I've been looking at a nicely priced 1979 PIPER TURBO ARROW IV. It has about 800 hrs SMO. What kind of cost would be involved when it comes time for a major overhaul? What kind of fuel burn could be expected?
Gary, fuel burn has been an interesting topic for us TSIO-360 operators in T-Arrows. I think we all have differences in our view and practice. Let me bore you with mine.
I fly at 8 - 15k altitude at about 65% rated hp and burn 13.2-13.4 gph. Wow, some would say. That's a lot of fuel for only 65% hp. Nope, I don't agree. It's a lot compared to the fuel flow that would drive a 50 deg F rich of peak (or even more for LOP operation) lean temp target. But given that the T-Arrow can experience quite hot CHT's even in normal operations in normal ambient OAT's, we have to cool our engines using intercoolers or fuel flow. I don't have an intercooler. So fuel flow is the way for me ... at present. The fuel pressure controller has been adjusted up to the top end of the range for the high power setting, meaning that more fuel mass is available to flow through the cylinders that if the adjustment is low. And I run the mixture to flow 13.2-13.4 gph. My EGT's are 1480 on average with TIT at 1520. My CHT's (using a JPI EDM 700) are 300 to 350, even on a hot southern day.
Here is the punch line for me. I've owned and operated my T-Arrow for 14 years now and only overhauled two cylinders. And I am at TBO. 1802 hrs. Compressions are still quite good. I think that running the engine conservatively and keeping the CHT's in the mid-300 range is a key.
So for me, running 1.5 to 2.0 gph more through the engine is worth it. So that's my fuel flow story.
