Plugging distributor hole

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Mike von S.

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These are probably dumb questions, but what's the best way to plug the distributor hole on the VW? The various build manuals I have all presume that either a distributor or some sort of replacement is used. Bob Hoover's blogs also seem silent on the topic. I will be installing the Leburg dual electronic ignition system, and have no use for the distributor. What about the pinon gear? Should this be installed even if no distributor is used (perhaps to control oil flow)? If so, does it need a spring above to hold it in place?
Thanks in advance.
 

Hot Wings

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2 other options:
A simple freeze plug of the appropriate size.
In the old days some simply used an over-center rubber plumbing plug........probably a last resort method.
Vaxell-PNG.png
 

Hot Wings

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What about the pinor gear & spring?
Leave them out - IF - you aren't using a stock VW fuel pump.
If you are using the fuel pump the freeze plug method won't work. You need something to keep the driven gear from being pushed out of the bore.
 

Mike von S.

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Leave them out - IF - you aren't using a stock VW fuel pump.
If you are using the fuel pump the freeze plug method won't work. You need something to keep the driven gear from being pushed out of the bore.
I am using a Schadek 26mm pump. (Oddly, the GPAS kit came with a 30mm pump, but a flat cam gear, so I had to order the Schadek).
 

Mike von S.

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Leave them out - IF - you aren't using a stock VW fuel pump.
If you are using the fuel pump the freeze plug method won't work. You need something to keep the driven gear from being pushed out of the bore.
Hotwings, thanks.
Lynn Williams, designer of Goblin I am building, advises that there is an ample head of fuel for all of his Flitzer series aircraft, even at high AOA. So I won't be using a fuel pump. Sounds like that makes plugging the distributor hole easier, but begs the question, how to plug the fuel pump hole?
Not knowing how the oil flows in the case, and at what pressures, these questions worry me.
I appreciate the input from this experienced group!
 

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how to plug the fuel pump hole?
Not knowing how the oil flows in the case, and at what pressures, these questions worry me.
Plugging the fuel pump hole is one of the simpler holes to plug. It just takes a small plate with holes to match the studs and some kind of gasket. The pic I posted in #5 shows similar in the lower right to cover the dipstick hole on the universal case. You can get a nice cast version with cooling fins from the VW parts sources or just cut your own. Depends on how you trade time/money and how important cosmetics are to you.

There is no high pressure oil under either opening - just splash and crankcase pressure.

Edit:
If the distributor driven gear is already installed it can be a real pain to remove because of the thrust shim under the gear. It tends to stick to the gear and when it contacts the brass drive gear it cocks and locks things in place. A bit of wire can be used to hold the thrust washer down while the driven gear is extracted.
 

Mike von S.

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Plugging the fuel pump hole is one of the simpler holes to plug. It just takes a small plate with holes to match the studs and some kind of gasket. The pic I posted in #5 shows similar in the lower right to cover the dipstick hole on the universal case. You can get a nice cast version with cooling fins from the VW parts sources or just cut your own. Depends on how you trade time/money and how important cosmetics are to you.

There is no high pressure oil under either opening - just splash and crankcase pressure.

Edit:
If the distributor driven gear is already installed it can be a real pain to remove because of the thrust shim under the gear. It tends to stick to the gear and when it contacts the brass drive gear it cocks and locks things in place. A bit of wire can be used to hold the thrust washer down while the driven gear is extracted.
Cool. Thanks!
 

Pops

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In trying to same every ounce, I made the block off plates from a couple small pieces of 1/8" thick aluminum. For the distributor hole I drilled and tapped for 3-- 8-32 screws. To save weight I also make a new aluminum bottom oil plate and a small oil sump with a 1/8" pipe plug. Lot lighter than the stock steel plate.
In the picture you will notice the oil dipstick tube is plugged off. I moved the dipstick the the rear to make it easier to get to. Before it was behind the nose bowl.
 

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Mike von S.

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In trying to same every ounce, I made the block off plates from a couple small pieces of 1/8" thick aluminum. For the distributor hole I drilled and tapped for 3-- 8-32 screws. To save weight I also make a new aluminum bottom oil plate and a small oil sump with a 1/8" pipe plug. Lot lighter than the stock steel plate.
In the picture you will notice the oil dipstick tube is plugged off. I moved the dipstick the the rear to make it easier to get to. Before it was behind the nose bowl.
Pops,
Looks great. Interesting baffling.
I assume you did NOT install the pinion gear?
As for the distributor hole, how did you drill and tap the three bolt holes? Do you have a mill or a drill press large enough to fit the case, and a jig to hold it? The case is machined at an angle there, and the lip around the hole is quite thin. Seems very difficult to do by hand.
I still haven't worked up the nerve to ream and tap the small plug holes by hand, worried I'll ruin the case.
Thanks
 

Pops

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No mill. Just center punched the location. Put a small drill bit in the drill. And looked from 2 different locations an drilled. :)
If I missed up, could weld up and try again.
The baffling does a great job of keeping the CHT's in line at the slow speed of a high drag airframe.
 

Hot Wings

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And looked from 2 different locations an drilled.
@MvS
This comes with experience. If you don't trust you eye just drill a hole in any little piece of hard wood on the drill press and then use that as a disposable drill guide. Any Sin/Cos error over the thickness of the cover plate is going to be very small.
 

Pops

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@MvS
This comes with experience. If you don't trust you eye just drill a hole in any little piece of hard wood on the drill press and then use that as a disposable drill guide. Any Sin/Cos error over the thickness of the cover plate is going to be very small.
I have some 1"x1" x6" blocks of steel with different size drilled holes for drilling guides in drilling a straight hole when I can't use the drill press. Made these in about 1975 when I was building the KR-2. They have seen a lot of use.
 

Mike von S.

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No mill. Just center punched the location. Put a small drill bit in the drill. And looked from 2 different locations an drilled. :)
If I missed up, could weld up and try again.
The baffling does a great job of keeping the CHT's in line at the slow speed of a high drag airframe.
Pops - I admire your sharp eye and steady hand!
 

Mike von S.

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@MvS
This comes with experience. If you don't trust you eye just drill a hole in any little piece of hard wood on the drill press and then use that as a disposable drill guide. Any Sin/Cos error over the thickness of the cover plate is going to be very small.
HotWings,
Thanks, I'll try something like this
 
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