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0235 powered RV-3

J

jim miller

Well Known Member
Years ago as I recall I talked to someone at Van's about using a 115hp 0235
in a light weight RV3 and was told it was possible. Van had published a RV3
HP/performance chart which showed performance numbers as a function of
HP. I am looking to do this very thing as I have a very good 0235 and airframe
to put it on. I can live with the expected decrease climb and cruise performance as long as there are no safety issues. Has there been any RV-3's
using this engine?

Thanks
Jim Miller
 
I owned an RV-3 with a 108 HP 0-235. With the correct prop the plane was perfectly safe and very fun to fly. An extra 150' take off roll, climb was respectable at 750 fpm. Cruise was 155 mph. Fuel burn around 5. I'm a 6'1" 200 pounder.

Man I miss that plane. :(


The O-235 would not be my first choice of engines if I was starting from scratch, but if you have a nice engine and want to use it, go for it. A 2 blade Catto prop worked great for me. :D
 
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Larry
Thanks for the reply. If the deal for the project goes thru I have a whole
bunch of questions for you. I am presently flying a Colt I restored with a
overhauled 0235 C1B with new everything including Lycoming cylinders and
about 250 hours since I had majored. I intend to use this engine and sell
the airframe.

Jim Miller
 
A friend has a Long EZ with an O-235. He really hated that engine and putting up with all the ribbing from those he flew with. Blew it up when an oil line failed and replaced it with a Sparrowhawk conversion and is now a happy camper. That little extra compression made all the difference. Now the performance is much better and still very economical.
 
jim miller said:
Larry
Thanks for the reply. If the deal for the project goes thru I have a whole
bunch of questions for you. I am presently flying a Colt I restored with a
overhauled 0235 C1B with new everything including Lycoming cylinders and
about 250 hours since I had majored. I intend to use this engine and sell
the airframe.

Jim Miller
Click to expand...

Since it is in a Colt an issue is building in a duel fuel pump system. I believe the C1B accessory case does not allow for an engine driven pump. Other than that it was a pretty straight forward set up.

Do you have an RV-3 airframe or will you be building it? Definitely build wings tanks instead of the header tank, IMHO.
 
Geico266 said:
Since it is in a Colt an issue is building in a duel fuel pump system. I believe the C1B accessory case does not allow for an engine driven pump. Other than that it was a pretty straight forward set up.
...
Click to expand...
Changing out the accessory case is an easy task. Any O-320 case should fit, IIRC.

You can look at the engine page of my web site to see how to make the change.
 
Good info Bill. This would be a good for the Colt engine. Having two electric pumps and seperate electrical systems was an issue in the plane I had.
 
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Weight vs HP

Jim,

I flew an 0-235 powered RV3 back in the 90's doing a pre-buy at a guys farm strip in the midwest. No electrical system, climb wood prop, no starter or alt, 15 gal nose tank hand-held radio. Naked metal and neatly applied Krylon on the fiberglass. Weighed 690 Lbs as I recall and flew...simply awesome. It didn't have the high comp 0-290 pistons (sparrow hawk). The climb prop would turn up 2900 in level flight indicating 175 mph.

If you can avoid adding weight, I think it's very plausible.

Smokey

PS: of course there's always Nitrous :)
http://www.eaavideo.org/video.aspx?v=96946806001
 
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0-235 9a

We have a 108 hp rated 0-235 C2C in our 9a. PMags, Rotec TBI and a two blade Katto prop are bolted onto it.
Our 9a's empty weight is 893 lbs (and that is still heavier than a -3). The Katto prop is a climb prop. Climb rate one up is 1100 fpm, and two up is around is 900-850 fpm.
Wheel pants and fairings haven't been fitted yet, but I'm interested to see what sort of performance it will do once the pants and fairings have been fitted. And decide then if we need to change the prop pitch.
 
Thanks for the replies. I have already checked on the fuel pump and can
have one of my accessory cases machined to accept fuel pump. The boss is
on all the cases ready to be machined if needed. The 0235 is a much maligned
engine but lycoming thinks enough of it to have a 2400 TBO if equipped with
the newer cylinders. One thing that will help is I am a small person 5' 11"
155lbs. The airframe (which I have purchased ) has flown several years with
0320.

Jim Miller
 
Center of gravity

jim miller said:
One thing that will help is I am a small person 5' 11"
155lbs. The airframe (which I have purchased ) has flown several years with
0320.

Jim Miller
Click to expand...

Jim,
155 pounds is a good match for a small engine up front. Using my airplanes W&B spreadsheet as a base case, I pulled all electrics. Guestimated losing 40# in the engine downsize at station 23. The tool projected a empty weight of 702 # and cg at 61.7. Using wing tanks and pilot at 155# at somewhere around half fuel, the CG goes out to the aft. Obviously, this is a WAG, but it probably does illustrate that the O-235 may create some CG challenges, even with a light pilot.

For me, I don't like aft envelope in this airplane. The elevator is wonderfully responsive with an aft cg, but what also comes is tailwheel first landing when doing slow 3 pts, and that has given me main gear bounce. One is also prevented from using aft baggage.

In the spreadsheet, I added back about 45 pounds, starter, alternator, Odyssey battery on the firewall and saw the cg come forward around 2 inches. Nice. If you aren't interested in electrics, there is the Landoll flywheel balancer and I recall Saber can make heavy crush plates. Both those give quite a bit of movement for the weight, as they are far forward.

Best of luck!
 
Jim, I have an O-290 in my -3. Same crank as the -235.. I would suggest crank flange support ala O-290G... have the drawings for them, used my last one on my project.. aircraft spruce use to sell them....
Jeff
 
O235 accessory case change

I remember hearing Burt Rutan tell Long Eze builders to NOT to put and 0320 case on and 0235 to add a fuel pump or an oil cooler. Later I figured out why.

You can't just put an 0320 case on the 0235 without modification. The 0235 accessory case has holes drilled into the main oil passage on each side to lubricate the mag/fuel pump drive idler gears. The 0320 accessory case does not since the lubricating oil comes from the main case side for these gears. If you swap out the 0235 case for an 0320 case in order to add the engine driven fuel pump, or the oil bypass for an oil cooler, the idler gears will be starved for oil.

I built a drill jig to drill these holes into the 0320 case so it would work on the 0235. I have a modified case in storage.

The 0235 C2C like used in the Grumman AA1 series had the fuel pump, but did not have the oil bypass for a cooler. The Cessna 152 series 0235 also did not have the fuel pump pad machined.
 
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gearup said:
Jim, I have an O-290 in my -3. Same crank as the -235.. I would suggest crank flange support ala O-290G... have the drawings for them, used my last one on my project.. aircraft spruce use to sell them....
Jeff
Click to expand...

I would definitely be interested in that. I just closed the deal on the RV3
less engine. Plane flew for 3-4 years. How does the flange support work
with the Van's 4" spool type extension? I have a SAE2 flange (holes on
4 3/4 inch centers).

Thanks
Jim Miller
 
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