ETLB Squawk Forums — Archive

So I have been really thinking about building a max but unsure which one. I don't have a license and obviously will need some training in a tail dragger but that's another story for another day.  I have been doing tons of reading about engines, and can't seem to find an answer. So if I go with the 1100r and use a half veedub, will it still make 103 weight?  I have read the 2 strokes drink fuel and my experience with snowmobiling is they can be unreliable. Anyone have thoughts on that?

It's possible to make 103 weight with a 1/2 VW, according to some who have done it.  It requires careful work to cut every ounce out of the plane and engine.

But, suppose you finish the plane and find that its 1 lb overweight.....will you still fly it as a UL?  What if it's 5 lbs over, or 10 or 20?  The truth is that no one but you will ever know or care.  Keep it light, keep it simple, fly it the way you're supposed to and don't sweat the small stuff.

Quoted from homer SI have read the 2 strokes drink fuel and my experience with snowmobiling is they can be unreliable. Anyone have thoughts on that?

I don't think two strokes are inherently less reliable than four strokes if properly operated and maintained.  I've had engine failures with both types.  Modern two strokes have been highly developed from the days when we used converted snow mobile engines.  A friend of mine flys a Hummel with a 1/2 VW and has had one failure when the crank broke.

A two stoke may burn more fuel per hour than a four stroke....or not.  But, practically it doesn't matter much.  You will find that 5 gals of gas is more than enough for 1.5 hour of flight which is a very long time flying a small airplane.

The weight difference is around what 50 lbs?  And yes proper maintenance and up keep makes a difference in reliability of any engine. This will be my first actual airplane so I have lots to learn. Thanks for the input. Is the birth f33 better than the rotax 277?  Been reading up on my options, lot of info and seems like it boils down to just preference than anything. I like 4 strokes, just in my experience with small engines, they tend to be more reliable

The 1100 Minimax can be built weighing about 170-175 lbs less the engine.  Then you have firewall forward weight budget of 80-85 lbs. So you'll need a cut case 1/2 VW and a light engine mount.  Armstrong starter of course  

Quoted from homer I like 4 strokes, just in my experience with small engines, they tend to be more reliable

You would think so.  But consider this.  Take a factory built, highly developed two stroke (Hirth, Rotax, Moster, etc) and compare it to a home built four stroke like a 1/2 VW.  Which is more likely to be built to "spec" and with no unforeseen defects?

Cutting a VW engine in half and making it run reliably isn't a foregone conclusion.  The 1/2 VW that I built had lots of problems with the oil system and the engine eventually self destructed at 32 hours of use.  My friend's 1/2 VW also sort of self destructed when the crank broke and the prop left the scene.  Oil pressure issues and broken cranks aren't all that uncommon with this engine.

If I were going to use a 1/2 VW again I would likely buy one from Scott Casler.  

Consider this: a 2-stroke has three moving parts. How many in a 4-stroke? And isn't it moving parts that usually fail?