Topics

BMW 1200cc engine

John Hoxie
 

I recently heard of someone putting a 1200cc BMW motorcycle engine on a plane. I don't remember if it was light sport category or not. They claim 120 h.p. Has anyone looked into this engine as viable for the Q2?

charlie
 

The power at the crank will be closer to 105-110 at best depending how the intake and exhaust are configured.
Petty close to 200# or so.
Probably work pretty well.
CharlieN


At 08:06 AM 4/9/2020 -0700, you wrote:
I recently heard of someone putting a 1200cc BMW motorcycle engine on a plane. I don't remember if it was light sport category or not. They claim 120 h.p. Has anyone looked into this engine as viable for the Q2?
_._,_._,_

Michael
 

HP @ a given RPM is the problem. Did the plane in question use a reduction drive between the engine and propeller?
--
-MD

John Hoxie
 

MD,
I didn't get that information. I did some more research on it. To get more than about 50 h.p., one would need a reduction to get up to 110 h.p.


On Fri, May 1, 2020 at 2:23 PM, Michael
<dunningme@...> wrote:
HP @ a given RPM is the problem. Did the plane in question use a reduction drive between the engine and propeller?
--
-MD

Rich Gillen
 

For Airplane use you have to Derate any Engine

Manufacturer: BMW Motorrad
Production:         1997–2004
Engine:             1,170 cc (71 cu in) two-cylinder boxer
Bore / stroke:    101 mm × 73 mm (4.0 in × 2.9 in)
Power:               61 hp (45 kW)
Torque:              98 N⋅m (72 lbf⋅ft) @ 3,000 rpm

1170cc at 90% VE at 5000rpm = 62hp!

============================================
BMW R1200 GS
Manufacturer: BMW Motorrad
Production:     R1200GS (2004–12)
Engine:             1,170 cc (71 cu in) boxer twin: air/oil cooled
air/liquid cooled (LC)
Bore / stroke: 101 mm × 73 mm (4.0 in × 2.9 in)
Compression ratio: 12.0:1         12.5:1 (LC)

Top speed:   130.8 mph (210.5 km/h)

Power:         81 kW (109 hp) @ 7,750 rpm

                    70.42 kW (94.43 hp) (rear wheel)

                    92 kW (123 hp) @ 7,750 rpm (LC)

                    Torque 120 N⋅m (89 lbf⋅ft) @ 6,000 rpm

                    97.38 N⋅m (71.82 lbf⋅ft) (rear wheel)

                    125 N⋅m (92 lbf⋅ft) @ 6,500 rpm (LC)
-----------------------------------------------------------------------------
7750rpm Derated by 25% for Airplane use is Max 5812.5rpm for just Takeoff! 5812.5rpm - 25% = 4,359.4rpm for Crusie!      1170cc = 71.4 ci.

1170cc making 109 hp @ 7750rpm is 102% VE.
1170cc making 105 hp @ 7500rpm is 102% VE.
1170cc making 102 hp @ 7250rpm is 102% VE.
1170cc making   98 hp @ 7000rpm is 102% VE.
1170cc making   95 hp @ 6750rpm is 102% VE.
1170cc making   91 hp @ 6500rpm is 102% VE.
1170cc making   88 hp @ 6250rpm is 102% VE.
1170cc making   84 hp @ 6000rpm is 102% VE.

1170cc making   82 hp @ 5812rpm is 102% VE. Max Takeoff! Rotax 912 uses 5800rpm 2 Min!

1170cc making   81 hp @ 5750rpm is 102% VE.
1170cc making   77 hp @ 5500rpm is 102% VE.
1170cc making   74 hp @ 5250rpm is 102% VE.
1170cc making   70 hp @ 5000rpm is 102% VE.

1170cc making   61 hp @ 4360rpm is 102% VE. Crusie

Compare a Rotax Rick 670 (669cc)  92hp@6350rpm!

Rich


Bill Higdon
 

Here's a link to discussion about the BMW 1200 as a aircraft engine it started of with a discussion of theR1150 & progressed to the R1200
https://www.homebuiltairplanes.com/forums/threads/bmw-r1150.29290/

John Hoxie
 

I went to the site. It is so de-rated for aircraft use, its too low hp for a Q2.

 
John Hoxie
He is no fool, who gives up what he can not keep, to gain what he can not loose -- Jim Elliot


On Sunday, May 3, 2020, 02:36:00 PM MDT, Bill Higdon via groups.io <willard561@...> wrote:


Here's a link to discussion about the BMW 1200 as a aircraft engine it started of with a discussion of theR1150 & progressed to the R1200
https://www.homebuiltairplanes.com/forums/threads/bmw-r1150.29290/

Rich Gillen
 


I see you guys always talking about different Engines and Hp, but what's more Important is the Length & Number of Prop Blades used and the rpm you turn them.

Q2

1000 lbs = 453.5924 kg / 10 kg = 45.35924 kw needed = 60.82774 hp needed.

Most People have Upgraded to an O-200 (100hp @ 2750rpm).

So what is the Max Length of Prop that can be used? The Length and Number of Blades and rpm used dictates thrust made!

So is it the added hp, or the Wrong Prop or Reduction Ratio being used or both?

Like a Rotax B Gear Drive is limited to a (2) Blade 68", or (3) Blade 64". It comes in 2.0, 2.24, 2.58 ratios. Industry Standard for 2 Strokes is 6500rpm.

For comparison will use the same 68" Prop Length and Number of Blades (2).

Revmaster 2100-DQ converted auto-engine, 64 hp (47.7 kW) at 3,200 rpm. Direct Drive. Dry weight: ??? lb.
A (2) Blade 68" x 15 Pitched for -100rpm = 3100rpm = 550.93 lbs needs 64.912 hp.
A (2) Blade 68" x 14 Pitched for -100rpm = 3100rpm = 550.93 lbs needs 60.584 hp.

O-200 (100hp @ 2750rpm) Direct Drive. Dry weight: 170.18 lb (77.19 kg) dry, without accessories.
A (2) Blade 68" x 37 Pitched for -100rpm = 2650rpm = 402.59 lbs needs 100.020 hp.
A (2) Blade 68" x 36 Pitched for -100rpm = 2650rpm = 402.59 lbs needs 97.317hp.

Rotax Rick 670 (92hp @ 6350rpm). Using a 2.0 Gear Box. 6350rpm/2 = 3175rpm. Dry weight: (119 lb) with electric starter, carburetors, fuel pump, air filters and reduction gear.
A (2) Blade 68" x 22 Pitched for -100rpm = 3075rpm = 542.08 lbs needs 92.919 hp.
A (2) Blade 68" x 21 Pitched for -100rpm = 3075rpm = 542.08 lbs needs 88.696 hp.

A (3) Blade 64" x 20 Pitched for -100rpm = 3075rpm = 595.49 lbs needs 92.795 hp.

So what have we learned. Could we turn all of these Engines for the same Prop 3100rpm, for same Thrust Numbers, Yes. The difference would be hp/Torque made which translates into shorter takeoff distance, and time to reach Altitude.

Revmaster 2100-DQ converted auto-engine, 64 hp (47.7 kW) at 3,200 rpm. Direct Drive. Dry weight: ??? lb.
A (3) Blade 68" x 11 Pitched for -100rpm = 3100rpm = 771.30 lbs needs 66.643 hp.
A (3) Blade 68" x 10 Pitched for -100rpm = 3100rpm = 771.30 lbs needs 60.584 hp.

John Hoxie
 

The 670 with it's lighter weight is appealing. It is de-rated for aircraft use to 61 h.p. though. People fly to a new engine usually because there's some thing(s) about the current engine they're flying or in their project that they don't like (reports after kit purchase). Sometimes there are options $ & time to overcome those unliked things. I don't mind a bigger engine for time to climb but I want assurance there is still endurance - similar range. A heavier engine is a heavier plane, which usually means more fuel consumption. My 2100DQ I don't like magnetos, adjusting valves & most report the case is shot after 300 hours. I see 2 coins - the 2 sides of one coin are reliability & maintenance time the 2nd is performance & efficiency.


On Mon, May 4, 2020 at 11:24 AM, Rich Gillen via groups.io
<Armilite@...> wrote:

I see you guys always talking about different Engines and Hp, but what's more Important is the Length & Number of Prop Blades used and the rpm you turn them.

Q2

1000 lbs = 453.5924 kg / 10 kg = 45.35924 kw needed = 60.82774 hp needed.

Most People have Upgraded to an O-200 (100hp @ 2750rpm).

So what is the Max Length of Prop that can be used? The Length and Number of Blades and rpm used dictates thrust made!

So is it the added hp, or the Wrong Prop or Reduction Ratio being used or both?

Like a Rotax B Gear Drive is limited to a (2) Blade 68", or (3) Blade 64". It comes in 2.0, 2.24, 2.58 ratios. Industry Standard for 2 Strokes is 6500rpm.

For comparison will use the same 68" Prop Length and Number of Blades (2).

Revmaster 2100-DQ converted auto-engine, 64 hp (47.7 kW) at 3,200 rpm. Direct Drive. Dry weight: ??? lb.
A (2) Blade 68" x 15 Pitched for -100rpm = 3100rpm = 550.93 lbs needs 64.912 hp.
A (2) Blade 68" x 14 Pitched for -100rpm = 3100rpm = 550.93 lbs needs 60.584 hp.

O-200 (100hp @ 2750rpm) Direct Drive. Dry weight: 170.18 lb (77.19 kg) dry, without accessories.
A (2) Blade 68" x 37 Pitched for -100rpm = 2650rpm = 402.59 lbs needs 100.020 hp.
A (2) Blade 68" x 36 Pitched for -100rpm = 2650rpm = 402.59 lbs needs 97.317hp.

Rotax Rick 670 (92hp @ 6350rpm). Using a 2.0 Gear Box. 6350rpm/2 = 3175rpm. Dry weight: (119 lb) with electric starter, carburetors, fuel pump, air filters and reduction gear.
A (2) Blade 68" x 22 Pitched for -100rpm = 3075rpm = 542.08 lbs needs 92.919 hp.
A (2) Blade 68" x 21 Pitched for -100rpm = 3075rpm = 542.08 lbs needs 88.696 hp.

A (3) Blade 64" x 20 Pitched for -100rpm = 3075rpm = 595.49 lbs needs 92.795 hp.

So what have we learned. Could we turn all of these Engines for the same Prop 3100rpm, for same Thrust Numbers, Yes. The difference would be hp/Torque made which translates into shorter takeoff distance, and time to reach Altitude.

Revmaster 2100-DQ converted auto-engine, 64 hp (47.7 kW) at 3,200 rpm. Direct Drive. Dry weight: ??? lb.
A (3) Blade 68" x 11 Pitched for -100rpm = 3100rpm = 771.30 lbs needs 66.643 hp.
A (3) Blade 68" x 10 Pitched for -100rpm = 3100rpm = 771.30 lbs needs 60.584 hp.

John Hoxie
 

My Q2 gross weight will hopefully be 1100 lbs with the LS-1 forward wing.


On Mon, May 4, 2020 at 3:00 PM, John Hoxie via groups.io
<hoxdesigns@...> wrote:
The 670 with it's lighter weight is appealing. It is de-rated for aircraft use to 61 h.p. though. People fly to a new engine usually because there's some thing(s) about the current engine they're flying or in their project that they don't like (reports after kit purchase). Sometimes there are options $ & time to overcome those unliked things. I don't mind a bigger engine for time to climb but I want assurance there is still endurance - similar range. A heavier engine is a heavier plane, which usually means more fuel consumption. My 2100DQ I don't like magnetos, adjusting valves & most report the case is shot after 300 hours. I see 2 coins - the 2 sides of one coin are reliability & maintenance time the 2nd is performance & efficiency.


On Mon, May 4, 2020 at 11:24 AM, Rich Gillen via groups.io
<Armilite@...> wrote:

I see you guys always talking about different Engines and Hp, but what's more Important is the Length & Number of Prop Blades used and the rpm you turn them.

Q2

1000 lbs = 453.5924 kg / 10 kg = 45.35924 kw needed = 60.82774 hp needed.

Most People have Upgraded to an O-200 (100hp @ 2750rpm).

So what is the Max Length of Prop that can be used? The Length and Number of Blades and rpm used dictates thrust made!

So is it the added hp, or the Wrong Prop or Reduction Ratio being used or both?

Like a Rotax B Gear Drive is limited to a (2) Blade 68", or (3) Blade 64". It comes in 2.0, 2.24, 2.58 ratios. Industry Standard for 2 Strokes is 6500rpm.

For comparison will use the same 68" Prop Length and Number of Blades (2).

Revmaster 2100-DQ converted auto-engine, 64 hp (47.7 kW) at 3,200 rpm. Direct Drive. Dry weight: ??? lb.
A (2) Blade 68" x 15 Pitched for -100rpm = 3100rpm = 550.93 lbs needs 64.912 hp.
A (2) Blade 68" x 14 Pitched for -100rpm = 3100rpm = 550.93 lbs needs 60.584 hp.

O-200 (100hp @ 2750rpm) Direct Drive. Dry weight: 170.18 lb (77.19 kg) dry, without accessories.
A (2) Blade 68" x 37 Pitched for -100rpm = 2650rpm = 402.59 lbs needs 100.020 hp.
A (2) Blade 68" x 36 Pitched for -100rpm = 2650rpm = 402.59 lbs needs 97.317hp.

Rotax Rick 670 (92hp @ 6350rpm). Using a 2.0 Gear Box. 6350rpm/2 = 3175rpm. Dry weight: (119 lb) with electric starter, carburetors, fuel pump, air filters and reduction gear.
A (2) Blade 68" x 22 Pitched for -100rpm = 3075rpm = 542.08 lbs needs 92.919 hp.
A (2) Blade 68" x 21 Pitched for -100rpm = 3075rpm = 542.08 lbs needs 88.696 hp.

A (3) Blade 64" x 20 Pitched for -100rpm = 3075rpm = 595.49 lbs needs 92.795 hp.

So what have we learned. Could we turn all of these Engines for the same Prop 3100rpm, for same Thrust Numbers, Yes. The difference would be hp/Torque made which translates into shorter takeoff distance, and time to reach Altitude.

Revmaster 2100-DQ converted auto-engine, 64 hp (47.7 kW) at 3,200 rpm. Direct Drive. Dry weight: ??? lb.
A (3) Blade 68" x 11 Pitched for -100rpm = 3100rpm = 771.30 lbs needs 66.643 hp.
A (3) Blade 68" x 10 Pitched for -100rpm = 3100rpm = 771.30 lbs needs 60.584 hp.

Rich Gillen
 


John, the 582UL is rated 65hp@6500rpm, the 618UL was rated 73.4hp@6750rpm. The 670 in a Sled is 115.7hp@7750rpm. Derated for Airplane use there 92-95hp! With Rotax Ricks Exhaust it's 92hp@6350rpm! The 670 is around 9 lbs heavier than than a 582UL. Rotax Rick has a 450hr TBO on his Engines. He totally Rebuilds the Engine with all New parts.

The Rotax 532UL/521 Skidoo, 582UL/580/582/583 Skidoo, 618UL/617 Skidoo, and the 670 are all from the same Family of engines, just different Bores & Strokes used. The 618UL/617 and the 670 have RAVE Valves is all.

Reliability of any Engine is the Person Flying it, Maintaining it, and who Built it. There are 503's and 582's out there with over 1300hrs and still Flying with just a Decarbon every 200 hrs. So who ever told you there shot after 300 hrs is a liar. Rotax's #1 Failure is Detonation. Easy to solve, just always use Fresh 91+ Octane, or better 100LL is best. Most Airports only carry 100LL and Jet Fuel. A 670 is (78mm x 70mm) 669.2cc and can be Big Bored to (82.5mm x 70mm) 748.6cc. At 6500rpm and using 11.5cr with a Good Wide Band Tuned Pipe it takes 7cc to make 1hp. 669.2cc/7cc = 95.6 hp and a 748.6cc/7cc = 106.9 hp. Things rick does to his Engines is use Ceramic Top Coated Pistons and 40:1 Oil, and uses Amsoil Interceptor Oil. With the larger CC if you don't need the extra hp, you can turn it even lower rpm and still make same 92hp!

I would say 85% of all Rotax Engine Failures is attributed to Detonation.
10% from Oil Injection Failure.
5% from People using a Bad 2 Stroke Oil with a Low Flash Point. Not all 2 Stroke Oils Burn Clean either.




1b. 
Re: BMW 1200cc engine
From: John Hoxie
Date: Mon, 04 May 2020 14:00:36 PDT

The 670 with it's lighter weight is appealing. It is de-rated for aircraft use to 61 h.p. though. People fly to a new engine usually because there's some thing(s) about the current engine they're flying or in their project that they don't like (reports after kit purchase). Sometimes there are options $ & time to overcome those unliked things. I don't mind a bigger engine for time to climb but I want assurance there is still endurance - similar range. A heavier engine is a heavier plane, which usually means more fuel consumption. My 2100DQ I don't like magnetos, adjusting valves & most report the case is shot after 300 hours. I see 2 coins - the 2 sides of one coin are reliability & maintenance time the 2nd is performance & efficiency.

Rich Gillen
 


For MTOW of 1100 lbs = 498.9516 kg / 10 kg = 49.89516 kw needed = 66.91051 (67 hp) needed! Rotax UL Engines don't really use a Tuned Pipe it's a Tuned Muffler Exhaust. It's like a Mega Phone Open Header with a Muffler.

Like a:
Skidoo 470
462UL is (69.5mm x 61mm) 463.0cc rated 52hp@6500rpm. 463cc/7cc = 66.1hp@6500rpm with a Tuned Pipe!

Skidoo 521
532UL is (72mm x 64mm) 521.3cc, rated 64hp@6500rpm. 521.3cc/7cc = 74.7hp@6500rpm with a Tuned Pipe!

Skidoo 580/582/583
582UL is (76mm x 64mm) 580.9cc, rated 65hp@6500rpm. 580.9cc/7cc = 82.9hp@6500rpm  with a Tuned Pipe!

Skidoo 617
618UL is (76mm x 68mm) 617.2cc, rated 73.4hp@6750rpm. 617.2cc/7cc = 88.1hp@6500rpm  with a Tuned Pipe!

Skidoo 670 is (78mm x 70mm) 669.2cc/7cc = 95.6hp@6500rpm!



1c. 
Re: BMW 1200cc engine
From: John Hoxie
Date: Mon, 04 May 2020 14:02:05 PDT

My Q2 gross weight will hopefully be 1100 lbs with the LS-1 forward wing.

John Hoxie
 

I read that somone put in Polaris pistons in a 670 to make it a 720. Do you have any info on that? Do you have a fuel burn chart comparing the Rotax engines. I have a 277 for one of my ultralights I am restoring. Is there a way to get a manual on that?


On Tue, May 5, 2020 at 11:14 AM, Rich Gillen via groups.io
<Armilite@...> wrote:

John, the 582UL is rated 65hp@6500rpm, the 618UL was rated 73.4hp@6750rpm. The 670 in a Sled is 115.7hp@7750rpm. Derated for Airplane use there 92-95hp! With Rotax Ricks Exhaust it's 92hp@6350rpm! The 670 is around 9 lbs heavier than than a 582UL. Rotax Rick has a 450hr TBO on his Engines. He totally Rebuilds the Engine with all New parts.

The Rotax 532UL/521 Skidoo, 582UL/580/582/583 Skidoo, 618UL/617 Skidoo, and the 670 are all from the same Family of engines, just different Bores & Strokes used. The 618UL/617 and the 670 have RAVE Valves is all.

Reliability of any Engine is the Person Flying it, Maintaining it, and who Built it. There are 503's and 582's out there with over 1300hrs and still Flying with just a Decarbon every 200 hrs. So who ever told you there shot after 300 hrs is a liar. Rotax's #1 Failure is Detonation. Easy to solve, just always use Fresh 91+ Octane, or better 100LL is best. Most Airports only carry 100LL and Jet Fuel. A 670 is (78mm x 70mm) 669.2cc and can be Big Bored to (82.5mm x 70mm) 748.6cc. At 6500rpm and using 11.5cr with a Good Wide Band Tuned Pipe it takes 7cc to make 1hp. 669.2cc/7cc = 95.6 hp and a 748.6cc/7cc = 106.9 hp. Things rick does to his Engines is use Ceramic Top Coated Pistons and 40:1 Oil, and uses Amsoil Interceptor Oil. With the larger CC if you don't need the extra hp, you can turn it even lower rpm and still make same 92hp!

I would say 85% of all Rotax Engine Failures is attributed to Detonation.
10% from Oil Injection Failure.
5% from People using a Bad 2 Stroke Oil with a Low Flash Point. Not all 2 Stroke Oils Burn Clean either.




1b. 
Re: BMW 1200cc engine
From: John Hoxie
Date: Mon, 04 May 2020 14:00:36 PDT

The 670 with it's lighter weight is appealing. It is de-rated for aircraft use to 61 h.p. though. People fly to a new engine usually because there's some thing(s) about the current engine they're flying or in their project that they don't like (reports after kit purchase). Sometimes there are options $ & time to overcome those unliked things. I don't mind a bigger engine for time to climb but I want assurance there is still endurance - similar range. A heavier engine is a heavier plane, which usually means more fuel consumption. My 2100DQ I don't like magnetos, adjusting valves & most report the case is shot after 300 hours. I see 2 coins - the 2 sides of one coin are reliability & maintenance time the 2nd is performance & efficiency.

John Hoxie
 

How much $ is Rotax Rick's 670? I was saying Many Revmasters need rebuilds/ upgrades at 300 hours.


On Tue, May 5, 2020 at 11:14 AM, Rich Gillen via groups.io
<Armilite@...> wrote:

John, the 582UL is rated 65hp@6500rpm, the 618UL was rated 73.4hp@6750rpm. The 670 in a Sled is 115.7hp@7750rpm. Derated for Airplane use there 92-95hp! With Rotax Ricks Exhaust it's 92hp@6350rpm! The 670 is around 9 lbs heavier than than a 582UL. Rotax Rick has a 450hr TBO on his Engines. He totally Rebuilds the Engine with all New parts.

The Rotax 532UL/521 Skidoo, 582UL/580/582/583 Skidoo, 618UL/617 Skidoo, and the 670 are all from the same Family of engines, just different Bores & Strokes used. The 618UL/617 and the 670 have RAVE Valves is all.

Reliability of any Engine is the Person Flying it, Maintaining it, and who Built it. There are 503's and 582's out there with over 1300hrs and still Flying with just a Decarbon every 200 hrs. So who ever told you there shot after 300 hrs is a liar. Rotax's #1 Failure is Detonation. Easy to solve, just always use Fresh 91+ Octane, or better 100LL is best. Most Airports only carry 100LL and Jet Fuel. A 670 is (78mm x 70mm) 669.2cc and can be Big Bored to (82.5mm x 70mm) 748.6cc. At 6500rpm and using 11.5cr with a Good Wide Band Tuned Pipe it takes 7cc to make 1hp. 669.2cc/7cc = 95.6 hp and a 748.6cc/7cc = 106.9 hp. Things rick does to his Engines is use Ceramic Top Coated Pistons and 40:1 Oil, and uses Amsoil Interceptor Oil. With the larger CC if you don't need the extra hp, you can turn it even lower rpm and still make same 92hp!

I would say 85% of all Rotax Engine Failures is attributed to Detonation.
10% from Oil Injection Failure.
5% from People using a Bad 2 Stroke Oil with a Low Flash Point. Not all 2 Stroke Oils Burn Clean either.




1b. 
Re: BMW 1200cc engine
From: John Hoxie
Date: Mon, 04 May 2020 14:00:36 PDT

The 670 with it's lighter weight is appealing. It is de-rated for aircraft use to 61 h.p. though. People fly to a new engine usually because there's some thing(s) about the current engine they're flying or in their project that they don't like (reports after kit purchase). Sometimes there are options $ & time to overcome those unliked things. I don't mind a bigger engine for time to climb but I want assurance there is still endurance - similar range. A heavier engine is a heavier plane, which usually means more fuel consumption. My 2100DQ I don't like magnetos, adjusting valves & most report the case is shot after 300 hours. I see 2 coins - the 2 sides of one coin are reliability & maintenance time the 2nd is performance & efficiency.