Quantcast

best 100 HP auto/motorcycle engine conversion?

HomeBuiltAirplanes.com

Help Support HomeBuiltAirplanes.com:

Pilot-34

Well-Known Member
Joined
Apr 7, 2020
Messages
626
The Goldwing/Silverwing, etc water cooled engines? I remember a Contact article by someone converting one to acft use ( was planning to use a VW Rabbit wheel bearing as a prop bearing, or something' like that). The engines are very smooth and well made, but his conversion ended up quite heavy for the HP it made.
Actually I was thinking of 105 hp air cooled Honda CBX Six cylinder
 

120mm

Active Member
Joined
Oct 13, 2020
Messages
41
Maybe my research is not up to par, but I'm not seeing the tremendous value in the Yamaha. Starting with a used engine, I'm seeing parts costs north of 10k for a conversion, or 20k for a ready to run engine. This might make sense if you need 150+ horsepower, but the Aeromomentum comes ready to run at 10k and it's a new engine.
 

Pilot-34

Well-Known Member
Joined
Apr 7, 2020
Messages
626
Actually I was thinking of 105 hp air cooled Honda CBX Six cylinder



If it's on a Honda best leave it there.These are hard to find and getting very collectable.

I’m getting to the age where it seems like anything I’ve ever touched is collectible.....
 
Last edited:

pictsidhe

Banned
Joined
Jul 15, 2014
Messages
8,812
Location
North Carolina
Rotax have competed directly with Yamaha in several markets. The 912 was designed as an aero engine, the Yamaha was not. I therefore favour the Rotax. If Yamaha had built an aero engine and Rotax the inline conversion, I'd favour the Yamaha. Both companies know how to design and build an excellent engine for a specific task. Use one of those engines for some other duty, it probably won't be quite so well suited.
 

stanislavz

Well-Known Member
HBA Supporter
Joined
Aug 21, 2016
Messages
747
Location
Lt
Only if the Rotax is quite used. New, the Rotax is about $7k more than the 100 hp AM. If you are going to compare used, then maybe you go used to used and look at rebuild costs.

Billski
Used to used is a hard way. Used rotax, stripped down as per heavy overvaul manual is a proven engine, and you know that you have. Expenses are orings a lot of cleaner. Could be sub 1k if done not iriginal parts.

Used Yamaha is totally black box. New is less black box, but it is unproven.
 

Air Trikes

Well-Known Member
Joined
Dec 21, 2015
Messages
57
Location
Montreal Canada
Best 100HP... It can be a very long discussion. I don't like long discussion, no time for them. I build, fly and prove this way. I build and fly Suzuki G from 1998. My trike with G13BB is a world champion for 4 last years. It is simply flying better than Rotax 912 trikes.
 

Attachments

Niels

Well-Known Member
Joined
Aug 15, 2019
Messages
67
Best 100HP... It can be a very long discussion. I don't like long discussion, no time for them. I build, fly and prove this way. I build and fly Suzuki G from 1998. My trike with G13BB is a world champion for 4 last years. It is simply flying better than Rotax 912 trikes.
How many horsepower,prop rpm and prop diameter do You have in Your Deltajet Apollo to be competitive?
How much mass is the engine,gearbox and prop?
Lot of questions because I have a dream of something better.
I have never piloted a trike but being passenger on some was very fun and pleasant.Best way to funfly if You ask me.
 

tr7v8

Member
HBA Supporter
Joined
Jul 24, 2014
Messages
16
Location
Kent, UK
Been following these conversations with interest from the UK. The Rotax is expensive to buy & very expensive to service. I understand that Rotax will not sell anything which involves splitting the cases. This has led to a lot of engine thefts in the UK & I suspect across Europe. Reputedly by East Europeans. I quite like the look of the BMW as it can be easily converted to twin plug, which I don't think you can do to the Yams & Suzukis.
Our CAA won't permit a Light aircraft in the UK with single ignition systems. The Germans have converted quite a few BMWs & that tends to be a country that is concerned about unreliability, even if their cars don't seem to be that great these days.
Looking for alternate power to a VW for something like a VP1, FRED or similar
 

AIRCAB

Well-Known Member
Joined
Feb 6, 2015
Messages
89
Location
Vancouver Island
Greetings,

I've recently been looking at the BMW R1200 conversion. Air Trikes sells a nice gearbox for it, and the engine has a great reputation for reliability. I love the thought of fuel injection rather than carbs, and it would be a fun project to create the engine management system. The engine is really compact, which would make it easier to fit in the cowl as well. The downside I fear would be smoothness, since two big cylinders likely wouldn't be as smooth as 4 smaller ones. As nice as they seem on paper, they sure don't seem very popular here in the US. Is anyone actually running one?

In looking at the Air Trikes site, I see that they sell gearboxes for lots of different engines, but I haven't had a chance to sort through all the various models to figure out what is a good 100 HP option. If you wanted to make a 100 HP alternative to the 912S, using a modern engine. What's the best engine to start with? I don't have an immediate need for this, but I thought it might make an interesting discussion.

Rusty
Have you looked at Yamaha Apex.
 

13brv3

Well-Known Member
Joined
Feb 14, 2018
Messages
122
Location
Tellico Plains, TN
Thanks for the comments so far. While there are a number of engines in development, it's really hard to find conversions that have been flying in any quantity, and for any length of time. I keep coming back to the BMW R1200 conversion, which has been around for a long time, and seems successful.

As we know, it's hard to beat an engine developed for aircraft use, particularly when you are operating on a small budget for development. I plan to put the 80HP 912 on my Onex, but I wouldn't mind having a 100+ HP engine on a test stand as a future upgrade.
 

AIRCAB

Well-Known Member
Joined
Feb 6, 2015
Messages
89
Location
Vancouver Island
Maybe my research is not up to par, but I'm not seeing the tremendous value in the Yamaha. Starting with a used engine, I'm seeing parts costs north of 10k for a conversion, or 20k for a ready to run engine. This might make sense if you need 150+ horsepower, but the Aeromomentum comes ready to run at 10k and it's a new engine.
My reaserch indicates under $10 grand CDN. You can buy the sleds in good running condition for around $3500CDN
 

120mm

Active Member
Joined
Oct 13, 2020
Messages
41
My reaserch indicates under $10 grand CDN. You can buy the sleds in good running condition for around $3500CDN
It sounds like a good deal if I needed the power. But I don't, and the AM13 appears more sorted. Still thinking a used O200 is a better deal, though I'm a sucker for an auto conversion
 
Top