[SkyKing]

Sure would be nice if there was a way to respond after each message to that particular individual's comments... SO, sorting through all of this, here's my nickel (hope to keep this somewhat straight forward!):

First, DON: You may indeed have a governor problem if your rear engine won't keep steady with the front, or vice-versa... I do hope you run the friction knob up good and snug, as that does help to keep things steady. But I've noticed it kind of depends on the operating WX environment... I've had days when things just purr along beautifully without having to readjust the props.... and then there are those days when nothing wants to stay synched up. Wonder if when you've experienced the variations in MP if you tried selecting a higher RPM and/or boost pumps?

Second, GMAs & MARK: As to the dissonance (I assume the wow-wow-wow sound), I'm only hearing this occur during the very early part of the takeoff roll... in the climbout, and in cruise, we don't have any of that occurring, like Don is apparently experiencing. When we've experienced the MP/Fuel Flow gyrations, the governor's have held the engine RPM's very close, and again, I think this may be "bootstrapping"... and that's what we're looking into now. Next time out we'll try a higher RPM and see if that cures the MP gyration problem up in the teens. Oh, and no "sagging oil pressure"... all is top green and no oscillations-rock steady.

BTW, I was looking on the type certificate for the TSIO-360C/CB, and it lists "5 useable quarts" in the oil department. Last couple of flights we've used 5.5 and no belly scum... clean as a whistle!

Third, BOB: As to the AvBlend, it's probably good stuff and we might give that a whirl... but another product out there without the "A" word attached has done a magnificent job of cleaning out our front engine and lubricating the upper end... and would you believe it's only about a $1.99 a Quart (32-ounces) from Wal-Mart!!! It's called Rislone... and it's GOOD STUFF! AvBlend is $19.95 for 12-ounces and I see they recommend two-cans for a 6-Cyl engine. BTW, my rear engine runs cooler than the front.

The last oil filter change on the front showed almost no carbon... and before we started using it we saw the oil filter folds full of it and used to see little tiny carbon flecks attached to the leading edges of the white antennas on the belly in the exhaust slipstream... these days they only get coated with a very light tan color -minus the specks and flecks. So that's a good indication. We're changing the the oil & filters at 25-hours, but this last time we did the front engine at 20 hours.

Speaking of aircraft piston-engine oil... I'll bet if we knew the matching MIL number and specs of a good grade of automotive or diesel engine oil - in the same weight and viscosity as the aviation oil - I'm sure you'd find there's not a dime's worth of difference and your engine would run just as well. Of course, that's a well guarded secret by the oil companies. But YES, in that department, we continue to use the single-grade of AeroShell W100-50 year round.

Like a lot of things, the turbochargers are a standard automotive unit... but added to that is the "A" word (Aviation) and the God-like words, "PMA-FAA" approved. Yep, it's true... and a whole bunch of folks are capitalizing on this little deal. Look at your alternators... nothing much different except for the connection to the engine, at least on the TCM TSIO-360's.

Here's a clever trick the oil companies play on we pilots. Ever hear of the term "BRANDED aviation fuel"...? That's where the AvGas comes out of the same storage facility, but gets labeled AirBP, AVFuel, etc. Like up in Seattle, there's only ONE bulk plant for AvGas... it's the Equilon facility on Harbor Island. Equilon is really Shell. But when we get it at our local FBO, it's now "BRANDED" as AvFuel or AirBP. Cute, hey? So then, why the big variation in the end-user price??? Hhhmmm. Another little racket.

SkyKing