# Using truck diesels for Beaver-type large Bush planes. Perfect match?

Discussion in 'General Auto Conversion Discussion' started by Doggzilla, Aug 2, 2019.

1. Aug 3, 2019

### pfarber

#### Well-Known Member

Joined:
Feb 21, 2019
Messages:
194
9
Location:
Pennsylvania
One offs of 20year old installs are not giong to cut it. Yes, the LS1/2/4 is a good solid motor, but not in the power/weight of the 4 place sub 200kts cruiser. I don't see diesels getting the weigh down for a 2-4 place plane.

Once you get out of the 150-160-200hp range engines are plentiful. But the market really is the 150-200hp range.

If the FAA would allow a company to license O-360s prints to clone the engine you could put out a to-print-spec engine for less than $10k. You can get a custom one off forged crank for less than$3k. Yet new O-360 cranks are $8k with a$4k core. NO. Its not about low production numbers. Its about holding the market hostage with FAA regulations.
I wonder if the Magnuson-Moss act would apply to aircraft???

2. Aug 3, 2019

### TFF

#### Well-Known Member

Joined:
Apr 28, 2010
Messages:
11,424
3,170
Location:
Memphis, TN
Have to remember weight of fuels. Gasoline, auto or airplane is a little more than 6 lb gallon. Jet is close to 7 lb and diesel is 8.5 lb. you have to put that extra pound of fuel through the propeller power wise to be even. 100 gallons of Jet weights 100 lb more. Can you extract the power so you only have to carry 85 gallons just to be equal gross?

Wittman had two different Buicks in his plane. One was bigger displacement. One is on a stand in his Oshkosh hangar. The smaller engine is a little bigger than a O200 and the bigger one was smaller than a O290. Smaller prop and willing to spin it fast got the same performance as an airplane engine, 3200 rpm at least. I read he also pulled the power way back when cruising; back to normal airplane rpm speeds of 2200-2500. I’m sure it was some for noise and some for longevity.

3. Aug 3, 2019

### akwrencher

#### Well-Known MemberHBA Supporter

Joined:
Oct 16, 2012
Messages:
1,080
377
Location:
Gustavus, AK

Pretty sure it was a typo, Diesel can't weight 8.5lbs per gallon, it would not float on water.

4. Aug 3, 2019

### pictsidhe

#### Well-Known Member

Joined:
Jul 15, 2014
Messages:
6,414
1,665
Location:
North Carolina
Jet A and diesel are both close to 7lb/gallon. About 10% more than gasoline.

5. Aug 3, 2019

### TFF

#### Well-Known Member

Joined:
Apr 28, 2010
Messages:
11,424
3,170
Location:
Memphis, TN
it Is right... in imperial gallons. Oops

pictsidhe and akwrencher like this.
6. Aug 4, 2019

### pictsidhe

#### Well-Known Member

Joined:
Jul 15, 2014
Messages:
6,414
1,665
Location:
North Carolina
Heh, us Brits, Canucks and Aussies are supposed to be the ones making that mistake!

7. Aug 4, 2019

### Pops

#### Well-Known Member

Joined:
Jan 1, 2013
Messages:
6,919
5,833
Location:
USA.
Sweet little engine. I had one in a 1968 VW bug.

8. Aug 4, 2019

### Hephaestus

#### Well-Known Member

Joined:
Jun 25, 2014
Messages:
927
203
Location:
YMM
Lol, can't the Americans just start saying 3.785 liters instead. Aren't they the last imperial holdouts?

9. Aug 4, 2019

### PW_Plack

#### Well-Known Member

Joined:
May 25, 2015
Messages:
144
66
Location:
West Valley City, UT
Even if the factories don't turn out car engines which can run at 100%, there are aftermarket solutions. Nelson Racing Engines is building a twin turbo Chevy LS which, at only 260 cubic inches, has been test run at 1200 HP, full boost at 7,000 RPM, continuous for multiple five-minute dyno pulls.

Here's video of the first flat-out dyno pull.

The application is large hydroplane racing, where this engine will compete in the same class as 470 cubic-inch normally-aspirated V8's. There is another video discussing the internal mods done to keep the engine together under this severe use.

10. Aug 4, 2019

### litespeed

#### Well-Known Member

Joined:
May 21, 2008
Messages:
1,390
246
Location:
Sydney
Forget the truckdiesels and go a modern turbo diesel form a euro company. They have the power, engineering and low weight.

If going for Gas? My pick would be a 2 valve BMW V12 M70 at 5 or 5.3 litres. It is light weight, very compact, very simple for a modern engine and has standard completely separate ignition /ecu's per bank. So built in redundancy allowing at least 6 cyclinders if a ecu fails.

They were designed to move a limo, have heaps of low down torque and incredibly smooth. You can place a coin on its edge whilst running and it does not fall. I have done this. They easily powered a 2.2 ton limo at 170mph with limiter removed. No vanos or other complex stuff to fail. Just simple two valve OHC.

They are very well suited to aircraft either direct or redrive. The harmonics are very sweet been a silky smooth V12.

Stock they make 300hp , but were built very conservative for power and can easily make 450 hp atmo and still be happy to do big miles. Naturally they also turbo or supercharge very well. 450hp with a supercharger would be a simple matter.

With different heads this engine formed the mighty Maclaren F1 engine.

The engine is very compact as a 60 degree V12 and weighs only 40 odd lbs more than a period BMW 2.5 six. They have alloy blocks. It fits into even a old e30 3 series, any space that can take the six will take the V12, so cowl friendly.

They have been used successfully with redrives on aircraft.
The Vickers Vimy replica used them but BMW America sued them to stop it been flown in the USA. Stupid lawyers.
I would not expect this to be a problem anymore as long out of production.

Also make awesome boat engines and the hotrodders have finally started using them.
A friend who builds BMW engines for motorsport has 3 brand new ones in his workshop. Lovely engine.

I think this would be a lot better than a V8 when redriven due to inherent balance and smooth harmonics of a 60 degree V12.

11. Aug 4, 2019

### litespeed

#### Well-Known Member

Joined:
May 21, 2008
Messages:
1,390
246
Location:
Sydney
Just checked the weight sans accessories- 420lbs.

So no heavyweight.

12. Aug 4, 2019

### pictsidhe

#### Well-Known Member

Joined:
Jul 15, 2014
Messages:
6,414
1,665
Location:
North Carolina
5 minute dyno pulls do not come anywhere near aircraft use. You need to test for hours at a time, not minutes.

13. Aug 4, 2019

### pictsidhe

#### Well-Known Member

Joined:
Jul 15, 2014
Messages:
6,414
1,665
Location:
North Carolina
The BMW V12s do look good. Rolls Royce has used at least one BMW V12, so some nice valve covers may be found!
The Vimy injunction was overturned a few days later, by the same judge who orderd it. I guess he became a judge after failing to suck enough blood as a lawyer?

litespeed likes this.
14. Aug 5, 2019

### PW_Plack

#### Well-Known Member

Joined:
May 25, 2015
Messages:
144
66
Location:
West Valley City, UT
My point was five-minute pulls at more than 4HP per cubic inch are an impressive start, and certainly validate the block/head sealing and cooling mods NRE has come up with to keep engines alive. After 12 of these test runs, the bearings looked like new. I have no doubt a larger displacement Chevy LS running 200-300 HP could earn a long TBO in an aircraft with similar prep.

15. Aug 17, 2019

### Urquiola

#### Member

Joined:
Aug 23, 2013
Messages:
24
2
Location:
Don't forget this article: 'Power Struggle: Why car engines won't fly', Don Sherman. Air&Space, December 1996-January 1997, pgs 71-81. Salut +

16. Aug 17, 2019

### Turd Ferguson

#### Well-Known Member

Joined:
Mar 14, 2008
Messages:
4,661
1,624
Location:
Upper midwest in a house
Anybody that has a Beaver or large bush plane is likely trying to make a buck with it and a non-certificated engine will never be part of that equation. Bolt on a PT6 powerplant and its good for 4-5000 hrs of year round reliable service, which is what's needed in the bush.

akwrencher likes this.
17. Aug 17, 2019

### Turd Ferguson

#### Well-Known Member

Joined:
Mar 14, 2008
Messages:
4,661
1,624
Location:
Upper midwest in a house
The US has just announced they will be converting all measuring units to metric and be 100% within a few yrs. Due to the complexities they will be making the change inch by inch.

Mad MAC, Jerry Lytle and Sockmonkey like this.
18. Aug 17, 2019

### Sockmonkey

#### Well-Known Member

Joined:
Apr 24, 2014
Messages:
1,650
430
Location:
Flint, Mi, USA
I think you could get more out of a Beaver by putting a lifting tail on it like they did with the Westland Lysander, which is comparable to the Beaver in terms of role and configuration.

19. Aug 17, 2019

### TFF

#### Well-Known Member

Joined:
Apr 28, 2010
Messages:
11,424
3,170
Location:
Memphis, TN
The metric people must have been the ones who invented the trophy for all participants. Look we all have the same numbers. Same small cars. Same LSA airplanes. Same monetary system. Same. Inches and feet. Not the same. Different cars, airplanes, money. Always options.

20. Aug 24, 2019

### pfarber

#### Well-Known Member

Joined:
Feb 21, 2019
Messages:
194
The sweet spot is the 150-180hp class. Get a motor that can do 180hp for less than 300lbs that burns Mogas and if it costs less than $10k you'd have a winner. Auto conversions make the money at the buy.$10k vs $30-45k.$20k over the life of the motor means almost no ROI... its just a money pit.