# Lycoming O 320 questions

Discussion in 'Firewall Forward / Props / Fuel system' started by 4trade, Oct 20, 2013.

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1. Oct 20, 2013

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Is there narrow deck and wide deck engines at O 320 series like bigger O 360 have?

2. Oct 20, 2013

### TFF

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3. Oct 20, 2013

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What is differences for those two, except obvious one....so do these wide deck have angle valve like O 360?

4. Oct 20, 2013

### TFF

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The cylinder base bolt spacing is different. The cranks are different and cases. No angle valve versions, but people have mixed them. In a way they are different engines. I believe all conical mount are narrow but not all Dynafocal are wide. lycoming is terrible with their designations.

5. Oct 21, 2013

### kent Ashton

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Google "lycoming engine identification". Oh what-the-heck, here's one. Lycoming also has an official Service Bulletin or publication that shows the same.
Brian Meyette's Lycoming Engine Codes page

The narrow deck engines are older engines. Nothing really wrong with them except that, AFAIK.

Next question: Conical mount, Dynafocal I, Dynafocal II

6. Oct 21, 2013

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Thank you!

I presume that narrow deck engine is lightest one at that series. I am thinking lately that i might put that one for my Cassutt. Original plan was use turbocharged O 200, but turbo with all gizmos will add weight approx same level than stripped O 320. No point to hod rod O 200 if i can use more reliable bigger engine for this plane. Good used one cost same than overhauled and charged O 200, little more power too.

7. Oct 21, 2013

### TFF

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A turbo in an aerobatic airplane would be a mess. The narrow range an airplane engine runs and not being able to use pop off valve or automatic wastgates is a pain. I work on turbocharged piston helicopters and you cant have automatic controls. You have to have pilots skilled in not overboosting to keep the engine alive. If you use automatic controls and it has to dump pressure you will end up in the dirt, because the lag in the system to shut the valve and power it all back up; if you start it bootstrapping in a hover you just crashed. The reverse is needed; overboosting might save your life; you dont want something out of your control saying no. Lycomings are better aerobatic engines overall anyway.

8. Oct 21, 2013

### bmcj

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Not sure how much power you need and what your budget is, but maybe the new 6-cyl D-Motor?

D-motor dmotor LF39 liquid cooled side valve direct driven ultralight engine

D-motor dmotor LF39 specifiactions

Or if you want lighter and closer to 90 HP:

D-motor dmotor LF26 liquid cooled side valve direct driven ultralight engine

D-motor dmotor LF26 specifiactions

It also seem to have a lot of torque compared to the other engines, so you would probably have more (better) options for prop pitch and diameter.

Best of all (for you), they are made in Belgium, so I expect the price and availability would be good.

I don't have any stake in these compact little engines except that I'd like to see the results of their use and I would like to see them succeed.

Last edited: Oct 21, 2013
9. Oct 22, 2013

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I want all the power i can get...! I am not happy those flathead design looks, and it is out of my price range. I can get more raw power with less money for O 320. Power to weight ratio should be somewhere 5.5 lbs/ hp or less. Sounds like real fun!

10. Oct 22, 2013

### Dan Thomas

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More like 2.5 lbs/hp for the O-320. It weighs about 276 lb dry; add the prop and an alternator and oil cooler and some baffling and it's up to 330 or so. It makes 150 hp.

The Lycoming is a much more robust engine than the O-200. Having looked after both, and replaced both at TBO, and flown both, I much prefer the Lyc. The O-200 doesn't generate an honest 100 hp either, in my opinion. I flew a C-90 that pulled better. Jan Carlsson says they use 85 hp for the O-200 for prop development purposes.

Dan

11. Oct 22, 2013

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I was calculating full gross numbers, and these was pretty impressive. I am happy to find out that i can build that plane with this engine. It have been done couple of times before, and it is even possible to do without additional lead ballast at tail, if build carefully. I agree that Lycoming is better engine, and this one should give me impressive climb and vertical lines.

12. Oct 23, 2013

### TFF

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You could always move the seat back a couple of inches. The thing about going Lycoming is swapping different engines. A Conical Lycoming will let you mount 235,290,320,360 engines. Some are easier to find than others but lots out there. 235 and 320 cores can be had pretty cheap. I would go with the 320, but a high compression 0-235 might give you a weight break with 125 hp; aerobatic engines needing to be torn down every 800-1000 hours so shorter life of the high compression engine would match pretty well.

13. Oct 23, 2013

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I will recline my seatback, and that will move CG little farther back. Battery behind seat and light weight prop should do it. I am thinking that i may fill my tailfeather with foam and use carbon skin. That will add little more weight but give more weight at tail for better moment at heavier engine and long live skin life.

Thousand hours is plenty of engine life for private own aircraft, it takes lot of years to reach that mark.

14. Oct 24, 2013

### TFF

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Depends; friends RV7 is 4 years old and has 600 hours on it.

15. Oct 24, 2013

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Yes, it depends......your friend have a lot thicker wallet than me! Avgas cost here approx 15$gallon :shock:! Thousand hour is lot of gallons (read$)

16. Oct 25, 2013

### TFF

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A 150hp 0-320 can run auto gas for some savings. Stay away form any of the engines with AD in the designation. An engine from a Robinson R22 can make a good airplane engine.

17. Nov 3, 2013

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We can buy 98 octane autogas here. I will go with autogas for sure. Most of small airfield here don´t even have possibility to buy avgas. What is that AD stand for?

18. Nov 3, 2013

### TFF

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AD is just the designation with the "duel mag", two mags in one. The joke is AD engines have lots of ADs, Airworthiness Directives, which in the beginning they did. They were designed with smaller lifter surfaces like a car, and they were not tough enough. ADs with that and with the early mags. I dont know if the engine mount length is different because of the mag; block mount spacing is the same and they are Dynafocal.

19. Nov 3, 2013

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Thank´s! I really want to avoid anything like dual mag in one.....Cassutt landing speed is not really attractive for possibility of forced landing in bush country like Finland.

20. Nov 3, 2013

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