Van's Air Force
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LS-1 for -7
- Thread starter miyu1975
- Start date
pierre smith
Well Known Member
Hi Ryan
It may well be but hey, it's experimental aviation!! A coupla batteries in the back and so on, for CG purposes.
Jess Meyer has probably as good an alternate engine system for the -6 and -7 as anyone with his belt-driven props on the V-6 Chevies. A lot of them flying ...pretty reliably too.
www.beltedair.com
Regards,
It may well be but hey, it's experimental aviation!! A coupla batteries in the back and so on, for CG purposes.
Jess Meyer has probably as good an alternate engine system for the -6 and -7 as anyone with his belt-driven props on the V-6 Chevies. A lot of them flying ...pretty reliably too.
www.beltedair.com
Regards,
RV7Guy
Well Known Member
There was one
I think the one that was developed was by a company called Predator. Saw it at Copperstate a few years ago. The gross weight was listed at 2200lbs. Van's didn't want anything to do with it and was limited to 3 G's positive. I've seen three Gs of turbulence around here.
It sounded cool but scared the heck out of me. They were giving rides but most politely declined.
I don't know what happened to the plane or the company. I had heard that the plane had a forced landing but I don't know that to be a fact.
Stick with the Lyc or clone and you'll enjoy lots of trouble flying with minimal down time due to engine issues.
I think the one that was developed was by a company called Predator. Saw it at Copperstate a few years ago. The gross weight was listed at 2200lbs. Van's didn't want anything to do with it and was limited to 3 G's positive. I've seen three Gs of turbulence around here.
It sounded cool but scared the heck out of me. They were giving rides but most politely declined.
I don't know what happened to the plane or the company. I had heard that the plane had a forced landing but I don't know that to be a fact.
Stick with the Lyc or clone and you'll enjoy lots of trouble flying with minimal down time due to engine issues.
I'll second that!!
Ditto. .
Aluminum Block V6
I bet that Bud's PSRU will bolt right up to one of the aluminum block Chevy V-6's just fine. Those things will turn 200HP easy at 3500 RPM and will run all day long at that RPM. Aluminum block will set you back about 4k though. The weight of that engine combo (block is 74 lbs) will come in about the same as an IO360 I think.
I bet that Bud's PSRU will bolt right up to one of the aluminum block Chevy V-6's just fine. Those things will turn 200HP easy at 3500 RPM and will run all day long at that RPM. Aluminum block will set you back about 4k though. The weight of that engine combo (block is 74 lbs) will come in about the same as an IO360 I think.
No! A LS1 is suitable in a Chevy or a Corvette, I had three, 1 LS2 and now a LS9. The airfoil on my vettes is turned the correct way for the LS series of engines! I'm waiting on some one to try a V10 Viper engine on a RV3. Its not suitable either, but someone will try and yes, my Viper airfoil is turned the correct way as well. Thank God Mooney quit with the Porsche engines or my Boxster would need hamsters and a wheel.
I beg to differ with my dear friend Pierre, but this is not experimental aviation, its nuts!
Sorry for the rant, but I saw Dennis Miller in concert last Thursday and I've not been the same since!
I have seen the plane in southeast Idaho. It was flying last summer when I saw it.
Rotary10-RV
Well Known Member
For the 10 OK but 7...
The LS-1 Package is way to large and heavy for the -7. As a -10 engine to replace the IO-540 OK. The -7 is designed for around 200 HP, if you got the thing flying and could actually turn the engine up into the power band you would be over VNE in a heart beat. Read the designing section of the RV-10 on the Vans site. Van was concerned that as soon as he published the design HP for the RV-10 (260 max recomended) then people were calling in to ask if they could use a 300 HP engine! The plane hadn't even been built yet! Come on guys, I'm a dyed-in-the-wool alternative engines guy and I think putting an LS-1 on a RV-7 is just plain stupid. The result would be a aircraft in search of a catastrophic failure. Like the engine pulling itself off the firewall, or pulling the firewall off the airplane. Or the airplane going over VNE and fluttering the wings off. The part of alternate engine design responseability that we have is to use an engine that is as close to the design HP as we can. If you use something radically different in HP from the original YOU have just become the aircraft's head designer, act accordingly.
Bill J
The LS-1 Package is way to large and heavy for the -7. As a -10 engine to replace the IO-540 OK. The -7 is designed for around 200 HP, if you got the thing flying and could actually turn the engine up into the power band you would be over VNE in a heart beat. Read the designing section of the RV-10 on the Vans site. Van was concerned that as soon as he published the design HP for the RV-10 (260 max recomended) then people were calling in to ask if they could use a 300 HP engine! The plane hadn't even been built yet! Come on guys, I'm a dyed-in-the-wool alternative engines guy and I think putting an LS-1 on a RV-7 is just plain stupid. The result would be a aircraft in search of a catastrophic failure. Like the engine pulling itself off the firewall, or pulling the firewall off the airplane. Or the airplane going over VNE and fluttering the wings off. The part of alternate engine design responseability that we have is to use an engine that is as close to the design HP as we can. If you use something radically different in HP from the original YOU have just become the aircraft's head designer, act accordingly.
Bill J
Many use the higher hp engines not to get full hp but to get a good amount of hp while at lower rpms. Still the LS series is no good for the -7. Good fit for the -10 though. The rotary engines are pretty cool also.
fmarino1976
Well Known Member
direct drive?
The stock LS1 puts out 200 HP and 350 ft-lbs at 3000 rpm (according to
http://www.gmperformanceparts.com/E...p?engId=LS1&engine=LS1&sku=25534322&engCat=ls ).
Could it be possible to match it to a prop that would allow the engine to spin up to 3000 rpm for takeoff?
Weight might still be an issue, I couldn't find the weight of the LS1 really easily so I can't tell what the difference would be.
Any engine gurus care to say yay or nay?
The stock LS1 puts out 200 HP and 350 ft-lbs at 3000 rpm (according to
http://www.gmperformanceparts.com/E...p?engId=LS1&engine=LS1&sku=25534322&engCat=ls ).
Could it be possible to match it to a prop that would allow the engine to spin up to 3000 rpm for takeoff?
Weight might still be an issue, I couldn't find the weight of the LS1 really easily so I can't tell what the difference would be.
Any engine gurus care to say yay or nay?
Hey I need another test pilot! You up for the job?
Did you get a new Corvette, Todd? If so I'm in!
SSSSHHHHHHH! I believe the government already outlawed lawn darts due to safety concerns. Could auto engines in experimental airplanes be far down the road?
pierre smith
Well Known Member
Yaaaawn..
My quote was really tongue-in-cheek since I wasn't even thinking of going there because this whole discussion is so old hat. Heck, I wouldn't be surprised if some guy isn't scrounging up an Allison V-12 to stuff into something like an RV-3...
Oh well, you can lead a horse to drink but you can't make him water...no...wait!...something like that
Oh well,
My quote was really tongue-in-cheek since I wasn't even thinking of going there because this whole discussion is so old hat. Heck, I wouldn't be surprised if some guy isn't scrounging up an Allison V-12 to stuff into something like an RV-3...
Oh well, you can lead a horse to drink but you can't make him water...no...wait!...something like that
Oh well,
The LS2 weight is about 345lbs. You would probably have to go with a short 3 blade prop which would let you run the rpm's up. I would move the radiator to the rear and use an electric water pump that could be put in rear.
Rotary10-RV
Well Known Member
Not a rational thing to do. RV-7 not a RV-10
Group,
First of all I have to say that considering the crankshaft center line there is NO WAY you can fit an LS-2 without an offset drive or a completely new cowl. Even if you could this is a case of what I call, "Spec sheet daydreaming." If you read the spec sheet the engine is supposed to make X horsepower at a given RPM. In reality that engine probably has poor performance at that RPM because it wasn't designed to operate there continously. The reality is that there can be a multitude of issues, tortional vibration, bearing oil feed, etc. You are MUCH better off if you run the engine in a normal operating range. This is where we get into the problem with automotive conversions by spec sheet readers. There are lots of now belly-up companies that thought, "I'll make a motor mount for this engine and run it at lower speed and it will be fine." Most of the time they find out that the engine will make nowhere near the sheet HP when max loaded by a prop to make only 3000 RPM. Typically those numbers are simply connected dots on a dyno chart when the operator is spinning through that range on the way to maximum hp! Often the dyno operator won't even dial down the water brake until the engine is in the intended range. I have been there many times and seen exactly that proceedure. If you can get it to run in those lower ranges and make the published hp it is usually because the engine has re-designed manifolds and carbs to run there. That isn't an easy or cheap task either.
Lastly does that weight include a PSRU? Does that weight include a prop shaft extension with the proper bearings to withstand 800 pounds of end thrust? Does that include the Radiators and the coolant? Will the stock water pump be OK? Even if you don't run a reduction box most auto engines require a prop adapter that can handle the prop thrust. If you can get even a aluminum V8 to come in under the weight of an IO-540 you have done an excellent job of systems design. It isn't impossible but like LYC you must account for every nut and bolt to get the designed result. You have just turned your self into the systems engineer. Some people can do this, and others are not up to the job. (I'm speaking as a guy that intends to run an auto conversion in my aircraft!)
The point I'm making here is this will not be a bolt in conversion even if, (and it is a BIG if), the engine will produce specified HP when loaded down to that RPM by a prop. The casual disregard for the engineering involved is what gets a lot of people in trouble. The W&B will just be wrong for a RV-7. Sorry but I have to say this anybody doing this on an RV-7 is just ignorant, or possibly stupid! The difference is that if only ignorant they can probably be cured of the idea. DO NOT EVEN THINK ABOUT THIS CONVERSION. Period.
Bill Jepson
Group,
First of all I have to say that considering the crankshaft center line there is NO WAY you can fit an LS-2 without an offset drive or a completely new cowl. Even if you could this is a case of what I call, "Spec sheet daydreaming." If you read the spec sheet the engine is supposed to make X horsepower at a given RPM. In reality that engine probably has poor performance at that RPM because it wasn't designed to operate there continously. The reality is that there can be a multitude of issues, tortional vibration, bearing oil feed, etc. You are MUCH better off if you run the engine in a normal operating range. This is where we get into the problem with automotive conversions by spec sheet readers. There are lots of now belly-up companies that thought, "I'll make a motor mount for this engine and run it at lower speed and it will be fine." Most of the time they find out that the engine will make nowhere near the sheet HP when max loaded by a prop to make only 3000 RPM. Typically those numbers are simply connected dots on a dyno chart when the operator is spinning through that range on the way to maximum hp! Often the dyno operator won't even dial down the water brake until the engine is in the intended range. I have been there many times and seen exactly that proceedure. If you can get it to run in those lower ranges and make the published hp it is usually because the engine has re-designed manifolds and carbs to run there. That isn't an easy or cheap task either.
Lastly does that weight include a PSRU? Does that weight include a prop shaft extension with the proper bearings to withstand 800 pounds of end thrust? Does that include the Radiators and the coolant? Will the stock water pump be OK? Even if you don't run a reduction box most auto engines require a prop adapter that can handle the prop thrust. If you can get even a aluminum V8 to come in under the weight of an IO-540 you have done an excellent job of systems design. It isn't impossible but like LYC you must account for every nut and bolt to get the designed result. You have just turned your self into the systems engineer. Some people can do this, and others are not up to the job. (I'm speaking as a guy that intends to run an auto conversion in my aircraft!)
The point I'm making here is this will not be a bolt in conversion even if, (and it is a BIG if), the engine will produce specified HP when loaded down to that RPM by a prop. The casual disregard for the engineering involved is what gets a lot of people in trouble. The W&B will just be wrong for a RV-7. Sorry but I have to say this anybody doing this on an RV-7 is just ignorant, or possibly stupid! The difference is that if only ignorant they can probably be cured of the idea. DO NOT EVEN THINK ABOUT THIS CONVERSION. Period.
Bill Jepson
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Bill did you miss one?
And this one following Ross'.
Phil
Well Known Member
I think you would have way too much power......
The LS1 is really too much power for the -10, but mangagable.
From what I've heard (direct reports) the LS1 will push the RV-10 over VNE in straight and level flight. It's a power house.
Can't imagine what it would do to a -7.
Phil
The LS1 is really too much power for the -10, but mangagable.
From what I've heard (direct reports) the LS1 will push the RV-10 over VNE in straight and level flight. It's a power house.
Can't imagine what it would do to a -7.
Phil
Rotary10-RV
Well Known Member
Sorry Todd, but...
Todd,
No I didn't miss that one, but the later post just gave the engine weight. Somebody reading the thread by using the "first unread" click could misconstrue the post since it seems an acceptable starting weight. I posted the reply to "group" and I didn't want to imply that you didn't understand Todd. Sorry, since it does seem to imply that you condoned the idea, and I KNOW that you don't. You, more than anyone, know what the all up system weighs. I probably should have used a link and started my rant in a new thread. I always get upset when the idea of using a mismached engine, of any kind, in experimental aircraft. RVs have considerable reserve built in and can also be successfully modified for different engines. (Like the various Rockets for instance) The trouble starts when non-mechanical people are convinced by someone, (or themselves), that these changes are easy or safe. Mostly it just results in someone being parted from their money. That is bad but not as bad as when it puts a low-time pilot in comand of a "hot rock" of an airplane. Bad decisions or lack of knowledge can cause even a proven good flying machine to become deadly. I always feel the need to inform the mechanically-challenged who are lurking on the list. I say this all the time, but
it bears repeating, If you can't work out the mechanics of an alternate engine design you are better off using a Lyc or a clone.
Bill Jepson
Todd,
No I didn't miss that one, but the later post just gave the engine weight. Somebody reading the thread by using the "first unread" click could misconstrue the post since it seems an acceptable starting weight. I posted the reply to "group" and I didn't want to imply that you didn't understand Todd. Sorry, since it does seem to imply that you condoned the idea, and I KNOW that you don't. You, more than anyone, know what the all up system weighs. I probably should have used a link and started my rant in a new thread. I always get upset when the idea of using a mismached engine, of any kind, in experimental aircraft. RVs have considerable reserve built in and can also be successfully modified for different engines. (Like the various Rockets for instance) The trouble starts when non-mechanical people are convinced by someone, (or themselves), that these changes are easy or safe. Mostly it just results in someone being parted from their money. That is bad but not as bad as when it puts a low-time pilot in comand of a "hot rock" of an airplane. Bad decisions or lack of knowledge can cause even a proven good flying machine to become deadly. I always feel the need to inform the mechanically-challenged who are lurking on the list. I say this all the time, but
it bears repeating, If you can't work out the mechanics of an alternate engine design you are better off using a Lyc or a clone.
Bill Jepson
