MPG

[JNijst]

Gents,

MPG with the $7.00 / gal price in Holland is high on my list. Below a few comments from Dennis and Jake:

Posted: Tue May 15, 2007 10:06 am Post subject:

The Pinz aircooled engine is a bit of a bastard child since it runs on full cool and in many cases never reaches stabilised temperatures unless its used aggressively. Those clever Steyr people designed it that way for max reliability but it gives lousy fuel economy. I suspect the 230 figure is a result of the engine attaining stabelized temperatures, other comparisons are just that; comparisons given a differing set of operating conditions.
Dennis


Posted: Tue May 15, 2007 11:55 am Post subject

I have made a make shift thermostat flap from a hodgepodge of VW and Porsche components to help get my head and oil temps elevated to the point that I have found most optimum for similar aircooled engines..

The result was breaking the 20 MPG mark with my EFI system

Before I did this my oil would not get over 190F and the heads would not peak past 275 on most days, even when loaded. Now my oil temps run 220F and the heads between 325 and 340 most of the time. With these mods the engine runs more stable, less rich and has much better throttle response, especially when the humidity is high in the mornings here.

Of course the Pinz purists crucify me for doing such a dastardly thing, but they don't buy my gas so I really don't care!
_________________
Jake Raby
Owner, Raby's Aircooled Technology


Posted: Thu Jun 08, 2006 12:06 pm Post subject:
my back and forth testing between carbs/EFI I have been able to get a solid 18 MPG from my Pinz with CARBS!

The best so far with injection is 20 after I went to direct ignition and optimized the advance curve.

I learned early on that the exhaust system is a huge limiitation on better MPG... I have been testing since week#3 with a fully merged arrangement I am developing with a detailed collector.

I have logged 9,300 miles in my Pinz since September!

Good things are going on behind the green curtain!
_________________
Jake Raby
Owner, Raby's Aircooled Technology

Well, what I understand from this this is that a continuously cooled engine might be good for reliability, but not MPG. Jake also elevates his head and oil temp up for better MPG and also found the exhaust system a major influence.

Is there any use for a device, that we all could install on our engines, that would measure the head / oil temp and mix / regulate the intake air with hot air from the heat-exchanger ?

My engine already has some regulator at the air-intake, but that is to just start the engine on hot air and prevent the carbs from freezing up at a first cold start, but after that it reverts to plain outside air. This would be a continuously controlled air-inlet (fresh air + heat-exchanger air).

I seem to remember from long ago that the length of the exhaust-pipes had a major influence on power, an extra inch gave e few extra HP. But Jake find it also affects MPG.

Anybody can shed their knowledge light on this ? I know everybody wants better MPG, but what are the reasons and cuases for good or low MPG ? I am new to engines and would love to learn about this issue

Thanks and regards

Jules