View Full Version : Cessna 185 w/TUROTECH 350 HP LYCOMING CONVERSION

Steve Pierce
07-20-2006, 06:37 AM
Anybody know anything about this conversion or this particular airplane.


07-20-2006, 07:00 AM
I have no personal knowledge, but the late Mark Hawkins told me that he knew of at least one that had major cooling issues. I think Stancil had one for sale for a long time a few years ago.


07-20-2006, 08:22 AM

Remove the top cowl on one of those babies and you still can't see the engine. They have a plenum (if that's the right word) for a set of baffles.

A friend has one in Fairbanks, and loves it. He flys it a fair bit on floats and skis both, and swears by it. Lots of power, but all heat and complexity issues associated with a turbo-anything.

Also a heavy motor for a 185. But, man are they smooth.


Frank T
07-20-2006, 02:54 PM
If it's going on floats, ask how much lead it needs on the tail.


07-20-2006, 03:01 PM
[quote="Steve Pierce"]Anybody know anything about this conversion or this particular airplane.

Jeepers Steve, you just got a pacer. That 185 is QUITE an upgrade but at least you can take the whole family in it.


07-20-2006, 05:52 PM
It sure has a cool paint scheme and colors.

Student Pilot
07-20-2006, 07:37 PM
Has anybody heard of a straight 540 conversion, no turbo?

07-20-2006, 07:54 PM
Student Pilot wrote

Has anybody heard of a straight 540 conversion, no turbo?
I think there is a Yates conversion for 180's using an O-540.

Steve Pierce
07-20-2006, 10:35 PM
I won the lottery. :o Supposed to go and look at it for a friend.

07-21-2006, 08:28 AM

You ain't gonna believe the engine room on that baby.


Ruidoso Ron
07-21-2006, 08:57 AM
Has anybody heard of a straight 540 conversion, no turbo?

My brother bought a 185 that had been converted to a straight IO-540 by the previous owner. It was to be the first article for a new STC. It had so many problems that the owner demanded that the people put the 520 back in, which they did. Not exactly sure what the nature of the problems was.

12-12-2006, 12:16 AM
Steve did you ever go look at this plane? I too have wondered about the 540 turbo. I do know that there is a lot less room under a T210 cowl over a non turbo 210.

I have been watching trade a plane for some time and this aircraft has been in there some time. I have never flown a 185,but have an intrest. I like lycomings too.

I figured some of these guys on this site would know the pros and cons.

I have been interested in the Texas Skyway conversion 550,and wonder if any here have any experience with this. I am interested in all opinions.

Steve Pierce
12-12-2006, 07:52 AM
No. They ended up with a real nice Cont. powered 185. The 550 powered 180/185s I have seen are awesome. There are several folks here who have them. I am sure they will chime in. If you can make it to the Red River Fly-In this year there will probaly be several doing their thing.

12-12-2006, 07:54 AM
I wasn't just joking about the space in the engine compartment in these. They install a shroud over the engine for cooling, as opposed to just using the normal lash up with baffles and the pressure cowl.

A friend owns one and operates it on floats. It is a remarkably smooth running airplane, as are all 540's, and it makes a LOT of power, even at sea level. He's been running his on floats and skis for a number of years, so it must work.

It is a heavy installation, and turbos are maintenance intensive at best.

If you were going to do a conversion, I'd stick with the IO-550. Much cheaper, much more straightforward installation. There is also an STC to turbo normalize the 520 if you just need some more poop at altitude.

Bottom line is this is going to be a VERY expensive conversion.


Dave Calkins
12-12-2006, 09:05 AM
I echo everything said so far on this installation....good and bad.

There is one around here (Alaska somewhere) That a customer talks about like it is THE thing.

350HP, I mean come on!! 350 HP! .......at altitude, to boot!

The Chieftains around here seem to dispatch like 99.9% with the same engine, so she's reliable, too.

12-12-2006, 06:43 PM
Thanks for the input.

12-13-2006, 09:18 AM
I have no personal knowledge, but the late Mark Hawkins told me that he knew of at least one that had major cooling issues.

I agree with this. A friend of mine had a 185 on amphib floats with this conversion, and it was a major pain in the you-know-where from a maintenance standpoint. There's so much heat packed into that cowling that EVERYTHING gets cooked. We were always replacing wires and other stuff due to heat damage.

Performance was pretty impressive, but I would never have one just due to the maintenance headaches. The performance ain't worth the trouble if you ask me.


12-28-2006, 01:51 AM
I put an IO-550D in my C-185 when the IO-520 timed out. Also took the 2 blade off and put a 3 blade McCaulley 401 on. No tricks. Good fit. Airspeed went up 10-15mph with the gas consumption staying around 13gph. Very smooth setup. Didn't have to fool with a motor mount change as the IO-520 mount worked with the STC. I just gained 34lbs, mainly because of the 3 blade.

12-28-2006, 02:42 AM
A 550 D with a 13 gph consumption?? Need t5o re-check those numbers. Lean of peak ops perhaps or flying around at 100 kts but not at cruise and rich of peak. Closer to 16 gph at best, but a VERY nice engine . Mine has the ECI titan cyls and its a HUGE improvement over the continental stock cyls.

Bob Breeden
12-28-2006, 06:12 AM
Steve Pierce,

What I have heard about the TSIO 540 Lyc in the 185 mirrors what MVivion says.

I owned the brother to this plane, N60VA. It had the TurboTech conversion retrofitted to the original Continental IO 520. The first landing after purchase in Nevada, (and subsequent second takeoff) was in the high, thin air of Telluride, Colorado. Yes, the Turbo works!

Two throttles, once the original throttle is firewalled, just proceed with the second, up to 29.98 inches of Mercury on the MP. Don't forget to only lean to the altitude that the engine then thinks it is at! Cowl flaps as you would a stock 185. I honored those commonsense rules regarding the max manifold pressure, leaning and cowl flaps, and the engine was trouble free. I only had to change the oil and filter, and clean the plugs, the entire time I owned it.

The negatives: 1.) It was a high pilot workload engine to operate. 2.) The cabin temp was 10F hotter than ambient winter and SUMMER, with the heat off. Picture a glowing red hot bowling ball sized piece of iron just ahead of the firewall. 3.) Though the engine assembly is lighter than the Lyc conversion, the airplane was heavy and draggy (radios, autopilot, Robertson) I added sportsman stol, VG's and Gar-Aero's.

I sold it and replaced it a few years later with a nice light '53 C-180, with a later model 0-470, otherwise stock.

Bob Breeden


12-30-2006, 11:29 PM
ppl185, do your homework. the factory data will verify my numbers, not to mention the jpi ff indicator. the engine/prop combination is a vast improvement over the io-520 with a 2 blade...

08-22-2007, 10:50 PM
I do my homework evrytime I fly my 185. It has IO 550D with an 88in three blade 401 Mac, Shadin ADC and GEM 610 (Insight). I lean to peak with the 610 and run rich by 75 degrees. Usually around 125 kts Indic for a 70 degree day at sea level. Shows 16-17 gph on the 430 which reads off the Shadin and about 16 gph off the analog fuel flow gauge. This is with ECI titan cylinders with 100 hours use. I could run 50 of peak but that only gives my a few tenths/hr off the burn. I prefer the cooling. I run below 380 CHT. If 75 rich of peak won't give me that I modulate cowl flaps open to get it . If it STILL is above 380 w/ cowl flaps wide open, I richen mixture. Only way to get 13 gph on MY 550 D is LOP which I won't do. The loss of HP would be the same as running a healthy ROP at reduced power settings.

08-23-2007, 12:33 AM
I went with a factory IO-550. Their operator's manual shows rich of peak, peak, lean of peak for most operations. The fuel flows are consistent with my operating experiences. I run rich of peak, always. At 23 inches and 2100 rpm, my fuel flow is about 13gph and indicating 150-155mph. Some days I am slower, some days faster but that is the average. You sound like you have an aftermarket rebuild, in which case, your numbers will probably be different. My empty weight on my 185 is 1749lbs. Yours will probably be different. Also if you leave the prop speed up around 24-2500, you will see 16-18gph at sea level.