7-AC engine upgrades

[scottdenny81]

I know this has been beaten to death, however I am going to do it again. Will anybody with an upgraded engine please post there performance specs. I am asking for cruise speed, climb performance, takeoff distance and so on so forth. Please state which engine you have and what your upgrades are. Also does the O-235 conversion really affect gross that much? Thanks in advance. Scott Denny. 1946 7-AC

[WWhunter]

I am sorry but I can't help a whole lot since my 7AC-CONV is on floats. It has an O-235C2C with a metal prop that is set up for floats. My cruise on wheels is right around 100mph but to be truthful I never fly it at that speed, most of my flying is just putting around enjoying the scenery. My Champ very heavily modified. I have a few hours on wheels and it takes off in about 300 feet (rough guesstimate). Since I don't have a VSI nor have I ever timed it I can't give you an exact climb rate but will say it is a great preforming plane. As I have stated, my Champ is HEAVILY modified and its empty weight is 891 on wheels. If you do a search of planes for sale or my 'name' you will see all the mods done to the Champ. I feel it is fairly light for all the stuff it has and still LSA compliant.

[rkittine]

I have a C-90 in my 7AC-CONV - 95 HP for takeoff. It also has vortex generators and will get off the ground too quick, so I hold it on, but am still up in a few hundred feet with 2 - 210 pounders on board. Climbs out aqt well over 700 FPM , but I have a Seaplane Prop on it and it will not go much over 85 in cruise.

[joea]

Look into the "Don's Dream Machines" upgrade.

Have heard many (over 20) owners talk about what a changed airplane it is after doing Don's "85 hp upgrade" on their airplane. Its really a o-200 crankcase and bits that is legally a 85 hp engine.

[scottdenny81]

Thanks for all the info so far. I am not to concerned over cruise normally if I were I wouldn't have bought a champ. But I do plan on flying it from eastern NC all the way to Washington State, and then to Alaska so a little speed would be nice. I look forward to hearing more from you guys.

[MikeB]

Scott,
As I've posted before I have a L16 (or 7BCM) with the Wagner 0200 conversion. I see about 90-95 mph at 24-2450 rpm and burn somewhere in the neighborhood of 6-7 gph. I fly from a 2100 ft. strip with no problem and climbout somewhere in the 700-800 feet per minute range depending on temperature and wind, etc. Mine is on the heavy side at 955# but I have a 25 amp battery, Sky-Tec starter, mufflers, interior, metal prop, etc. so it all adds up. Everything was done by either STC or approved 337.

Be advised though that the Wagner STC is not a 'drop in installation'. It takes a lot of creative engineering with the air cleaner location, baffles, cables, etc. On the other hand, it's written so loose that that it allows for a lot of 'creative leeway'.

Hope this helps!

Mike Berg

[Dennis]

Scott,

I have the Buzz 0-200 STC with a 6948 prop. I see about 85 to 90. If I recall, MikeB has the 6950 prop hence a little more cruse speed. If I wanted speed, I would try a 6952 or even a 6954. If you can get static RPM, your good. As mike said, the STC is rather"loose".

If I wanted more speed, I would look around for prop I could borrow to check RPMs.

Dennis

[rkittine]

I put a Don's Dream Machine engine (105 HP on the Dyno) and it is a SUPER performing engine. I have it on floats so I can not tell you much about how it would be on Wheels, but after flying a bunch of C-85s on floats, the increase in performance is substantial. If I had put it on wheels I probably would have changed to a cruise prop. It was expensive though. $18K

[pmanton]

I put a Don's Dream Machine engine (105 HP on the Dyno) and it is a SUPER performing engine.

I second that about the O-200 crank & rods STC making a super performing engine.

Paul
N2426E
N1431A
2AZ1

[MikeB]

Just out of couriousity, what is the fuel burn on Don's Super 85's ? I know my 0200 will burn somewhere between 6-7 gph.

As a matter of cost I don't think Don's is too far out of line for a 'new engine'. My 0200 rebuild ran somewhere around $12,000: $1000 for the core when I bought it, $5000 for Bolduc to overhaul and assemble the lower end (crank, cam, lifter bodies, gears, etc. were good), $3600 new ECI nickle cylinder kits, $1800 new Slick mag kit, $700 rebuilt carb exchange and I'm probably missing something . My IA and I installed the cylinder kits, etc. so we probably saved something there and we also didn't get a 'run in' like I assume Don does. Having said that, I like the 0200 installation once I got everything 'shoehorned into place' and I do have a Sky-Tec starting system to save swinging the prop to start. If I was going to do something different (and didn't mind paying for it) I'd shoot for the 13 gallon per side fuel rather than the 13 gallon nose tank and 5 gallon wing tanks most for weight and balance purposes as it seems a bit nose heavy.

Mike

[rkittine]

I use 6 gallons per hour for the Chief with the C-85-12 / 0-200 parts, but that is to be on the conservative side. In normal play mode, I was only burning 5 to 5.5 gallons an hour.

The cost was $18,000.00 for the engine, less $3,000 for the core swap. The starter was extra and I never put on an alternator, though there is now a light weight, shallow one that will fit in a Chief if you put a Pimple into the firewall.

The BluePrinted C-90-12 will be $18,000 after the core trade in or my C-90-8.

Bob

[MikeB]

Hey Bob,
How is the storm affecting you? OK, I hope!
Mike