turbines all derated as you go up. that is why the tbm 700 is now a 900 or as tey need that big an en=gine to develop 350 hp or so up high. turbocharged or supercharged piston engines can keep sea level pressure air being pushed into the engine up to 20,000 ft or higher.

the Turbine Aerostar had 350 hp at sea level as I remember but would only develop175 or so at altitude so the standard 601P was far faster once you got into the high teens. as well as having far more fuel used per Hp down low. small turbines have fuel specifics of .65 LB/hp hr or worse where the 601P engines normally run about .44 lbs / hp hour and diesels get down to .32 to .35 at all altitudes.

Pistons are naturally more efficient and diesels much better because of their very high compression ratios make for more efficient combustion. the big problem is to get over 350 or so hp requires a very complex or extremely highly tuned piston engine with existing technology engine at this time

12 cylinder diesel aircraft engines are capable of 600 to 700 hp all day long. at very good fuel specifics. If they finally come into production they will be better than all the small turbines (far better fuel specifics and total weight (fuel and engine) equal for a 3 hour endurance required flight) thus the market for more than 5000 engines per year.

V-12’s gonna make a comeback?

turbines all derated as you go up. that is why the tbm 700 is now a 900 or as tey need that big an en=gine to develop 350 hp or so up high. turbocharged or supercharged piston engines can keep sea level pressure air being pushed into the engine up to 20,000 ft or higher.

the Turbine Aerostar had 350 hp at sea level as I remember but would only develop175 or so at altitude so the standard 601P was far faster once you got into the high teens. as well as having far more fuel used per Hp down low. small turbines have fuel specifics of .65 LB/hp hr or worse where the 601P engines normally run about .44 lbs / hp hour and diesels get down to .32 to .35 at all altitudes.

Pistons are naturally more efficient and diesels much better because of their very high compression ratios make for more efficient combustion. the big problem is to get over 350 or so hp requires a very complex or extremely highly tuned piston engine with existing technology engine at this time

12 cylinder diesel aircraft engines are capable of 600 to 700 hp all day long. at very good fuel specifics. If they finally come into production they will be better than all the small turbines (far better fuel specifics and total weight (fuel and engine) equal for a 3 hour endurance required flight) thus the market for more than 5000 engines per year.

The original lycomings work pretty good too, with all the money you save not putting 250,000$ worth of diesels on it you can buy a lot of 100LL

https://youtu.be/mrmmrNm1y_Y

Trey, I'm not sure if it's the cylinder work you had done but that thing is a RINGER. I don't recall seeing another 601P true out at 250kts.

Based on the power tables I have seen for multiple turbines posted over the years; you would need a turbine with more than double the 350HP to match the performance of the io540 at FL250 - Fl300.
Turbines are naturally aspirated, and this aspect is often overlooked. With the use of turbochargers, you can have a piston engine maintain power to a higher critical altitude. For a turbine, they work the problem in reverse, the determine what power you want at altitude and cap it at lower altitudes.

Tim

Any Aerostar guys have any paint shop recommendations?

Priority in order:
Quality.
Downtime
Price
Location. (West coast, but not against going all the way to east coast for this)

Bonus would be some place that could do some minor interior work at the same time.

Short story:

This AM flew from KBQK to Norfolk @ FL210.

LOP noticed a little less airspeed and left engine TIT was running higher than normal.

JPI 760

Then the #5 cylinder (left engine) EGT jumped up (I was in normalize mode).

To confirm I did LOP mag check, watching EGT temp for the #5.

Left mag: ran rough and EGT for number 5 dropped

Right mag: ran rough but EGTs rose along with other cylinders.

Bad plug on #5

Which plug?

Left mag on an IO 540 does bottom plugs on left side cylinders and top plugs on right side cylinders.

Left side cylinders are 2, 4, 6
Right side cylinders are 1, 3, 5

Bad plug is top plug on #5

Mech changed plug today

Problem resolved

JDI 760 is a good piece of gear.

Forrest do you have dual TIT per engine?

I’ve been contemplating having dual TIT. It would be useful I think, especially for economy power settings.

I used Master Aviation in Danberry CT as my primary. I sold almost a decade ago, not sure they are still around since the owner was close to retirement.
Otherwise, out west I used the AAC factory. They could do interior work and also avionics. I never did check if it was subs or their own shop.

Tim

Yes

TIT probes for both turbos.

I used Master Aviation in Danberry CT as my primary. I sold almost a decade ago, not sure they are still around since the owner was close to retirement.
Otherwise, out west I used the AAC factory. They could do interior work and also avionics. I never did check if it was subs or their own shop.

Tim

Not so fast buckwheat.

On run up this AM.

Left engine:

#5 EGT drops on Left Mag
#4 EGT drops on Right Mag.

;(

Not so fast buckwheat.

On run up this AM.

Left engine:

#5 EGT drops on Left Mag
#4 EGT drops on Right Mag.

;(