Replica Plans 7/8 S.E.5a plans

My father is quite fond of the S.E.5/5a, and is looking for a new aircraft project. Has anyone had and experience with the Replica Plans 7/8 scale S.E.5a plan by "Gogi" Goguillot and Dan McGowan? I have read there are more than 150 replicas built with this plan, so I assume it is a good one, but would like to get some input from the builders and WW I buffs here.

[wolfenbill]

They're good plans Mike and the plane flys well. It does have a rather small cockpit so I hope your father is not a big man. I'm helping to build a full scale SE5a but it is for a flying museum/aerodrome and will take longer to build than the 7/8 scale a/c. Also the 7/8ths a/c can use a Continental engine while ours will have a Hisso, therefore your reliability factor will be very much higher. The 7/8ths a/c looks great in the air

Thanks for the info, wolfenbill!

My father is about 5'8" and 150lbs, so he'll probably fit fine, I hope I can squeeze in my 5'11" 190lbs body and take it up once in a while.

We are planning to use a non-certified engine so we can do the maintainence, we are looking at VW engines in the 105-120hp range, but there are several other non-certified options to explore.

[Brad]

A VW over about 65 hp is rated VERY optimistically. You have to turn some pretty serious RPM to get much more than that, and run a reduction drive.

Brad

A VW over about 65 hp is rated VERY optimistically. *You have to turn some pretty serious RPM to get much more than that, and run a reduction drive.

Brad

Have a look at this page, Brad. They have some interesting VW powerplants.

http://www.altimizer.com/specs.html

[Brad]

Have a look at this page, Brad. They have some interesting VW powerplants.

http://www.altimizer.com/specs.html

I've talked to VW guys (that do CAR motors) and they don't recommend going that large due to reliability issues. Note that those are near 2300cc displacement- a stock motor is 1600cc. Per the guys I have been talking to (that do cars, not aircraft) the largest they would consider due to issue with stud placement vs. bore for the cylinders is in the 1900 cc range for a reliable motor. For the larger bore sizes, the opening for the cylinder gets too close to the location of the studs, making the case prone to cracking around the studs and pulling out, even with "case savers" installed. Larger strokes run into clearance issues, having to modify (and thus weaken) the case for clearance on the crank throws and counterweights. I would be very cautious with this.

Brad

Thanks for the heads up Brad, I'll have to look carefully into the durability issue. I wonder though if durability is as much of a problem when you are doing a complete overhaul every 1000-1500 hours.

[monoqook]

There are a great many reasons why you DO NOT want to over work engines .If the VW could do the figures you quote, then trust me, it would have been done years ago. the original Se5a used a high torque engine with a big slow turning prop. A VW producing sufficient horsepower to drag even a 7/8 Se would be "toothpick thrashing" ie; a very small prop turning very,very fast.Much of your prop would be masked by the fuselage reducing effective thrust even more so.To give you an idea of the sort of plane designed to use a VW check out the volksplane or corby starlet. Add another draggy wing ,wires ,messy undercarriage ,and so forth then you soon get the picture as to how well your machine will perform. Have a look at books by Richard Finch for some good ideas of how to use car motors, you would be surprised at what can be done!
It would be an awful shame to write off your machine or blow a piston through the fuselage etc by using a powerplant that is not up to the challenge. The VW is not a racing engine .
As a point in case , at a nearby field a 7/8 nieuport 17 was built using a Subaru motor.Turning a small prop very fast,fairly low Hp,big cowl,lots of drag etc the first circuit was done in ground effect the WHOLE way around and the second ended upside down about 50m past rotation point. messy, expensive ,and a waste of 15 years.
Im not saying dont do it, if you want to go for it then Ok , BUT ,like my old man says
" a crappy engine is like the airspace above you, useless"
"the throttle can only go so far forward"
"your sphincter can only keep you in the air until its eaten the seat cushion"
28,000+ thousand hours of 747s boiled down to 3 sentances....

[StephenLawson]

Greetings all:

Here's the Lafayette Foundation's 7/8 (Tallini) Se5a in a walk around. previously own by the Ryder Foundation. It has a 185 hp Lycoming. *We can seem to rely on anything less than a 165 hp at our altitude in the Denver area. *We had another 7/8 Se 5a that couldn't do very well with a 145 hp. *The forced landing was pretty ugly but no injuries to the pilot.

http://us-aircraft.com/walk/se5a.htm

[StephenLawson]

The Tallini SE 5a.