Move over ROTAX...

[spacesailor]

Water cooled " scot " bikes were really fast in their day 

AND

That " Jowett Jupiter " was a  beautiful sports car .

Or

Then again was it the " jowett Javlin " .

Great cars of their day.

spacesailor

Edited December 5, 2023 by spacesailor

[LoonyBob]

Britten blended a leading double-arm linkage suspension, which gave phenomenal cornering speeds and outstanding braking, with a composite frame and an engine of his own design. A generation ahead of anything else on two wheels...

 

[skippydiesel]

17 hours ago, LoonyBob said:

From the Chicago Convention of 1922 to the Chicago Convention of 1944, it was hammered out that Airworthiness is defined in terms of "Acceptable Probability of Failure", and that Airworthiness is achieved by: Control of Design; Control of Manufacture; Control of Maintenance; Control of Operations; and Control of Training.

 

Your argument is economic; your position is that you bought the engine, you don't want to spend significant money on it until the TBO is reached. Bad luck; the engines for London Buses were designed that way; but that is NOT how safety is achieved in aircraft that are light enough to fly.

 

It boils down to the physics of flight; there would be no turboprops if empty weight / MTOW ratio were not the penultimate expression of aircraft effectiveness....

You are only partly correct in stating my argument is economic. As I have already stated, this debate started around the contention that TBO can be used as a comparative measure of aircraft engine reliability/safety and durability - I disagreed. I have repeatedly pointed out the each manufacturer, in making their TBO claim, are doing so from a different perspective - this invalidates any ability of the purchaser to use TBO as a comparative tool/assessment.

 

 

[turboplanner]

1 hour ago, skippydiesel said:

You are only partly correct in stating my argument is economic. As I have already stated, this debate started around the contention that TBO can be used as a comparative measure of aircraft engine reliability/safety and durability - I disagreed. I have repeatedly pointed out the each manufacturer, in making their TBO claim, are doing so from a different perspective - this invalidates any ability of the purchaser to use TBO as a comparative tool/assessment.

 

 

Correct.

[BrendAn]

6 hours ago, skippydiesel said:

You are only partly correct in stating my argument is economic. As I have already stated, this debate started around the contention that TBO can be used as a comparative measure of aircraft engine reliability/safety and durability - I disagreed. I have repeatedly pointed out the each manufacturer, in making their TBO claim, are doing so from a different perspective - this invalidates any ability of the purchaser to use TBO as a comparative tool/assessment.

 

 

tbo or not tbo , that is the question

[micus]

Hello Gentlemen! I see lots of you are from Australia, im making an assumption here but i can only imagine there arent lots of snowmobiling opportunities for many of you where you live.

 

anyway, I have been around sledding quite a bit in my life and have owned a number of them. From a Canadians perspective (who sleds regularly) the Yamaha 4 strokes are considered to be the most reliable sleds a guy can get. They arent popular in the rockies because of the sleds weight compared to the Skidoo etec/ arctic cat/ or polaris 2 strokes that are available- this is a sled weight issue not an engine issue. Anyway, out east where they dont do much powder riding and stick to trails the Yamys are super popular.  It is not rare to see these sleds with over 30,000k on them. Hours wise this is 2000hrs + (the sidewinders and Apex's have hr meters in the gauge cluster for maintenance). The YG4 Apex is the NA 4cyl, the Yg3 NA is in the Nytro 3 cyl, and the Yg3 turbo (998t) is the sidewinder which yamaha is still producing in 2024.  Notably the sidewinder (998t) is a fn beast. the internals are good to 400hp, aftermarket tunes bring the sleds to 300hp just on tuning but with injectors/turbo and fuel rail guys are pushing stock rotating assemblies beyond 300hp regularly. 

 

For what its worth, from my perspective anyway, i wouldnt think twice about flying behind one at all, lots of guys in the states have been flying Gyros and LSA's for over a decade with the raven adapters when only the old RX1 bike motors (same as YG4 apex engine) were available and logged many hundreds of hours.

Some interesting resources for anyone interested in powering aircraft with the Yamaha, you should check out some of the following:

 

BD Turnkey engines

Steve Henry and Wild West Aircraft

Edge performance engines (Epex line)

Project Kitfox (youtube)

Eddie Sanches highlander (devil girl)

Skytrax gear boxes

GT gyro Raven PSRU's and adapters

 

Anyways gents take care, hope all is well in the land of Aus. 

 

Mike.

[BrendAn]

2 hours ago, micus said:

Hello Gentlemen! I see lots of you are from Australia, im making an assumption here but i can only imagine there arent lots of snowmobiling opportunities for many of you where you live.

 

anyway, I have been around sledding quite a bit in my life and have owned a number of them. From a Canadians perspective (who sleds regularly) the Yamaha 4 strokes are considered to be the most reliable sleds a guy can get. They arent popular in the rockies because of the sleds weight compared to the Skidoo etec/ arctic cat/ or polaris 2 strokes that are available- this is a sled weight issue not an engine issue. Anyway, out east where they dont do much powder riding and stick to trails the Yamys are super popular.  It is not rare to see these sleds with over 30,000k on them. Hours wise this is 2000hrs + (the sidewinders and Apex's have hr meters in the gauge cluster for maintenance). The YG4 Apex is the NA 4cyl, the Yg3 NA is in the Nytro 3 cyl, and the Yg3 turbo (998t) is the sidewinder which yamaha is still producing in 2024.  Notably the sidewinder (998t) is a fn beast. the internals are good to 400hp, aftermarket tunes bring the sleds to 300hp just on tuning but with injectors/turbo and fuel rail guys are pushing stock rotating assemblies beyond 300hp regularly. 

 

For what its worth, from my perspective anyway, i wouldnt think twice about flying behind one at all, lots of guys in the states have been flying Gyros and LSA's for over a decade with the raven adapters when only the old RX1 bike motors (same as YG4 apex engine) were available and logged many hundreds of hours.

Some interesting resources for anyone interested in powering aircraft with the Yamaha, you should check out some of the following:

 

BD Turnkey engines

Steve Henry and Wild West Aircraft

Edge performance engines (Epex line)

Project Kitfox (youtube)

Eddie Sanches highlander (devil girl)

Skytrax gear boxes

GT gyro Raven PSRU's and adapters

 

Anyways gents take care, hope all is well in the land of Aus. 

 

Mike.

Can't beat Japanese quality.

[FlyBoy1960]

On 30/11/2023 at 8:05 AM, onetrack said:

Cat engineers failed to understand that loco engines require extremely heavy duty build, as the load on them is huge and almost constant and unrelenting.

 

And on long railway grades with a huge tonnage behind them, the stress buildup on loco engines producing maximum power on a constant basis for long periods, soon sorts the men from the boys.

 

from what I always understood a locomotive is a diesel / electric installation with the engine basically operating as a generator to supply electricity to the electric motors which are doing all the work. Therefore there would be very little difference in the loads on the diesel motors because they are not driving directly. Perhaps someone in the railways can clarify but anything in the last 50 years has been diesel engine operating DC generator running to electric motors

[facthunter]

Have a bit  of know how with  some DE. The generator-electric motor connection just replaces clutch and gearbox's and the LOAD certainly changes from just loafing along in slight downhills to  really barking on the long climbs.  Nev

[rodgerc]

Move over ROTAX…..move over PEUGEOT 

 

 

[onetrack]

Flyboy1960, the load on the diesel loco engine driving the generator does alter substantially with increasing railway line gradients. Facthunter is correct, when full electrical draw is required from the generator, the diesel engine really loads up and starts barking.

The power draw requirements of the traction motors is only modest on level ground, but it goes up massively on gradients with a loaded train. Get a listen to some of the locomotive videos on YooToob of the big locos pulling freight trains up long gradients in the U.S. with a full consist or rake, those big V16's are really barking.

I used to work on a minesite in the mid-1970's where the mine winder was run by a 1000KVA genset run by a big 1600HP V16 Dorman engine. When the winder driver starting pulling up a full skip of ore, that big old V16 would pull down and bark under maximum load, like nothing I've heard before or since. When the skip stopped at the ore bin on the surface, you could hear the big Dorman ease off in load substantially.

Generator output load can be huge, it will pull engines right down. I had a number of minesite camp generators, they were 15KVA single phase Dunlites powered by 3 cyl Ruston diesels.

One day we got a dead short in the main power cable of one genset, and current fed back into the generator. The electrical short pulled that Ruston, running at 1500RPM, down to a dead stop, in about 3-4 seconds!

I wouldn't have believed a shorted generator could provide such a massive braking effect, until I heard it with my own ears.

[FlyBoy1960]

I am always happy to learn more than what I knew yesterday, and the way you have described it is very easy to understand. Thank you !

[facthunter]

 When  they pull away you will' hear the revs and electrical whining/moaning go in steps and after a long climb is crested it will sound like a big SIGH as the load comes back. Nev