That is true.
Most of the dozen conversions I did were on trikes with Suzuki engines. After doing 8, I think our 9th, 10th and 11th were very consistent and same down to a science. The 12th was a Subaru --- heavy as crap engine.
In the Suzuki line I found the 3-cyl 65 HP one to be troublesome. The 4-cylinder 16 valve G13BB engine was nice but we ended up deciding to chuck its ignition coils, alternator system as well as intake for custom made items to make it lighter and more reliable and use a different ECM system instead of the OBD-II compliant version that came from the car. By the time, we were done making all those custom components, buy the right ECM and doing a custom wiring harness, the engine cost at the time with hours of labor paid a shop rate was only $3000 cheaper than Rotax 912.
So the car conversion stuff only is viable when there is volume or when a one-off is being done by the home-builder as he provides his labor for free. It is absolutely not economically feasible for a business unless the business gets plenty of volume for it to spend the resources. However, with the home-builder, it will always be a one-off so yes the quality of it will suffer and that is just how it is.
Abid
--- In Sport_Aircraft@yahoogroups.com, Peter Walker <peterwalker58@...> wrote:
>
> Hello Abid
> The auto conversions tend to die because of the quality of the conversion No one really has a built from new and tested to even LSA standards FWFÂ Cooling is often marginal wiring is a modified harness and all done as a R+D with a production of 1
> Â Similarly your plane and a similar Kitfox kit have greatly different build quality A plans built version has much more variation in quality
>
> Peter
>
>
>
> ________________________________
> From: apollonorthamerica <apollonorthamerica@...>
> To: Sport_Aircraft@yahoogroups.com
> Sent: Friday, December 30, 2011 2:15 AM
> Subject: Re: Light-Sport Aircraft Yahoo group Military Rotax 912/914 with fuel injection..
>
>
> Â
> Hi Peter,
> Having done hands on about a dozen car engine conversions (Suzuki and Subaru) on aircraft, I think you have got this wrong:
> "A late model car engine in a plane would likely reach a TBO of 2000 hours with only oil filters plugs and timing belts"
>
> I don't think that will happen quite like that :).
> Auto engine conversions can reach the TBO in isolated cases. Sometimes a certain combination of parts makes a system that will reach TBO but they are rare.
>
> Rotax reaches its TBO and beyond because it -IS- designed from the get-go as an aircraft engine. Just not the 1950's tractor technology aircraft engine.
> Abid
>
> --- In Sport_Aircraft@yahoogroups.com, Peter Walker <peterwalker58@> wrote:
> >
> > Hello
> > A Rotax (912) is not a real aircraft engine to a large group of pilotsIt round or a lyconental Add EFI and electronic ignition and try selling it Cessna put a toe in the water and it was too cold even with the runs it has scored
> >
> >  A propely engineered EFI system will run till the tank is as dry as a carb setup It will get you futher before it runs dry too (Mean tine between failures) if far higher on an EFI The good old days of easy to fix carb and coil cars is seen throught the thickest darkest rose tinted glasses ever They were easy to fix because they were being fixed often
> >
> >  About the only time I look at my cars engine is to change oil (3 Toyotas 500 000k / 300 000 miles) A late model car engine in a plane would likely reach a TBO of 2000 hours with only oil filters plugs and timing belts Im ignoring the redrive Selling a plane with an auto based EFI equipped FWF would be a brave step
> >
> > Peter
> >
> >
> > ________________________________
> > From: circicirci <acensor@>
> > To: Sport_Aircraft@yahoogroups.com
> > Sent: Thursday, December 29, 2011 6:51 AM
> > Subject: Light-Sport Aircraft Yahoo group Military Rotax 912/914 with fuel injection..
> >
> >
> > ÂÂ
> >
> > That is interesting indeed Helen.
> >
> > I always wondered why since the 912 is about a 20 year old design and EFI s wawell evolved by then Rotax did not go with EFI rather than carbs, because as Peter says EFI gets better fuel efficiency and is more easily tuned optimally for automatically adjusting mixture as altitude changes, no problems of synching carbs, etc.
> > Some aircraft engines do have EFI.
> >
> > I _imagine_ the downsides of EFI include these:
> > # If your electrical system (battery/alternator system) fails your engine stops dead as the injectors are electrically driven with a current draw that, unlike the sparkplugs, normally could not be engineered to draw off the magnetos.
> > # Probably higher cost on initial manufacturing and on rebuilds and maintainance.
> > # EFI engines do not tolerate getting air into their fuel systems. Unlike a carb which has a float bowl to dissipate air bubbles, if air is present on the high pressure side of the pump, air will be injected along with the fuel. This will lead to a lean condition until the air is purged. It should also be noted that most EFI pumps do not process air very well due to their design nor do they reprime well if there is much head involved. In short, a constant, air free fuel supply must be available at the inlet of the high pressure pump.
> > # The fuel pumps and fuel lines have to be run at much higher pressure than fuel fed to carbs.
> >
> > --- In Sport_Aircraft@yahoogroups.com, Peter Walker <peterwalker58@> wrote:
> > >
> > > Hello
> > > They are looking for best efficiency (endurance) EFI is adjustable on the fly
> > > Peter
> > >
> > >
> > > ________________________________
> > > From: Helen Woods <Helen_Woods@>
> > > To: Sport_Aircraft@yahoogroups.com
> > > Sent: Monday, December 26, 2011 11:25 PM
> > > Subject: Re: Light-Sport Aircraft Yahoo group Is there any carb-icing proceedure for t...
> > >
> > >
> > > ÂÂÂ
> > > Interesting but little known fact is that the military converts their 912s and 914s (used on Predator drones) over to fuel injection. I've always wondered why and assumed it had to do with the altitudes they fly them. Any thoughts?
> > >
> > > Helen
> > >
> >
>
------------------------------------
Yahoo! Groups Links
<*> To visit your group on the web, go to:
http://groups.yahoo.com/group/Sport_Aircraft/
<*> Your email settings:
Individual Email | Traditional
<*> To change settings online go to:
http://groups.yahoo.com/group/Sport_Aircraft/join
(Yahoo! ID required)
<*> To change settings via email:
Sport_Aircraft-digest@yahoogroups.com
Sport_Aircraft-fullfeatured@yahoogroups.com
<*> To unsubscribe from this group, send an email to:
Sport_Aircraft-unsubscribe@yahoogroups.com
<*> Your use of Yahoo! Groups is subject to:
http://docs.yahoo.com/info/terms/
