P337 with 350hp TSIO-550s

rhurt · #1 09-13-08, 02:45 AM

I flew an experimental P337 yesterday with 350 hp TSIO550 engines. WOW! 3000fpm climb on a 93F day with 5300 lbs gross wt. Cruise climb 2000 fpm. Cruise speed numbers are not in yet, as it was only flight 5. I did see 200 kt tas at 9500' and 65% power.

Incredible plane! 2000 hr tbo. He should have the STC by March 09.

WebMaster · #2 09-13-08, 05:18 AM

If you get some pictures, please post them. That would be interesting to see.

rhurt · #3 09-20-08, 03:12 PM

I should have some pics in the next couple of days.

I flew it again yesterday and I remain impressed. We did some takeoff roll and climb tests at 5500 lbs and 310 hp setting. Takeoff roll was 1350 feet and a five minute climb from 3000 feet put us at 12,500.

With the 3-bladed schmitar props the thing is quieter than a stock p337, so the gross weight increase should not be a problem. He's going for 5,700# with the 550s or with the Riley 520s.

Next week we'll take it up to fl 250 and do some speed tests. I'm expecting to see way more than 230 kts.

By the way, the flights were on a 87f day, but the cabin temp was 72 because of the Aviation Enterprises A/C system.

rhurt · #4 10-01-08, 02:06 AM

I did not get to fly last Friday. I turned wrenches instead. The chief pilot flew it though, and at 5,700 lbs, with slightly more headwind and a more nose up attitude, he got the thing off the ground in 1150 feet. Still had good grond sound measurements, even at 800' agl and 310 hp power settings.

I should be taking it to fl 250 this Friday for a speed run. And I'll get some pictures.

Had an Aspen Avionics Pilot Pro PFD installed in my '66 -A, mated to an ARC 400 autopilot. I should have it back this week and will start another post to tell how well it works with the a/p and the 530.

Also, some of the mechanic work I was doing last Friday was on some 25-gallon underwing fuel tanks, four in all, mounted to the hard points used in the O-2's. May have some pics of those also.

rhurt · #5 10-02-08, 08:53 AM

Some phone camera pix of the p337 with TSIO 550s. Obviously all the work is prototype.

WebMaster · #6 10-02-08, 10:06 PM

Thank you for posting the pictures.

It looks like the intakes for the front engine are smaller than I would have thought. Also, it looks like there is a supplemental intake, on the front engine. The rear engine looks just really massive.

thank you again for posting the pictures.

rhurt · #7 10-07-08, 07:28 PM

The front engine cools very well and the rear engine cools better than the front. Last Friday as I was climbing to 17,500 and noticed the rear engine chts were starting to creep up. I realized I left the cowl flaps closed and the engine immediately cooled down when I opened them. By the way, there are no cowl flaps in front, just cowl outlets/exhaust pipe fairings similar to the Piper Malibu.

At 17,500 I saw about 235kt tas at about 70% power.

I haven't gotten the "66 back yet. They are dialing in the Aspen PFD. During the test flight the compass swung 15 degrees off when we turned on the air conditioning. Aspen is sending a new module.

hharney · #8 10-07-08, 08:33 PM

What was the cost to install the Pro? This seems to be an unknown at most shops. It really depends on the aircraft and not too many 337 drivers are installing these yet. Do you know of any other 337's that have installed the unit? Who is installing yours?

rhurt · #9 10-08-08, 10:19 PM

The installed cost was quoted at $14k, including moving some of the vacuum instruments around. I don't know of any other 337's with it installed.

Chad, with Cumberland Avionics at KJWN (Nashville - John Tune) is doing the install, and has done work on several Skymasters, but this is his first pro in one.

A big part of the cost justification for me was getting GPSS in the plane, so my big question is how well it works with the old navomatic 400. We'll see.

Randy Hurt

EthanTrull · #10 01-03-09, 02:29 PM

I'd love to hear the current status of this project.

EthanTrull · #11 01-03-09, 02:31 PM

Also, probably stupid question, but at 240kts, aren't you way over Vne?

rhurt · #12 01-03-09, 10:00 PM

The P337 belongs to Owen Bell and he has been flying it every few days, but is still limited to a 75 mile radius from BNA. He cleaned up and painted the front and rear cowlings and added installed some underwing fuel tanks that mount on the O2 hard points. They hold 25 gallons each , but he can increase the diameter a little to make them hold 50 gallons each. There are four hard points, so four tanks can be installed.

Owen is pushing all the paper through the FAA to get the STC for installing the TSIO 550s and plans to also get an STC for only installing one in the front. The thing is a real rocket.

Yes, 235 kts calibrated airspeed is waay over Vne, but he's getting 235 true airspeed, and in the flight levels the calibrated airspeed is still well under Vno, but converts to 235 true airspeed.

skymstr02 · #13 01-04-09, 10:02 AM

Here is a photo of my plane with a 150 gal drop tank installed.

http://www.337skymaster.com/messages...hread.php?t=17

rmorris · #14 01-05-09, 06:29 PM

Quote:

Originally Posted by rhurt

The installed cost was quoted at $14k, including moving some of the vacuum instruments around. I don't know of any other 337's with it installed.

Chad, with Cumberland Avionics at KJWN (Nashville - John Tune) is doing the install, and has done work on several Skymasters, but this is his first pro in one.

A big part of the cost justification for me was getting GPSS in the plane, so my big question is how well it works with the old navomatic 400. We'll see.

Randy Hurt

Randy,
How is your Navomatic 400 to a 400A conversion coming along? I'm interested in doing something similar if it's successful. Pls drop me an email at rmorris@agsi.us
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