Milling a VW engine case, etc.

[n3480h]

One of the members here asked if I could post some pics of machine ops on my VW engine build. Don't have a lot of pics, but you'll get a glimpse of the madness. Decking the case with a flycutter I made on the mini lathe and mini mill. The case is about as large a piece as the little mill will hold. Decking the case is done to precisely match cylinder capacity and to ensure cylinder squareness to the crank on all four jugs, and to make certain all four cylinders will have identical capacity. The case is a magnesium alloy, so great care must be taken to avoid burning the house down. The engine has a custom 86mm stroker crank, 92mm jugs, ARP rods, and dual ignition, among other custom parts. Projected HP is ~100 @ 3800rpm. It is built for torque, and will power the airframe I've built over the last 5 years.

 

[Hybridyne]

That is great !!! Can you give us a brief description on how you indicated the block "in"

 

[n3480h]

Don't know how brief, lol. Measurements were taken when the engine was "preassembled" and the case torqued to specs. This was primarily a rotational check, to make sure there was nothing hitting. Then heads and cylinders were removed and the OEM spigots were measured from the center of the crank, and from the case split line on both sides. This indicated that the spigots were out of parallel (to crank centerline) a total of .004". The case split line was used as a known datum for milling. On the mill, the case was set on precision 1-2-3 blocks and clamped down. Reassembly for the final rotational check shows the parallelism and perpendicularity to be within .0015" total. Not perfect, but far better than stock. All this effort is to end up with balanced cylinder capacity. New h eads carry the large SS valves and have been CC'd to within .1CC, with all chambers at 60CC +/-.05CC. This work results in a VERY smooth engine which is not fighting itself, and greatly increased reliability. In an airframe that weighs ~580 pounds, this engine should produce a climb of 1200-1500 feet per minute. Not quite as fast as some of your builds.

 

[BirdFanatic]

Dont go flying over any air fields now lol or area 51 lol

 

[Poboy kartman]

Crap.....I'm gonna duck now....before I get hit by friendly fire or indiscriminate senseless shrapnel........

 

[n3480h]

Dont go flying over any air fields now lol or area 51 lol

Ah, aircraft are normally based at airfields. That's because that is where they keep the aviation fuel, the hangars, the runways, and the popcorn.

As a civilian pilot, only an idiot would fly over "Area 51". Your advice seems to indicate that you think either:
1. I am an idiot in need of your advice.
2. You feel you have much more knowledge of aeronautics, FARs (Federal Aviation Regulations - but I shouldn't have to spell that out for you, should I?), and the physics of building a very strong and efficient aircraft from plans.

Which is it?

And how's that hydrogen system coming along?

 

[Badot]

Just out of curiosity, how hard is it exactly to light up magnesium by machining it? Do you need to take it easy for the one in a million chance some freak incident happens, or will it reliably light up if you push it too hard?

And of course, you know you've gotta post an onboard flight video once you finish that plane.

 

[n3480h]

Just out of curiosity, how hard is it exactly to light up magnesium by machining it? Do you need to take it easy for the one in a million chance some freak incident happens, or will it reliably light up if you push it too hard?

And of course, you know you've gotta post an onboard flight video once you finish that plane.

It's not difficult to light it up at all Badot. Doesn't matter if you take it easy or push it, one spark is all it takes. I used an end mill to lower the height of the threaded steel inserts around each cylinder spigot before I started the flycut on the casting. Water or coolant will not prevent or extinguish a magnesium fire, nor will the normal fire extinguisher. Foam is said to work, and a small mountain of sand will work. Ironically, magnesium alloy VW cases used in aero conversions and many dragsters have a welded in web to strengthen an area on the back of the case. Mine has that. Not something I'd care to try to weld.

There will be video. Many of us are mounting Go Pro or Contour cameras on our experimental aircraft.

 

[firemanjim]

Magnesium is a B to put out.... Heavy foam works ok. In most car fires, even though magnesium is highly reactive to water, we flood the engine bay with 1000's and 1000's of water in just a few minutes. It has to be A LOT of water to put it out, or you'll just make things worse. Water will make a magnesium fire snap crackle and pop! It's highly reactive and will shoot sparks and flames, if enough water/foam isn't used. The foam actually suffocates the fire by covering it with a barrier to block out the oxygen the fire needs as fuel......

 

[Joe-405]

I had a 2332 which is 84x94 and it made 200+ on motor and 550+hp with a turbo so you should easily hit your 100hp goal. It was all in a unlimited street 1970 VW bug that was driven and not trailered usually.

 

[Poboy kartman]

I had a 2332 which is 84x94 and it made 200+ on motor and 550+hp with a turbo so you should easily hit your 100hp goal. It was all in a unlimited street 1970 VW bug that was driven and not trailered usually.

Yeah.....but you have to figure drag in ......and N3480h....is dragging his feet on this build......JK,,,,,

 

[n3480h]

Haha! Poboy is right, I am dragging my feet on this build. But, building an aircraft that will carry my carcass at 150mph . . . probably not a good idea to rush the build. A lot of research, learning . . . sometimes making a part 3 times to get it just right. No doubt, arrival at the destination will be a great thing, but for me . . . the journey is just as enjoyable.

Joe, a pilot friend in Wisconsin is turbocharging his VW in a single seat version of the plane. He races the aircraft. Before the turbo, he averaged 200mph. It will be interesting to see how fast he goes with the turbo. There is absolutely no room left inside his cowl.
http://www.youtube.com/watch?v=M0UiDIohV5s

 

[KevinN]

Sounds good. I'm sure building an exhaust system and turbo to fit in a Sonerai cowl was not a one day job.

 

[firemanjim]

Keep your eyes on the prop!! That's FAR out, man! I thought I was seeing s.....
That's a great video Tom! Thanks for the link!!

 

[jeepguy79]

Is that a soneraiII LS? I have a friend who has a moni with a rotax that is 103 compliant. (well almost... the speed thing is a nogo really) I have been looking for one for years

Cool plane you have a build thread of it somewhere? I looked up the n number in your username. is that you erco ercoupe? if so I like the paint scheme. nice

 

[n3480h]

Jeep, the aircraft in the video is a Sonerai 1. What I am building is a Sonerai IILS, sort of the "limo" 2 seat version.

N3480H is indeed an Ercoupe 415C/D. It was the first aircraft I owned, and I put ~500 hours on it, many memorable hours with my son in the right seat. It is a number I will never forget, therefore my username, lol. I see now it is pretty much derelict and it makes me sad. When I had it, we refurbished it to the point where you could shave by your reflection in the aluminum. I sold it to buy a basket case Cinquanta Hornet, which I rebuilt and flew (including a lot of aerobatics). Wish I had them both back, but life happened along the way.

 

[jeepguy79]

I meant the one in your photo up there in the first post. How many hours on the entire build?

The biplane is cool, but that erco is so sweet. I think you downgraded there (no disrescpect). I think sonerai's are really nice planes. Got any pics of the interior?

I have a rally IIb. I hope to get a real plane one day. I may try to find a piper cub in the meantime. do you have a private or LSA license?

 

[n3480h]

Jeep, I don't keep track of the time - or the $ spent. There's just some things I don't want to know. Another 2 years or less to go, but I do have everything but final paint bought.

I have held a Private license about 20 years, and have flown 30+ different types of aircraft. Nearly got my Instrument rating, but then my instructor died of cancer. The man had nearly 40,000 hours of flight time, and was awarded the Lindberg Award by the FAA. Since then, I've decided I prefer the freedom of VFR.

Rally II, nothing wrong with that. I've also got a Skylite ultralight in refurb right now. They can be a lot of fun.

Interior's not finished yet, but I do have a pic of the inside from the pilot's position. It has carbon fiber floors, instrument panel, seat pans, and the electrical panel.

 

[jeepguy79]

That's going to be a nice aircraft. You have the wings done?

On that video of the sonerai in the street you can really see the coning of the prop.

 

[n3480h]

Thanks Jeep. Wings are scheduled to be built this winter, along with final engine assembly. Wings require 2200 holes, all precision drilled, deburred, countersunk (dimpled, actually), then riveted. I have formed the ribs, the spars, and the full span ailerons. I have built the fixtures for wing assembly, and I have the aluminum skins on hand. I've also drilled the spar caps. All these parts will be etched and alodined before assembly to prevent corrosion.

The coning of the prop in the video is the result of the digital video camera's 25-30 frames per second VS a prop speed of 1,000 to 4,000 RPM (direct drive), so it is kind of a strobed effect. Fortunately, our brains (well, most of us), process the visual information much more quickly, so we see no coning in real life. Film video doesn't seem to have this problem to this degree, but wagon wheels still appear to turn backwards in the old westerns, lol.