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RV-3 O-320 160 hp STC

AV8Tricks

I'm New Here
Hi guys:
I just (five hours ago) bought my first RV. After about a three-hour long, "Whoo-hoo!" my neighbors threatened to break out the nets and thorazine darts. I finished doing cartwheels out in the yard, and am now beginning the research process that precedes the liquidation of C.D.'s, selling of sundry toys and unwanted relatives in exchange for cool stuff, like horsepower. So.....here I am at the Oracle starting the, "now what?" process....
My first quandary is on the engine. It's got the 0320E2D, which as I understand it has a STC available for 160 hp conversion. I've not yet been able to track down the holder. This aircraft has been sitting ten years and I'll have to go through it anyway, so I'm thinking now's a good time to throw ten more HP on it. I haven't found (maybe haven't looked in the right place for) info on what prop would be good with either the 150 or 160 HP Lyc. The prop on this one is shot (delaminated bad) and needs replacement anyway.
Have any of you guys had any experience with a 160 HP RV3? I've been flying a RV-4 with IO-360 c/s. I'm thinking (usually where the trouble starts) that it would perform about the same.
Any advice/knowledge/pearls 'o wisdom you guys could toss my way would be much appreciated.
Deb
 
Simple

"Experimental aircraft don't need no stinkin' STC." Humphrey Bogart said something like that.

And it's true. Build your engine anyway you want. You're certifying its airworthiness. I believe the added 10 hp on the E2D comes from nothing else but 8.5:1 pistons (you have 7:1 now), but the case needs a different journal at the prop end. At least that's what my A&P said when the thought of bumping a 172's mill was discussed.

John Siebold
 
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Humphry's my hero

That's good news, simple piston swap. Wonder if the journal is for potential constant speed/hyd.... Thanks for the info.
Deb
 
I don't believe there is a need to modify any bearings when converting to 160hp. The cheap way to do it is to install the high compression pistons. The expensive way is to buy new cylinders (the choke of the bore is different). You will probably also need to bore out the main jet of the carb, otherwise you will run lean and get rather hot CHTs. Doesn't need much (a few thousandths), but it makes all the difference. Prop pitch will need to be 2 or 3" greater.

Pete
 
No on the C/S prop,160HP ?

The E2D is a fixed pitch prop engine. :( Sorry

The E is usually NOT acceptable to upgrade to 160 HP, but think the E2D is the exception? Some of the "E" models where economy models and the cylinders (steel bore) and main bearing (narrow split) are not made for 160HP. The following is from Skyranch:

"Lycoming builds 0-320 engines that produce 150 HP or 160 HP. The 150 HP O-320-E series engines operate at a compression ratio of 7.0:1. The 0-320-D series has high compression pistons which raise the compression ratio to 8.5:1, and increase rated output to 160 HP. Those who believe that the pistons are the only difference in these engines will be disappointed when they plan to upgrade their 0-320-E to the higher horsepower by simply changing pistons. Many models in the 0-320-E series were designed for the purpose of keeping the cost down. Thousands of these low compression engines were built with plain steel cylinder barrels instead of the Nitrided barrels used in the 0-320-D series engines. They also had two narrow bearings instead of one long front main bearing. The engines were certified at 150 HP and were not intended to withstand the additional stress of higher horsepower."

However RAM Aircraft has the STC for a 160HP, which includes among the applicable models the E2D! :D (As noted before you don't NEED a STC but it is a good guide to determine what is involved.)

Click link: STC for Lycoming O-320-E2D 160HP conversion from RAM Aircraft

"As modified per STC SE3692SW, install Lycoming O-320-D2G, O-320-D2J, or O-320-E2D engine rated for 160 hp take-off and 150 hp METO for models 172I, 172K, 172L, and 172M; or installation of Lycoming O-320-D2G, O-320-D2J, or O-320-E2D engine rated for 160 hp takeoff and 145 hp METO for models 172D, 172E, 172F, 172G, and 172H; or Lycoming O-320-D2G, O-320D2J or O-320E2D (160 hp, 2700 rpm) in model 172N."

Notice, the language and model number (of aircraft). It states that 160 HP is for T/O and 150 HP "METO" (Maximum Except TakeOff) for the C172-I/M, which is the O-320-E2D. You don't need to follow the STC but it is good to know.

I would talk to someone who is knowable. If you are not a member try the Lycoming Yahoo Group: http://groups.yahoo.com/group/lycoming/

Mahlon is on the Lycoming Yahoo list and would know all the ins-N-outs, he also lurks around here also. I think he is with Mattituck, who is also a good place to do business. (East end of Long Island NY)

You mention the engine was not run for 10 YEARS. I would consider a full tear down if you decide to make the change to the engine. At least get some oil analysis and may be borescope cylinders and check the screens, filters, plugs on a more often schedule at first.

With the 160HP change you will need more fuel out of the Carb. Drilling the main jet out is hit and miss. You may consider getting the proper Carb for the conversion. Precision can help you with this: http://www.precisionairmotive.com/

If you call Precision, you want to look at the metal tag on the side of the carb and note all numbers and any stamped letters (indication of mod level). When you call Precision they can tell you about any outstanding service bulletins (SB's). Being in service from many years, it no doubt has a few SB mods needing to be complied with (some may be important). The fact it sat for 10 years means it sould be overhauled anyway. By drilling the main jet you are making it an experimental carb. My point is don't mess around too much with the Carb unless you know your stuff. There is a good Carb shop in OK, but forgot the name. They have good prices. You can go direct to Precision but they are expensive and my or may not give credit for the core depending on the model.

This engine BTW is out of a Cessna 172-I thru -M or 177 (Cardinal).

Here is a thought, leave it alone, at lest until it needs a rebuild. You will only add maybe 2% to your top speed (4 mph) and rate of climb may increase 150 fpm.

George
 
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I had an O-320 150hp on my RV-6A, running an AVIA veriable speed prop. Could not go with a Hartzell CS prop because of sold crankshaft. One of my best friends had an RV-6A O-320 with a Sensansich fixed pitch prop. My RV-6A outperformed his in takeoff distance, climb and cruise.

For the extra 10 HP I wouldn't upgrade but would give serious consideration to the AVIA prop if you have a solid crankshaft and want the extra performance. In addition the AVIA prop was a wonderful aerobatic prop. If you want more info on the AVIA contact me offline at dav1111 at cox.net

Russ Daves
N710RV (Reserved RV-10 on main gear)
N65RV RV-6A sold
 
150HP vs 160HP

Thank you so much, all. I?m pulling the engine tomorrow for tear-down. The tach. says 386 hrs. While it?s probable on the airframe, best guess from the previous owner is that the engine has around 1800 hrs TTSN. When I pull the plastic bags from the intake, I believe there?s a family of spiders living in the carb., so it either needs O/H or I?ll exchange it. I can?t find any data on the spiders, so they?re outta the pool as well. Anyone needing spiders can have them for the price of the freight.

George, given the minor increase in performance, the 160 HP conversion may not be worth it. 150?s plenty for it. However, depending on the shape of things, it may be six of one, half-dozen of another if I wind up replacing cyls. anyway. My next stop is to join the Lycoming group on Yahoo. Four mph is four mph, hmmm, 150 fpm..?.okay, I talked myself into it. That is interesting about the HP/RPM limitations by airframe model for the converted O 320 E2D engine, though. Probably figured with the different 172 props to keep it within RPM range, but good to know the limits regardless. I bet I could look into 172 spec?s by model/prop and come up with a fair approximation of RPM ranges on mine. The tach. that?s in it isn?t marked or anything. On the fixed-pitch vs. constant-speed, oh well. Hah, new owners! Next thing I?ll be asking about putting dual Rayjay?s on it?..

Thanks again for all the help,
Deb
 
Don't forget the piston pins

Deb,
If you do go for the higher compression pistons besides needing hardened choked cylinders and the 75089 pistons, you also need thick wall piston pins Lw-14077 or equivalent. These may already be installed but you could also have thin wall pins in a low compression engine, that would need upgrading on a compression ratio change.
Good Luck,
Mahlon
"The opinions and information provided in this and all of my posts are hopefully helpful to you. Please use the information provided responsibly and at you own risk."
 
Cyls & Piston Pins

Mahlon:
Thanks for the info. These look pretty much like the original cylinders on the engine. In fact, pretty much everything looks original. I'm hopefully getting the logs in the next couple of days and will be able to speculate further. Those 75089/LW-14077 numbers ring a bell....is that also the piston/pin for the 360?
Any tips on good places to get Lycoming/new OEM stuff?
Thanks,
Deb
 
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Yes it is, the high compression 320's and the entire parallel valve 360's that use 8.5:1 compression use the same piston 75089 and the same pin Lw-14077.
You can find a list of Lycoming distributors here:
lycoming domestic distributors
Any one of them should be able to help you out with OEM Lycoming parts.
We are stocking distributors for them and feel free to all our parts department at 1-800-324-6680 for quotes. Also Our website www.mattituck.com has some limited parts displayed.( like cylinder kits).
Good Luck,
Mahlon
"The opinions and information provided in this and all of my posts are hopefully helpful to you. Please use the information provided responsibly and at you own risk."
 
Engine Overhaul

Hi Deb
I am overhauling my O320E2D in the same manner you are. I had my engine builder install 8.5:1 pistons and the heavy wall wrist pins. Next (after reloading the money gun) I will have the case overhauled. My engine builder assured me that the split front main bearing in the E2D isn?t an issue with the higher compression pistons.
 
160 vs 150

Hey Dayton:
What are you doing on the cylinders? I flat love Lycomings, used to work on 540's quite a bit. Was really glad that's what this a/c had in it.
 
Hey 12S

How's the fuel consumption? Vague memory of 172's makes me think it will be in about the 4.5 to 5 gph range at cruise.
 
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