---------------------------------------------------------- RV7-List Digest Archive --- Total Messages Posted Wed 02/23/05: 10 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 08:30 AM - Diesel engine for an RV-7 (springcanyon) 2. 08:59 AM - Re: Diesel engine for an RV-7 (Hinde, Frank George (Corvallis)) 3. 09:45 AM - Re: Diesel engine for an RV-7 (Gary Dwinal) 4. 10:25 AM - Re: Diesel engine for an RV-7 (Gary Dwinal) 5. 10:45 AM - Re: Diesel engine for an RV-7 (Rob Prior (rv7)) 6. 11:15 AM - Re: Diesel engine for an RV-7 (Gary Dwinal) 7. 11:28 AM - Re: Diesel engine for an RV-7 (Gary Dwinal) 8. 12:06 PM - Re: Diesel engine for an RV-7 (Hinde, Frank George (Corvallis)) 9. 12:18 PM - Help..."Extra" holes in wing spar stub and F704 (Steve Noujaim) 10. 02:25 PM - Re: Diesel engine for an RV-7 (cgalley) ________________________________ Message 1 _____________________________________ Time: 08:30:04 AM PST US From: "springcanyon" Subject: RV7-List: Diesel engine for an RV-7 --> RV7-List message posted by: "springcanyon" I am working on an RV-7 and am approaching the time when I need to know which or what engine I am going to install. I love the idea of a diesel engine. Since this is a major investment as well as one of the most important parts of my airplane I would like some other opinions. I have talked with Delta Hawk and their engine sounds good and looks good. The thing that bothers me is the total lack of field experience with this engine. Anyone have opinions about this? Thanks, Don Owens springcanyon@mymethow.com ________________________________ Message 2 _____________________________________ Time: 08:59:55 AM PST US Subject: RE: RV7-List: Diesel engine for an RV-7 From: "Hinde, Frank George (Corvallis)" --> RV7-List message posted by: "Hinde, Frank George (Corvallis)" Any ...and I mean any water cooled engine out there will produce more cooling drag than an aircooled one will. Note a good aircooled Lycosaurus will do around 200mph on 10 GPH. Similar fuel burn on a very good water cooled automotive conversion will give less than 180mph. It will still do 200mph but the fuel burn will get significant...I think fuel burn is proportional to speed squared (or is that cubed?) and that part of the curve will get pretty steep. Not saying that drag can't be reduced (P51 Mustang style scoops and optimised radiators) but it certainly won't be a bolt on package. I hate to say it but about the best bet is a Lycoming...And I spent a year trying to prove otherwise...I even fly behind a little Subaru in a Zenair Zodiac....A total engine rebuild for a couple of grand is sure attractive but I just can't have a slow plane anymore and to burn another 3 to 4 GPH to make the speed I want gets to be a big bill over 2000 hours as well... My 2 cents Frank -----Original Message----- From: owner-rv7-list-server@matronics.com [mailto:owner-rv7-list-server@matronics.com] On Behalf Of springcanyon Subject: RV7-List: Diesel engine for an RV-7 --> RV7-List message posted by: "springcanyon" --> I am working on an RV-7 and am approaching the time when I need to know which or what engine I am going to install. I love the idea of a diesel engine. Since this is a major investment as well as one of the most important parts of my airplane I would like some other opinions. I have talked with Delta Hawk and their engine sounds good and looks good. The thing that bothers me is the total lack of field experience with this engine. Anyone have opinions about this? Thanks, Don Owens springcanyon@mymethow.com ________________________________ Message 3 _____________________________________ Time: 09:45:32 AM PST US From: Gary Dwinal Subject: RE: RV7-List: Diesel engine for an RV-7 --> RV7-List message posted by: Gary Dwinal Not flying yet, but I have a GM V6 truck engine in my plane along with the firewall forward package from Belted Air Power. The air intake is the original size and the radiator is mounted on the firewall with the original air exit openings. My engine (modestly modified) will produce around 225 HP and should make the plane cruise comfortably in the 200MPH range and the fuel burn should be no more than 10 GPM. Again, this is purely speculation on my behalf, but after talking with several others that have gone the GM V6 route with the kit from BAP, I think the assumption that a liquid cooled engine will always create more drag is controversial at best. There is a reason Burt Rutan absolutely required one of the engines in his "non-stop around the world airplane" to be liquid cooled! Gary Dwinal RV7A -----Original Message----- From: Hinde, Frank George (Corvallis) [mailto:frank.hinde@hp.com] Subject: RE: RV7-List: Diesel engine for an RV-7 --> RV7-List message posted by: "Hinde, Frank George (Corvallis)" --> Any ...and I mean any water cooled engine out there will produce more cooling drag than an aircooled one will. Note a good aircooled Lycosaurus will do around 200mph on 10 GPH. Similar fuel burn on a very good water cooled automotive conversion will give less than 180mph. It will still do 200mph but the fuel burn will get significant...I think fuel burn is proportional to speed squared (or is that cubed?) and that part of the curve will get pretty steep. Not saying that drag can't be reduced (P51 Mustang style scoops and optimised radiators) but it certainly won't be a bolt on package. I hate to say it but about the best bet is a Lycoming...And I spent a year trying to prove otherwise...I even fly behind a little Subaru in a Zenair Zodiac....A total engine rebuild for a couple of grand is sure attractive but I just can't have a slow plane anymore and to burn another 3 to 4 GPH to make the speed I want gets to be a big bill over 2000 hours as well... My 2 cents Frank -----Original Message----- From: owner-rv7-list-server@matronics.com [mailto:owner-rv7-list-server@matronics.com] On Behalf Of springcanyon Subject: RV7-List: Diesel engine for an RV-7 --> RV7-List message posted by: "springcanyon" --> I am working on an RV-7 and am approaching the time when I need to know which or what engine I am going to install. I love the idea of a diesel engine. Since this is a major investment as well as one of the most important parts of my airplane I would like some other opinions. I have talked with Delta Hawk and their engine sounds good and looks good. The thing that bothers me is the total lack of field experience with this engine. Anyone have opinions about this? Thanks, Don Owens springcanyon@mymethow.com advertising on the Matronics Forums. NOTICE: The information contained in this communication is intended solely for use by the designated recipient(s). This communication may also contain confidential or proprietary information and may be subject to confidentiality protection under the law. If you are not a designated recipient, you may not review, copy, or distribute this message. If you receive this message in error, please notify the sender and destroy your copy. Thank you for your cooperation. Fisher Engineering, a division of Douglas Dynamics, LLC ________________________________ Message 4 _____________________________________ Time: 10:25:38 AM PST US From: Gary Dwinal Subject: RE: RV7-List: Diesel engine for an RV-7 --> RV7-List message posted by: Gary Dwinal The only experience I have had with the Delta Hawk is a non flying running demonstration at Osh Kosh and couple of years ago. The engine was extremely noisy. It seemed to run very well and very smooth though. I do not know what the fuel burn is for them. Gary Dwinal -----Original Message----- From: springcanyon [mailto:springcanyon@mymethow.com] Subject: RV7-List: Diesel engine for an RV-7 --> RV7-List message posted by: "springcanyon" --> I am working on an RV-7 and am approaching the time when I need to know which or what engine I am going to install. I love the idea of a diesel engine. Since this is a major investment as well as one of the most important parts of my airplane I would like some other opinions. I have talked with Delta Hawk and their engine sounds good and looks good. The thing that bothers me is the total lack of field experience with this engine. Anyone have opinions about this? Thanks, Don Owens springcanyon@mymethow.com advertising on the Matronics Forums. NOTICE: The information contained in this communication is intended solely for use by the designated recipient(s). This communication may also contain confidential or proprietary information and may be subject to confidentiality protection under the law. If you are not a designated recipient, you may not review, copy, or distribute this message. If you receive this message in error, please notify the sender and destroy your copy. Thank you for your cooperation. Fisher Engineering, a division of Douglas Dynamics, LLC ________________________________ Message 5 _____________________________________ Time: 10:45:11 AM PST US From: "Rob Prior (rv7)" Subject: RE: RV7-List: Diesel engine for an RV-7 --> RV7-List message posted by: "Rob Prior (rv7)" On 9:44:22 2005-02-23 Gary Dwinal wrote: > --> RV7-List message posted by: Gary Dwinal > Not flying yet, but I have a GM V6 truck engine in my plane along > with the firewall forward package from Belted Air Power. The air > intake is the original size and the radiator is mounted on the > firewall with the original air exit openings...I think the assumption > that a liquid cooled engine will always create more drag is controversial > at best. The fact that the size of the inlet and exit openings is the same doesn't mean much on it's own. If you just put a radiator between the inlet and exit like on your conversion, and don't put one there on a Lycoming installation, the drag will be higher on the engine with the radiator due to the back pressure it generates as air slows down to flow through the rad. It is possible to control the air flow to and from the rad with well-designed expansion (upstream) and compression (downstream) chambers around the rad. I seem to recall reading that on a P-51 in the right cruise configuration you could realize a small amount of *thrust* from this arrangement. But that's some finicky engineering to get the cooling to that point. I guess what i'm saying is that if you have an airplane that's designed from the start to use a water-cooled engine, you can design the airplane to take advantage of the water cooling and to realize the least drag. But when you have an airplane that's designed for an air-cooled engine, trying to retrofit a water-cooled one later isn't likely to be as efficient. > My engine (modestly > modified) will produce around 225 HP and should make the plane cruise > comfortably in the 200MPH range and the fuel burn should be no more > than 10 GPM. As the original poster pointed out, 200MPH can be achieved with a 200HP Lycoming, so it sounds like you need an extra 25HP to get there with your conversion. Not saying the fuel burn will be higher as a result, but it's quite likely. -Rob (Considering the Renesis Rotary engine for my -7, so i'm really not against auto-conversions... really!) ________________________________ Message 6 _____________________________________ Time: 11:15:26 AM PST US From: Gary Dwinal Subject: RE: RV7-List: Diesel engine for an RV-7 --> RV7-List message posted by: Gary Dwinal The fact that the size of the inlet and exit openings is the same doesn't mean much on it's own. If you just put a radiator between the inlet and exit like on your conversion, and don't put one there on a Lycoming installation, the drag will be higher on the engine with the radiator due to the back pressure it generates as air slows down to flow through the rad. It is possible to control the air flow to and from the rad with well-designed expansion (upstream) and compression (downstream) chambers around the rad. I seem to recall reading that on a P-51 in the right cruise configuration you could realize a small amount of *thrust* from this arrangement. But that's some finicky engineering to get the cooling to that point. I guess what i'm saying is that if you have an airplane that's designed from the start to use a water-cooled engine, you can design the airplane to take advantage of the water cooling and to realize the least drag. But when you have an airplane that's designed for an air-cooled engine, trying to retrofit a water-cooled one later isn't likely to be as efficient. > My engine (modestly > modified) will produce around 225 HP and should make the plane cruise > comfortably in the 200MPH range and the fuel burn should be no more > than 10 GPM. As the original poster pointed out, 200MPH can be achieved with a 200HP Lycoming, so it sounds like you need an extra 25HP to get there with your conversion. Not saying the fuel burn will be higher as a result, but it's quite likely. -Rob (Considering the Renesis Rotary engine for my -7, so i'm really not against auto-conversions... really!) advertising on the Matronics Forums. NOTICE: The information contained in this communication is intended solely for use by the designated recipient(s). This communication may also contain confidential or proprietary information and may be subject to confidentiality protection under the law. If you are not a designated recipient, you may not review, copy, or distribute this message. If you receive this message in error, please notify the sender and destroy your copy. Thank you for your cooperation. Fisher Engineering, a division of Douglas Dynamics, LLC ________________________________ Message 7 _____________________________________ Time: 11:28:39 AM PST US From: Gary Dwinal Subject: RE: RV7-List: Diesel engine for an RV-7 --> RV7-List message posted by: Gary Dwinal >As the original poster pointed out, 200MPH can be achieved with a 200HP Lycoming, so it sounds >like you need an extra 25HP to get there with your conversion. Not saying the fuel burn will >be higher as a result, but it's quite likely. >-Rob Rob - I pretty much agree with everything you said - but, What has not been said on this thread is the highly documented fact that liquid cooled engines do not require nearly the same amount of fuel as air cooled engines do per BHP. Air cooled engines require additional fuel to help cool the engine. I do not believe my 225HP liquid cooled engine will require 10GPH to operate at 200 MPH like the 200HP Lycoming does. I have a brand new lycoming 0-360 in my Cherokee and it requires a lot more than 10 GPM at only 155 MPH. But then that airplane is a slug aerodynamically when compared to the RV's. This is an argument that will go on for years and years, but Jess Meyers has been flying his GM V6 powered RV6 for about 9 years now with only routine maintenance and I for one am very impressed with that statistic. Plus I am old hot rod guy that has built many, many race car and hot rod engines and I have always wanted to build my own car type engine for an airplane! Gary Dwinal (Considering the Renesis Rotary engine for my -7, so i'm really not against auto-conversions... really!) advertising on the Matronics Forums. NOTICE: The information contained in this communication is intended solely for use by the designated recipient(s). This communication may also contain confidential or proprietary information and may be subject to confidentiality protection under the law. If you are not a designated recipient, you may not review, copy, or distribute this message. If you receive this message in error, please notify the sender and destroy your copy. Thank you for your cooperation. Fisher Engineering, a division of Douglas Dynamics, LLC ________________________________ Message 8 _____________________________________ Time: 12:06:18 PM PST US Subject: RE: RV7-List: Diesel engine for an RV-7 From: "Hinde, Frank George (Corvallis)" --> RV7-List message posted by: "Hinde, Frank George (Corvallis)" All I can tell you is that when I finally nailed down some builders of the Eggenfelner Subaru FWF the numbers were as I described. I honestly think it MAY be possible to design a cooling system (pressure recovery ducts etc) that will produce close to the same drag as an air cooled motor, but remember you got 2 to 3 times the flowrate of air in a water cooled motor than an aircooled unit (in theory)...If true thats a lot more drag. One guy built two identical RV 7's the soob did 178mph at 10 GPH and the Lyc did 200mph. Once again both our perpestives are purely speculative and builders have been known to stretch the truth...Heaven forbid!...:) I wonder how Burt Ruan designed the cooling system for his motor..Is it not possible it was only designed for say 75% power?...I.e full power on take off but throttle back before it overheated? He could have significantly have reduced the cooling drag that way too. Liquid cooled motors are more evently cooled and can therefore be built with tighter tolerances which makes them more efficient and reliable. My guess is Burt was looking for really good economy cruise at reduced power with exceptional reliabitlity. Best of luck with your project. Frank -----Original Message----- From: owner-rv7-list-server@matronics.com [mailto:owner-rv7-list-server@matronics.com] On Behalf Of Gary Dwinal Subject: RE: RV7-List: Diesel engine for an RV-7 --> RV7-List message posted by: Gary Dwinal Not flying yet, but I have a GM V6 truck engine in my plane along with the firewall forward package from Belted Air Power. The air intake is the original size and the radiator is mounted on the firewall with the original air exit openings. My engine (modestly modified) will produce around 225 HP and should make the plane cruise comfortably in the 200MPH range and the fuel burn should be no more than 10 GPM. Again, this is purely speculation on my behalf, but after talking with several others that have gone the GM V6 route with the kit from BAP, I think the assumption that a liquid cooled engine will always create more drag is controversial at best. There is a reason Burt Rutan absolutely required one of the engines in his "non-stop around the world airplane" to be liquid cooled! Gary Dwinal RV7A -----Original Message----- From: Hinde, Frank George (Corvallis) [mailto:frank.hinde@hp.com] Subject: RE: RV7-List: Diesel engine for an RV-7 --> RV7-List message posted by: "Hinde, Frank George (Corvallis)" --> Any ...and I mean any water cooled engine out there will produce more cooling drag than an aircooled one will. Note a good aircooled Lycosaurus will do around 200mph on 10 GPH. Similar fuel burn on a very good water cooled automotive conversion will give less than 180mph. It will still do 200mph but the fuel burn will get significant...I think fuel burn is proportional to speed squared (or is that cubed?) and that part of the curve will get pretty steep. Not saying that drag can't be reduced (P51 Mustang style scoops and optimised radiators) but it certainly won't be a bolt on package. I hate to say it but about the best bet is a Lycoming...And I spent a year trying to prove otherwise...I even fly behind a little Subaru in a Zenair Zodiac....A total engine rebuild for a couple of grand is sure attractive but I just can't have a slow plane anymore and to burn another 3 to 4 GPH to make the speed I want gets to be a big bill over 2000 hours as well... My 2 cents Frank -----Original Message----- From: owner-rv7-list-server@matronics.com [mailto:owner-rv7-list-server@matronics.com] On Behalf Of springcanyon Subject: RV7-List: Diesel engine for an RV-7 --> RV7-List message posted by: "springcanyon" --> I am working on an RV-7 and am approaching the time when I need to know which or what engine I am going to install. I love the idea of a diesel engine. Since this is a major investment as well as one of the most important parts of my airplane I would like some other opinions. I have talked with Delta Hawk and their engine sounds good and looks good. The thing that bothers me is the total lack of field experience with this engine. Anyone have opinions about this? Thanks, Don Owens springcanyon@mymethow.com advertising on the Matronics Forums. NOTICE: The information contained in this communication is intended solely for use by the designated recipient(s). This communication may also contain confidential or proprietary information and may be subject to confidentiality protection under the law. If you are not a designated recipient, you may not review, copy, or distribute this message. If you receive this message in error, please notify the sender and destroy your copy. Thank you for your cooperation. Fisher Engineering, a division of Douglas Dynamics, LLC ________________________________ Message 9 _____________________________________ Time: 12:18:21 PM PST US From: Steve Noujaim pieces? Subject: RV7-List: Help..."Extra" holes in wing spar stub and F704 pieces? --> RV7-List message posted by: Steve Noujaim pieces? Hi They are may be either for tooling or for that extra wiring I reckon. You may wish to check out Dan Checkoways site rvproject.com he has loads of pictures and its full of handy hints ________________________________ Message 10 ____________________________________ Time: 02:25:59 PM PST US From: "cgalley" Subject: Re: RV7-List: Diesel engine for an RV-7 --> RV7-List message posted by: "cgalley" Basic reason for the water cooled Continental on the Voyager was it was FREE! and they threw in a prop as well. ----- Original Message ----- From: "Gary Dwinal" Subject: RE: RV7-List: Diesel engine for an RV-7 > --> RV7-List message posted by: Gary Dwinal > > Not flying yet, but I have a GM V6 truck engine in my plane along with the > firewall forward package from Belted Air Power. The air intake is the > original size and the radiator is mounted on the firewall with the > original > air exit openings. My engine (modestly modified) will produce around 225 > HP > and should make the plane cruise comfortably in the 200MPH range and the > fuel burn should be no more than 10 GPM. Again, this is purely > speculation > on my behalf, but after talking with several others that have gone the GM > V6 > route with the kit from BAP, I think the assumption that a liquid cooled > engine will always create more drag is controversial at best. There is a > reason Burt Rutan absolutely required one of the engines in his "non-stop > around the world airplane" to be liquid cooled! > > Gary Dwinal > RV7A > > -----Original Message----- > From: Hinde, Frank George (Corvallis) [mailto:frank.hinde@hp.com] > To: rv7-list@matronics.com > Subject: RE: RV7-List: Diesel engine for an RV-7 > > > --> RV7-List message posted by: "Hinde, Frank George (Corvallis)" > --> > > Any ...and I mean any water cooled engine out there will produce more > cooling drag than an aircooled one will. > > Note a good aircooled Lycosaurus will do around 200mph on 10 GPH. Similar > fuel burn on a very good water cooled automotive conversion will give less > than 180mph. > > It will still do 200mph but the fuel burn will get significant...I think > fuel burn is proportional to speed squared (or is that cubed?) and that > part > of the curve will get pretty steep. > > Not saying that drag can't be reduced (P51 Mustang style scoops and > optimised radiators) but it certainly won't be a bolt on package. > > I hate to say it but about the best bet is a Lycoming...And I spent a year > trying to prove otherwise...I even fly behind a little Subaru in a Zenair > Zodiac....A total engine rebuild for a couple of grand is sure attractive > but I just can't have a slow plane anymore and to burn another 3 to 4 GPH > to > make the speed I want gets to be a big bill over 2000 hours as well... > > My 2 cents > > Frank > > -----Original Message----- > From: owner-rv7-list-server@matronics.com > [mailto:owner-rv7-list-server@matronics.com] On Behalf Of springcanyon > To: rv7-list@matronics.com > Subject: RV7-List: Diesel engine for an RV-7 > > --> RV7-List message posted by: "springcanyon" > --> > > I am working on an RV-7 and am approaching the time when I need to know > which or what engine I am going to install. I love the idea of a diesel > engine. Since this is a major investment as well as one of the most > important parts of my airplane I would like some other opinions. I have > talked with Delta Hawk and their engine sounds good and looks good. The > thing that bothers me is the total lack of field experience with this > engine. Anyone have opinions about this? > > Thanks, > Don Owens > springcanyon@mymethow.com > > > advertising on the Matronics Forums. > > > NOTICE: The information contained in this communication is intended > solely > for use by the designated recipient(s). This communication may also > contain > confidential or proprietary information and may be subject to > confidentiality protection under the law. If you are not a designated > recipient, you may not review, copy, or distribute this message. If you > receive this message in error, please notify the sender and destroy your > copy. > Thank you for your cooperation. > Fisher Engineering, a division of Douglas Dynamics, LLC > > >