Van's Air Force
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IO-375
- Thread starter hydroguy2
- Start date
JakeLewis22
Well Known Member
Anyone?
Bart at Aero Sport sold me on the IO-375 but I'm about 6 months away from needing to order one. Does anyone have one flying in an RV yet? If so, please share your thoughts.
Bart at Aero Sport sold me on the IO-375 but I'm about 6 months away from needing to order one. Does anyone have one flying in an RV yet? If so, please share your thoughts.
panhandler1956
Well Known Member
Me too
I'm in the same boat - about 6 months or less from buying and very interested in the 375, but there's not much info out there. Unfortunately I'm not the early adopter type, so I may end up with a 360. Hope someone can weigh in on this.
I'm in the same boat - about 6 months or less from buying and very interested in the 375, but there's not much info out there. Unfortunately I'm not the early adopter type, so I may end up with a 360. Hope someone can weigh in on this.
CZ75shooter
Member
I too am interested
I'm also interested in a 0-375 for my RV-7A. I'm thinking about the high compression engine and 3 blade Catto prop. Anybody flying one?
Thanks,
Larry
850 hrs on RV-9A Building RV-7A
I'm also interested in a 0-375 for my RV-7A. I'm thinking about the high compression engine and 3 blade Catto prop. Anybody flying one?
Thanks,
Larry
850 hrs on RV-9A Building RV-7A
Peter.Fruehling
Well Known Member
I bought one and put it on but am about a year away from flying it. ...lightweight, 200hp and 8.0:1 pistons, enough said. Buying from Bart was the icing on the cake!
- Peter
PS - The Superior cold air sump allowed me to sneak over 200hp.
- Peter
PS - The Superior cold air sump allowed me to sneak over 200hp.
Just as a personal opinion, If I were buying an engine today I would not choose one with high compression. Doing so may eliminate the option of using unleaded if/when 100LL goes away. The extra 10 hp really isn't worth being locked into a fuel which may be discontinued, IMHO.
rushmckelvey
Member
IO 375
I just installed my IO 375. She turned out 206HP on the test stand. Should have her running mid summer 2010. Turning a MT three blade PROP
I just installed my IO 375. She turned out 206HP on the test stand. Should have her running mid summer 2010. Turning a MT three blade PROP
JakeLewis22
Well Known Member
Where did you find the horse power?
Rush,
I received my IO-375-M1S from AeroSport a few weeks ago and I can't find a horse power number in any of the data. I was going to call Bart but it slipped my mind until I read your post. Did you run your own test or is it in here somewhere and I'm missing it?
Rush,
I received my IO-375-M1S from AeroSport a few weeks ago and I can't find a horse power number in any of the data. I was going to call Bart but it slipped my mind until I read your post. Did you run your own test or is it in here somewhere and I'm missing it?
rocketbob
Well Known Member
I have never seen a shred of empirical evidence that shows a Lycoming can't be operated with a higher compression ratio and lower octane fuel. I am coming close to having over 1000 hours running on 87 octane pump gas (standard compression) and have never had a minute's trouble. I also keep very close watch on my oil filter and change at 50 hour intervals, and I barely have any trace amounts of metal in the filters. I run the thing hard quite often.
Interesting - do you run standard mags, or electronic ignition? I know the electronics can get upwards of 40 degrees BTDC, which is probably closer to the realm where detonation could be an issue.
I think it would be fantastic if I could run my IO-320 with 10:1 compression on even 92 Octane. But, I have electronic ignition and I'm chicken...
Still waiting back for a response a few posts back, but my non-scientific understanding was that with 8:1 or 8.5:1 you could run Premium, and with 7:1 you could run Regular, without fear of detonation. My assumption is that this means with a modern electronic ignition (which advances more than 25 degrees BTDC). But that is all assumption and based on heresay.
I'm hoping one or more of the engineering-types will chime in with a factual and scientific answer.
frankh
Well Known Member
well the theory goes
That detonation is primarily dependant on temperature..The higher the temperature the faster the flame front travels. So if the engine is running at high temp (Arizona in Summer) and then you add more advance then the flame front is so fast that it is in effect detonation..I.e the whole charge goes bang at once..i,e the flame does not travel across the cylinder.
Having said that it is clear now that the engine supplies have large margins for error..They have to cus most pilots look at the mixture control as a direct link to Satan himself and rarely touch the thing!
So you have to allow for the pilot that absolutely has no clue how to lean properly and will more often than not run the motor in the worst possible position (now thought to be about 50F ROP).
if you run the motor the right way (probably 100F ROP or even better 25 to 50F LOP) then the 8.5:1 CR number is probably very conservative.
i currently run 91 octane and am considering a swap to 87..Maybe running 91 in the Summer,..I have two Pmags and run almost exclusively lean of peak.
Frank
That detonation is primarily dependant on temperature..The higher the temperature the faster the flame front travels. So if the engine is running at high temp (Arizona in Summer) and then you add more advance then the flame front is so fast that it is in effect detonation..I.e the whole charge goes bang at once..i,e the flame does not travel across the cylinder.
Having said that it is clear now that the engine supplies have large margins for error..They have to cus most pilots look at the mixture control as a direct link to Satan himself and rarely touch the thing!
So you have to allow for the pilot that absolutely has no clue how to lean properly and will more often than not run the motor in the worst possible position (now thought to be about 50F ROP).
if you run the motor the right way (probably 100F ROP or even better 25 to 50F LOP) then the 8.5:1 CR number is probably very conservative.
i currently run 91 octane and am considering a swap to 87..Maybe running 91 in the Summer,..I have two Pmags and run almost exclusively lean of peak.
Frank
nomocom
Well Known Member
Compression and an unapologetic sales pitch for engine monitors
RocketBob said
"I have never seen a shred of empirical evidence that shows a Lycoming can't be operated with a higher compression ratio and lower octane fuel."
True enough, but it can be complicated and there are safety implications to the fuel we choose to run. These Lycoming engines years ago were going in the spam cans with very little engine instrumentation. If you were a lucky enough pilot to have instrumentation, you probably knew what 1 of the 4 or 6 cylinders were doing. Lacking information, the detonation safety net was the high octane fuel. Thanks to the instrumentation folks, we have engine computers available that let us know what each cylinder is doing. That multi-probe monitor without too much work, should be able to keep us out of dangerous detonation, and help us as operators decide on what makes sense as a fuel. Somewhere I read significant detonation makes itself clearly known with CHT's going up 2 degrees a second or more. (help, reference) I suppose it would be nice to have a "rate of change" alarm for just that situation, but with a CHT high alarm set for say 380, still should give you time to adjust operations to interrupt runaway detonation.
No multi-probe monitor, 100LL, and high compression, you still have some margin for error. All the same, think I'd feel just as safe, maybe safer with mogas in the tank, high compression, plus the engine monitor. Something as simple as a intake vacuum leak or a plugged injector can put one cylinder 50 ROP on climb out, when the others cylinders are nice and cool at 250 ROP. That is a good recipe for an overheated cylinder, runaway detonation, scouring of the protective boundary layer, more heat transfer, more detonation, a very, very, bad feedback loop. if you run that way long enough, that hot cylinder will destroy a piston, whether you've got MOGAS or 100LL. Rather, a better situation, you've got the monitor set up and you are paying attention, that scenario doesn't play out to engine self destruction. (Thank John D. for your great Pelican Perch description of detonation).
In addition to avoiding engine loss, the monitor will give you feedback on fuel quality. Once you know your engine doesn't have chronic high CHT's or runaway CHT's on say 92 octane, an operator may as well try lower, though to me if running a high compression lycoming, the small price advantage of 87 octane wouldn't be that attractive, I'd rather rather pay for a bit more octane.
IO375? Ok, my wish list just got longer.
RocketBob said
"I have never seen a shred of empirical evidence that shows a Lycoming can't be operated with a higher compression ratio and lower octane fuel."
True enough, but it can be complicated and there are safety implications to the fuel we choose to run. These Lycoming engines years ago were going in the spam cans with very little engine instrumentation. If you were a lucky enough pilot to have instrumentation, you probably knew what 1 of the 4 or 6 cylinders were doing. Lacking information, the detonation safety net was the high octane fuel. Thanks to the instrumentation folks, we have engine computers available that let us know what each cylinder is doing. That multi-probe monitor without too much work, should be able to keep us out of dangerous detonation, and help us as operators decide on what makes sense as a fuel. Somewhere I read significant detonation makes itself clearly known with CHT's going up 2 degrees a second or more. (help, reference) I suppose it would be nice to have a "rate of change" alarm for just that situation, but with a CHT high alarm set for say 380, still should give you time to adjust operations to interrupt runaway detonation.
No multi-probe monitor, 100LL, and high compression, you still have some margin for error. All the same, think I'd feel just as safe, maybe safer with mogas in the tank, high compression, plus the engine monitor. Something as simple as a intake vacuum leak or a plugged injector can put one cylinder 50 ROP on climb out, when the others cylinders are nice and cool at 250 ROP. That is a good recipe for an overheated cylinder, runaway detonation, scouring of the protective boundary layer, more heat transfer, more detonation, a very, very, bad feedback loop. if you run that way long enough, that hot cylinder will destroy a piston, whether you've got MOGAS or 100LL. Rather, a better situation, you've got the monitor set up and you are paying attention, that scenario doesn't play out to engine self destruction. (Thank John D. for your great Pelican Perch description of detonation).
In addition to avoiding engine loss, the monitor will give you feedback on fuel quality. Once you know your engine doesn't have chronic high CHT's or runaway CHT's on say 92 octane, an operator may as well try lower, though to me if running a high compression lycoming, the small price advantage of 87 octane wouldn't be that attractive, I'd rather rather pay for a bit more octane.
IO375? Ok, my wish list just got longer.
They must not be all that.. How come no one has given us a report yet on how well these engines perform. I have been hoping to read something from someone here who has experience running these engines first hand and would love to see some performance numbers from these people. Also some operational numbers as far as temperatures and fuel flow would be nice too, carbed or injected. Come on and give us a report!!! If I missed a thread somewhere here on VAF someone please redirect me. Thanks.
Dan Langhout
Well Known Member
Not flying Yet
There are several of us here on the forum who have bought IO-375's but aren't yet flying. If you can wait about a year, I'll be glad to post some numbers!
There are several of us here on the forum who have bought IO-375's but aren't yet flying. If you can wait about a year, I'll be glad to post some numbers!
CZ75shooter
Member
I'm flying now
I'm flying now with a 0-375 high compression 205 HP engine from Aero-Sport with a 3 blade Catto on my 7A. I asked Bart and Craig about turning it 2800 RPMs. Both seemed to think it would be OK. I not going to do that much, mostly 2500 RPM. but I asked Craig to pitch the prop for 2800 at 1000' MSL.
It's dead on the money. I will post some speeds, climb rates and more details soon.
Just from the little bit that I've flown it, I'm disapointed with the speed.
Looks like 205 MPH everything forward at 1500' MSL. It may be off as I still have some other issues with left roll and ball not centered.
CHTs and EGTs are good, oil temp a little high. Drinks gas like there is no tomorrow.
I'll post more details in a week or two.
Larry
I'm flying now with a 0-375 high compression 205 HP engine from Aero-Sport with a 3 blade Catto on my 7A. I asked Bart and Craig about turning it 2800 RPMs. Both seemed to think it would be OK. I not going to do that much, mostly 2500 RPM. but I asked Craig to pitch the prop for 2800 at 1000' MSL.
It's dead on the money. I will post some speeds, climb rates and more details soon.
Just from the little bit that I've flown it, I'm disapointed with the speed.
Looks like 205 MPH everything forward at 1500' MSL. It may be off as I still have some other issues with left roll and ball not centered.
CHTs and EGTs are good, oil temp a little high. Drinks gas like there is no tomorrow.
I'll post more details in a week or two.
Larry
Romeo Victor
Member
hi Jake,
I've found a comment regarding the IO375 in the Vansairforce forum. I am here in Germany and building my second RV8. This time I'd like to install the IO375 as well. Presently, the control items for the engines must be ordered and installed. Can you remember the lengths of your control cables (throttle,mixture,prop) in combination with the CT83 levers?
Thank you
Best Regards
Stephan Servatius
Bockhorn
Germany
I've found a comment regarding the IO375 in the Vansairforce forum. I am here in Germany and building my second RV8. This time I'd like to install the IO375 as well. Presently, the control items for the engines must be ordered and installed. Can you remember the lengths of your control cables (throttle,mixture,prop) in combination with the CT83 levers?
Thank you
Best Regards
Stephan Servatius
Bockhorn
Germany
smokyray
Well Known Member
Speed is Life???
Larry, having rigged one or two RV's in the past I can assure you your numbers can change based on several factors. First, the A models are slower. I don't care what anybody out there has found, posts or claims, they are slower. Bob Axsom has found a way to make his A model very fast with some fine attention to detail and prolific design. Stock however is a different story.
I helped a friend tweak his 7A with IO-360/Hartzell BA/Sam James everything over the past 4 years. He posts very respectable speeds now. However comma, my well-faired 150HP RVX tail dragger can nearly match it across the board with a Catto 2 blade. There is a wall out there the RV can't breach without some serious fairing and drag reduction detail installed, HP or fuel flow notwithstanding. Dave Anders has probably the closest RV to perfection with several others that regularly race in the SARL group right alongside. Join the SARL guys, get some tips and don't give up.
You can go faster...
http://www.youtube.com/watch?v=gCONImxbs7g
V/R
Smokey
PS: Of course, when you live on a very short strip, I like to go slower....
Larry, having rigged one or two RV's in the past I can assure you your numbers can change based on several factors. First, the A models are slower. I don't care what anybody out there has found, posts or claims, they are slower. Bob Axsom has found a way to make his A model very fast with some fine attention to detail and prolific design. Stock however is a different story.
I helped a friend tweak his 7A with IO-360/Hartzell BA/Sam James everything over the past 4 years. He posts very respectable speeds now. However comma, my well-faired 150HP RVX tail dragger can nearly match it across the board with a Catto 2 blade. There is a wall out there the RV can't breach without some serious fairing and drag reduction detail installed, HP or fuel flow notwithstanding. Dave Anders has probably the closest RV to perfection with several others that regularly race in the SARL group right alongside. Join the SARL guys, get some tips and don't give up.
You can go faster...
http://www.youtube.com/watch?v=gCONImxbs7g
V/R
Smokey
PS: Of course, when you live on a very short strip, I like to go slower....
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