Hear! Hear!

Back in my miss-spent youth, I worked in a VW independent repair shop in San
Mateo, Ca. A place called Father Noel's. I rebuilt three engines a week and
saw it all. The same 47 reasons why the air-cooled VW needed "periodic
replacement of heads, carb, distributor, clutch and oil pump with rebuilt
units, all for a nominal charge, when the vehicle was brought in for
service."

Here is a partial list of what WILL go wrong with your fan drive up front
WITH A STOCK TYPE ENGINE ( for those about to flame me, please read that
last statement several times least you look foolish):

Exhaust valve stems stretch to the point of the valve heads breaking off and
trashing engine. You'll know when this is about to happen when your engine
won't hold a valve adjustment.
Cylinder heads crack between seats.
Cylinder heads crack to spark plug hole. You'll know this when the spark
plug seizes when being removed because of accumulated carbon in the threads.
And then the spark plugs blow out...
Valve guides that wear out as soon as engine starts (a lot like old Triumph
motorcycle engines)
Cylinder head sealing surface leaks due to case studs stripping threads out
of the case. You'll know this when your brand new muffler sounds like it is
falling off under acceleration.
Ever present oil leaks from the case crack developing in the number 3
cylinder area behind the flywheel (ok...prop drive).
Loss of oil pressure at low rpm due to case separating at the center main
bearing area.
Flat cams and worn lifters due to great German metallurgy.
New version of air-cooling when rod escapes confines of case.
And on...and on...and on...

Granted, all of these things can be fixed with a generous infusion of money,
maybe two shoe-boxes full of 20's will do the trick. But the basic idea is
that this engine isn't adequate to push around a 1500 pound car at part
throttle let alone an aircraft. And by the time it is capable, it is more a
Lycoming (no great accomplishment in itself) than a VW i.e. a horizontally
opposed four cylinder engine in the same vein as a water-cooled chevy based
aircraft engine is no more a chevy than a Nascar prepped race engine with
origins in a dozen speed part catalogs.

A common statement by some of the longer haired VW owners ( this was the
70's) was that VW's were great because they were easy to work on to which I
would reply that is fortunate as one works on them a lot. We made a lot of
money off those types. Now today, would the owner of a present day vehicle,
with all of the subsequent technology advances, put up with that repair
frequency? Oh wait! They do! They are called Volvo, Mercedes and BMW owners.

If you are going to rely on a VW or other small displacement engine to keep
your aircraft an aircraft and not a smoking hole full of parts, build it
with the best parts possible with the best information available and don't
skimp.

By the way, I'm have not been immune from thinking poorly or emotionally. In
the 80's, I raced a Ducati bevel-drive twin in AMA Twins. It developed
enough horsepower to break cases every two races. I welded a chain to it and
took it fishing once. When I was done fishing, I cut the anchor chain and
went home.

Gotta realize when you have gone down a road too far...

Ready for flames now...

Dale Alexander


wrote in message
...
On Jan 29, 2:29 am, "oilsardine" wrote:
compared to the '85 HP aircraft cylinder head' the VW head doesn't look
so
bad after all...
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Looks can be deceiving.

The maximum output of the carburetted 1600cc VW engine was the 1971
model which could produce about 57bhp... for about ONE MINUTE.
Maximum SUSTAINED output (ie, CHT of 450F) was about 44bhp under
Standard Day conditions. At that level of output you could expect the
exhaust valves to drop out of spec after about 200 hours. NOMINAL
output of the 1600VW was about 15bhp, which allowed the exhaust valves
to survive for up to 1000 hours (although 600 t0 750 was more the
norm). After-market 'hot-rod' heads do even worse since they have
less fin area. Volkswagen dealers commonly swapped-out worn heads
without bothering to inform the owner, other than to list their
replacement in the 'OTHER SERVICE - AS REQUIRED' block on the work-
order.

To understand why the VW head does so poorly simply compare it to the
early 1500cc (85hp) Porsche heads. Then compare those to the Corvair.

-R.S.Hoover

PS -- Here in the States many VW owners insist their vehicle NEVER
required anything other than normal maintenance when in fact,
examination of its service records usually shows periodic replacement
of heads, carb, distributor, clutch and oil pump with rebuilt units,
all for a nominal charge, when the vehicle was brought in for service.