What Engine to Buy?

Its time for me to obtain an engine for my RV-9A. I am considering a Penn Yan Aero O-320 Fixed Pitch, 160 hp ($19,900). I am looking for advice, comments or links to the answers. Here are some of my questions.

Is the price of an electronic ignition system worth it? What system (SLICK, Lightspeed) is better and why? What is the difference between Plasma II and III? What pickoff is better, crank or Hall Effect?

Is an In Line starter worth the extra $160? On the lower compression engine is it worth Porting, Polishing, and Flow Matching ($1300)? What is a piston cooling oil nozzle kit ($85)?

After I ship out this e-mail I will search the forum for answers, but I though I would ship this out for latest experience.

Check out the Emag/Pmags for your magnetos. The Pmag is self powered so you don't have to worry about a duel bus electrical system and you can replace both mags with electronic ignition. Even better, you can use auto plugs rather than $20 aviation plugs.

Barrett Precision Engines

Give Allen Barrett at BPE a call. He builds a very nice (I)O-320-X. Perfectly balanced engine, dyno run, the works. Tell him Matthew sent you.

Allen Barrett
[email protected]
918-835-1089

In my opinion, I guess the answer to that is your own personal preference. There are many, many, 360's out there running with just two mags. They work great and are reliable and safe. However, even when you have a good system, others will try to improve it, that's why there are alternative systems available. Do those alternatives make the engine more efficient? Probably. Safer? Maybe,maybe not. More reliable? Not necessarily. More expensive to purchase? Most likely. So when you take all the variables, into consideration, it comes down to whether you want electronic ignition or not, what type of redundancy you want, and what you want to spend for it.
If you want dual electronic ignition, each using the other as the back up you could use two of a system like Lightspeed or some of the others available like Emag /Pmag. If you want 1/2 electronic ignition and 1/2 standard ignition, the only way to do that exactly, is to use a mag on one side and a system like Lightspeed or Emag on the other side. If you want to run dual electronic with dual magneto backup, then the LASAR system from Unison is the way to go. All of these systems, standard magneto ignition, full electronic, partial electronic and partial mag, LASAR, in my experience, work well and are reliable. Another possibility is the FADEC system, from Aerosance. This system gives you full double redundant electronic ignition but also gives you electronic fuel injection as well. So with that system besides getting the advantages of the electronic ignition, you also get a very precise fuel metering system that also performs all of the leaning functions on the engine( No more mixture control). The FADEC system adds considerable cost to the engine over standard carburetor equipped with any of the ignition options listed. In most cases about $7500.00 more than a standard O-360. The Lightspeed system adds about $350.00 to $900.00 per side additional, depending on which of their systems you want to use over the standard engine. The LASAR system typically adds about $1800.00 to the engine, over standard ignition. These costs assume that you are getting some sort of credit for not using the standard ignition system. If you weren't getting a credit you would add about 600.00 for each mag and harness, you weren't using to the costs and of course you would have those components as not installed spare parts.
The Hall Effect sensor from Lightspeed is a gear driven unit that mounts where one of the mags used to. It requires removal and periodic inspection. The crank sensor mounts behind the crank flange and is a fixed unit with no moving parts and never needs to be removed to be inspected. The crank sensor system provides more accurate system information to the LSI system then does the rear mounted Hall Effect sensor but for all practical purposes either is extremely accurate. The crank sensor system is harder to install as compared to the rear mounted Hall Effect sensor. The crank sensor is less expensive then the Hall Effect.
It is my understanding that the Plasma III system produces a hotter longer duration spark at a slightly different timing curve. This system is more tuned for very high performance engines and may be overkill for you on a O-320 that will be used more routinely, then say a racing machine.
Piston oil cooling nozzles are nozzles that can spray oil in the underside of the dome of the piston to help keep the piston head cooler. In high compression and turbocharged engines these are used to cool the pistons to help with wear and detonation margin. Not really necessary on a 8.5 or 7:1 compression engine O-320 in my opinion. They can help keep piston temps down especially with electronic ignition.
What is the standard starter offered? Hard to say if the in line is worth the extra dollars without knowing what to compare to. It has been my experience that in most cases any of the common lightweight starters will provide very good service life and are able and up to the job with out going to a high torque unit. Some swear by them, but I don?t think they are always necessary.
I don?t know what Penn Yan is doing with porting polishing and flow matching but I can tell you that the processes we do, here at Mattituck, for those items makes the engine run dramatically smoother then one without them. If its? worth it to you to get them done is a personal choice but I think it is.
Good Luck,
Mahlon
"The opinions and information provided in this and all of my posts
are hopefully helpful to you. Please use the information provided
responsibly and at you own risk."

So many questions

Larry said:

I am considering a Penn Yan Aero O-320 Fixed Pitch, 160 hp ($19,900). (Check out Mattituck also)


Is the price of an electronic ignition system worth it? What system (SLICK, Lightspeed) is better and why? What is the difference between Plasma II and III? What pickoff is better, crank or Hall Effect? (Big question, yes EI is well worth it. Magnetos are fine but if you are starting from scratch and get a good credit on the magnetos go EI. Mattituck gives a fair credit off the price of the engine to sub an EI for the mags. Last I checked if you get a Superior engine direct they basically tack on the cost of EI to the basic engine which has the cost of the mags already, so you are paying for the mags and you dont get them. If the engine builder will install it, the crank pick up for the LS is lighter, cheaper and reliable. Nothing wrong with hall effect magneto drive set-up, but you have than have to buy expensive magneto gears. Use Lycoming/ECI PMA mag gears not experimental gears that E-mag/P-mag uses. Nothing wrong with the P-mag/E-mag EI units but they so sell some "aftermarket" gears and there were some early problems. They are cheaper like $80, where the lycoming/ECI gears new are about $250. You can find mag gears used for about $80. As far as aviation plugs vs. auto plugs being better, per Bill Repucci, they are cheaper but they have less performance, which is documented. There also have been a few problems with the auto plugs getting too hot and malfunctioning, although rare it happens. I do agree with Bill that the P-mag/E-mag option is a good one, and they do have an aviation plug harness option. If you go with LS EI you have to go with autoplugs because they don't offer a harness for aviation plugs. LS is a top of the line EI with a little more installation and you may elect to install a small aux back-up battery. The P-mag as mentioned is self powered like a magneto but with the advantage of EI. The absolute performance of the LS should be a little better than the p-mag/e-mag. Also the LS has more features (rpm, map, advance readout and cockpit advanced option. For daily flying the P-mag/E-mag is good enough.)

Is an In Line starter worth the extra $160? (No, a basic Flyweight Skytec is fine. You can go up to their wire wound model; The top of line inline is for airplanes with retract gears that the other models of starters don't fit.)

On the lower compression engine is it worth Porting, Polishing, and Flow Matching ($1300)? What is a piston cooling oil nozzle kit ($85)? (You are building an RV-9A not a reno racer. Save your money. Piston cooling is for turbo-charger, high compression. Build up a stock (I)O-320 with EI. I like Carb over fuel injection for cost and simpler installation, but that is a whole debate in itself. The main reason for FI is better gas mileage, but in small engine like a 320 the advantage is smaller the say a bigger 360 or IO-540. )

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GGGGGGGGGGGG

my 2 cents

Save your money on the whistles and bells and put it toward a constant speed prop and governor. You will save money on fuel, save wear and tear on the engine, have greater options on selection of power settings at altitude, be able to reduce the noise level and vibration and increase climb performance.
I am an A&P and subscribe to the keep it simple theory, but I put a constant speed on my -9 and couldn?t be happier!
Like I said, just my 2 cents.

Agreed

Agreed there....Whatever you do be sure and go constant speed.

Even if

N819VK said:

Agreed there....Whatever you do be sure and go constant speed.

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Even if you choose a fixed (recommend sensenich) get the constant speed (hollow crank engine) vs a fix only. If you decide to go c/s later it will be possible without changing engines. Resale will be better with the C/S capability of the engine even if the fixed is mounted. I always had C/S props on my RV's as well as my current project, but I must admit for the money the Sensenich is a good value and gives great performance. Being that it is made specifically for the RV and is metal (low maintenance) I think it is a good economy option. G

Thanks all for all the input. I just finished touring the Penn Yan facility and I am happy with what I saw. The people there were very helpfull and knowledgable. They advise to schedule receite of the engine so it sits unrun for the least time. Receive, install and fly as soon as possible. This prevents damaging corrosion. They showed me many examples of what corresion can do. Still not sure of what I am going to get. I will reevaluate the Fix Pitched vs Constant and the inline starter. Probably go with one mag and one EI. Inline starter, no porting/polishing and no oil injection.

Thanks Again

Sorry this is late but, directly relevant. I toured Penn Yann last summer and asked specifically about porting, polishing and flowing. The answer: "a waste of money unless it's an IO and really only worth the expense if it has high compression pistons".

They are more than happy to accommodate drop in visitors. I recommend you take a fishing pole, they are a half mile from Lake Keuka, the second largest Finger Lake.

Jekyll

Auto or Aircraft plugs

Now for the real reason I'm in this thread today. Searching for some information to help me decide whether to use auto or aircraft plugs. I bought a TMX-IO-360 today from Mattituck with E-MAG and P-MAG. I'm just not sure yet whether to get the auto plug option or go with aircraft plugs. I have a bit of time to decide.

George mentioned "documentation" that indicates auto plugs achieve less performance. Where can I find that? Anyone with a good recommendation on the way to go? I read the thread on NKG plugs but that really didn't help other than highlight that replacement auto plugs are MUCH less costly.

Longevity, plug adapter reliability, electrical interference or anything else to consider?

For anyone else considering Mattituck, the current delivery time is 16 weeks. TMX-IO-360, CS with roller tappet is base priced at $22,800 and the P-MAG/E-MAG is an additional $705. All new Lycoming parts except I opted for ECI Titan cylinders for an extra $450.

I hope to have that puppy singing by hunting season (I admit, chasing deer and spawning salmon distracts me from building from October to December).

Jekyll
7A
installing systems

Get biggest engine recommended by designer.

I have been flying my 160 HP RV-6 for over 8 years. There is 1,839 hour on it. What would I do different? Get the largest engine recommended by the designer. I already have a Constant Speed prop and would not want an RV without it. All the LARGE engine shops are good and have great experimental clone engines at good prices. I am saving for a 360. I have a depost down on 2 P-Mags. I like the Lasar system for its backup but if the P-Mag lives up to 75% of what they advertise, I will be happy.

The constant speed prop, even on a 160, will give you all the performance that you can get out of the airframe. The fixed pitch props are more of a compromise and will only allow you to use about 80% if the airplanes capabilities. Yes that 80% is more than any spam can using the same horsepower.

All the extra porting, polishing, and balancing is nice and will give you a smoother engine but it does cost more money. I know that the Superior parts are well matched and balanced. My guess is that ECI also holds closer tollerances on their parts.

I like the Superior XP engine. Take a look at the TMX engine also. Prices are close so pick the one that impresses you the most. Mahlon provies a LOT of support to the engine groups and although we never met, I am impressed with what he has to say. I know that Mahlon can build a TMX engine using the best parts from Superior, ECI, and Lycoming at a great price and is with an outfit that will PROVIDE support after the sale.

Check the difference in price of a new experimental 320 compared to the 360. Add the constant speed prop to that. Compare total amount you will have in the airplane with and without constant speed prop to see that the percentage increase is small. Spread the cost delta out over 10 years and you will see the cost difference is very small.

Gary A. Sobek
RV-6, N157GS O-320 Hartzell flying 1,839+ hours in SoCAL
EAA TC
FAA A&P
FAA DAR function code 46

I did the tour, was happy, and got the engine. It is now hung on the plane. I went with a fixed with provisions for CS. Yes the area was very nice but I did not have my fishing pole. Its pretty cold there now.

Jekyll said:

Now for the real reason I'm in this thread today. Searching for some information to help me decide whether to use auto or aircraft plugs. I bought a TMX-IO-360 today from Mattituck with E-MAG and P-MAG. I'm just not sure yet whether to get the auto plug option or go with aircraft plugs. I have a bit of time to decide. Jekyll
7A
installing systems

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My TMX-IO-360 is supposed to be ready sometime in April, and my two P-mags are supposed to be shipping directly from E-magair to Mattituck in about a week.

I was faced with the same question and at first I thought I'd go with auto plugs, but when it came time to decide, I went with the aircraft harnesses and plugs. Maybe it was because Brad at EMagair didn't seem terribly excited about using auto plugs in general even though he says the Pmags work fine with them.

In the end, I just wasn't comfortable with running auto plugs even though many have done so successfully, but the main reason to do so is to be able to buy cheaper plugs. Well, I just don't think the cost of AC plugs is going to make the difference between affording to fly or not, and I didn't like the idea of having to use inserts necessary for the auto plugs.

All I can really say is that aircraft plugs "feel" better to me, and if it ain't about feelins', what is?

Choice must match the use

RV6_flyer said:

Check the difference in price of a new experimental 320 compared to the 360. Add the constant speed prop to that. Compare total amount you will have in the airplane with and without constant speed prop to see that the percentage increase is small. Spread the cost delta out over 10 years and you will see the cost difference is very small.

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Good thoughts indeed, but have some questions:

What is the weight difference between the 320 and 360?
What is the weight difference between the FP and CS?
What is the price difference between the FP and CS route?
What is the break even point in hours/year?

I fly 100 hours per year. Getting there really, really fast is not as important as the activity of sitting in the plane and doing the flying thing. 150MPH vs. 180MPH will only cut my flying time for the day and I like to spend time in the airplane flying not on the ground. It's hard enough to find days to go flying, so the last thing I want is to do is a 100 Mile burger run in 30 minutes instead of 45 minutes.

I think if somoene flies 300 hours a year on x-countries the heavy stuff is OK and the expense well justified, but for some of us doing low hours per year we can live with the lighter side and keep the weight where it belongs: in the wallet. Of course, if the wallet is not a problem then by all means.... help thyself to the best, but if a guy is on a budget the engine choice should be made based on the hours per year and missions flown.

What good is $25000 worth of engine and CS prop sitting in a hanger and being used 70 hours a year (if lucky enough to have the free time to go places)?

Jose Borja
Elk Mound WI

Jose,
I'm going to jump in here before the "constant speed" guys do. A lot of people think that I am against constant speed props because I promote fixed pitch. Not true. I've owned several planes with c/s props and they are great. My stand is that unless you really want one, they are not necessary on an RV. My fixed pitch gets me and my wife out of my 1500', Texas strip in August just fine, and has been doing so for 13 years. My cruise @75% is 201mph (of course I don't run 75% very often because I'm cheap). My prop cost $1600 and weighs 16 lbs. and has virually no maintenence requirements. If you want a c/s then by all means get one. The whole idea of building is doing your own thing. But don't let these guys convince you that they are necessary. $.02 worth included!
Mel...DAR

PepeBorja said:

Good thoughts indeed, but have some questions:

What is the weight difference between the 320 and 360?
What is the weight difference between the FP and CS?
What is the price difference between the FP and CS route?
What is the break even point in hours/year?

I fly 100 hours per year. Getting there really, really fast is not as important as the activity of sitting in the plane and doing the flying thing. 150MPH vs. 180MPH will only cut my flying time for the day and I like to spend time in the airplane flying not on the ground. It's hard enough to find days to go flying, so the last thing I want is to do is a 100 Mile burger run in 30 minutes instead of 45 minutes.

I think if somoene flies 300 hours a year on x-countries the heavy stuff is OK and the expense well justified, but for some of us doing low hours per year we can live with the lighter side and keep the weight where it belongs: in the wallet. Of course, if the wallet is not a problem then by all means.... help thyself to the best, but if a guy is on a budget the engine choice should be made based on the hours per year and missions flown.

What good is $25000 worth of engine and CS prop sitting in a hanger and being used 70 hours a year (if lucky enough to have the free time to go places)?

Jose Borja
Elk Mound WI

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Jose

According to Lycoming tables that I have seen, there is 10 pounds difference in weight on the parallel valve 320 / 360.

You need to do some research for the other answers. If the fixed pitch was much lighter, my RV-6 would be unusable with an aft cg problem.
See: http://www.rvproject.com/wab/ for weight and balance info of over 100 flying RVs.

LIFE CYCLE COST is LOWER with the constant speed. Look at the TOTAL cost of ownership. Fuel flow at reduced power setting will average 1.5 GPH less on the constant speed prop. At $3.50 / gallon that is $5.25 / hour less fuel costs to operate the constant speed prop. That is $10,500 less fuel burn in 2,000 hours.

I for one would NOT own an RV without the constant speed prop. Do you need a constant speed prop? NO. To quote Ken Scott at Van's Aircraft, "Without the constant speed prop, you can only get 85% of the capabilities of the airplane."

Gary A. Sobek
RV-6, N157GS, O-320 constant speed, 1,839+ hours
1st flight Sepetember 1997
EAA TC
DAR

Constant speed can give better fuel efficiency,

Up to 10% efficiency increase with injection versus carb, especially with GAMI Jectors,

Roller cam can give up to 5% efficiency,

EI can give up to 15% fuel efficiency...

I guess I should install bigger tanks to capture the fuel my engine will be making once I install all the efficiency measures. I half expect to see an Exxon Mobile team at my hangar to conduct a geological survey in search of the next big petroleum find.

Sorry, I'm not sniping. I just see a bit of humor in the situation.

Jekyll

Gary,
Not sure why you would have an aft c/g problem with a wood prop on a -6. My -6 has a light weight starter, light weight alternater, no vacuum system, O-320-E3D (lightest of the O-320s) and I've been flying for 13 years with a light weight prop. Until I got the Catto, my prop weighed 11 lbs. The only w/b limit I have is 80 lbs. of baggage. I have found that this is more than enough.
Mel...DAR

CG Problem???

Gary,

Thanks for the insights... I am building a 7TD and plan to install a 320 and FP prop. I am trying to build the lightest, all manual, least expensive, complexity free, RV possible. That is my stated goal for a quality build, but I am starting to think my problem will be a whacked out CG problem. I am not installing anything (antenas, boxes, wiring, etc) other than the manual trim deal past the flap actuator rod to keep the weight forward.

I'll have to ask the factory about those of us that wish to build a very light airplane with no frills. My goal is to be able to remain below 1000 lbs EW. Call me crazy, but the 150HP should do great on a plane that weighs 150 pounds less than its bigger HP cousins. Also the smaller engine will need less fuel for 3 hour legs and that means less takeoff weight. I have a friend with an RV6, 320 wood prop and runs auto gas. His plane is plenty fast for my taste.

I don't want to go fast. 160MPH sounds great to me for the type of flying I do. Am I in for a nasty surprise due to CG problems? How are folks dealing with light builds?

Jose Borja
Elk Mound, WI

PepeBorja said:

I am building a 7TD and plan to install a 320 and FP prop. I am trying to build the lightest, all manual, least expensive, complexity free, RV possible. That is my stated goal for a quality build, but I am starting to think my problem will be a whacked out CG problem. I am not installing anything (antenas, boxes, wiring, etc) other than the manual trim deal past the flap actuator rod to keep the weight forward.

Jose Borja
Elk Mound, WI

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It has been shown that building a '7 the way you are will probably be tail heavy enough to affect the CG to where you might have to limit your baggage to less than it's rated 100lbs.

Some things you might think about:

Fly with less baggage. (Simple, but obvious).

Go with the Sensenich FP metal prop rather than composite.

Go ahead and add a second battery. It's easy to do, and who can argue with a backup battery?

Sabre makes extra heavy prop extensions. Since you will need a prop extension anyway, using a heavy one would put another few pounds right at the front where it would do the most good for the least amount of added weight.

Don't put ANY accessories in the tail. Anything like a strobe supply or ELT should go as far forward as possible.
Mount your fire extinguisher up front (who can argue with having a fire extinguisher handy? )

Remove your tail wheel, lengthen the strut, install it up front under the engine and hang a little sign on it that says "nose wheel".

You'll probably be fine if you think ahead and plan for installing everything (as practically possible) as far forward as possible.

the math does not lie

Mel said:

Gary,
Not sure why you would have an aft c/g problem with a wood prop on a -6. My -6 has a light weight starter, light weight alternater, no vacuum system, O-320-E3D (lightest of the O-320s) and I've been flying for 13 years with a light weight prop. Until I got the Catto, my prop weighed 11 lbs. The only w/b limit I have is 80 lbs. of baggage. I have found that this is more than enough.
Mel...DAR

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IN 2001, I had 134 pounds of bagage for two people for a three week trip in Alaska. The shotgun and survival gear was on the floor forward of the spar and it accounted for 34 pounds. With two people, and baggage, it is easy to get a lot of weight. One needs to be aware that the LIGHT prop will get to the aft CG limit very fast. Run the numbers as the math does not lie. On my airplane, the CG moves 1/2 inch aft going from full fuel to no fuel.

To save weight, I used a lot of Aluminum washers, all metal MS nuts, cut large radius corners on parts. These are all weight saving tips that I followed from a retired Lockheed worker. It is difficult (not impossible) to build the airplane ligher than what the factory prototypes have been.

I fly a lot of formation. Having 160 HP engine is a LARGE handicap when flying with the guys that have 180s. They want to fly faster. I have to have the prop set at 2,700 RPM to stay with them. I have also been safety pilot in fix pitched 320 airplanes and they will over rev on the downlines that serious formation pilots use during practice.

In 2002, one of my friends with O-360 CS RV-6 left Southern California for Oshkosh. We did not travel together. At Oshkosh, we compaired notes. We flew just about the same route. It took me 12 hours and it took him 11 hours. Our fuel burn was the same. (less than 1/2 gallon difference) Tom few faster on the same gas I used to fly slower. If you get out the Lycoming charts that show fuel flow, it shows that the O-360 uses less pounds of fuel per hour per horsepower produced.

As John Thorpe said about the T-18 design: "Built it as LIGHT as possible and only as strong as necessary."

Gary
SoCAL DAR