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0-340 stroker engine, any thoughts good bad ugly??

jongurley

Active Member
Me and a partner are building our RV7a and we have bought a good 1600smoh 0-320 which is already mounted on the airframe but not plumbed, and we are having thoughts about pulling it off and overhauling with the 0-340 kit that ECI sells, claims light weight with 180horsepower, any thoughts or experiences on this 0-340 thanks.
 
I have an IO-340 in my 9A. I have around 300 hours on it now. It is a great engine. PM me if you wish to discuss details.
 
You should consider the rebuild with an injection system fro either Precision Airmotive or Airflow Performance as the first priority.

Extra cubes?.sure, but second to the above.
 
As a practical matter, if one already has an O-320, going to an IO-340 makes a lot of sense to me. Seems to be a very reasonable way to obtain some more performance.

I have an O-320 (wanting an IO-360 or a RR Merlin:p) and when the time comes; I'm heavily leaning to making it an IO-340. I try to stay tuned to the "340" story and haven't heard much on the down side. It would save a lot of cowl re-working I'm thinking.

I like the idea of going to fuel injection also.

Just my 2 cents about supporting your notion. I'll be monitoring your thread with you.

Good luck and best regards,
 
This is more of my thought process than fact or advice...

I was forced to rebuild my 1025 hour O-320-E2D because of a broken piston. I was dead set on doing the ECI 340 stroker kit but after speaking with the Prop guy he told me the engine would only make about 2 more MPH on the top end. He said Take-off would be dramatically different.

I decided that $6k will pay for a lot of avgas and it wasn't worth it.

My steel parts are out getting checking and recertified now and if they fail I may go to the 340.
 
Why?

You should consider the rebuild with an injection system fro either Precision Airmotive or Airflow Performance as the first priority.

Extra cubes….sure, but second to the above.

Extra cubes gives more power, whiles injection is more efficient than carburation I have seen no claimes for more power, so why are you so strong on this?

BTW when ever I go to the Airflow site my browser throws me out saying it is a malicious site!!!
 
I figure that the fuel injection on my Rocket saved me almost $6K in 350 hours. That is the difference I saw between ROP and LOP operations.

Personally, I don't see carburetors as a viable, long term solution if I'm buying the gas.

I recently bought an ECI Titan engine. The cubes were a variable, but the fuel injection was a "must have" item. I ended up with the IO-370, dual P-mags, with cold air injection. I can't wait to get it in the air.
 
Strokin....

Me and a partner are building our RV7a and we have bought a good 1600smoh 0-320 which is already mounted on the airframe but not plumbed, and we are having thoughts about pulling it off and overhauling with the 0-340 kit that ECI sells, claims light weight with 180horsepower, any thoughts or experiences on this 0-340 thanks.

Jon,

Stroker vs stock crank and injection vs Carb are separate issues IMHO.

First, Stroker vs stock crank: I have modified several engines over the past 20 years including 2-0320's my Rocket's LyCon IO-540 and my current 0-360J2A in the RVX. I also mounted an 0-340 from a twin Navion in an RV4 for a friend. The 0-340 was originally built back in the 1950's by Lycoming to get more HP from the 0-320A. They discontinued it with the advent of the 0-360. The major difference between an 0-320 and 0-360 is the stroke, the 0-360 has a longer stroke. The 0-340 stroker crankshaft brings the 0-320 stroke in line with the 0-360 and combines the best of both worlds. If you want more HP, it's a good call. However...

Personally, I liked my stock crank 0-320E2D that I installed 9.0:1 pistons shot peened rods and forged pistons with flow matched cylinders and an Ellison TBI (175HP). The secret is weight. No gain, no pain. If you can increase HP without weight gain and increase efficiency as well, it's a win win. Higher compression equals higher volumetric efficiency and better burn efficiency. My RV4 with this mod burned less fuel afterward at equal power settings and outperformed any 0-360 RV I flew alongside and still does!

Electronic ignition also greatly improves efficiency BTW.:)

Injection vs Carb: Having had 2 injected and 2 Carb engines both have advantages depending on your mission. The Carb is very simple and easy to start hot or cold. Requires a low pressure fuel pump and is reliable. Injection has more parts, a high pressure fuel pump and more lines and are harder to start hot or hand start in a pinch. Vince is right, injection is more efficient and you dial the mixture down to LOP settings on long trips. I installed a Carb on my RV4 and RVX as I like the simplicity and I can easily prop start it in the back-country with a dead battery. I also used an Ellison TBI on the X for awhile and liked it. Once I set it up it was flawless.

Overall, rebuilding your current stock crank 0-320 with higher (9 or 10:1) compression is a no brainer and not that expensive compared to the stroker crank mod. Another stroker limitation is limited parts production and size. They are wider and you might have to make new baffles. To get more HP without the mod: Lycon sells forged pistons online of any compression ratio you choose and offers cylinder flow matching (as do several other companies). http://www.lycon.com/ly-con/news.html

Email me offline anytime: [email protected]

V/R
Smokey

PS: I recently installed an 0-360J2A in my RVX with 185HP. No weight gain from my 0-320...it can be done...
 
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Extra cubes gives more power, whiles injection is more efficient than carburation I have seen no claimes for more power, so why are you so strong on this?

You answered your own question ;)

And

I figure that the fuel injection on my Rocket saved me almost $6K in 350 hours. That is the difference I saw between ROP and LOP operations.

If you are going to operate LOP it makes tuning the F/A ratio's possible, and if you are a ROP pilot you can run at the appropriate ROP setting on all cylinders using less overall fuel.

There is not an RV alive that is better with a carby. Not one!
 
Thanks for the info so far guys good stuff, after hearing SmokyRay's info I'm leaning towards saving the money and going with a 0-320 with higher compression pistons. my partner previously built a RV7 with 0-320 160hp and catto prop with vetterman exhaust and could run with and outrun some 0-360's, the climb was alittle better on a 0-360 in most cases, but his plane with 0-0320 was LIGHT and flew so good and we are shooting for light, and his plane climbed GREAT so we don't really need the extra climb i guess.
 
+1 for FI

I would go with the 9 to 1s which will cost you nothing during an O/H and spend the money on fuel injection, after running FI for the last 1400 hours since 2005 I would never have a carb again, the engine is much smoother and more efficient, also after you learn how to start it you won?t have any problems hot or cold, mine catches and runs on the first or second blade every time hot or cold. I bet a good FI cost half the price of that stroker kit.
 
Thx for info Russ, Yeh I got the FI down pat, sold my decathlon last year, been there and learnt about FI, but got it down pat.
 
.......my partner previously built a RV7 with 0-320 160hp and catto prop with vetterman exhaust and could run with and outrun some 0-360's, the climb was alittle better on a 0-360 in most cases.....

This is one place we miss Racer Bob Axsom. He would pull out all the SARL listings for RV Red (320 power) and RV blue(360 power). Then he would say, enter a SARL event to see what your 320 or 360 powered RV is really capable of doing.
 
Im just telling you what I witnessed my self, lol. Thats why were stuck on a 0-320 with carb(simplicity) but thought the 340 would be interesting to inquire on but sounds like the 9-1 pistons would suite what we need. but it is great to hear everyones thoughts and opinions .
 
You answered your own question ;)

And



If you are going to operate LOP it makes tuning the F/A ratio's possible, and if you are a ROP pilot you can run at the appropriate ROP setting on all cylinders using less overall fuel.

There is not an RV alive that is better with a carby. Not one!

I disagree with that last line. Better is to be defined by the builder/pilot. Not everyone's mission is the same.

About the 340. I know very little about it but I would not go with that if I were looking to buy an engine. If I had a 320 I might look into upgrading, but buying an engine, why not go with a 360. There is very little weight gain and you can still run mogas. With the way the 100LL debate is going, I see GA getting hammered with whatever alternative they come up with. It would be great if it were cheaper but I really doubt it.
 
I disagree with that last line. Better is to be defined by the builder/pilot. Not everyone's mission is the same.

Different mission has little to do with it. We could make the same comment about cars and drum brakes Vs Disc brakes. I struggle to find an RV mission that is better with a Carbed engine.

I am yet to read a thread where people are falling over themselves in a rush to convert IO-XXX to O-XXX.

A Piper Cub, yeah the old Carby engine is probably all it needs and there would be not a great deal to gain by having an injected one, but there was no mention in my previous post about cubs, just RV's.

I am happy enough that you disagree though. :)
 
Induced induction...

Different mission has little to do with it. We could make the same comment about cars and drum brakes Vs Disc brakes. I struggle to find an RV mission that is better with a Carbed engine.

David,
The original discussion was Stroker 0-340 modification comments for a simple HP increase. Fuel injection, as I mentioned earlier is a separate subject which could be argued either way in the same vein as Mags vs Electronic Ignition. So not to hijack the thread any more than it already has, I will add that the beauty of these airplanes is free choice. I believe the inputs for the Stroker mod were presented with good options thereafter. Nuff said...
V/R
Smokey

PS: I have been blessed to amass over 3500 hours in my two RV's and Rocket with all three types of fuel atomization over every conceivable type of terrain and long over-water jaunts. (Carb, Ellison TBI, Servo F.I.) I don't know how much RV experience with all three types you have, but I actually learned a few things in those 25 years. :)
The Carb actually has it's place in the induction spectrum. How? Lower cost and simplicity. It is also easier to start with fewer prop swings in the outback. If you are on a budget and want the lowest cost fuel atomization, the Carb is still King, and by a large margin. Is it the best and most modern efficient fuel induction system? No, but neither is the servo F.I. FADEC wins that argument with synchronized fuel injection and ignition. Get your wallet out though, it is spendy. So, a mission for the Carb is still there and knowing what I know about all three fuel atomization systems, my RVX has a Carb on it for the very reasons mentioned. Being an A&P I can also assure you Fuel Injection is higher maintenance and cost when things break.
 
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I disagree with that last line. Better is to be defined by the builder/pilot. Not everyone's mission is the same.

About the 340. I know very little about it but I would not go with that if I were looking to buy an engine. If I had a 320 I might look into upgrading, but buying an engine, why not go with a 360. There is very little weight gain and you can still run mogas. With the way the 100LL debate is going, I see GA getting hammered with whatever alternative they come up with. It would be great if it were cheaper but I really doubt it.

Actually, I was able to save about 8 lbs off the weight of my plane with the IO-340 while still getting the same 180 hp as the 360. I don't consider 8 lbs "little". Especially when I can see the same HP. So my choices were:
IO-320 -- ~250 lbs -- 160HP
IO-340 -- 7-8 lbs less than IO-360 -- 180HP
IO-360. -- 7-8 lbs more than IO-340 -- 180HP
 
They are wider and you might have to make new baffles.
This is not an issue! I used Van's stock 320 baffle kit on my IO340. I actually used 90% of all the stock 320 firewall forward kit. If it were not for the ECI forward facing cold air induction that required different exhaust I think I could have used all of the 320 FF kit.
 
Actually, I was able to save about 8 lbs off the weight of my plane with the IO-340 while still getting the same 180 hp as the 360. I don't consider 8 lbs "little". Especially when I can see the same HP. So my choices were:
IO-320 -- ~250 lbs -- 160HP
IO-340 -- 7-8 lbs less than IO-360 -- 180HP
IO-360. -- 7-8 lbs more than IO-340 -- 180HP

8 lbs to have the ability to run fuel that could potentially cost $1.50 a gallon less. In my eyes, an 8 lb penalty for that is "little." I don't know if the 340 is capable of running mogas though, seems to me the high compression pistons would make it unwise. Seems like most guys want to get an engine then pump it up to make as much power as it can. I would be more inclined to go the other way, buy a little bit bigger engine, say an 0-360, then put in 7 to 1 pistons so I could run regular pump gas and still have 170 hp. But I'm not swimming in money so I cut costs where I can, if I had more, I'd buy more horsepower.
 
Different mission has little to do with it. We could make the same comment about cars and drum brakes Vs Disc brakes. I struggle to find an RV mission that is better with a Carbed engine.

I am yet to read a thread where people are falling over themselves in a rush to convert IO-XXX to O-XXX.

A Piper Cub, yeah the old Carby engine is probably all it needs and there would be not a great deal to gain by having an injected one, but there was no mention in my previous post about cubs, just RV's.

I am happy enough that you disagree though. :)

Me too, wait, WHAT
 
8 lbs to have the ability to run fuel that could potentially cost $1.50 a gallon less. In my eyes, an 8 lb penalty for that is "little." I don't know if the 340 is capable of running mogas though, seems to me the high compression pistons would make it unwise. Seems like most guys want to get an engine then pump it up to make as much power as it can. I would be more inclined to go the other way, buy a little bit bigger engine, say an 0-360, then put in 7 to 1 pistons so I could run regular pump gas and still have 170 hp. But I'm not swimming in money so I cut costs where I can, if I had more, I'd buy more horsepower.
Well, price wise the 340 was a little more than the 320 but not as much as the 360. So using the logic you just spelled out I got 360 level HP for less than the 360 price then, on top of that, I saved around 8 lbs off of the nose of my A model RV. In my case I think I came out pretty good. As for running mogas, I have not done so yet but I think it will do fine on it. Just my opinion on this, but I think we are all just a bit too anal worrying about whether a 9:1 piston will blow up on anything less than 100 octane. I think we are all buying in to the corporate mentality of fear driven decision making. Will my 9:1 cylinder really crater on 87-90 octane fuel in a cruise setting? Or even in a full throttle climb setting if the CHT's are running 320-375 deg while doing it? Even if that is dangerous territory shouldn't I, being an educated pilot, be able to monitor and consequently successfully manage the situation?
 
Well, price wise the 340 was a little more than the 320 but not as much as the 360. So using the logic you just spelled out I got 360 level HP for less than the 360 price then, on top of that, I saved around 8 lbs off of the nose of my A model RV. In my case I think I came out pretty good. As for running mogas, I have not done so yet but I think it will do fine on it. Just my opinion on this, but I think we are all just a bit too anal worrying about whether a 9:1 piston will blow up on anything less than 100 octane. I think we are all buying in to the corporate mentality of fear driven decision making. Will my 9:1 cylinder really crater on 87-90 octane fuel in a cruise setting? Or even in a full throttle climb setting if the CHT's are running 320-375 deg while doing it? Even if that is dangerous territory shouldn't I, being an educated pilot, be able to monitor and consequently successfully manage the situation?

How did your CG come out RVsdi, we were discussing this the other day , and I hear several stories about the rv7a like were building coming out on the tail heavy side with a 0-320, because of landing gear, Ive heard guys say that with two people and a 0-320 up front only 50lbs of baggage etcetc.. (i know everybody's will vary alittle) but it sounds like if you go with a 0-320 this is the case from what people say, any input.
 
How did your CG come out RVsdi, we were discussing this the other day , and I hear several stories about the rv7a like were building coming out on the tail heavy side with a 0-320, because of landing gear, Ive heard guys say that with two people and a 0-320 up front only 50lbs of baggage etcetc.. (i know everybody's will vary alittle) but it sounds like if you go with a 0-320 this is the case from what people say, any input.
I don't have my actual CG #'s in front of me now but I basically could not push CG forward of the forward limit no matter how I loaded the plane. I could only reach the aft CG limit if I had 100 lbs in the baggage area, me and my wife and only 2 gallons of fuel in the tanks. That is absolutely not a condition I will ever allow to occur (some of that "educated pilot" decision making I was referring to earlier). Again, I don't have my numbers in front of me just now but if I remember correctly the weight on my nose gear was 275 lbs. A very important number to keep in mind also.

FYI the Stroker has had issues leading edges departing from the prop on the Carbon Cub... do your research. :)
300 hours on my IO-340 with a 3-blade Catto. Nary a leading edge issue to date. I have nothing more to add to that except to say that if this is one of your concerns pick up the phone, call Craig Catto and discuss that concern with him personally. He builds the props for the Carbon Cub guys. I am sure he will give you the real skinny on any of that info.
 
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Ahh...That is where the issue came to light. On the Carbon Cub. :) It is a harmonics issue.
 
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I don't have my actual CG #'s in front of me now but I basically could not push CG forward of the forward limit no matter how I loaded the plane. I could only reach the aft CG limit if I had 100 lbs in the baggage area, me and my wife and only 2 gallons of fuel in the tanks. That is absolutely not a condition I will ever allow to occur (some of that "educated pilot" decision making I was referring to earlier). Again, I don't have my numbers in front of me just now but if I remember correctly the weight on my nose gear was 275 lbs. A very important number to keep in mind also.

.

Im alittle confused Steve, so your saying in that setup with 100 pounds i nthe baggage etcetc, if you added more than 2 gallons your bringin the CG back in to range correct.
 
I was told that 9:1 pistons in my 360 would be fine with premium autofuel. but should probably watch the temps and adjust timing down if it was running hot.

I haven't ever run Auto fuel..yet. Mostly because I run my plane hard often and also not sure I trust the quality and cleanliness of most gas station gas I've seen.
 
For whatever it's worth, I chose a low-compression OX-340S to hang on the nose of my -9A. Here's why:

Lighter than an O-360.
Can run Mogas quite happily.
I can bolt the Rotec TBI to it and get better efficiency than a traditional carb with less weight than a fuel injection setup. Though you can do that with most any Lyclone...
At 165HP and an (initial) 1320Lb MTOW, it'll go like a scalded cat. And will keep Van happy. 5HP over recommended isn't going to be the end of the world.
Because it was cheap. Free, really. I only had to buy an ECI baseball cap. That was the single most expensive cap I've ever bought, at $30,000... :p

I'm yet to fly, aiming for around the February/March timeframe, but for the type of flying I'll be doing, it suited my needs, with the option to upgrade to higher compression pistons down the track if my needs change. FI remains an option too, but for simplicity and cost, the couple of hundred extra over a -320 made it worthwhile.
 
KR

Funny thing I observe there. On one hand you talk about efficiency with the Rotec Vs Carb, but you are yet to fly it. And on the other you went for lower compression pistons.

Sure I will grant that IF the Rotec gives a better F/A ratio spread across all cylinders, and it might, that you will be slightly more efficient than the carb, but the lower compression is less efficient not matter what.

Interesting choices.

How did the cost in USD$ stack up compared to the IO320? The price from Vans was $24,500 last time I looked.
 
Im alittle confused Steve, so your saying in that setup with 100 pounds i nthe baggage etcetc, if you added more than 2 gallons your bringin the CG back in to range correct.
yes, the fuel is really forward of CG. Everything stays within CG range until it gets down to 2 gallons. Anything 2 or less with a fully loaded plane pushes past the aft limit.
 
KR

Funny thing I observe there. On one hand you talk about efficiency with the Rotec Vs Carb, but you are yet to fly it. And on the other you went for lower compression pistons.

Sure I will grant that IF the Rotec gives a better F/A ratio spread across all cylinders, and it might, that you will be slightly more efficient than the carb, but the lower compression is less efficient not matter what.

Interesting choices.

How did the cost in USD$ stack up compared to the IO320? The price from Vans was $24,500 last time I looked.

If lower compression allows you to save money on fuel costs, at a penalty for some efficiency, cost wise, wouldn't it be cheaper to fly. "Less efficient no matter what" I can get 87 octane regular for $3.5 a gallon, a 2 dollar a gallon savings, or 17 bucks an hour at 8.5 gallons per hour. The amount of fuel you burn will probably be greater I agree, but that's a lot of money to save. And before we go into why 87 octane car gas is **** and we all shouldn't use it, this is strictly a cost/efficiency comparison.

Randy
8A
 
Well, price wise the 340 was a little more than the 320 but not as much as the 360. So using the logic you just spelled out I got 360 level HP for less than the 360 price then, on top of that, I saved around 8 lbs off of the nose of my A model RV. In my case I think I came out pretty good. As for running mogas, I have not done so yet but I think it will do fine on it. Just my opinion on this, but I think we are all just a bit too anal worrying about whether a 9:1 piston will blow up on anything less than 100 octane. I think we are all buying in to the corporate mentality of fear driven decision making. Will my 9:1 cylinder really crater on 87-90 octane fuel in a cruise setting? Or even in a full throttle climb setting if the CHT's are running 320-375 deg while doing it? Even if that is dangerous territory shouldn't I, being an educated pilot, be able to monitor and consequently successfully manage the situation?

That's why its Experimental. We all do whatever we feel comfortable doing and that's the great thing about it. But even the most educated pilot can become distracted. How you choose to stack your deck is your business. It sounds like you got exactly what you wanted out of your package, and that's all that matters. Start running mogas with your combo and get back to us so we have more data.
 
KR

Funny thing I observe there. On one hand you talk about efficiency with the Rotec Vs Carb, but you are yet to fly it. And on the other you went for lower compression pistons.

Sure I will grant that IF the Rotec gives a better F/A ratio spread across all cylinders, and it might, that you will be slightly more efficient than the carb, but the lower compression is less efficient not matter what.

Interesting choices.

How did the cost in USD$ stack up compared to the IO320? The price from Vans was $24,500 last time I looked.
The total cost for my -340S was $25,604USD, made up of the following:

$22,019.25, the base OX-340S-B4J4N4
$250.67, Low pressure fuel pump
$2,594.12, dual P-Mag ignitions
$440.40, lightweight starter
$300, Crating

Shipping wasn't included, but from memory was around $1,500. I'd have to dig out the paperwork to see the exchange rate that applied at the time, but IIRC, customs fees and the GST were around $4,000 at a rate of 0.97ishAUD/USD.

Outright efficiency isn't what I was after, but a reasonably efficient engine that can run Mogas without problems, with the potential for upgrading the engine down th track if I so chose.

A standard IO-320 with dual P-Mags can really only increase the compression ratio and will end up around 175HP as a guesstimate - but will then be restricted to running Avgas. I can install standard or high compression pistons in my -340, retrofit an injection system if I chose and end up around 190HP, but I've got several options that I otherwise wouldn't have if I just went with a -320. Even just installing standard compression pistons and FI I would expect to still be able to run 98 Octane Mogas without problems, and I'm then I'd be getting 185HP out of my donk.

Notwithstanding the above, even with my low compression -340, I'd expect the same performance as a IO-320 equipped -9A, the difference being my fuel will cost anywhere from 50cpl less (and quite often the difference will be a lot more) than the Avgas burning -9A. At 25LPH, that's a minimum $12/hr difference, or $70 less for me to fill the tanks than the other bloke.

To my mind anything that makes flying cheaper means I can do more of it - and that can only be a good thing.
 
The total cost for my -340S was $25,604USD, made up of the following:

$22,019.25, the base OX-340S-B4J4N4
$250.67, Low pressure fuel pump
$2,594.12, dual P-Mag ignitions
$440.40, lightweight starter
$300, Crating

Shipping wasn't included, but from memory was around $1,500. I'd have to dig out the paperwork to see the exchange rate that applied at the time, but IIRC, customs fees and the GST were around $4,000 at a rate of 0.97ishAUD/USD.

Outright efficiency isn't what I was after, but a reasonably efficient engine that can run Mogas without problems, with the potential for upgrading the engine down th track if I so chose.

A standard IO-320 with dual P-Mags can really only increase the compression ratio and will end up around 175HP as a guesstimate - but will then be restricted to running Avgas. I can install standard or high compression pistons in my -340, retrofit an injection system if I chose and end up around 190HP, but I've got several options that I otherwise wouldn't have if I just went with a -320. Even just installing standard compression pistons and FI I would expect to still be able to run 98 Octane Mogas without problems, and I'm then I'd be getting 185HP out of my donk.

Notwithstanding the above, even with my low compression -340, I'd expect the same performance as a IO-320 equipped -9A, the difference being my fuel will cost anywhere from 50cpl less (and quite often the difference will be a lot more) than the Avgas burning -9A. At 25LPH, that's a minimum $12/hr difference, or $70 less for me to fill the tanks than the other bloke.

To my mind anything that makes flying cheaper means I can do more of it - and that can only be a good thing.

I couldn't agree more, I like your logic.
 
I'm wondering why you guys think your can't run mogas on an injected engine. I've seen that comment a few times and don't understand it.
 
Randy,
If lower compression allows you to save money on fuel costs, at a penalty for some efficiency, cost wise, wouldn't it be cheaper to fly. "Less efficient no matter what" I can get 87 octane regular for $3.5 a gallon, a 2 dollar a gallon savings, or 17 bucks an hour at 8.5 gallons per hour. The amount of fuel you burn will probably be greater I agree, but that's a lot of money to save. And before we go into why 87 octane car gas is **** and we all shouldn't use it, this is strictly a cost/efficiency comparison.

I think you will agree, KR in his posted did not talk about the cost of fuel. He talked about efficiency which is usually far more important. Particularly where range is concerned.

I understand that the Americans reading this do not get it, but if you fly in Australia, you are damned lucky to get Avgas at most places you fly, let alone a good source for BP98 or something that is known to be good mogas. If all you do is fly from your home field and do local jollies, then cart your 20L drums and think you are saving some money. You are but not a lot. Travel anywhere, and how do you cart around 7 x 20L drums? Or do you take one and pay for 7 taxi fares in and out of town at $40 return trip.

There is more to efficiency when you start flying around the country. This is why most down here fit tip tanks or build in more in the wings. because we need to. Unlike the USA where at 10,000' you can close the throttle and glide to 1, 2, 3 maybe more airfields all with Avgas on the field. I can show you a list of sealed runway towns that have no fuel and you would be lucky to get BP98 at all. That is 94AKI or (R+M)/2 in your language. You might get 91 (our RON95).

Sid,
Simple answer is vapour lock on the IO's. But to help answer your question better, you can run ANY gasoline in your engine, it will run. However there is more to fuel chemistry than even I understand. Far more, and I have a more involved knowledge than most. Take a look at the Petersen STC list. Note they are all carb engines and ask why? There is no problem burning bog standard mogas, if your engine will run it, but the certification limits have margins for all sorts of things and doing so erodes or wipes out the margins.

The three big issues to me are these. MON (detonation margin. Now with small HP engines that run cool on cool days, they will never detonate, except if the fuel has a tiny bit of JetA or something in it. How well do you know your fuel???

Next is RVP, so the problems of vapour locking concern me a bit, in the RV10 on a hot day climb through 6-8000' without the boost pump on and see what happens. Better still do it on a hot day after the plane has been sitting in the sun. And that is with avgas. Do it with mogas with an even higher RVP :eek:

Olefins : This deserves the triple :eek::eek::eek: and when you understand the serious nature of what gum content of fuel is, and compare avgas with ordinary ULP you will see why I will not run mogas?EVER. I have a almost new Yamaha 175HP V6 outboard on my ski boat. I reckon I can whip the carbs of that and clean them, refit quicker than most outboard mechanics. Don't ask me why! :mad:

If you don't fly your plane as much as you drive your car, how will a similar event to my boat go for you??.ohhhh let me convert that?.about 400' after takeoff, not sure how to convert returning from a bit of fishing in the bay, but anyway you get my point.

Now there will be hundreds on VAF that will jump up and down and argue and defend their position on mogas. I am not here to argue that they are not doing it. I know they are. Maybe many of them have never had a gum build up in a fuel servo, fuel spider or nozzle, but a blocked main jet or similar will get their attention one day.

Study the fuel spec's, get to know what is what, make up your own mind.
 
yes, the fuel is really forward of CG. Everything stays within CG range until it gets down to 2 gallons. Anything 2 or less with a fully loaded plane pushes past the aft limit.

Thanks Steve thats good info. thats what I was thinking just claryifing.
 
If you are making the (I)O-320, 340, or 360 decision on a blank piece of paper (Meaning you didn't already own an O-320.), here are a few items to consider. (and the thought process I went through a few years ago.)

The -320 is a great engine and the thing we RV builders forget is that is was designed as an engine for a four place draggy plane like a C-172. When fitted to a light and clean airframe like an RV, it will provide amazing performance!

The (I)O-340 stroker kit that ECi sells is based on a certified engine and was an intermediate step while Lycoming developed the (I)O-360. As soon as the -360 came out, the -340 was dropped. Should ECi go out of business, 340 support will go with them. Also, the -340 is the most expensive of the three engines discussed here.

The (I)O-360 is only a few pounds heavier than an O-320 and is slightly more expensive but produces 11% more power.

Here is the spreadsheet I put together back when I had to replace my original engine. All the numbers, other than price, came from ECi, and the prices are from 2009.

..............O-320..........O-340.....................O-360
...........(CR 8.5:1)....(CR 8.3:1)....Delta....(CR 8.5:1)....Delta
Price......$15,900........$16,500.......4%.......$16,400........3%
HP...........164...............174..........6%..........185..........11%
Weight.....240...............240..........0%..........244............2%
in Lbs
 
But since the 340 is based off the 320, just with a different crank/rod set, if ECI goes out of business and for some reason you need a crank, you can put a 320 crank right back in. All the other parts are pretty much stock Lyclone parts, including 320 pistons.

I'm a fan of the idea, may or may not make it in my airplane, but its a good one.
 
But since the 340 is based off the 320, just with a different crank/rod set, if ECI goes out of business and for some reason you need a crank, you can put a 320 crank right back in. All the other parts are pretty much stock Lyclone parts, including 320 pistons.

I'm a fan of the idea, may or may not make it in my airplane, but its a good one.
Yes, that is true, but you will also have to replace your prop, (adjust/replace?) your carb/FI, and redo your flight testing while you put it back into Phase 1 for five hours.

Not the end of the world but still a consideration.
 
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