My engine has returned from Zipper Big Bore!
Discaimer - I am not affiliated with ZBB. I received no consideration for anything I say good or bad.
I never have met anyone nor know anyone who works for ZBB other than what's been said here, in this post,
these forums and video's of Hal Stockman and the ZBB engines flying in various aircraft.
Also please excuse this wordy post...
I purchased the engine used, with the 1998 outback kit. Came out of a wrecked kitfox IV. No logs with only the
seller claiming 270 approx. hrs and no prop strike. I like to believe everyone... but I'm old school - trust but verify.
That being said the hobbs did read 273 hrs. (the hulk and instrument panel of the old IV was in the corner of the
hanger.) The engine and the propeller were not all banged up. The old motor mounts were bent but not broken.
The compression checked out and it turned over easily with the plugs out. The oil looked and smelled good. I am
comfortable saying I valued the engine at about 3K.
Still a big gamble and a lot of money if it turns out to be junk!
I thought it was just a bit foolish to install an engine from a very questionable background on a new aircraft and
expect perfection, so I started talking to Jay Stewart from Zipper Big Bore and decided to ship ZBB the engine.
Hal Stockman was great to deal with and talk to. He has a lot of experience with this engine.
I'm a very good Ford FE engine guy but as I had Zip, Zero, Nadda experience with the 912 and now was not the
time to cut costs. Bottom line was I wanted to have confidence in the engine, make 100+ hp and run on 87 octane
fuel. Hal spent a lot of time on the phone with me as the engine, gearbox were torn down and inspected. As well
as when it was on the test bench running. Great customer service!
What we found out that the engine was in fact low time, older 912 that was mfg. in 2001. So far so good...
The engine was torn down and checked for any damage, none found. Ok, that's better...
Crank and heads were checked and looked great. Wow! that's a relief...
I chose to have Hal machine and thru bolt the case and make it heavy duty. It was not necessary but I thought this
would be a good long term investment as displacement was increased by 30 hp.
The Zipper High Torque 1484cc big bore kit was installed as well as a new high profile cam, rocker shafts polished,
cleaned up the valve seats, new fuel pump, new radiator cap, ignition mounts, hoses, fuel lines, magneto cover and
a new inline thermostat. Carburetors were set inboard and installed a new larger manifold crossover, installed new
float bowl gaskets and new air filters.Gearbox was torn down, checked for any damage. None found. Installed new
slipper clutch, bushings, o rings and seals, magnetic drain plug and re-shimmed.
Engine bench tested with no discrepancies except the old starter died and was replaced. I made new log books on the
gearbox and engine documenting in detail all work performed. Time set to Zero.
I know some of your eyes are rolling into the back of your heads so I'll conclude by saying I did spend more than
Initially wanted to. However I'm confidant in my engine now. Total cost came in at about 9.4k. So I have approx.
12.4k in a virtually new, zero time, 110hp engine that weighs in about 140 lbs. Sweet.
At this price point I'm comfortable with what I spent considering what a new 912uls or 912ils costs.
Did I spend to much?
Could I have done more work myself and saved a few $$?
Was it worth the $$ to have an experienced Rotax mechanic perform the work on this engine?
You be the judge.
Yes! I will paint the case, cylinders and rocker covers as well as polish and buff a few items. The engine looks a little sad
in it's dated 2001, 80hp look. More on that later!
When I maiden the aircraft and lift off for the 1st time... I can only hope that it's money well spent and with any luck,
my shorts will remain unstained.
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