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Back in town
Well, a LOT happened this last week. I'm back from
Boston. I found I like clam chowder ... a lot, and
lake Quabbin is very pretty. I got back on Saturday, and then
on Sunday my partner and I went to Jewitt Texas to visit
George Heinly the Franklin Guru.
The purpose of the trip was to collect as much information
about the current and past state of the Franklin engine. We took
a videocamera and collected about four hours of tape ... I suppose.
I don't know how long we talked but it was a very long time.
George has an airstrip that I would like to try my hand at in a STOL
one of these days. It's 1200 feet (according to George), but I stepped
it off and measured the flat part to be about 1000 feet. It starts
at the bank of the lake and a peninsula makes up about 750 of it.
I suppose on would come in from the lake and use the inclined bank as
an overrun area. Likewise you would get a running start on the bank
and keep the airplane in ground (water) effect if you run out of runway.
Anyway, on to business.
For a 90 year old man he is very sharp. He can remember details and talks
about them like they were yesterday. I asked him a lot of questions
and he talked about many more things than I could catalog. I'm
glad I have a tape for reference. I asked him about the
fuel pump problem. I really need to watch the tape again to verify,
but basically here is what I understand:
The American Franklin manufactured engines do not have the
same problem as the PZL Franklins. The pump housing that bolts
to the accessory pad was modified by PZL so that engine oil
could lubricate the cam cam and rod. By doing this, they expose
the fuel pump to the engine oil pressure. He gave me
an old worn out pump so that I could make my own measurements.
The original pump was indeed an AC Delco 4886 as used on the
Corvair. There is a set screw hole that does not require
a plug in order to function properly. The pump that PZL
uses (aluminum) does not have the same hole. So basically
PZL made a change to the fuel pump housing by drilling an oil
I asked about the oil cooling problem. George was adamant
that our problems were not due to the fault of the Franklin
engine. I told him that we have approximately 30 feet of
an oil path in the Velocity. His solution is to move the
cooler closer to the engine. I don't completely agree
with his assesment of our cooling situation. He has a lot
of knowledge, that much is certain. Until I can get some
hard numbers in terms of Kcals generated, Kcals radiated,
oil flow and oil pressure, and the reason why it does or
does not work, I'm not going to be satisfied with what
I consider anecdotal evidence.
I have the name of the turbo manufacturer for the American
Franklins. I am going to check in and see what fabrication
will be required for a normalized turbo Franklin. If one
simply normalises then one can use the 10.5:1 pistons
as on the PZL Franklin. If one wants to boost above
ambient, then that person will need some changes to his
engine. The only difference between the non turbo and
the turbo engine is the low compression piston, and the
wrist pin. The crank, and bearings are the same.
I don't recall the name of the turbo right now.
George says that the intake manifold of the Franklin
is very efficient. He maintains that FI does not
result in any performance increase. He suggests that
to get around carb icing, that you do the simpler
and cheaper alternative which is a carb heat box. He
also mentioned that it is still possible although unlikely
that you are still susceptible to carb icing if you
go to fuel injection.
George does not have any opinion on EI ... he's got no
experience with it, so he's got no opinion on it.
I asked him about the leaky starter problem. We shouldn't
be having this problem. I got the part number we should
be using and will compare that to what my PZL manuals say.
That's all I've got for now. We talked about a lot of
other things though, like oil pans, lifters, cylinder
sleeves, cams ... gosh a million things. I'll make
a transcript of the tape and make it available
sometime. Don't expect it tomorrow though. This will
take some time.
Brian Michalk <http://www.awpi.com/michalk>
Life is what you make of it ... never wish you had done something.
Aviator, experimental aircraft builder, motorcyclist, SCUBA diver
musician, home-brewer, entrepenuer and SINGLE!