cooler, cowl louvers and new cylinder baffles before I got the temps where they needed to be. My next 6 will be a FI, EI and 8.5:1 on a 320 PV case and a Catto prop pitched for extreme cruise.(HP is useless unless effectively converted into thrust).

If you like to tinker, try the 200HP AV with the battery in the back. If you want to fly the airplane and enjoy the GRIN, forget it and ditch the nose wheel.
 
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I have an RV6 completed in the year 2000 with an angle valve engine. It has 1500 hrs on it now. When I bought it the Sam James cowling had cracking near both front cylinders from interference during engine movement. I have since modified the cowling slightly (bumped out) to address that issue which worked great. It is hard to detect the bump out areas unless I point it out. It also has the Sam James plenum. CHT were always reasonable, oil temps were not (I also live in Phoenix, so that did not help!). The cooler is mounted on the engine mount behind the #3 cylinder with a nice transition duct. It had a 10599 SW cooler when I bought it. I have now switched to a larger dual pass cooler from a Seneca in the same location which is working well. Last year I installed transition ducts on the #2 and #3 cylinders to address the zero fin depth areas of those cylinders. I also removed sheet metal "dams" that were installed on the forward facing fins of #1 and #2 cylinders. My #3 was always the hottest on CHT. Those two changes made a big difference on #3. With those changes it was almost running too cool this winter but I resisted blocking off some of the cooler (lazy mostly) and just ran closer to peak that I normally would to keep oil up to 160 deg F. Summer is coming, but I am confident the cooling is well sorted now. It has always been manageable in the summer, but it definitely needed management.

So my conclusions on the Angle Valve in the RV6

Pros - Horsepower is fun, fantastic ROC, virtually no DA concerns, higher speeds possible, unique

Cons - Heavier airplane, W&B will need to be carefully looked at, cylinders will cost way more when they need replaced, cowl fitting likely needed, engine cooling may take some work.
 
I have an angle valve in mine as well. I believe my cowl is also a -7. I bought it like this and got it for a very good price. The guy I bought it off of chased high oil temps for 3 years and only flew 30 hours. Turns out it was just the sender he was using. I did put 2 separate oil coolers on and the EZ cowl flap and I have no issues blasting off in FL on a hot day and climbing straight to altitude at 110KIAS. W&B is a consideration when my wife flies, but a 30# lead weight in the baggage takes care of that. 160 true at 7.5 gph. Stunning t/o performance. If I was building I would go back with the same setup. I also have the hartzell B/A prop hanging on the nose. 1300 hours with it in this air frame
 
No Cooling Issues with 200HP AV! Great Engine!

For those who comment you can't cool a 200HP AV I disagree. I don't have an RV6 but I have an RV8 that I swapped the 180HP 0-360 for a BPE XIO-360 200HP AV. Very tight fit for sure! I carefully trimmed new baffles and installed a 13 row oil cooler and the highest CHT I've seen is about 345 in a climb with 190 oil temp. In cruise CHT is just under 300. and oil temp 180-190.
It is heavier for sure so flying solo I add 20 LBs to the aft baggage but with 2 people its about centered on the CG for cross country travel. I would buy the same engine again in a heartbeat, as it makes the power without making the engine work harder to produce it. I also went with the Hartzell Composite constant speed prop to help the extra weight from the AV engine. Take off performance is awesome and cruise is 190 knots versus 170 knots with 180HP fixed pitch Catto prop.
I will say the swap was a lot of work but for me it was worth it!

YMMV
 
For those who comment you can't cool a 200HP AV I disagree. I don't have an RV6 but I have an RV8 that I swapped the 180HP 0-360 for a BPE XIO-360 200HP AV. Very tight fit for sure! I carefully trimmed new baffles and installed a 13 row oil cooler and the highest CHT I've seen is about 345 in a climb with 190 oil temp. In cruise CHT is just under 300. and oil temp 180-190.
It is heavier for sure so flying solo I add 20 LBs to the aft baggage but with 2 people its about centered on the CG for cross country travel. I would buy the same engine again in a heartbeat, as it makes the power without making the engine work harder to produce it. I also went with the Hartzell Composite constant speed prop to help the extra weight from the AV engine. Take off performance is awesome and cruise is 190 knots versus 170 knots with 180HP fixed pitch Catto prop.
I will say the swap was a lot of work but for me it was worth it!

YMMV

One difference would be that the horizontal induction RV-8 cowl was designed from the start to have the cooling inlets and outlet sized for the 200 HP angle valve engine.
The standard RV-6 cowl was not. At the very least an RV-7 horizontal induction cowl should be used (but that only solves one of the problems).
 
Doug, in general, a fuel injected parallel valve 360 delivers an honest 180 HP, while an angle valve "200 horse" is actually about 195.

Given you're working with an "A" model, there is no way I'd install the heavier angle valve for only 15 HP. The 6A nose gear is not something you want to abuse, and it wouldn't be much faster anyway.
 
One difference would be that the horizontal induction RV-8 cowl was designed from the start to have the cooling inlets and outlet sized for the 200 HP angle valve engine.
The standard RV-6 cowl was not. At the very least an RV-7 horizontal induction cowl should be used (but that only solves one of the problems).

On a cooling note I have a modified vertical induction cowl converted to horizontal induction for the AV 200hp. The induction air intake is right below the spinner so all air entering the cowl is for engine cooling.

The weight difference between the 180hp and 200hp was more than I expected. In my case the swap to 200hp and a constant speed prop added about 70 LBs. I agree with Dan I wouldn't want to add the extra weight to the nose of an A model.

Kevin
 
It’s your airplane, your money and your TIME. Do what you want but I think you will do a bunch of work and never know the difference

The extra HP will increase speed by maybe 2 knots, the extra climb performance will be negated by the extra weight. I suspect 90%+ of KGT’s performance increase came from switching to a CS prop, not from the engine swap.

Very little juice from that squeeze.
 
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So back to more hp at same weight, engine, gear, etc.

Higher compression and porting seems like the ?easy? answer to extra performance AND it?s getting time for a top overhaul?
 
Worth it to me...

It?s your airplane, your money and your TIME. Do what you want but I think you will do a bunch of work and never know the difference

The extra HP will increase speed by maybe 2 knots, the extra climb performance will be negated by the extra weight. I suspect 90%+ of KGT?s performance increase came from switching to a CS prop, not from the engine swap.

Very little juice from that squeeze.

I'm not recommending 200hp AV for the 6A at all. Too much added weight up front. Constant speed Hartzell composite prop is surely a huge impact (I don't believe its 90%) to my performance. It is a great highly refined prop. I believe the prop would be great on a 180hp 6A if you can tolerate the price.

I completely disagree that the climb performance was negated by the added weight as I flew it before and after. Climb performance is amazing!

Worth the squeeze to me, but I enjoy the challenge and the outcome. Each to his own! That's the beauty of building you can do it the way YOU want!

Kevin
 
I just flew an io360 angle valve engine, rv6 to the new owner. It is VERY nose heavy. The plane will climb like a rocket, but it is heavy in pitch. I prefer my modded 0320 engine pitch feel on my rv6. The 200hp is being removed and replaced with a narrow deck 0360a1d and prince prop. This plane has an rv7 installed and i really like how it dampens out turbulence. My short tail -6 wags along, but this thing is like having a yaw damper installed.
 
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