Q1_Aircraft: VW engines

AO32 is a military engine with 5.5 or 6 to 1 compression ratio, and an
advertised power of 10.8 hp. It have a breathing system that is worse than
worse. It's designed for military bulk fuel at 60 octane, and is a completely
'de-tuned' engine.

Both the AO32 and the AO84 can be tuned back again pretty easily, and that is
what you have to do., I would say especially the AOL32 as it is such a small
engine, the bigger AO84 will deliver such a good load of power anyway, but the
AO32 is only a bit over 500cc so you need to do to all the trick in the book to
make it work for you.

Make another attempt.

Take the engine to your shop, and shave the heads to a compression of 8.5 to
1.

Port the whole engine, the breathing system is abysmal, you need to spend some
hour on each head, and make really good flowing ports.

Intake runners need to be either ported up or redone (the center piece, the x
formed intake manifold is pretty good though, but the knees at the cylinder
heads is designed by a drunk plumber. you could use conduit pipe, you can hard
soldier or epoxy those.

Get another carbureator, that will sustain better flow, get hold of (preferbly
an older type from a lawnmower shop, the new ones are completely useless, as
they are sealed because of smog requirements, you need to experiment a bit there
in order to get a good set up.) The original carb, will not drill up enough to
be a good one, once you drill the ventury, it will go out of shape of the
optimal form it has to have, it will work if you do it very conservative, but
the hole needed, is going to be too big for that carb to be 'fixed'.

Get rid of all the original exhaust, you can cut and save the stubs that bolt
onto the head, but the rest, with 90% angles and T connections are a nightmare.

One of the most important part of the AO32's 'rehabilitation' is the camshaft.

AFTER you have shaved your heads to a compression of 8.5 to 1 ( have it
measured, dont just 'think'that you have that compression) put the head back on
the engine, with a little bit of childrens clay, between the piston and the
valves, turn the engine, and make an impression in the clay with the valves.Open
up the heads, and carefully peel off the clay, cut it with a razorblade and
measure how much you have left between the top of the piston and the valve.

Take that measurement, and take the measurement of the rocker arms ratio, and
go to a cam grinder. Ask to get a camprofile with a modern fast opening fast
closing profile, that will sweep over the whole follwer (lifter) without falling
off, and get as high lift as you can get away with.

Dont do more overlap than between 6 or 8Deg.

Ask for the same timeopening as the original camshaft except if they can do a
couple of more degrees time opening on the exhaust side.

Put it back on the engine and put ONE head on, turn slowly and see if the
clearance is good, if it touches, dont despair, you can grind a couple of
reliefs on top of the piston, that's ok if you dont overdo it.

Do this one by one with all the heads.

Smaller displacement engines, are inherently less thermal efficiant and they
will benefit from thermal coating, there are kits you can buy, and bake the top
of your pistons, and the inside of your heads in the owen. Do that AFTER all the
machinery, and porting is done.

The electronic ignition system...dont touch it, it is superb.

Set the engine up in a stand, and work out all the bugs. Run it, and tweak it
until you are satisfied.

Preferably if you get hold of a prop with a known stall speed of another
engine, that is, if a 22 hp Onan will stall prop X at 3000 RPM in a static run,
then get THAT prop for your bench trials.(and if you're happy with it, for your
flight as well).Set a goal to get as good static RPM as the comprable engine,
and when you have your 3000 RPM with that prop, you're ready to go.

I would also get a thrust bearing installed between the prop and the engine
case, to take care of side and gyroscopic loads. The AO32 have a center clip
around the center bearing, and the rod ends are a bit dinky, so I would beef up
the front end. Talk with a machinist on how to get one of those in there.

Unscrew that oilfilter , it is a huge barrel and contains tons of oil, it is
there because of low maintenace purposes, you will do much more maintenace, so
go to a carstore, and find the smallest oilfilter that will screw on and you
will drop the weight by sixteen ton.

The AO32 is a small handy engine that you can easily work with on any garage
bench, just get some good lights in there turn on the radio and have fun.

You have just had a flight trial with a 10.8 hp engine, that is at a rated
3600 RPM and I am pretty sure that the RPM you were running at the time was not
in that range, if it was around 2500 RPM you would have at your disposal about 6
maybe 7 hp.

Lets say you had a 75% efficcient prop, that leaves you with about 4-5 HP that
was pushing you along at the time of your original flight trial.

Follow the steps above and you should have around 20 honest HP out of that
thing.

It will take some serious engine work though, dont just shave the heads and
'Hope'for the best, or go over the ports with a sandpaper and say that you have
ported the heads.

Read enginebooks in how to measure and determine swept volume, total volume
and compression ratio( dont forget the thickness of the gasket, measure that one
too)

Work out everything on the ground, do all your bench tests, also once
installed back onto the Q1, work out any and all conceivable problems, dig a
hole, and dip the tail , run the engine full speed, and see if you will get a
fuel starvation problem.

Once you're happy with it, have the power you want, go for it, but dont go up
and 'try it'.

If you have set a goal on 3000 RPM,stall speed with a prop, dont go if youre
only getting 2300RPM. Then you know you're not done. Do it all, THEN fly.

You can do it, let us know how it is working out for you

Good luck,
Roger












Ryan < rryan@... > wrote:

Roger,

I bought my Q1 to put a new 4A032 engine in it. I did. It would
reach lift off speed and then mush back on the runway from lack of
power.

Ryan

--- In This email address is being protected from spambots. You need JavaScript enabled to view it. , Isaksson Roger
<scratchdeeper@...> wrote:
>
> Perhaps this is a philolosphy more than anything else.
>
> In the human development of things we always have to do it a bit
bigger and more powerful for each step.
>
> Every year a car model comes out, it is a couple of inches
bigger, more powerful than the year before, and at the end of the
model line, the original concept of the first model is almost always
lost, and the car have now grown into a bigger class of cars.
>
> Your fishing boat, a small aluminum boat, did just fine with a
10 hp outboard engine, but by some reason or the other, it's sitting
a 65 HP engine there now.
>
> A normal car takes about 20 to 30 HP to maintain freeway speed,
any more hp is used for acceleration or hills, and man, do we have
hills nowadays, we absolutely neeeed 300HP.
>
> Dont get me wrong, I like power as well as the other guy, but
powerful vehicles are designed to be powerful vehicles.
>
> I have two vehicles one is a Mercedes 560 SEC, and the other is
a VW Rabbit Diesel.
>
> Those vehicles are two completely different concepts, the only
similarities are that they both have four wheels on the ground.
>
> I am happy with both, because they fullfill their task, each one
of them respectively.
>
> It would be so far fetched to try to make a hotrod out of the VW
Rabbit Diesel, getting bigger engines and make it go faster, make it
climb the hills faster, and make it a red light screamer.
>
> The whole concept of what a VW Rabbit Diesel can do, would be
completely lost with that effort, besides, if I wanted to do a
hotrod, I wouldnt choose a Rabbit Diesel in the first place.
>
> Why go with all these mega heavy engines in a Q1? Just because
it has been done, does not make it the norm. it's still a mutation.
>
> Dont put a blown Hemi in a VW Diesel Rabbit, find a Dodge
Charger and it will bolt right in.
>
> Ryan <rryan@...> wrote:
> Dave,
>
> The Vari-eze started with a VW engine then the 0-200 Continental
or
> later an 0-235 Lycoming.
>
> The LongEZ started with an 0-200 Continental then a Lycoming 0-235
> and now an 0-320 Lycoming as the best choice.
>
> The Q1 started with 18hp then 22+hp then 503cc Rotax 52hp. Several
> flying with 4 cylinder VW engines (I am one). Except for the
3.6gph
> fuel burn it is a reliable way to get in the air with plenty of
> engine history.
>
> I do not understand the negative responses to an excellent
> alternative to the Onan or Rotax engines. Yes it is heavier than
the
> Onan.
>
> Ryan
>
> --- In This email address is being protected from spambots. You need JavaScript enabled to view it. , 'davedrosen' <d2r@> wrote:
> >
> > All,
> > I'm searching for engines, at this point, to replace the non-
> > exsistant hexadyne engine. I have some vw questions. Isn't it a
> bit
> > heavy for the hp. Why just use the 1600 if the next size up or
two
> > weighs the same. What about PRSU's. How does the GPlains engines
> > compare to AeroVee etc. How fast did a Q cruse with a VW, with
and
> > without a prsu? How are they mounted? does one use rubber mounts
> on the
> > firewall? Is there any good reference for installation advice
for
> a Q1?
> > Thanks,
> > Dave R.
> > N4YQ
> >
> > Hexatron NOT--Gotta sue them for my deposit back.
> >
>
>
>
>
>
>
>

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