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

https://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.

[Ol' Ron]

I'd go with a stroker assy, 294ci, alittle compression and definitely EFI. This should produce some decent Torque ar 2500. Our first airplane was a 1947 Commonwealth with 85 hp and the ROC indicator was calibrated in furlongs=gs per fortnight, but it was allot of fun to fly..
PS maybe an L-100 cam, naw!!

[G.M.]

What about the aluminum engines someone was making, that would be the answer. Maybe the radiator in the rear tube?? G.M.

[Dave D]

Here is a Flathead V8 aircraft for you, for the life of me I just can't remember the name of the darn thing!

https://www.youtube.com/watch?v=fPxBZT5wouU

[Dave D]

Another http://www.dmairfield.org/airplanes/NC16470/index.html

[Dave D]

The Arrow Model F or the Arrow Sport V-8 was a two-seat low-wing braced monoplane aircraft built in the United States between 1934 and 1938. It was built originally to a request by the US Bureau of Air Commerce to investigate the feasibility of using automobile engines to power aircraft. Accordingly, the Model F was fitted with a modified Ford V8 engine. Like the Arrow Sport before it, the Model F seated its pilot and passenger side-by-side in an open cockpit and was marketed for $1500.[1]
A preserved example is on display at San Francisco International Airport.
Development

The Arrow Sport F was specifically built to accommodate the low-cost, yet heavy Arrow F V-8 engine, an aircraft modification of the Ford V-8. The engine was designed by Ford Engineer David E. Anderson with an aluminum oil pan, aluminum cylnders, and a 2:1 gear reduction to drive the prop at reasonable rpm ranges. The engine weighed 402 lbs for 85 hp vrs 182 lbs for an equivalent Continental aircraft engine.[2]

[Dave D]

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OK, last one!

http://www.homebuiltairplanes.com/fo...-f-300x297.jpg

[HarveyH]

Fordors,
So it looks like the V8 is about 150lbs heavier than the Model A engine. That's not too bad. And with some careful parts substitutions (heads, etc like you mentioned) that weight could be brought to within 100lbs of the Model A engine. (After subtracting the tranny from the equation, of course.) Therefore, the extra 100lbs won't be a killer to the idea but there's still lots of other parameters to check before this project gets the green light.

Bad Daddy,
Many thanks for that list! It will help a lot.

Everyone else,
Thanks for the pictures and articles of aircraft that used the Ford V8. There were quite a few designs and I wonder what kept them from being more plentiful? WWII maybe?

Harvey

[B-nut]

Everyone disses the 60 hp v8 of 1937-40 but with their 1/2 inch thick cylinder walls they can bored out a great deal. With proper speed equipment their horsepower can be more than doubled.Read the book on them.Now watch for the disagreements.

[Tom Morookian]

Originally Posted by Dave D

Here is a Flathead V8 aircraft for you, for the life of me I just can't remember the name of the darn thing!

https://www.youtube.com/watch?v=fPxBZT5wouU

HUH? Maybe a marine version because it counter rotational??????

Special propeller?

[51 MERC-CT]

Originally Posted by Tom Morookian

HUH? Maybe a marine version because it counter rotational??????

Special propeller?

It's counter rotational because of the gear reduction mounted to the bell housing. (not marine)

[ThomasN]

The structure would not be strong enough. Just take a look at the wood spars and spindley ribs. The landing gear with those spokes do not look beafy enough to support that much weight either. I have been watching a homebuilder build his and it just dont look safe to me even with a 65 hp cont that is 170lbs.
I highly recommend a different choice! You will have a very hard time passing the inspections with such a mod from the original FAA approved design, home built or not.

[TonyM]

Let's see a photo of the Stearman.

[HarveyH]

ThomasN,

Thanks for your input. The one plane that Mr Pietenpol built with a V8 was built specifically with the extra weight of the V8 engine in mind. Even the wing chord was increased from 5ft to 6ft to provide increased lift. It would be logical to assume that the landing gear and its fuselage attachment points were beefed up as well.

By the way, the FAA doesn't approve or disapprove homebuilt designs. It is up to each builder to determine that his or her aircraft is flyable upon completion. In addition, the "inspections" are to ensure compliance with approved aircraft construction techniques (i.e. using bolts to mount an engine instead of duct tape) and to make sure that the aircraft continues to be in an airworthy condition (i.e. the wood spars aren't starting to rot). Otherwise, the FAA doesn't determine whether a particular homebuilt design is a good or bad one. The FAA leaves that decision up to the person who intends to fly it. (The person who's betting his life on the design.) However, aviation insurance companies also have a major say in what flies and what doesn't (i.e. what they're willing to insure, and what they won't).

Before somebody posts that the FAA should be more responsible in ensuring that all homebuilt designs are safe, notice that the current policy is similar to how your hot rods are "approved" or "disapproved" for operation on public streets. The DMV doesn't determine whether your car is drivable or not. All it cares about is whether it will fit in amongst the other traffic (i.e. doesn't have its headlights 18ft above ground), incorporates some mandatory safety standards (seat belts, safety glass, etc) and that you used sound construction techniques (again, no duct tape). And much like aviation, the ultimate decision on whether your hot rod ever leaves your driveway may rest on your ability to get insurance for it.

Harvey

[DICK SPADARO]

You may be in luck with the new aluminum version flathead engine. This would cure the nose weight problem. Last word that i heard was there is an ok given 10 aluminum engines to be built. This wont be a cheap item but then again planes are cheap either so its a toss up. Having ridden in the test mule engine powered car i can say that this engine does perform and run very smoothly. You should contact mark kirby for more information

[HarveyH]

Originally Posted by DICK SPADARO

You may be in luck with the new aluminum version flathead engine. This wont be a cheap item but then again planes aren't cheap either so its a toss up.

The good thing about our consumer-driven economy is that successful products get sold, and the more sold usually means prices come down.

Harvey

[HarveyH]

Originally Posted by TonyM

Let's see a photo of the Stearman.

Here ya go Tony. It's getting close to flying.

Harvey

[V8COOPMAN]

Originally Posted by TonyM

Let's see a photo of the Stearman.

Originally Posted by HarveyH

Here ya go Tony. It's getting close to flying.

Harvey

Harvey...Interestingly, the OKC "paperwork" on that thing shows it had a 1340 on it back in a previous, "working" day?!?! Musta been a beast! DD

Engine ManufacturerP&W ClassificationRestrictedEngine ModelR1340 SERIES CategoryAgriculture and Pest Control</SPAN> A/W Date03/15/1956Engine ManufacturerP&W ClassificationRestrictedEngine ModelR1340 SERIES CategoryAgriculture and Pest Control</SPAN> A/W Date03/15/1956

Engine ManufacturerP&W ClassificationRestrictedEngine ModelR1340 SERIES CategoryAgriculture and Pest Control</SPAN> A/W Date03/15/1956

[rotorwrench]

Yor credentials give you a leg up on the building of established kit designs like the Pietenpol. If you have an engineering degree in aeronautical sciences then you can design your own. With all this knowledge you are also likely to know that automobile engines are not good designs for turning a propeller in their OEM state. No one to my knowledge has ventured into the reengineering of an engine that has limited horse power and high weight to HP already built in. This challenge might be do-able but it also might be more trouble and expense than it's worth. The Pietenpol was never know to be a fantastic performer but it does fly. An aluminum case engine with a heavy journal bearing for the prop would have made it fly better but it was a design that could be built by the home DIY guy in his spare time with much of the raw material being locally accessible. Materials for a prop reduction gearbox are a whole different matter. A guy would need a sizeable radiator too plus all the plumbing for an adaquate cooling system.

[HarveyH]

Originally Posted by V8COOPMAN

Harvey...Interestingly, the OKC "paperwork" on that thing shows it had a 1340 on it back in a previous, "working" day?!?! Musta been a beast! DD

Hi Dave,

Yes, she was a crop duster after the war and was fitted with a 600hp P&W (firewall forward off a T-6). I got the airplane without an engine and prop so the choice of power was up to me. Since I already had Jacobs experience, tools, and spare parts due to my LC-126 (C195), I opted to install an R755 and Ham-Std C/S prop (FWF duplicate of the LC/195). The 275hp Jake is a nice improvement over the original 225hp Continental but without the vulgar fuel burn of the popular P&W 450hp installation.

If you're a retired FAA Systems Engineer from the Houston area, we might know some common people.

Harvey

[HarveyH]

Originally Posted by rotorwrench

...you are also likely to know that automobile engines are not good designs for turning a propeller in their OEM state. No one to my knowledge has ventured into the reengineering of an engine that has limited horse power and high weight to HP already built in. This challenge might be do-able but it also might be more trouble and expense than it's worth...

Wrench,

You are very correct in that there are waaaaaay better engine choices for an aircraft than a converted 80 year old truck motor. However, you've overlooked the primary driving force behind the homebuilt aircraft movement: We build what we want, not necessarily what's best.

Not much different than the Hot Rodder's mantra, doncha think?

Harvey

[HarveyH]

Here are the poll results as of Monday morning...

Of the 40 total pollers, half thought my idea might just work. I appreciate your optimism.

Another 14 thought that I'm crazy and 7 thought my idea is dumb. There is a distinct possibility that these guys are right but in my mind, the DUMBEST thing for me to do would be to launch into such a project WITHOUT asking other's opinions.

It's nice to note that not a single person (so far) said that my idea can't be done. While there is also the possibility that this will turn out to be the correct answer after all is said and done, it's nice to know that there are no know-it-alls forcing their opinion on us (unlike most other internet forums!)

However, the 2 who chose "no comment" are probably the smartest of the lot.

Thanks for all of your inputs so far. Keep 'em coming!

Harvey

[rotorwrench]

My credetials don't overlap the airplane world as much since I'm mostly involved with the rotorcraft section of the aerospace pie. In my many years of experience I have had the horible task of spooning up remains from ill faited attempts in the experimental aviation world. I guess this is part of what makes it exciting for some but for me not so much. The last two were enough for me. It can be exhilarating enough to fly in type certificated aircraft with genuine aircraft engines.

[Jim Brierley]

The Model B engine was rated at 50 HP, but I suspect its torque curve was better suited for aircraft than the V8 would be?

[JM 35 Sedan]

Try to get one of Mark Kirby's (@ Shadow Rods) aluminum block FH engines. Probably one of the best HP to weight ratio FH engines you could find. The question might be does he actually have one he would sell?.

[Carbroke]

Most of the V-8 conversions for V-8 in in the Experimental world use a RPM reducer (most seem to use a planetary unit) with a viscous drive between crank and planetary to achieve proper prop speed at the engine RPM which yields the proper HP and torque to achieve the overall power needed. The ford made 85 HP at high rpm. You will need to cam the engine to lower that.

There are gear reduction axial units made by others that you should look into purchasing, unless you want to completely re-invent the V-8-in-an-airplane scenario. There are also units using cogged belts as well.

They also use as much aluminum accessories, heads, etc in attempts to lighten the power plant.

I would guess the Pietenpol , being rag and tube, would require significant rear off-setting weight to get a balance point within limits. This is going to put more stress on the tail end when landing and in rough field strips. Also, more stress on the front wheels due to engine weight.

I know you are wanting to do something different from what others have done; that's the whole idea of the experimental world. But by virtue of placing that big block of weight into that plane, just be aware that you are introducing the need for modifications elsewhere in the frame of the airplane.

That all said, I'd look into the later flatheads (24 stud versions) for two reasons. They are better manufactured, and there is way more speed parts available for them which will allow you to get a much better HP/Weight factor out of the deal.
you will still likely need to do a reduction gear of some type to keep the blade tips from going supersonic at the engine RPM that delivers proper power.

[HarveyH]

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Originally Posted by Jim Brierley

The Model B engine was rated at 50 HP, but I suspect its torque curve was better suited for aircraft than the V8 would be?

Thanks, Jim, for your input. I value your opinion as I know you to be a respected leader on the subject of Ford 4-bangers! (Not to discredit any of the others who've contributed to this thread.)

Harvey

[Carbroke]

Sorry, forgot to add this to my other post.

An airplane application has another aspect those who don't fly don't often think of and that is the fact that when you are tooling along on the road trip in a car, if the engine quits, you just pull over to the curb and check it out.

I'd look at dual ignition system made of a magneto and a normal ignition system (like the old Republic Seabees had for instance) and I'd use a modern hall effect system rather than the Ford breaker points style.

And I'd also look at your oiling system as applicable to use in flight where roll and climb is more than what is experienced in a car application.

A lot of folks aren't aware that generally a water cooled engine is lighter than an air cooled version, and shock cooling is a real engine killer which is avoided in a water cooled unit. So it has it's merits OK.

[HarveyH]

Originally Posted by Carbroke

Most of the V-8 conversions for V-8 in in the Experimental world use a RPM reducer... you will still likely need to do a reduction gear of some type to keep the blade tips from going supersonic at the engine RPM that delivers proper power.

Yeah, there is a possibility that a PRU (prop reduction unit) may end up being the only way to make the high-revving V8 work but to be honest with you, such a requirement would kill this project. A PRU would add more weight forward of the firewall where it's not wanted and PRUs generally have failure rates higher than their engines.

I DO appreciate the points that you brought up in your subsequent post. I already plan to go with the dual ignition option regardless whether I install a V8 or the as-designed Model A engine. The oiling system of either engine would also have to be altered for the reasons that you pointed out as well.

Thanks for your insights!

Harvey

[El Rat]

I just don't get it? Sorry! The flatties made / make great harbor motors for sail boats and great power any sort of roadster ever built. It's sacrilege to put a SBC in a roadster but semi reasonable. However, a flattie in an airplane is just "plane" stupid. Obviously it can be done but what's the point?
A very good friend of mine made a great gear reduction device for automotive engines in airplanes. He may still have a website.His name was Buddy Warren, you may have known him...
He died when his SBC powered homebuilt crashed on the way to an airshow. g

[HarveyH]

Originally Posted by El Rat

I just don't get it? Sorry! Obviously it can be done but what's the point? g

El Rat, point taken.

Guys, let me be perfectly clear here in that I've never considered the early Ford V8 to be the ideal motor for an airplane. Same for the Model T and A engines that the Pietenpol and a few others were designed around. The Pietenpol is not an airplane to load up the family and fly cross-country for Thanksgiving dinner at Grandma's. It is a very-limited puddle jumper with an enormous vintage appeal due, almost entirely, to its archaic engine installation.

I am NOT considering this plane as viable transportation, an aerobat, and definitely not cutting edge design. This plane will have one distinct purpose: To get attention at the gas pump.

Now, what old car nut cannot understand THAT concept???

Harvey

[Ol' Ron]

A word of caution here. The 239 ci 100 hp engine actually only produces about 80 hP. John Lawson wrote a book called "Flathead facts" This is an engineering white paper on the mdifications done to this engine and the testing of every modification. Aircraft engines produce approximately .5 hp per cubic inch our Cessna 182 had a 470 ci engine rated at 230 hp. very few flatheads will make that kind of power, so the weight factor is not the only problem. I do think a 150 p Flathead can be built with a reasonable amount of reliability under 450 lbs. I have a 294 coming into the shop in a few days and I'll weight it.

[Bob G/Spanaway]

I can understand that concept perfectly!

[El Rat]

Now, what old car nut cannot understand THAT concept???
Ok I guess I kinda get it. It's just that if you said you were going to put it in upside down and backwards, mount it in the middle and run the prop with a chromoly driveshaft between your legs I would say, WOW far out that will really be kwel! Enough said, be safe. I for one would like an update as this progresses. g

[HarveyH]

Originally Posted by El Rat

Now, what old car nut cannot understand THAT concept???
Ok I guess I kinda get it. g

You had everyone worried there for a minute!

Harvey