The rise of FrankenEngine - An engine for the VP-21

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Hot Wings

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Okay, those are two good reasons. You've answered my question, which was meant only to help focus on the "why." Thank you.
And I often need 'focus' !
Hang around, if this develops, if for nothing else but keeping us focused.

Just to ask: Why the opposed twin rather than opposed 4? Simplicity, weight vs smoothness, TV?
When I first came up the the idea that I could 'roll' my own' I looked at 4 cylinders. I found that there just weren't many examples of small displacement 4 cylinders on which to build. I was also constrained by this engine having to be usable on the Quickie.....My personal goal.

The half-VW is close to the weight, some work could be done to shave off that 5 pounds without too much aggravation, but you'd be making a new case casting, oil pan, rear case, etc. just like Pete did with his project.
My original CAD shows this very lineage - except I tossed the constraints imposed by that $#@!%^@ camshaft configuration from the start. My project and Pete's were very similar in approach and philosophy. He started with the O-200 and I with the VW.................. and generic OTS parts for the reasons TFF mentioned.

You could keep everything else on the VW - case, crank, rods, pistons, cylinders, valve train,
That feature HAS to be eliminated. It causes all kinds of problems. Some are:
It puts side load on the rocker arms making them prone to pop off the shaft.
It restricts exhaust port configuration.
It puts side load on the lifters leading to increased bore wear.
It's too close to the crank requiring grinding to clear stroker cranks.
Oil for flat tappet cams is not readily available at Walmart.

I'm convinced that Ferdinand chose this configuration for ground clearance reasons only.
 

WonderousMountain

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As much as I do not care for Ford's engineering style,
They have winner with Modular 3 valve series heads.
A couple bevel drives, cross timed waste spark plugs.
Dual port injection. 100mm Bore, 2.5 in gives 997cc.

The short stroke will help on weight, but you will need
aluminum or magnesium case, and to be serious with
weight shavings. Think thin, or missing components.

How it might look.
R (1).jpeg
 
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Topaz

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You can weld additional cooling fin area on aluminum heads, y'know. T'aint rocket science. Another 40-50 square inches of total fin area near the exhaust port might solve the entire VW CHT issue. ...
Emphasis mine.

And I often need 'focus' !
Hang around, if this develops, if for nothing else but keeping us focused.
Oh, I'm great at kibitzing other people's projects. It's a gift. ;)

That feature HAS to be eliminated. It causes all kinds of problems. Some are:
It puts side load on the rocker arms making them prone to pop off the shaft.
It restricts exhaust port configuration.
It puts side load on the lifters leading to increased bore wear.
It's too close to the crank requiring grinding to clear stroker cranks.
Oil for flat tappet cams is not readily available at Walmart.

I'm convinced that Ferdinand chose this configuration for ground clearance reasons only.
Entirely possible. So now you have a "real" challenge. New heads and new valve-gear. Let's see how far down this rabbit-hole goes. ;)

And, with respect to the deceased, that was where Pete ran into some issues with the O-100: One change led to another, which led to another, which... At one point, the O-100 was basically a new engine using O-200 cylinders and valve gear. I'm exaggerating a little, but not a lot. He backed off on that a little and brought more "stock" O-200 parts back in, because "perfect is the enemy of good enough." Pete and I talked about that a couple of times. I'm not at all taking credit for that retrenching - Pete came to those conclusions on his own - but it's a good example of how it's very easy to start with "We'll use OTS items for almost everything," and end up with an almost completely custom-designed thing. Resisting that process takes iron-bound discipline.

Caveat emptor.
 

Hot Wings

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I'm exaggerating but not a lot.<< >>and brought more "stock" O-200 parts back in, because "perfect is the enemy of good enough."
BTDT. And you aren't exaggerating a bit. I'd already been down that path before I heard of the O-100 and saw a lot of the same development progress. It's just like someone thinking "I'll just add a couple of rib bay to the span. It can't be that hard". It's a rabbit hole with snakes, spiders and carnivorous Tribbles.
I've got work to do today so I'm leaving this for the rest of you to ......... develop.
 

Pops

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Picture of the little 1200 cc, 40 hp engine that I used on the SSSC for the first 32 hours. With a Culver 54"x 24" prop it was turning 3600 rpm on climb out and I cruised it at 3200 rpm. ROC with my 230 lbs was about 450 fpm. Great little engine and very smooth. If I was 160 lbs and had the oversize pistons and cylinders for 1300 cc and the extra 5 hp I would have kept it on. Then I built the 1835 cc , 60 HP engine and installed it.
 

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Geraldc

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I thought I saw somewhere that Jabiru trialed a 2 cylinder 1100cc 40hp motor.
Maybe make one with a pair of gen 4 cylinders.
 

Brünner

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Now that would be a worthwhile project - to design new heads for VW's that help solve the heat problems once and for all. Even if you just removed the max-rated/continuous power limitation it'd be a huge step forward. You could keep everything else on the VW - case, crank, rods, pistons, cylinders, valve train, and just focus on the heads themselves.

It's a worthwhile project, but not really the one HotWings is looking to do, which is also worthwhile.

Sorry for the topic diversion.
Now isn't that what a certain company called Rotax did? Sort of....
 

Hot Wings

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Hot Wings - Why the specification call-out for an opposed 'boxer' configuration?
Caveman machine tools and jigs. Think being able to machine the castings with little more than a lathe and a drill press.
I realize they may not be the most aerodynamic configuration.
If you can make a good case for an inline/v-twin/radial we can always take another fork in the road.
Tea is drunk - back to work.
 

Goflybefree

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The past 40 years are a chronical of failed small 4 stroke engine projects:

Global 7892 (2 Cyl, 32 hp, 76 lb) - based on VW parts with new case etc but claimed to be about 10 lb lighter. Hundreds made.
Mosler MMCB (2 Cyl, 38 hp, 85 lb) - further development of the global engine (more than 1000 made)
Hapi Hornet (2 Cyl, 35 hp, 74lb) - small number made. Basically a better 1/2 VW using the Scat individual heads
Aeromotion Twin (2 Cyl, 52 hp, 100 lb)
Emdair Weslake W40/50-73-02 (2 Cyl, 50 hp, 85 lb)
Emdair Weslake W44/60-77-02 (2 Cyl, 60 hp, 85 lb) saw limited production (I have seen one)
Technopower II Twin (2 Cyl, 50 hp, 77 lb)
KFM 105 (2 Cyl, 40.5 hp, 88.1 lb)
KFM 112 (4 Cyl, 50hp, 99 lb) - limited production - this is the engine that the Jabiru was inspired by when KFM stopped production
Jabiru 1100 (2 Cyl, 40 hp, 88 lb) - only prototype made
Lotus Magnum 2.25 (Eipper) (2 Cyl, 25 hp, 31 lb) - prototypes only - the project died with Colin Chapman
Lotus Magnum 4.50 (Eipper) (4 Cyl, 50 hp, 56 lb) - prototypes only - the project died with Colin Chapman
Pong Dragon 35-1.4 (6 cylinder, 2 row radial, 35 hp, 46 lb) - prototypes only
Rebel Twin 2-45 (2 Cyl, 50 hp, ??lb) - prototypes only
HKS-700E (2 Cyl, 60 hp (55 cont), 121 lb) - 1000+ produced.
PAL-95 (2 Cyl, 65hp, 137 lb) - small number produced
and I am sure there are more ....

Also remember the conversions of 2 cylinder DAF and Citroen auto engines ....

The Franklin 2A-45 etc is probably the most recent certified production engine in this class. A few might still exist if they haven't shaken themselves to death !

Every single one of those projects failed. Some of them had significant resources behind them (Lotus, HKS, Jabiru). I would start by asking why they failed and what is it about a new project that will succeed where all these previous projects failed. A better 1/2 VW has already been done (Global --> Mosler + Hapi Hornet) so why reinvent that ? Someone was selling the manufacturing drawings for the Mosler engine recently.

Why did all these projects fail ? Failure to read and understand the market ? Did the cost of manufacture not meet what the market was willing to pay for a 40-50 hp engine ? Vibration ? Under resourced ? (clearly not in some cases). Bad layout - not suitable for installation in an aircraft ? Reliability ? Market resistance to new engines ?

Also designing and producing a new engine is not easy. Jabiru and Rotec have had significant issues and Jabiru has produced something like 6000+ engines (hopefully the Gen 4 engine has fixed the issues).

The most successful conversion of an industrial engine for aircraft use is one that no one has mentioned. This is the Bailey V5 paramotor engine. 20.5 hp, 35 lb including re drive. This is a very extensive modification of an industrial engine with new case etc.
 
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blane.c

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I believe what you are asking for is a four stroke engine of approximately 1/2hp per pound for 80Lb maximum with max rpm of 3600? But what does it include? Exhaust, carburetor with anti icing or fuel injection, magneto(s) or electronic ignition or both, starter motor or hand prop, does it include motor mount does it include a generator or alternator? It is ambiguous without more detail. You cannot ask for other ideas that make actual sense without a more complete picture of the requirements. Apples to apples not apples to oranges.
Maybe a firewall forward (or rearward) overall weight including propeller might be more useful and then individual differences like hand propping vs starter motor can be judged in comparison with other features you like or dislike to end up with the monster you like the best?
 
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Hot Wings

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and I am sure there are more ....
Was the Weslake mentioned the same as the Hexadyne P60?
Had forgotten about the Pong. That was a while ago............
Not sure you can call a 1000+ production run a fail in the aviation market? The fact that they are no longer around is significant.
 

Tiger Tim

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Not sure you can call a 1000+ production run a fail in the aviation market? The fact that they are no longer around is significant.
This is Aviation, where dinosaurs still walk the earth. For all practical purposes extinction is failure.
 

Victor Bravo

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If you can make a good case for an inline/v-twin/radial we can always take another fork in the road.
Yes possibly, but it would de-rail the concept of this particular thread.

At the risk of doing that to one degree or another from a different direction, perhaps the question should be what exactly can and should be done to the half-VW to create a better 80 pound 40HP HBA engine? Your list of issues with the VW above is most of it, so the question then becomes can you make or modify new components to create the "Hot Wings' Half", a half-VW that does significantly better than the Casler?

Another entry to the long list goflybefree posted is the Verner 3V cylinder radial, which apparently works very well, using VW components.
 

Goflybefree

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Another entry to the long list goflybefree posted is the Verner 3V cylinder radial, which apparently works very well, using VW components.
Verner also made the VM-133 2 cylinder horizontally opposed engine but that was 81 hp (TO) 72 hp (Cont) and about 132 lb. Note sure if this one is still in production. A nice engine if it were a bit smaller.

Verner VM-133 (1).jpgVerner VM-133 (2).jpg
 

Goflybefree

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.... and if we think this is a modern problem, the search for a 2 cylinder 30-40 hp engine goes all the way back to 1926 (and probably beyond) ... Bristol Cherub. 36 hp, 95 lb.

Bristol Cherub 1 - Flight 1926 - 0019.jpg
 
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