Building a VW Aero-Engine

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Vigilant1

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Yes, someone could use two ignition systems and not use a mag.
Your dual ignition setup is going to be nice.
A dual ignition system with an electronic ignition (variable timing, for starting and regular ops, run off a battery) and simple B&S ”magnetrons" (fixed 28 deg BTDC) on the flywheel might be popular. Not as traditional as a magneto, but inexpensive and the whole setup would allow for hand propping (magnetrons "OFF"and) for continued flight with total failure of the electrical system.
Thanks again for the update.

Mark
 

Vigilant1

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Just to mention it: Golf carts with gasoline engines often use a belt driven starter/generator. I don't know if it would turn over a 60 HP VW, but it will start a 401cc single cylinder Kawasaki (13 HP).

These units are heavy (about 20 lbs), so not a good fit for Pops's present project (simple, light, hand-start). But if someone wanted to go a similar route but wanted a starter, maybe this would be appropriate.

Hat tip: Karmarepair mentioned these starter generators here, but didn't imply they'd work with VWs)
 
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Pops

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The VW is the easiest engine there is to hand prop. 95% of the time on the first blade.
 

Pops

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On the flywheel drive VW engine the thrust is opposite than normal. The end play of the crankshaft is set by 3 shims between the rear of the flywheel and a flange on the #1 main bearing. When the engine gets hot the crankshaft and the magnesium case expands at a different rate. Factory setting is a clearance of .003 to.006 ". The clearance is set by using 3 shims ( has to be 3 for a reason). The shims comes in various thicknesses of between .009 and .015". So you measure the end play and decide the thickness of 3 shims + the .003- .006 gap to make the total for the endplay.
Since the thrust on the flywheel drive engine is in the opposite direction the shims has to go between the crank and the thrust shoulder on the other side of the main #1 bearing. So you have to make new oil grooves on the thrust side of the main bearing as on the other side. Easy to do with a few strokes of a 1/4" fine file. Just make the 4 grooves the same as the other side.
On this engine the endplay is .005" This is what I always try to set the endplay on all of my VW engines.
Do this with the case half setting on its side with the case studs pointing up with the crankshaft installed. If its not a flywheel drive engine the endplay can be set after the engine is together and before installing the flywheel and real main seal.

Years ago, I built a 1/2 vw engine. I machined the crank and crank cam gear and install a #1 bearing with 3 shims on each side for the thrust bearing so it could be used as a pusher or tractor engine.
 
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Pops

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No, I aways relocate the dip stick to the rear of the engine when having the prop on the pulley end. The stock dip stick location in hard to get to under the nose bowl and engine baffling. I removed this rear dip stick and installed a blocking plate for the flywheel drive engine before I put the case together. Took the picture when I was dry fitting the clearance on the pulley clearance of the case before the case was closed.
Here is a picture of a blocking plate installed on another case. Yes, I know the block-off plate is a little thick, but being so little the extra weight is almost nothing and the aluminum was handy.
 

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Mike von S.

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On the flywheel drive VW engine the thrust is opposite than normal. The end play of the crankshaft is set by 3 shims between the rear of the flywheel and a flange on the #1 main bearing. When the engine gets hot the crankshaft and the magnesium case expands at a different rate. Factory setting is a clearance of .003 to.006 ". The clearance is set by using 3 shims ( has to be 3 for a reason). The shims comes in various thicknesses of between .009 and .015". So you measure the end play and decide the thickness of 3 shims + the .003- .006 gap to make the total for the endplay.
Since the thrust on the flywheel drive engine is in the opposite direction the shims has to go between the crank and the thrust shoulder on the other side of the main #1 bearing. So you have to make new oil grooves on the thrust side of the main bearing as on the other side. Easy to do with a few strokes of a 1/4" fine file. Just make the 4 grooves the same as the other side.
On this engine the endplay is .005" This is what I always try to set the endplay on all of my VW engines.
Do this with the case half setting on its side with the case studs pointing up with the crankshaft installed. If its not a flywheel drive engine the endplay can be set after the engine is together and before installing the flywheel and real main seal.

Years ago, I built a 1/2 vw engine. I machined the crank and crank cam gear and install a #1 bearing with 3 shims on each side for the thrust bearing so it could be used as a pusher or tractor engine.
Pops - Very helpful! I too am building a flywheel drive VW and had not seen this mentioned previously by anyone. Thanks
 

Pops

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Pops - Very helpful! I too am building a flywheel drive VW and had not seen this mentioned previously by anyone. Thanks
This is my first flywheel drive engine. In putting the flywheel shims on the other side of the #1 bearing , I didn't have enough room for 3-- .009" thick shims, just 2. So I cut down the face of the main bearing in the lathe for the third shim and used one .009 shim on the other side of the bearing so if the crank slides rearward the .005 endplay there will be a shim between the thrust surface of the bearing and the surface of the flywheel center.
Also the ID of the shims for a 1600 cc VW engine will not slide over the crank bearing surface without opening up the ID a little ( Maybe .015"). I used a round stone in the Dremel and did a grind and test, quick easy job of about 2 minutes each.

When I dis-assembled the 1835 cc, 60 hp , VW engine in the SSSC with about 305 hrs on it because of the prop strike I just didn't want to trust the crank. All the engine measured no wear. I installed another STD VW crankshaft that I had and all new bearing. I will be using another set of heads that are drilled for dual spark plugs.
 

Pops

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Did you make the prop spacer as well?
No, my little lathe is to small so Dallas did it for me in his far better and larger lathe. Old friend since about 1970 and next door hanger and flying and building buddy.
 

Vigilant1

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This is my first flywheel drive engine.
It'll be interesting to read your observations of building/running/flying a flywheel drive vs a pulley drive. The pros/cons may boil down to the goals of the user (full electric? Total loss electric? magneto ?). I get the impression that integrating the magneto onto a flywheel drive was a challenge.

I will be using another set of heads that are drilled for dual spark plugs.
Have you got a pair of heads already, or do you plan to buy some? You're planning on dual ports for this engine, or going single port? I'd like to find somebody knowledgeable who has built an aero VW with the CB Performance Panchito heads. The 35.5mm exhaust/40mm intake valves are bigger than an 1835cc engine (or a 2180cc engine) needs at our RPMs. Still, the fins are supposed to cool especially well and the valves have been moved apart a bit to help reduce cracking between them. With the modified valve geometry, I hope there's still room for a second plug.
 
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Pops

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I have 2 extra set of heads. One set I have drilled for the lower spark plugs. I still need to install the new valve guides and valves on these heads yet. The only dual port heads I have is on my VW mud buggy . Even going to flywheel drive 2180cc's on an extra engine for the SSSC, I think I still want to stay with the single ports because of the dual port cracking problem. I know it will cost me a little HP, but the SSSC will have a lot of power with a 2180 engine. But, plan on using the flywheel drive 1835 cc engine first.

On the mag mount for the pulley end of the case, I still need to design and build the brackets that hold the aluminum ring in place that mounts the mag. Each day I work on the engine for a while and do more varnishing on the fuselage for a while. Fuselage varnishing is about finished. I need to get into my extra fabric, etc , to see what I need to order for the covering of the fuselage and wings.
 

Pops

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Installed the cut down flywheel center, torqued the large gland nut and safety wired the large nut to the 8/32 allen head screws that are drilled for safety wire. Used locktite on the threads of the 8/32 screws. Then bolted and torqued the 6 - 3/8" bolts for attaching the prop hub, and safety wired.
 

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Pops

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I have VW manuals that list the torque of the gland nut from 217 lbs to 270 lbs. I took the middle road of 240 lbs. I have a steel bar about 3' long drilled with holes to match the pressure plate bolt holes on the VW flywheel to hold the flywheel from turning . Had to drill one hole in the bar to match the threaded holes for the prop hub holes in the cut-out center of the flywheel. I always use a 3/4" drive torque wrench that goes to 300 lbs, and a little pipe cheater of about 24" long makes it easier for me.
Torqued to 240 lbs and safety wired the gland nut, not worried about anything coming loose.

Added-- If anyone needs a couple of the allen head 8- 32 screws with the drilled heads, Send me a private PM with your name and address and I will send you 6. I have about a 100. I didn't drill the hole all the way thru the flwheel, about 1/16" short. Tapped with a starter tap and ended with a bottom tap. You will have to cut the length of the screws to suit. Cut mine at 5/16" long.
 
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Quentin Nelson

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Hi all
I’m the VW engine guy out in the Seattle area. Not an airplane person, but I have a complete Areo-Vee kit for sale. You can see more pics on eBay or contact me for more details. The kit is quite complete & was wrapped up & stored indoors since 1980. No engine included with the Sonex kit, but I have a lot of parts new & used to build just about any size type1 motor.
I noticed the comments about modifying flywheel shims when putting them on opposite side of #1 main bearing. The shims for 1966 & older engines (non O-ring crank) have a larger OD & will slip all the way over the crank main journal without having to enlarge the hole. I have a supply.
I have also been doing an extra oil return hole from flywheel seal area on the other side of case. Works well along with Hoover oiling mods that get full-time oil pressure thru extra case galley, lifters, pushrods & rocker shafts/arms.
Quentin
2O6-66O-2834 voice or text
 

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karmarepair

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I have a complete Areo-Vee kit for sale.
This was what John called the EconoVee. Cheaper, simpler, lighter, than the original SuperVee. Shrink fit hub on the Pulley end of the engine. X-Casting to mount the Slick magneto and the engine. No alternator on this one that I can see. I think John was typically running slip-in 88mm P&Cs at the time. I would NOT run that hub on anything bigger than 1835cc, me, but this would be a great setup for a 1600cc hand-prop engine, say, on a Double Eagle or Cabin Eagle.
 

Pops

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Hi all
I’m the VW engine guy out in the Seattle area. Not an airplane person, but I have a complete Areo-Vee kit for sale. You can see more pics on eBay or contact me for more details. The kit is quite complete & was wrapped up & stored indoors since 1980. No engine included with the Sonex kit, but I have a lot of parts new & used to build just about any size type1 motor.
I noticed the comments about modifying flywheel shims when putting them on opposite side of #1 main bearing. The shims for 1966 & older engines (non O-ring crank) have a larger OD & will slip all the way over the crank main journal without having to enlarge the hole. I have a supply.
I have also been doing an extra oil return hole from flywheel seal area on the other side of case. Works well along with Hoover oiling mods that get full-time oil pressure thru extra case galley, lifters, pushrods & rocker shafts/arms.
Quentin
2O6-66O-2834 voice or text
Been using the Hoover mods. Yes, the 1200 and 1300 cc shims will slip over the #1 bearing. I had 2 left and used them. Don't know anywhere were you can buy them now.
I bought the EconoVee parts back when I was building the engine for the KR-2 that I was building in the 1970's. Didn't use them.
 
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