I'm considering powering a homebuilt airplane with a Ford V-8 Flathead

[HarveyH]

Hi Guys,

I know that the Ford Barn is focused primarily on stock restorations but my questions pertain to stock engines, with a slight departure in the chassis that I want to mount one in. Before y'all tell me that there are other websites devoted to homebuilt airplanes, please know that I've tried them all with the only responses being blank stares. Jim Brierley suggested that I go right to the den of Flathead Ford V-8 experts so here I am.

The airplane is a Pietenpol, which as you probably already know, was designed in the early 1930s to use a converted Model A 4-banger. The plane was and is successful and about 50 are currently flying with that engine. However, when Ford introduced its little V-8, Bernard Pietenpol immediately tried one in one of his planes. (This was about 1934.) Bernie was disappointed in the experiment and gave up on the idea. He considered the engine two heavy for what little extra horsepower it developed.

So now, I figure that after nearly 80 years of gearheads doing everything imaginable with Henry's flathead 8, the time is right to try it again. But there are a few things that I need to know before getting too deep in this: Just what are the weight comparisons between the early V-8s and the Model A engine? Also, I need to know the diameter of the crank journals so I can determine if the crank is capable of swinging a prop without breaking. (As a point of reference, the stock Model A engine will swing a 73" prop at 22-2600 RPMs which is a good speed for a prop. Anything over 3000 is too fast for a prop. Also, the heavier Model B crank is better for swinging a prop than the Model A engine.)

Your opinions, suggestions, and ideas are solicited. (I hope I don't end up regretting saying that! )

Can you imagine the sight and sound of a V-8 flattie-powered airplane?

Harvey

[TonyM]

It'll take all 85 horses to get that block into the air.

[V8COOPMAN]

I like what you're considering. Certainly you've run-across info on the early ARROW SPORT V8. Check the link below for a few more details. The engine was a Ford V8, but was alloy, and most-likely used some of the 10 elusive, aluminum blocks built by Ford for the project. The propeller was driven by a gear-reduction box. See the link below.

http://en.wikipedia.org/wiki/Arrow_Model_F

Also, see the link below for a couple of pictures currently displayed in another thread currently "playing" on the FordBarn. Interesting project! Filter thru the incidental stuff to get to the good stuff.

Any guy with a 195 (L126) and a Stearman must know his way around novel, old flying machines. DD

http://www.fordbarn.com/forum/showthread.php?t=117982

[4dFord/SC]

I remember my father telling about his one experience flying a flathead powered a/c around 1941. He was then in training at the Boeing School of Aeronautics (operated by United Airlines) in Oakland, CA. In order to build hours, he would hang around the Oakland airport looking for hops. One day, a man who had just purchased a Ford-powered plane, but didn't know how to fly it, asked Dad to take him up. They took off across the Bay and skimmed the wave tops headed for San Francisco. Dad said it was so underpowered he wasn't sure they would ever gain enough altitude to clear the the buildings on the SF side. He finally got high enough to turn around and head back to Oakland to land. Once was enough for him. He went on to fly for United and then Northwest before retiring in 1974. He never had an accident and liked to say he didn't take those trips.

[19Fordy]

Remember, Henry already tried this using his aluminum block flatty.

[VeryTangled]

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I love the thought, and pro'ly the sound, right up until...

Hi Everyone.

The power to weight ratio doesn't seem right to me, you can get a lot of power, over 200 hp likely, but the weight to do it.?.

I'm thinking Aluminum block? Or is that Unobtainum block?

-VT/JeffH

PS 19Fordy, simultaneous post, no comment re: your aluminum block idea. Great Minds Think Alike!

[ford38v8]

Harvey, I would think that to be a worthy project for discussion on this forum! By the way, I voted crazy and might just work! It took both my selections.

The picture here is of an engine recently posted here. It has a gear reduction on its bell, but if your prop has its limits, I'd think a governor would be needed to prevent over-reving the prop. The engine shown is peculiar, not having exhaust manifolds, and hard to see the water oulet on the head, but it is clear that this is a very early V8, having 21 studs and the bumps on the pan rail.

The first V8 was advertised at 65 horsepower, but it wasn't widely known that the model B engine had slightly highter horsepower than the V8. The 1934 V8 jumped up the horses to an advertised 85, which was better than the B engine. Later V8s ranged up to an advertised 125 horsepower, but wouldn't be correct for your application unless you don't mind that these engines weren't available in the early thirties.

Id think that a truck engine would be preferable, or an industrial engine. A truck engine would have a cam to deliver low end torque and high revving, and an industrial engine would deliver optimum power at a constant RPM.

Good luck in your endeavor, and please keep us posted, especially with pictures! (hint-hint)

[V8COOPMAN]

Link below to a little more info on the Sport hanging in a terminal building at SFO, with reference to the V8, and pic of radiator. DD

http://travelforaircraft.wordpress.c...minal-3-write/

[Pete]

Yes, it should work. It's been done before but not with adequate horsepower.
A flathead can be made aircraft reliable at a conservative 140 hp. If you go with fuel injection and dry sump oiling, it can be aerobatics capable although I don't think a Pietenpol would certify for that without a whole lot of modification.
You don't build an aircraft engine with stock or even new old stock parts though.
A steel billet crank will be more than adequate to swing any prop needed.

[HarveyH]

Thanks, Guys, for the positive comments! You've given me some info to start with. Note that I haven't actually started buying parts yet; I'm still trying to determine the feasibility of the idea.

I forgot to mention in my first post that I'm not interested in any propeller reduction unit as they (1) look awkward and (2) are an additional failure point.

Alan, I may end up hanging the picture that you sent in my office for motivation. That thing just looks cool!

Keep the info, suggestions & comments coming!


Harvey

[HarveyH]

Originally Posted by V8COOPMAN

Any guy with a 195 (L126) and a Stearman must know his way around novel, old flying machines. DD

DD,

I read your bio. PM me if you want to talk about "old round-motored, tail-draggin' airplanes".

Harvey
A&P-IA

[Dave D]

Back when they built the Pietenpol you could put that airplane down just about anywhere when it failed. In order to accommodate all the extra weight of the V8 you'd have to extend the fuselage another three feet...adding even more weight.

If you must have a Pietenpol stick with what worked (barely) back then.

[HarveyH]

Just how much weight are we talking?

Harvey

[Jack E/NJ]

HarveyH>>>Just how much weight are we talking?>>>

Fully loaded ready to run? Not much. Less than a half-ton. 8^)

Jack E/NJ

[Shadetree]

The plane may not fly well, but it sure will sound great!

[gmc1941]

The biggest problem is the center of gravity. The front will be overloaded. Check with the old Pietenpol info fro EEA. Pietenpol had to move the wings back several times to get up and flying. Good Luck

[HarveyH]

Thanks, guys, for your well-intended cautions on CG but I'm a commercial pilot and an A&P-IA. I also have a college degree in aviation. I understand aircraft balance. A V8-powered Piet may end up much like the WWI fighters that had very short noses and long tails because their engines were heavy too.

The sole v8-powered version that Bernie built DID fly successfully. However, Bernie considered the experiment unsatisfactory because the engine didn't deliver the improved performance that he was hoping for.

I'm still looking for an estimated weight of the flathead V8s so I can see just exactly what I'm faced with.

Harvey

[Fordors]

I looked around and a flathead seems to be about 550#, early quoted at 525 and late at 565. Aluminum heads and intake would certainly help bring that down. Model A four is quoted as 475#, but that is with transmission.

[Bad Daddy]

Originally Posted by HarveyH

I'm still looking for an estimated weight of the flathead V8s so I can see just exactly what I'm faced with.

Harvey

Here's a link with some helpful info on engine weights. . .

http://www.35pickup.com/mulligan/weight.txt

[BillM]

when I was stationed at Moffet Field around 1964 there was a plane I was told was home built that had a Ford flathead V8 in it. Owned by one of the officers. Never saw it fly.