Wrathall Mark wrote:
Al,
You are obviously well into your conversion project based on the 1.9L Ford.
Basically all the experienced engineers on this site think you are building
a hand grenade, and provide technically justification for their opinions.
Glad you haven't written off the ACRE's group as a bunch of religious
fanatics unwilling to accept a heretic. Stay on the group and learn. All the
rotary guys have also been through the thought process of using a piston
auto-conversion. Hell, I once thought the T-spark Alfa-Romeo engines would
be a good idea. <shudder>
Consider the differculties Ed/Tracy/Finn/Chuck/Ken/Perry etc have had with their 13B
installations, and one thing becomes very clear. The 13b's failure modes
when abused during the initial flight test phase are reassuringly gentle. It
seems everyone overheats their first rotary, shinks the housings and has a
water consumption problem. During all this the engine gives warnings but
keeps running. This is solved by optimising cooling. During this first
overhaul, everyone tweaks the engine to up the HP, and then proceeds to go
through an exhaust of the week phase. During all this the engine gives
warnings but keeps running. Those using the Ross drives start blowing oil
seals, have prop backlash problems, and wreck the engines thrust bearing,
until they overhaul/modify the box or replace it with Tracy's. During all
this the engine gives warnings but keeps running. The Dual ignition is
standard, dual injection standard on all who use Tracy's EFI.
Even if your engine has the mechanical reliablity to run at the HP levels
you are discussing, do you have dual ignition and independant dual
injection? You must expect to go through a phase of suboptimal cooling. The
scary thing is the failure mode of an abused high HP piston engine tends to
be sudden and fatal. Drop a valve, burn through a piston or break your crank
and you are flying a bad glider with few options.
Everyone wants to prove the pundits wrong, especially when you have staked a
claim and invested in their position. But the bottom line is that you being
wrong could well leave you dead, us feeling no better in the knowledge that
we tried to warn you, and handing more ammo to the anti-auto conversion
crowd.
I would request you step back from the money and effort invested, and fix
some tollgates that your engine must pass before you first risk your life on
it, and risk anyone elses life as passengers.
It is good to hear that you intend o run high power test runs on the ground.
My suggestion would be to run this engine with the prop that came off the
Lycoming, at the same speeds which the lycoming turned it static (likely
about 80% HP) for a minimum of 20 hours without modification or failure on
the ground. Connect up a garden hose to a spray bar on the radiator so you
know that core engines mechanical reliablity is being tested under optimum
cooling. Any failures or modification required reset the clock, and you
don't fly until it has given 20 hours reliable service.
After overhauling the engine, and confirming that it shows no wear or signs
of distress (magnaflux the crank), fly it within gliding distance of that
long runway running it hard for another 20 hours.
If at any stage you start feeling uneasy, take all your agression out on the
engine and PSRU with the biggest sledgehammer you can find, to avoid the
temptation of recouping your losses by flogging it off on some unsuspecting
victim.
Mark Wrathall
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