formulaphoto wrote:Lots of talk about the 85 or 90 engine here, but I have an opportunity to get a 65 horse J-3 for a really good deal. My airport is at sea level, but surrounded by mountains (Squamish, BC) plus lots of wind. I love the idea of the Cub and the lessons flying an underpowered plane would teach me...but am I dreaming? Is the 65 just going to be a total pain in the butt and unusable? What is the availability and cost of upgrading to the C85 or 90?

It's hard not to fall in love with a J3 hey! Like others have said though I think realistically when you do the W&B with a bigger 200lb+ guy it is hard to stay legal with a pax/instructor and any fuel. That was probably standard practice back in the day when instructing out of a J3 but a dangerous habit if you're a newer pilot. Not to dissuade you but I would just pay close attention to the W&B vs your mission is all. Also there's not much hanger space at Squamish and an old girl like that deserves and needs to be undercover.

Gump, I'm interested in that O-200 stroker. What crank did you use, or did you just weld and offset grind the O-200 crank? How many cubic inches did you take the O-200 up to after the offset grind?

Or, are you referring to the 85 Stroker that uses the stock C90/O-200 crank, but retains the reduced lift C85 cam?

I run an O-200 on a 46 J3 landplane by 337 rather than STC.
Would like more cubic inches.

For initial planning of a ferry flight, what numbers to use for TAS and fuel burn in a 90 HP J-3 with floats? What is the fuel capacity? Has both firewall tank and wing tank.

TIA

Get a 1956 or later PA 22 or 22/20. With 150-160 hp. Best bang for the buck and a lot of fun. DENNY

Pinecone wrote:For initial planning of a ferry flight, what numbers to use for TAS and fuel burn in a 90 HP J-3 with floats? What is the fuel capacity? Has both firewall tank and wing tank.

TIA

80 mph, depending on prop and pitch.

Fuel capacity in nose is 12 gallons. Many J-3s have been equipped with 8 gallon wing tank, but there are also 12 gallon wing tanks, and a few with 18 gallon wing tanks.

My old 90 hp J-3 had two eight gallon tanks, plus nose. So, lots of tank options out there.

I planned five gph, which was usually pretty conservative.

MTV

Just personal experience with old, tired engines, Mike, but I found slow turners like 65 and 90 Continentals and 235 hp O-540 Lycoming to run cooler in the heat of day than the faster turning engines. What was your experience?

Pinecone wrote:For initial planning of a ferry flight, what numbers to use for TAS and fuel burn in a 90 HP J-3 with floats? What is the fuel capacity? Has both firewall tank and wing tank.

TIA

I know a guy who was ferrying a J3 on wheels. He planned 4 gph and the tank ran dry 20 miles short of his planned fuel stop. Turns out he was burning 6 gph. Landed in a rough hay field, broke a gear leg, and bruised his ego.

80 year old carburetors without a mixture control? Perhaps a familiarization flight using a dipstick to accurately measure the fuel burn would be a good idea.

I was an Armor Officer. I learned not to bypass POL (fuel) points. The Russians evidently were not taught this. The same was expected of the small engine light airplanes with limited fuel. On cross country, manage fuel by landing and fueling whenever possible. The seat is not designed for more than an hour or two at a time sitting anyway. Sixty miles will easily get you to another airport in the East and Midwest. In the desert and mountains, expect to occasionally have to land on the road by a gas station.

kg wrote:

Pinecone wrote:For initial planning of a ferry flight, what numbers to use for TAS and fuel burn in a 90 HP J-3 with floats? What is the fuel capacity? Has both firewall tank and wing tank.

TIA

I know a guy who was ferrying a J3 on wheels. He planned 4 gph and the tank ran dry 20 miles short of his planned fuel stop. Turns out he was burning 6 gph. Landed in a rough hay field, broke a gear leg, and bruised his ego.

80 year old carburetors without a mixture control? Perhaps a familiarization flight using a dipstick to accurately measure the fuel burn would be a good idea.

Good advice, but three points:

1. We are required by regulation to PLAN for at least 45 minutes of reserve fuel upon reaching our destination. Headwinds can and often do foil planning, which is why I ALWAYS plan at least one hours fuel at destination.

2. Every legal J-3 with a nose tank has that little wire fuel guage sticking up (or not) right in front of the pilot. Did your friend not note it’s position prior to silence?

3. And perhaps most important: Only a fool makes hard and fast plans on things like fuel burn based on internet info…..even that (or perhaps especially that) offered by me.

Duh.

MTV

mtv wrote:

2. Every legal J-3 with a nose tank has that little wire fuel guage sticking up (or not) right in front of the pilot. Did your friend not note it’s position prior to silence?

MTV

Yes, and he said it was stuck in the "more fuel remaining" position. He surmised that the wind pinned it not allowing it to float freely. I dunno.