TBO VW?

[yodamancoda]

Does anyone have an idea what the TBO for Great Plains VW engines or other VW engines are?

What about other maintenance schedules? I found this http://www.greatplainsas.com/scmtce.html but no TBO info.

THANKS!

 

[garymedic]

Steve Bennett at GPASC says there is no "TBO" on the v.w. Since it is not a certificated engine, the FAA has no rules regarding overhaul. It's all a matter of how you build it, maintain it, and treat it....the same as your lawnmower, weedeater, auto, etc.

Gary

 

[yodamancoda]

Gary,

Hey thanks for the response. Yea I figured there wasn

 

[jwalin]

From what I have read about the VW's, the bottom end, when built correctly, will last at least 1000 hrs if you take care of it.

But, plan on rebuilding the cylinder heads in about half that time, because most likely they will crack or you will have valve problems.

But, when you can get new heads ready to fly for about $500, this seams quite reasonable.

The best way to extend the life of a properly built VW engine is threefold:

1. Pay careful attention to cooling requirements, both oil cooling and cylinder head cooling.
2. Clean high quality oil and use a high quality filtration system.
3. Don't ask too much of the engine. Don't overheat it, let it make power higher in the RPM range than certified engines.

These engines make great conversions. According to the Bingelis books, the VW is the third most popular engine flying. Not the third most popular CONVERSION, but the third ENGINE, behind Lycoming and Continental.

Good Luck!
Jeff

 

[yodamancoda]

Great INFO! Thanks for the post! -Mathew

 

[yodamancoda]

I e-mailed Steve at Great Plains and here is his response:

Hi Mat, there is not TBO for VW engines. We have a maintence schedule to follow. If you use avgas, the exhaust valves should be replaced every 250 hours. Other than that, its a compression check once a year and you moniter the oil pressure for wear.

Steve
Great Plains

 

[Gaston]

Hi all
In 12 years flying my 2L,the only weak part are exhausts valve.
probably because of 100LL fuel.
a little lapping of the valves in the winter time ensures a trouble free
summer.
A pair of spare heads on the shelf is another alternative, but I prefer lapping in the winter because I can take the time required for checking
all the valve train geometry.

but as Jeff said new complete heads are cheap so the problem is not that bad...

Gaston

 

[mike1]

You are right on about the exhaust valves. I've been building vw engines for 37 years and the only component which regularly fails is the exhaust valve. in a highway driven vw, the head usually breaks off the stem somewhere past 50000 miles. regular replacement in an aircraft engine seems prudent

 

[Schmleff]

"3. Don't ask too much of the engine. Don't overheat it, let it make power higher in the RPM range than certified engines."

While I agree with the first part, I don't agree with running in a normal certified rpm range. With 2700rpms as your max, you can't make much power at all. These engines were made to run at higher rpms.

I feel the real issue is cooling, not rpms. If you can cool it at 3500rpms, it should be fine.

 

[jwalin]

Yep, that is what I meant. So let me rephrase:

3. Don't ask too much of the engine. Don't overheat it. Let it make power in a higher RPM range than certified engines.

Cruise at over 3k RPM, climb out with all it will give you! But don't overheat it. In the Sonerai it is wise to keep your climb speed higher to maximize airflow through the baffles.

And please baffle the engine so there is flow through the heads and around the ports, not just the cylinders and fins around the combustion chambers. There are many flying examples of this poor practice. Also, use the bottom cooling tins on the cylinders, to shape flow around the cylinder, and to force more air through the heads. The germans did a pretty good job designing the cooling system on these motors.

Jeff

 

[jhoppe]

Steve and others mentioned that the exhaust valves should be replaced every 250hr or so if I use Avgas. Anyone have a recommenation as to what type or manufacture of the valve to replace it with. thanks Joel

 

[jwalin]

Manley or SI valves. Stainless Steel of course.

jeff