Anyone in the BCP community have a "go to" for a Conti 0-300 overhaul. To bad no one offers a "Pponk" style of treatment for these motors

Mapleflt

The airboat crowd slaps a set of IO360 cylinders on there and either a 2 barrel Holley or some carb off a Lycoming. You could call it a O300-60. I bet you could get a field approval[emoji38]

whee wrote:The airboat crowd slaps a set of IO360 cylinders on there and either a 2 barrel Holley or some carb off a Lycoming. You could call it a O300-60. I bet you could get a field approval[emoji38]

Except he lives in Canada. No field approvals up here and I can't even get an LSTC for oratex within the next 2 months... sounds like a fun mod though!

whee wrote:The airboat crowd slaps a set of IO360 cylinders on there and either a 2 barrel Holley or some carb off a Lycoming. You could call it a O300-60. I bet you could get a field approval[emoji38]

Do you know why they go that route vs grabbing an IO-360? Seems like older IO-360 bottom ends would be cheaper to find due to the crank AD.
Both engines have the same stroke (same crank actually) but I didn't know the cylinders would bolt up.
I wonder why they don't use the fuel injection.
(Sorry for the thread creep)

I've heard rumors that some of the C145/O300 Swifters run C85 pistons for higher compression,
you can do the same thing in an O200.
A bit of piston modification is required.
Not sure the small gain is worth it.

I didn't realize that the I0-360 jugs would bolts directly on to the 0-300 case. Any risk of "killing" the bottom end or would a full overhaul be a wise move maybe. This would retain the original 0-300 engine mount and accessories but for some carburetor "tuning". I guess you would have to retain the I0-360 induction and exhaust systems as well I guess.

Mapleflt

Mapleflt wrote:I didn't realize that the I0-360 jugs would bolts directly on to the 0-300 case. Any risk of "killing" the bottom end or would a full overhaul be a wise move maybe. This would retain the original 0-300 engine mount and accessories but for some carburetor "tuning". I guess you would have to retain the I0-360 induction and exhaust systems as well I guess.

I know you know I was kidding but it would be cool to see. Seems like lots of 170 and early 172 guys would be interested in it. I don't know what mods the case required, if any, but I imagine you might need to bore the case like when ponking a 470. It's possible the O300 exhaust would fit. I have some IO360 cylinders I could measure if someone has the dimensions of the O300 case.

This whole discussion is just academic though...approval would be near impossible. Then again the IO240 is very similar to the O200...

Bagarre wrote:Do you know why they go that route vs grabbing an IO-360? Seems like older IO-360 bottom ends would be cheaper to find due to the crank AD.
Both engines have the same stroke (same crank actually) but I didn't know the cylinders would bolt up.
I wonder why they don't use the fuel injection.
(Sorry for the thread creep)

Because the already have an O300 mounted to their boat and don't want to redo their rigging. The O300 doesn't have provisions for the fuel pump and they don't want to depend on electricity to run their boats. Keep it simple seems to be their mantra.

I owned a C170 for years, but never heard anythjng about IO360 jugs fittkng onto an O300 case. Not convinced they will, regardless of what "the airboat crowd" says.
BTW most if not all O300's have a fuel pump drive pad.
The ragwing 170 had a fuel pump, as does the Swift.

Mapleflt wrote:Anyone in the BCP community have a "go to" for a Conti 0-300 overhaul. To bad no one offers a "Pponk" style of treatment for these motors

Mapleflt

I'd wager an overhaul on that O-300 will cost $15K+. More if you buy all new cylinder assemblies.

Have you priced the upgrade to a Lyc O-360? If you're able to do much of the work yourself, it might start to look attractive and doable.

I built my IO-540 myself with my IA/mentor guiding me. It was fun an educational. But, all in, I have about $28K into it with new cylinders from lycon. If I was at a decision point on a certified engine, I would go the same route again if I had the resources available (agreeable IA.)

I agree with you Zzz, building a motor serious consideration. It could be done over a period of time while still operating the original engine until its ready. Anyone know the engine mount differences between the 0-300 and IO-360. I know a I0-360 can swing a fixed pitch prop but can it be configured as an "0-360" not I0-360, I'm a HUGE Conti fan as you can tell !!!

I have a friend that's in the middle of overhauling his o-300. He looked into the 180 conversion, and from what I recall, the STC was north of $20k, and that's without the engine or prop, so most people either rebuild the o-300 or sell the airplane and pay the money for a 180.

akschu wrote:I have a friend that's in the middle of overhauling his o-300. He looked into the 180 conversion, and from what I recall, the STC was north of $20k, and that's without the engine or prop, so most people either rebuild the o-300 or sell the airplane and pay the money for a 180.

Dave Stoots is a character, but really? $20K for the paper?

Zzz wrote:

akschu wrote:Dave Stoots is a character, but really? $20K for the paper?

According to the website:
Engine Mount
Exhaust System
Induction System
Air Box
Cowl Mods
Baffling
40 Amp Alternator
Oil Cooler
Oil Hoses
Fuel Hoses
Boost Fuel Pump
Control Cables
EGT/CHT Instruments
Tachometer
Manifold/Fuel Flow Instrument
Oil Temp Gauge
Scat Tubing
AN Hardware
Wiring
Switches
Breakers

And.... paperwork....

We have provisions in the land north of 48 that would allow an I0-360, Conti or Lycoming to be installed under the "provisions" of an existing approved STC without some of the larger costs associated.

We have provisions in the land north of the 48th parallel that would allow an I0-360, Conti or Lycoming to be installed under the "provisions" of an existing STC without some of the larger costs associated. Therefore the concept that Zzz has floated becomes a viable alternative to seriously consider if ones is so inclined

Mapleflt wrote:I agree with you Zzz, building a motor serious consideration. It could be done over a period of time while still operating the original engine until its ready. Anyone know the engine mount differences between the 0-300 and IO-360. I know a I0-360 can swing a fixed pitch prop but can it be configured as an "0-360" not I0-360, I'm a HUGE Conti fan as you can tell !!!

No, there is not currently an option for a Conti O-360. I've been kicking around this idea for a couple years. My prediction, based on real data, if that a O300 fitted with IO360 cylinders and maintaining the O300 carburetor will produce ~190hp @2800rpm. It would be a fun STC to pursue but I doubt it would ever make any money.

The IO360 uses different engine mount isolators than the O300.

O300 engine mount for C172:


IO360 mount for Cessna T41:
Best pics I have, sorry.

So that kind of wraps around to an earlier thought, will 360 jugs bolt directly onto a 300 ? I could live with the injection system if it could be done without the header tank

Mapleflt wrote:We have provisions in the land north of the 48th parallel that would allow an I0-360, Conti or Lycoming to be installed under the "provisions" of an existing STC without some of the larger costs associated. Therefore the concept that Zzz has floated becomes a viable alternative to seriously consider if ones is so inclined

I'm curious about these "provisions" and ho they'll save you money... Are you thinking you dont have to purchase the STC or??