RV6A with 200HP - Page 3

Gyrodoug · #21 04-04-2019, 07:54 AM

Quote:

Originally Posted by moosepileit

Assuming counterwighted crank and angle valve, over 30# heavier engine.

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!

rvbuilder2002 · #22 04-04-2019, 09:13 AM

Quote:

Originally Posted by Gyrodoug

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.

Gyrodoug · #23 04-04-2019, 09:49 AM

Thank you. I appreciate your answer...

jpowell13 · #24 04-04-2019, 10:23 AM

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

N62XS · #25 04-04-2019, 10:54 AM

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.

eaglen92ce · #26 04-04-2019, 10:54 AM

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.

Timberwolf · #27 04-04-2019, 12:32 PM

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

KGT · #28 04-04-2019, 07:25 PM

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

rvbuilder2002 · #29 04-04-2019, 09:05 PM

Quote:

Originally Posted by KGT

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).

DanH · #30 04-05-2019, 07:00 AM

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.