VW engine reliability or issues?

Since I'm leaning heavily toward a replica WW-I airplane, I'd love a rotac engine. But with it at least twice the cost, I can think of several thousand reasons I probably won't do that.

I've run across built VW engines, probably Great Plains, but I'm open to other brands, it's still a long way out. I really like the idea of building the engine and knowing it inside and out. I was a submarine TM/MM in the Navy so I understand the wrench turning and QA parts of this and I'm not worried about building an engine correctly.

Are the engines generally reliable? Loss of control and engine failures seem to be two big failure points for experimentals. Anything to think about or be concerned with regarding these engines?

The VWs build for Aircraft use seem to work OK with reasonably reliability. Great Plains and Revmaster both build a reliable front bearing that put an end to the crank failures. Plan to adjust valves at 25 hr intervals with your oil changes and expect to pull the heads for work at roughly 300 hour intervals. As a wrench bbender, you know it's a simple and inexpensive engine to repair and maintain once you've built it. You will have to decide what to use as an ignition source, and what you want to use as a carb. Most of the carb solutions work OK, but have issues, typically with less than optimum mixture control. There are lots of solutions for ignition systems. Some run duel electronic and use a coil switcher with one distributor and one set of plugs. Others use a dual mag. You'll find everything in between. You'll have to decide what fits your application best.

Steve Bennett has retired from Great Plains. It's now under new management with a long time aircraft builder that has a lot of time flying behind VWs. Revmaster now has a 2300cc VW based powerplant available and claims to have made a great improvement to their Revflow carb unit.

-Cub Builder

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Originally Posted by cub builder

The VWs build for Aircraft use seem to work OK with reasonably reliability. Great Plains and Revmaster both build a reliable front bearing that put an end to the crank failures. Plan to adjust valves at 25 hr intervals with your oil changes and expect to pull the heads for work at roughly 300 hour intervals. As a wrench bbender, you know it's a simple and inexpensive engine to repair and maintain once you've built it. You will have to decide what to use as an ignition source, and what you want to use as a carb. Most of the carb solutions work OK, but have issues, typically with less than optimum mixture control. There are lots of solutions for ignition systems. Some run duel electronic and use a coil switcher with one distributor and one set of plugs. Others use a dual mag. You'll find everything in between. You'll have to decide what fits your application best.

Steve Bennett has retired from Great Plains. It's now under new management with a long time aircraft builder that has a lot of time flying behind VWs. Revmaster now has a 2300cc VW based powerplant available and claims to have made a great improvement to their Revflow carb unit.

-Cub Builder

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Scott Casler at Hummel engines http://www.hummelengines.com builds a quality engine and is the most reasonably priced 85HP 2400cc dual ignition 1 mag 1 electronic.He uses the force one hub from great plains.Carb is your choice he will install whatever you wish.
I went with the Zenith carb.Old fashion but tried and true.
Cheers,
Mike

For light aircraft like WWI replicas, VW engines have a fantastic record of reliability. Just stay on top of the valve adjustments and standard maintenance. As engines go, an aircooled VW engine is about as bullet proof as they come.

Most of the problems I've noted come from asking too much from what it is, or from cooling problems. Good baffling and oil cooler placement are key.

One needs to look at the engine requirements of the aircraft and then at the engine. If one is going to need to run the VW at the top end of its abilities all of the time there's going to be problems, as there would be for all engines.

I bought a direct drive 1915cc VW FWF from Valley Engineering for my little 7/8th scale Airdrome Airplanes Nieuport 11 based on it's record in type. The KC Dawn Patrol guys have put well over 500 hours on theirs without overhaul! The beefed up crankshafts help out a lot, of course. My plane is so light that I don't need a PSRU to get the job done.

The PSRU's are reliable as well. I haven't heard of a single one failing - just check the belt and tension regularly.

The advantages are pretty clear - solid (if not spectacular) performance, ease of getting parts and maintenance, and low cost.

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I did waaayyy too much investigation on engine outs and off airport "unscheduled" landings in WWI type experimentals, and failure seems to come in two flavors - poor grounding and fuel (usually not enough). This makes sense, as most replica flying is sedate, without acrobatics or interest in high performance (leaning, etc.)

I recently built and am now flying an Aerovee 2.1. There are roughly a thousand of the Aerovee engines in the air now. It is a proven, solid design. They are fairly easy to build. You can also get a turbo charged version. Sonex has a great assembly video for the Aerovee. They have not had any issues with the crankshafts on the 2.1 version. You can also get the crankshaft and propeller hub pre-assembled as an option. I am very pleased with my Aerovee engine. Some people do not like the AeroInjector on the Aerovee and others love it. Many have had good performance from the Rotec TBI on the Aerovee. Either way, you have a rock solid engine with two separate ignition systems and an internal 20 amp alternator and Skytec starter.

As mentioned above, reliability is generally good. All aero conversions are using forged cranks. Revmaster pioneered an added thrust bearing at the front (my front/back usage is as the block is used for aircraft use, backward from auto use), greatly enhancing reliability. Others may have followed.

There are case issues: The center journal, web bracing at rear, and external flashing seams (stress risers) all have occasional cracking issues. And stock VW cases have become very limited in supply. There's a great one-stop fix for all this: a long-established VW after-market house --EMPI -- sells a new-design case from a Brazilian company. Same $ as a new stock case! Fixes are designed in. Case is already domed for stroker crank clearance, so no shaving metal on the inside. Any VW shop can get them. In addition to standard machining, it will need to be carved for the added thrust bearing (so you should have crank/bearing in hand), and there is an oil passage in the right rear that will need to be drilled open for correct routing.

I believe there are some aero conversions that don't include an oil filter option. I wouldn't go that route....

As mentioned by others, cooling has been an issue. Make sure you get lots of fins on your oil cooler & good air routing.
And head cooling--- This used to be a tough one for these VW's because fin design on the stock heads wasn't good. There are recent upgrade heads that greatly improve cooling, available from Great Plains & Revmaster, maybe others. A friend flying a VW got 150 degree improvement with these heads, with no baffling changes! Great Plains also drilled the bottom spark plug holes to a smaller diameter, making for more metal between top & bottom holes. This has been a trouble area in the past.

[QUOTE=Jake_Heino;47179]I recently built and am now flying an Aerovee 2.1. There are roughly a thousand of the Aerovee engines in the air now. It is a proven, solid design. They are fairly easy to build. You can also get a turbo charged version. Sonex has a great assembly video for the Aerovee. They have not had any issues with the crankshafts on the 2.1 version. You can also get the crankshaft and propeller hub pre-assembled as an option. I am very pleased with my Aerovee engine. Some people do not like the AeroInjector on the Aerovee and others love it. Many have had good performance from the Rotec TBI on the Aerovee. Either way, you have a rock solid engine with two separate ignition systems and an internal 20 amp alternator and Skytec starter.[/Q


Is the 2.1 and the turbo the only versions or are there other versions that had crankshaft failures? Tks