VW Air cooled engine power

Ludo · September 23, 2013, 07:03:58 PM

Thinking about putting a VW air cooled engine on a sawmill build. It's light, powerful, easy to rebuild and I have four in my garage. I would have to come off the pulley in the back (opposite the crank shaft/transmission) in order to compensate for the counter rotation of the motor. I know that there has been at least one major manufacture that uses these engines on their mills. Does anyone know how to hook one up? Is anyone aware of a pto/pulley kit that replaces the standard pulley that drives the air cooling fan/alternator? ???

jmouton · September 23, 2013, 07:18:47 PM

that sounds pretty kool ,, dont know much bout hooking them up to a sawmill , but it will be interesting to see if you can do it

jim

Al_Smith · September 23, 2013, 07:23:11 PM

There was a local guy who had some kind of a swing mill type rig that used a VW engine .He rope started that thing .I guess it did just fine sawing small logs .

Slingshot · September 23, 2013, 11:09:11 PM

Don't see why it wouldn't work on a sawmill if you can rig
up a cooling system. They make a neat aircraft engine. Here
is a thrust test these guys did.....

http://www.youtube.com/watch?v=2S22hONa3o8

____________________________
Charles

mobile demensia · September 23, 2013, 11:25:42 PM

My mobile dimension has a 1641cc vw. The crank has been modified and a large bearing has been mounted to the block to support side thrust. The power would be more than adequate for a bandmill.

redprospector · September 24, 2013, 01:49:35 AM

I used a 1600cc VW engine to power the band mill that I built several years ago. I had a plate made to bolt to the flywheel with a shaft centered on it, and added a "carrier" bearing at the end of the shaft. Works great, I have sawed quite a bit of lumber with it over the years.
One thing about the VW's... If it doesn't start, it's the points. :D

Andy

Ludo · September 24, 2013, 04:50:26 AM

Mobile Demensia- I have watched the videos of the Mobile Dimensions cut and they really can move, I have been told that the noise is god awful compared to other mills but the power is worth it. I am making (having made) a very large capacity band mill.

Andy-How did you correct for the counter rotation? Any chance you could post or send me a picture of your setup at the interface between the engine and mill? Thanks so much for the help.

mobile demensia · September 24, 2013, 09:23:13 AM

The noise is worth considering when you travel back and forth with the carriage. The vw is much loader than the 25 kohler on my bandmill. I wish I could take some photos of the bearing mobile puts on to deal with side load from belts but it is under the flywheel. Good luck with your build.

DanG · September 24, 2013, 10:52:24 AM

Ludo, I don't recommend running a belt directly off the crankshaft on a standard VW engine. That engine has a split case and the side force would be directly on the seam. MD gets away with it by modifying the case to accept a much larger bearing, extending the crank, and using six belts to maximize the belt friction while minimizing the side force. I can think of 2 ways to sidestep the side force problem: 1. Mount the engine sideways and couple it to a 90° gearbox, letting the gearbox worry about the side force. 2. Couple the engine to a jackshaft and put your drive pulley between two pillow-block bearings.

DanG · September 24, 2013, 12:13:06 PM

I have thought of a few more considerations that need to be addressed in the early planning stages. :P You will need to either keep the cooling shrouds or fabricate some new ones to direct the airflow over the jugs. These will fill up with sawdust rather quickly, so you need to make them easily removable for cleaning. That will need to be done much more frequently on a bandmill than on the MD because the sawdust is much finer. MD made the engine easy to remove from the mill, so I just pull it off to change oil and clean it up. ;) Next, you need to install a good governor on the engine. MD uses a rather pricey belt-driven mechanical governor. It is driven by a seventh pulley on the crankshaft, along with the hydrostatic drive unit. The governor is important on a sawmill because you need to maintain a constant speed for the blade to work as designed.

I'm not sure why, but MD does not use the standard VW starter. I suspect that it just isn't strong enough to get all of that sawmill plunder spinning. You may be able to avoid that by incorporating a clutch to disconnect the heavy stuff.

schmism · September 24, 2013, 03:22:56 PM

I would assume that the jackshaft setup would include a standard electrical-mechanical clutch found on the front of most air conditioning compressors. They are fairly simple to activate requiring 12v relay which you could trigger to the throttle up lever.

DanG · September 24, 2013, 05:01:49 PM

I hadn't really thought about where to put the clutch. My first thought is to put it adjacent to the engine to eliminate any moving parts while disengaged.

Ludo · September 24, 2013, 08:21:38 PM

Well, I guess I was being a bit simple but I was thinking of just scaling up the mill I have which is also "home made" as it was built by a machine shop. My set up is pretty simple, the engine slides back and forth on top of the saw head, the motor shaft has a pulley and by sliding the motor sideways with a long handle, the belt engages the pulley on both the motor and the drive wheel. I see now that the side force would be a problem because of the split case. Great suggestions, thank you so much. I was trying to avoid the weight of a large motor as well as the cost.

redprospector · September 25, 2013, 12:22:41 AM

Quote from: Ludo on September 24, 2013, 04:50:26 AM
Mobile Demensia- I have watched the videos of the Mobile Dimensions cut and they really can move, I have been told that the noise is god awful compared to other mills but the power is worth it. I am making (having made) a very large capacity band mill.

Andy-How did you correct for the counter rotation? Any chance you could post or send me a picture of your setup at the interface between the engine and mill? Thanks so much for the help.

PM me an email address and I'll send you some pictures.
I designed the mill for the VW engine, my driven wheel is probably on the opposite side from yours. Other than that just be sure to turn the blade "inside out" before putting it on the mill.

Andy

outerbanxer · September 25, 2013, 03:04:04 AM

Terrible Idea...

From a guy who used to drag race Vw's back in the 80's...

Terrible Idea. Carb's is what those motors live on...If you lean it out with sawdust "dust", well, that's gonna combust also in the cylinder, you'll never get the A/F mixture right no matter how much you play with the carb.

And then you'll blow it up because it's not cooled by anything else except air over external cylinder fins, if you keep the shroud directing air over the non-existant body.

So there you go...we used to blow up a motor every other pass on the dragstrip because we would lean it out to get max torque, then take 'em back and rebuild 'em. Each car had four motors for a weekend, we'd hone ring lands...Longetivity was measured in seconds.

Philmo · September 25, 2013, 04:37:10 AM

Haha, what an idea! Keep on man, you have my support

DanG · September 25, 2013, 09:38:39 AM

Outerbanxer, those are good thoughts, but the MD engines are highly modified as I said. The sawdust may be problematic on a bandmill, but the MD is a circular saw and doesn't produce much fine dust. We do use a good air filter on the carb.

Now I don't know much about the standard VW engine because I've never even seen one outside of the car, so I don't know which parts are VW and which are sawmill. There is a large blower that is built into the flywheel to direct air through a system of shrouds on the bottom of the engine. I don't have a cooling problem unless I allow them to get clogged up with sawdust. Cleaning them at every oil change seems to be sufficient. I'm pretty sure the shrouds and flywheel are fabbed by the sawmill company. ;)

Hilltop366 · September 25, 2013, 12:41:59 PM

The cooling fan is on top of the engine mounted behind the generator driven by a belt from the crank.

just search for VW air-cooled and click on images, should come up with lots of pictures and cutaway drawings.

To do away with the side load stress on crank and block I would think that a very short drive shaft or coupling and 2 bearings would do the job, drive pulley could be after the bearings for easy belt service. A idler tensioner next to the smaller pulley for clutch with bolts sticking out on each side of the pulley to keep the belt from spreading and rubbing on the end will help with the disengage position.

It shouldn't be too hard to make a trap door access to provide a place to blow out any sawdust and add a cooling air intake screen that could easily be removed for cleaning.

Hilltop366 · September 25, 2013, 12:45:35 PM

Quote from: Hilltop366 on September 25, 2013, 12:41:59 PM
The cooling fan is on top of the engine mounted behind the generator driven by a belt from the crank.

just search for VW air-cooled and click on images, should come up with lots of pictures and cutaway drawings.

Sorry I reread and see you have 4 engines, I'm sure you know what they look like.

loggah · September 25, 2013, 03:31:41 PM

I had a portable belsaw made up with a vw industrial pancake engine ,it had a factory clutch assembly, the engine worked great on the ill ,i just sold it last month to a friend,i didn't need two belsaws,heres the pictures of the mill

https://forestryforum.com/gallery/thumbnails.php?album=4672

tjhammer · September 25, 2013, 07:02:39 PM

ludo I don't know which end of the vw you have to come off to get rotation if its the flywheel side make a plate to bolt to the flywheel with a shaft for a centrifugal clutch to a jack shaft that would take care of your side force,on swing mills the centrifugal clutch works rewell.
tj

Ludo · September 26, 2013, 10:42:03 AM

Thank you all for the helpful suggestions, it seems that most applications are coming off of the fly wheel side. The idea of using a jack shaft makes perfect sense due to the split case of the motor design. I will either have to mount the engine almost cantilevered off the saw head, over the back of the head with the fly wheel facing forward, or I will have to reverse the mill when building from left hand side controls/drive wheels to right hand side to make up for the counter rotation of the motor. It will seem a bit odd since most mills are controlled and loaded from the left hand side. If anyone has other suggestions, please keep them coming. Since most of the build will be done by a machine shop, the idea and implementation of using a VW engine my prove too costly vs a standard Kohler 40hp engine. I can get a Kohler for less than 3k shipped, not sure how much it will cost in shop time to make the VW work. I'll post my progress as winter closes in.

nk14zp · September 26, 2013, 02:37:26 PM

Why not just turn the band inside out?

DanG · September 26, 2013, 02:49:11 PM

You need to be sure the mill is pulling the blade through the wood and not pushing it. ;)

Hilltop366 · September 26, 2013, 04:36:46 PM

Hmmm.... I wonder if the timing could be turned enough to run the engine the opposite direction, use to work on make in brake engines.

I even had my diesel tractor running backwards once (not on purpose) by stalling it with the logging winch when I realized the tractor was stalling I let the winch clutch off and the engine kicked back and started running backwards!