Bolt on Turbo Charger O-300

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Bolt on Turbo Charger O-300

Postby MoonlightVFR » Tue Jan 02, 2018 1:10 am

Twenty five plus years ago the aviation press was abuzz about adding turbo chargers.

I don't think it ever happened.

Why not ?

I remember being concerned about over boosting and blowing up a cylinder.

Are any Cessna 170s being legally operated with a turbo charger.

gradyb, '54 B N2890C
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Re: Bolt on Turbo Charger O-300

Postby 9976AJds » Tue Jan 02, 2018 6:16 am

Check with the experts, but RAJAY made several STC conversions for popular engines. I had one on a 225 Cont., in a Bonanza. EZ Manual Vernier control for maintaining 30 inches for take off and climb to 10K Plus. It worked great, also flew a AC 500A with RAJAYs no problems (1980's), too EZ. Find out who bought them out. Good Luck JD.
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Re: Bolt on Turbo Charger O-300

Postby n2582d » Tue Jan 02, 2018 2:13 pm

Mr. Doerstling has been trying to sell his experimental turbo 170B for about 10 years. I’m guessing there may be a reason it’s not selling like a pancake. In looking at a list of Rayjay STC’s it appears they don’t modify anything smaller than a IO-320. I think a major issue in adding turbo-normalizing to the O-300 would be high oil temperature. So you’d have to add an oil cooler. ... and a cabin heater ... and oxygen system ... . :lol: I’ve always wondered why the oxygen system was an option on the 170 ... who would ever operate it above 12,500’ for over 30 minutes? In looking closer at figure 107 I think I found the answer. Look closely at the rear seat outline. The oxygen system was designed be used for medical patients in conjunction with the optional stretcher in fig. 81.
Figure 107
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Re: Bolt on Turbo Charger O-300

Postby hilltop170 » Thu Jan 04, 2018 6:15 pm

Jacobs Engines never built a turbo version of their 7-cylinder R755 but a low-compression 245hp R755 Jacobs was turbo'd to 350hp, an increase of 43%. They are outstanding performers, getting up to 200mph TAS at 20,000' in C-195s.

I wonder if a crafty "experimental" guy might get the same % increase on the O-300 by using low compression pistons and a turbo?

145hp x 1.43 = 207hp

The O-300 crank is the same one used in the Continental IO-360 which goes to 210hp so the lower end should take it. The question is can the cylinders?

Maybe someone with an "airboat" engine will try it.
Richard Pulley
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1951 170A, N1715D, s/n 20158, O-300D
Owned from 1973 to 1984.
Bought again in 2006 after 22 years.
It's not for sale!
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Re: Bolt on Turbo Charger O-300

Postby ghostflyer » Fri Jan 05, 2018 12:28 am

While the crank shalf could be the same but the crank case has had a few changes for it to be a io-360 and other components also have had a tweak or 2. Oil temperature will be a problem [o-300] if the engine is performance enhanced . A number of years ago we received a set of new cylinders [ported and polished ,flowed] and some higher compression pistons . A remote oil filter was added with a heat sink added. A different exhaust was fitted . Every thing was balanced and a engine that really purred . BUT it had to have the best av gas around . This was done all legally via EO,s and STC;s.
Unfortunately the engine didn’t last long due to sabotage from a demented person . Unfortunately he had a stroke about a week later and the police could not take action . Wow I got off the subject of turbo changing.
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Re: Bolt on Turbo Charger O-300

Postby Azpilot » Sun Jul 08, 2018 5:02 pm

I'll do some weighing in here (please correct me if I'm wrong).

So I own N3JX, AKA the Turbo 170b. The engine that I have is a Turbo Normalized TSIO-360A. Which really gives you 32inHg up to 18k feet. But you can't use it for more than 5 minutes. You've got to fly it at 29inHg and 2400 after that. Which thats what most of the Ray Jays give you.

There's a lot more to turbocharging than just bolting one on. First you'd have to decide if you want to normalize or turbocharge. So theres a quite a bit of work you'd have to do to keep the engine from becoming a grenade. Normalizing is way easier. You'd have a vernier on a wastegate to control how much compressed air you'd put into the engine. Too much and you run lean. Which happens incredibly quickly. So you'd have to put in an EGT (or 6) to monitor the cylinders. Its a Tit for Tat deal. You're adding weight to gain power.

The TSIO-360A runs lower compression (7.5 to 1) than the IO-360(8.5 to one). It also has a scavenge pump to pull oil away from the turbo as well as a different fuel injection system.

Personally I'd rather have the IO-360KB. Same power, less weight. The Turbo is nice for density altitude, but its not great for local flying.
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