[skyfrog]

I know the pros and cons of a 235 vs. 320 for an RV-9A, but I'm not sure about the "C2C" designation.

Would there be any difficulties installing a Grumman Yankee engine into a 9? I have seen a couple on the web, but are there any mods that need to be made?

Thanks

 

[N941WR]

John,

I doubt you will have any problems, other than Van's doesn't really support any engine other than the O-320.

A lot of what I went through applies to the O-235 as well. Check out the engine page on my web site for some of the details.

 

[osxuser]

O-235 is a good enough motor, but given the higher cost of an overhaul (due to low quantity of parts sold) and it's limited performance potential (Turning 2800RPM to get 115hp).

I'd much prefer an O-290 (which parts are cheap for now, because everyone dumped them in favor of the -320). The O-290 case can also be modified to fit an O-320 crank, although I'm guessing cylinder availability will start to become an issue in the coming years.

 

[N941WR]

PS...

John,

I've posted this a number of times but there is a 108HP O-235 powered -9A here in NC and the the owner had previously built a -6A. (I can't remember which engine he had in his -6A.)

As it turns out, he likes the -9A much better than his -6A which he gave/sold to his uncle.

He reguallary cruises it at 150 MPH and thinks nothing of doing 800 mile legs on the standard tanks.

Don't let anyone tell you the O-235 is a bad engine, it regularly makes TBO on 152's used in training. I can't think of a better recommendation than that.

 

[skyfrog]

Thanks

Thanks for the replies guys...

I had a line on a very inexpensive 235, but decided against the idea anyway since it was a runout and disassembled.

I got some time to save up my pennies for an engine, so hopefully something better will turn up then.

 

[gmcjetpilot]

Here is some info that might help

I am familiar with the L2C flying piper tomahawks and C152's in my early flying career. Here is a snip from Lycs cert data......

The C2C is like a -C2A like a -C1. It has a type 1 prop flange and apparently has provision for constant speed prop (hollow crank and governor drive pad) or fixed (with blocking plug).

The down side of a -C2C has with 6.75:1 compression ratio (CR), which makes 115 HP, three less HP than what VAN specs out, but can use lower octane fuel.

The L2C has 8:5:1 compression which is comparable to a 180HP 360 Lyc, which also has the same 8.5:1 CR. The O-235 also comes with CR of 8.10:1 and 9.75:1. The higher CR of 9.75:1 is the 125 HP version and was taken off the market because of detonation issues. However there are approved STC's to convert O235's to 9.75:1 CR. Go figure. I don't recommend the high CR mod from personal experience. 8.50:1 is plenty.

I'm not 100% sure but I am guessing the -C2C has a conical mount, not the more desirable dynafocal (I). The Lyc data does not say conical explicitly, but if you follow the engines derived from the base -C1 engine, you see -J2A says the SAME except Dynafocal mount. That implies all the preceding engine models including the -C2C have a conical mount. Bottom line conical motors sell for less used because they are not as desirable. However you want to check with VAN that they have a RV-9 conical mount. Van does make some conical engine mounts for the 320 on the other RV models. Conical is not ideal or as good as dynafocal, but it works if you get the LORD engine mounts. They are not cheap but worth it.

O-235-C1 115 2800 80 6.75:1 Type 2 prop. flange, fixed or constant speed
O-235-C2A 115 2800 80 6.75:1 Same as –C1 but has AS-127, Type 1 prop. flange
O-235-C2C 115 2800 80 6.75:1 Similar to –C2A but with Slick Magnetos
O-235-E1 115 2800 80 6.75:1 Same as –C1 but has provision for controllable prop.
O-235-F2A 125 2800 100/100LL 9.70:1 Similar to –C2A but higher power and comp. ratio
O-235-J2A 125 2800 100/100LL 9.70:1 Same as –F2A but with Type 1 dynafocal mounts
O-235-L2A 118 2800 100/100LL 8.50:1 Same as –J2A but with 20° BTC timing, lower comp. ratio and lower power
O-235-L2C 118 2800 100/100LL 8.50:1 Same as –L2A but with Slick Magnetos

 

[N941WR]

...However you want to check with VAN that they have a RV-9 conical mount. Van does make some conical engine mounts for the 320 on the other RV models. Conical is not ideal or as good as dynafocal, but it works if you get the LORD engine mounts. They are not cheap but worth it.

Yep, they make a conical mount for the O-235, I've got one. It is 2" longer than the O-320 mount and gives you a full 12" behind the engine. It also requiers a longer cowling, which Van's also sells.

One of these day's I'll change out my rubber mounts for Lord's.

With a wood prop, the conical mount is probably just as good as the others, very low vibration.