Engine choice

[aviatre]

I am new to the vaf. I have an rv6 project that I purchased in its present 90% done and 90% to go state. It currently has a Mazda set up installed( that is for sale with mount). I want to change to a Lycoming 360 with a fixed pitch prop. I have an opportunity to acquire a mid-time engine from a Robinson r-22. This is a conical mount engine. Any thoughts as to why or why not to use this engine?
If I use this engine, I will have a dynafocal mount to sell.
Frank 530-622-4462
Any input is appreciated.

[nzrv8]

Hi,
For what its worth, you can have the conical mounts changed to dynafocal by a good engine shop, and it doesn't cost the earth. I know of several RV's that have converted R22 engines and dynafocal mounts.
Cheers,
Hugh

[Jesse]

Smoky Ray has an O-360 conical engine in his -6 (I know, it's really an RV-X, but the fuse is a -6). He loves his engine and Catto prop.

[rv7charlie]

Have you checked the specs on that particular engine? A lot of heli engines are either rated at higher rpm, or lower HP, or... Not necessarily a bad thing, but good to know all the variables, if you can.

Did it fly with the rotary? Isn't removing modern tech kinda like jumping out of a perfectly good airplane?

:-)

Charlie
RV-7 Mazda Renesis FWF

[N941WR]

Originally Posted by nzrv8

Hi,
For what its worth, you can have the conical mounts changed to dynafocal by a good engine shop, and it doesn't cost the earth. I know of several RV's that have converted R22 engines and dynafocal mounts.
Cheers,
Hugh

Yes, this conversion can be done but the engine must be disassembled, as in during a major overhaul. Since your engine is "mid-time" you may not want to do that.

Use "search", "advance search" above. There have been past threads on doing the conversion.

Good luck and welcome to VAF.

[Mike S]

Originally Posted by aviatre

I am new to the vaf.

Frank, from a few miles down the hill.

Good to have you here, have you joined up with EAA 512 yet??

[SHIPCHIEF]

I'd suggest you use the search function of this forum to look up Smokeyray's posts on helicopter engine(s) etc. Also, Mahlon the Lycoming guru has comments on it. Try HIO-360 for a search term.
For myself, this seems a good route to consider, but there will be special parts that you will have to replace, possibly the accessory gear case or the sump and induction tubes. I don't know, and there are several helicopter engine variations. Anyway, an inexpensive engine gets expensive quickly if you have to get missing or different parts so it will fit your application.
Some helicopter engines seem to have lower HP ratings, but if you look up the engine model's operating manual, you will find certain special criteria, like power rated at some altitude greater than sea level, or a manifold pressure less that could be attained at sea level. If they run at higher RPM, they can make more power, but I believe Mashlon said they all use the same cam as aircraft engines...
These engines are not configured to take a constant speed prop. Changing that could be a considerable expense. As you plan to use a fixed or ground adjustable prop, this won't be a problem.
Interesting about the Mazda Engine, I'm running one in my RV-8.

[Andy Hill]

The R-22 (or at least one model) 360 engine has lightweight cylinders.

Lyc limit it to 145HP by a table of Max MAP v RPM, which for you will be by willpower alone. Robinson limit it even further to ~128HP (?) due the drive system i.e. to get the correct limits, read the engine TCDS not the R-22 Manual.

With a FP prop, the low takeoff RPM means you can use Full Power IIRC. As the RPM rises with IAS, then the left hand has to start pulling back until the higher altitudes... which reflects why Robinson used the 360 as a 320 replacement - for hot/high performance, not SL.

All from testing an RV-8 with this engine some years ago..

Wiki gives O-360-J2A as only R-22 360- engine.

TCDS:

O-360-J2A 289 Similar to the O-360-C1C except has O-320-B2C prop flange bushings, light weight cylinders and lower power rating

HP v RPM v MAP
145 - 2400 thru 2700 +
26.5” Hg MP @ 2400
24.6” Hg MP @ 2700

[RV6_flyer]

Originally Posted by aviatre

I have an rv6 project that I purchased in its present 90% done and 90% to go state. It currently has a Mazda set up installed( that is for sale with mount).

If I use this engine, I will have a dynafocal mount to sell.
Frank 530-622-4462
Any input is appreciated.

How much? (Mazda set up with mount) and also (Dynafocal mount) how much?

Does either set up or mount include pre-drilled gear or un-drilled gear?

[Pitts#25]

I used a conical mounted HIO-360 on a racing Pitts. If I recall it was rated to turn 2900 RPM continuously, of course I turned it up a little higher than that. At one point it had 13:1 pistons in it and it proved to be a very powerful, tough engine. Coincidentally, it also had a Catto prop that was really designed for a guy cross country racing in a 180 hp RV-6.
The conical mount has a few advantages: It's lighter, and the little rubber mounts are cheap as compared to the dynafocal mounts.
Removing that automotive stuff is a smart move and greatly improves the value of the airplane...my opinion.

Dennis