Stover DV2 Engine
The Stover DV2 engine was manufactured in the thirties by the same folks who made the Stover flywheel gas engines. These images come from a Stover brochure. There were some variants of this power plant. As shown, it is radiator cooled. There also was a tank cooling option.
Here are some pictures of this cute little 2 cylinder Stover DV2 industrial engine. It has no data plate but I'm told that some of them were manufactured for the Alpha DeLaval company in Ontario, Canada.
The boss you see below the water inlet probably should have a serial number but it is blank. Although there is no starter and the flywheel for this engine has no gear, there is a cover plate where the optional starter would be. I found that this engine is listed on the Autolite website and the Autolite #216 or MP4316 (gapped at 0.025”) is the correct spark plug.
This particular engine is equipped with a radiator (not shown) and is crank started. If you have more information, please email me so I can include it. Specifically, the parts I need are an original crank, an oil filler/breather and radiator shell and any mounting brackets for it. I suppose the radiator cap is obtainable at an auto parts store but if I can find an original, I'd be all smiles.
It is an even firing engine (both pistons move together). The magneto is a Wico A257B (impulse). There’s no water pump. The fan is just an idler. The radiator has a tunnel through the bottom tank that the crankshaft goes through for the crank. The bolt mounted to the water outlet is the top radiator brace. It has a governor (in the housing at the front of the magneto).
Another DV2 owner
sent the following information:
"A 3.5 horsepower rating was given to the DV2 engine. Each of the two cylinders has a 2-1/2 x 2-1/4” bore and stroke. Radiator cooling was standard equipment. Retailing at $125, the DV2 could also be shipped with complete automatic starting equipment, including starter, generator, automatic starting switch and choke for another $50. Only 230 of the DV1 engines were built compared to the 2142 engines of the DV2".
manuals available from Hit-n-Miss Enterprises, www.hitnmiss.com.
manual for the Stover DV1 and DV2 is catalog number LS127 at $3.00ea.
manual for the Stover DV1 and DV2 is catalog number LS127 at $3.00ea.
I will be updating this page as more information becomes available.
12-23-03: I finally got around to pulling the head, flywheel, front pulley, magneto, manifold and fuel pump so I guess I have to go ahead and finish the job. The combustion chambers show very little carbon. When I removed the spark plugs, I was surprised that, although they were really rusty on the outside, they appear to never have been run. There is very little wiggle in the pistons and only the slightest ring ridge.
The starting crank socket unscrews from the pulley. DO NOT ATTEMPT TO PULL THE CRANKSHAFT PULLEY FROM THE CRANKSHAFT! It screws on (right-hand thread). There are two setscrews end-to-end in the pulley. I guess the second setscrew is to lock the first setscrew in place. After taking out the setscrews, the pulley can be unscrewed from the crankshaft.
12-26-03: I finished tearing down the engine. It's a bit of a puzzle to take apart. The engine is a 'barrel' type. This means that there are no main bearing caps. The crankshaft has to be removed from the end of the crankcase. This one is a little more puzzling in that you have to remove the bolt-on counterweights in order for the crankshaft to fit through the crankcase.
How do they say it - "once you've figured out how to do the job, you're done". Well, I started by removing the governor/magneto housing. That part was all right. I then removed the front timing cover. That was WRONG! What you have to do is to first remove the block from the crankcase. Now is a good time to ream the ridges from the cylinders. Take the governor housing off now but leave the front cover in place for the time being.
Take off the flywheel, starting crank socket and front pulley. The crank socket is threaded into the pulley and doesn't necessarily have to be removed unless a puller is needed to get the pulley off the shaft. The pulley is a slip fit on the crankshaft and is held in place by a couple of set screws end-to-end. The bottom of setscrew fits into a depression in the crankshaft and the top one locks both in place. There is no key. If, after you have taken out the setscrews, the pulley won't work out with gentle tapping, you can either use the crank socket to attempt to turn it or you can remove the crank socket and use an appropriate bolt threaded into the hole in the pulley to push it off the crankshaft.
The small cast cover beneath the fuel pump is removed to get at the fuel pump cam follower. The follower must be unscrewed and turned as it is removed to be able to disengage it from the fuel pump pushrod. It's not really necessary to take off the fuel pump to get the front (timing) cover off but, because the pump is a relatively fragile die casting, I'd strongly suggest doing so. The fuel pump cam follower is lubricated through a wick made of cotton rope like clothes line. Because it's probably absorbed a lot of crud, it would be a good idea to replace it before reassembling it into the engine.
Unbolt the block from the base and tip it over. Remove the counterweights from the crankshaft. They have to be removed in order to take the crankshaft out and it's also easier to get the pistons out (and back in) with them out of the way. After making sure there are witness marks on the caps and rods and remove the pistons. If you've left the counterweights in, you will have to turn the crankshaft until the pistons are near the top of the stroke so the big ends don't hit them when you pull the pistons.
To take out the crankshaft you must remove the counterweights. The crankshaft with the counterweights on it is too big to fit through the openings in the block. Remove the nuts from the studs on the counterweights and tap them off. You should put witness marks on one of the weights and the crankshaft because they can be reversed. I don't know if this makes any difference but it's a good idea.
Both of the end covers must be removed to get the crankshaft out. This is because the front main bearing is larger in diameter than the crankshaft timing gear so the crankshaft must be moved away from the gear to allow it to move lengthwise. Unbolt the timing cover and carefully pry it partially off so as to not put the main bearings in a bind. Unbolt the bellhousing and carefully pry it off the block without cocking it too much. Sometime during this process, the crankshaft will come loose so you may want to put shop towels in the crankcase to keep it from getting dinged. You also want to make sure that the cam gear doesn't get into a bind if the front main bearing is rusted tight in the timing cover. The ball bearing mains stay with the crankshaft. The counterweight studs are long enough to interfere with the cover bores so you will have to thread the crankshaft out from the rear.
If you need to remove the camshaft, you first have to remove the valves and springs.
The ends of the valve stems are threaded. A tappet is on the left. Next to it is the adjuster that screws on the bottom of the valve stem and strikes the tappet. To the right of it is the thin 15/16" lock nut nut that is threaded onto the valve stem. It is machined on one side to make the lower spring seat. To the right of the spring is the upper spring seat that goes around the valve guide in the block.
The valves are taken out by simply unscrewing the bottom nut and locknut and removing them. At this point, the valves come out. If all you are doing is a valve job, you can can leave the springs and upper spring seats alone. If you are removing the camshaft, you have to take out the valve springs and upper keepers to take the pressure off of the tappets.
To take the camshaft out, turn the engine so the crankcase is up to make the tappets move away from the camshaft. Inside the crankcase, remove the cotter key from the oil pump pushrod and remove the rod. Remove the nut at the front end of the camshaft and slide the fuel pump cam off remove the woodruff key and the front cam ball bearing. While holding the camshaft to the rear and and turning it, with a soft hammer, gently tap the timing gear toward the front until it comes off. Don't lose the woodruff key. The camshaft is removed from the rear. Reverse the procedure to put the camshaft back in.
I'm still uncertain if this engine was ever painted. On the left-hand picture is just about the only remaining paint on the outside of the engine. There is no hint of any other color that I can find. On the right is the inside of the valve chamber. It has the same color as does the inside of the crankcase. I think this particular engine wasn't painted at all. The red lead paint that is on the outside is overspray.
This particular engine has aluminum rods like it says in the brochure but, unlike the brochure, it has inserts. Thank goodness the bearings look good enough to put back in.
The pistons have four rings. The top three grooves are 0.095" wide and the oil ring groove is 0.126" wide. The top groove has an 0.067" wide ring and an 0.0235" wide spacer. The second ring is plain and the third ring is stepped. An 0.125" vented oil ring is used. As taken out of the engine, these rings show very little wear.
The bores are 2.500" and the piston skirts are 2.4995" in diameter diagonal to the wrist pins. There is slight scoring on the skirts, probably due to the close clearance. I'll probably hone the cylinders 'til they are 2.501" to give a little more clearance.
The piston heads only had some blackened oil on them and there was virtually no ridge so I think that either this engine has been rebuilt or it has very few hours on it.
I'm going to have to replace the rings and all three of the ball bearings (only the rear cam bearing is a 'plain' type). The ball bearings have been damaged by moisture. The cam lobes and the bottom of the cylinder bores have a very small amount of rust pitting but, unless I change my mind after looking more closely, I don't think anything needs to be done to them.
At last, after finishing disassembly I found a trace of what might be the original color. It was hiding on one of the bolts that hold the skid to the engine and was protected by a lockwasher. Does anyone out there know if this is the correct color? There was no trace of this color on any other part of the engine. My only guess is that it was either painted at the factory when the engine was oily or it was aggressively steam cleaned at some time in the past.
COLOR........After getting a couple of paint color numbers that weren't valid, I matched the color as close as I could and came up with off-the-shelf Rustoleum satin finish Hunter Green. See below. Close enough!
MAIN BEARINGS........At first, we thought we had a problem getting exact replacements for the ball bearing mains because of the difference in width of the outer and inner races and the offsets between them. Incidentally, they are metric. After going through the exercise of looking-up the closest bearing we could find, we discovered that the originals are still available. They are on order as is the easy-to-get cam bearing.
PISTON RINGS........Frank also has the rings on order from Dave Reed at Otto Gas Engine Works [email protected]. Dave was very helpful on the phone. He says that the cylinders should only be lightly honed and that the ring end clearance should be about 0.008". Instead of the spacer and narrow ring in the top groove, he's supplying one wider ring.
GOVERNOR........I also got the governor back together. If your engine is anything like mine, you should give the governor a really close look. If it has rust inside it or is full of sludge, you should take it apart for cleaning. On this engine, the governor was rusty and the spring was rusted to the inside of the speed adjusting screw making it impossible to adjust the speed. It isn't too bad to disassemble. Remove the nut on the front of the housing and gently tap the gear/flyweight assembly out. Don't lose the little woodruff key on the shaft! Now soak everything inside the housing in solvent or penetrating oil.
To get the spring out, first straighten the tines on the cotter key that sticks out of the end of the adjusting screw and tap it down a little. Now, figure out which way the spring has to be turned to make it get smaller in diameter. You'll probably have to use a rag or piece of leather on the screw and pliers to be able to turn it enough to make the spring shrink enough to start slipping in the screw. After it's turning, it's just a matter of patience to be able to get it worked loose enough to remove the screw and brass locknut. The spring should still be hooked to the brass fork inside the housing.
If it's really cruddy, to get the spring out, remove the slotted 1/8" pipe plug in the front of the governor housing. Using a small punch, drive the pin from the fork out through the hole where you removed the plug. You can now pull the shaft out and work the fork and spring out of the housing.
MAGNETO........The Wico magneto put out a really puny spark so I decided to take it apart to see if I could fix it. Besides being dirty, the impulse was rusty. I had to take it apart to clean it. Do this carefully because there is a stiff coil spring inside. The cotter pin is removed from the nut and the nut is loosened with a socket wrench and a mallet (or an impact wrench). After you get the nut off, you can pull the impulse out. The spring might get away from you if the impulse comes apart. Some wire brush work and a good oiling and it went back together without too much fuss.
The points were a little corroded so I took them out and dressed them enough to remove the oxide. The mag now makes a spark but only about 1/8" on impulse so I might need to see if the points can have slipped on the shaft (there's a screw on the shaft that holds the cam on). Although I didn't remove the cam, I also don't know if it's keyed to the shaft or not and will leave it alone until I find out for sure.
OTHER STUFF........The important gaskets (head, manifold, etc.) came off in one piece so I lucked-out in that department. The rest of them can be tapped out.
After looking closely at the instruction reprint as shown at the top of this page, I saw that this engine lost it's breather/oil filler at some time in the past and someone substituted a pipe plug! If the crankcase is sealed up without the negative pressure check valve as described in the literature, crankcase pressure will build up and will force oil past the rings and the felt seals on the crankshaft. I also think that the lack of ventillation in this area is the reason there was so much rust in the governor and magneto impulse. Now, I'm looking for a breather/oil filler as well as the radiator cap and shell! In the meantime, if no one can come up with one, I may have to make a substitute.
Here's a picture of the breather/oil filler from his DV2, sent by Vic in Canada (THANKS!)
The manual for the DV2 says the breather has a spring loaded leather faced checkvalve. This is all there is to Vic's breather. The checkvalve washer and spring may fit inside, underneath the washer shown and could be missing on Vic's breather. I don't know.
I'm now waiting for the paint to harden (3-4 days) and for parts to come in. Patience, patience, I tell myself........With luck, I could have it running soon.
I just got the mag back together and bolted to the governor housing. I'm not sure that the mag is strong enough to run the engine. I only get about 1/8" spark off the impulse. With an 0.025" plug gap, it might run.
1-9-04........Yesterday, I got the front cam and main bearings. If you're looking for replacements, here are some numbers and comments.
The mains were originally New Departure, number ENDEE 8206. We couldn't immediately locate this number but an exact replacement is an MRC brand, number 8506. The MRC bearing looks like it's single sealed which is better than the original bearing that looks like only a single shielded bearing. If you saved the felt rings that fit on the crankshaft between the bearing and the housings (or you are lucky enough to have an overhaul gasket set), I'd recommend re-using them because they'd act as dust shields.
The front cam bearing originally was a New Departure, number 3204 which is an 'open' bearing. The replacement bearing is an SKF brand, number 6204 2RSJEM. This bearing is a double sealed bearing. The seals have to be removed. It is an easy job with a sharp pick. The reason the seals have to be removed is that the only way for oil to get from the crankcase to the fuel pump cam box is through the front cam bearing. You'd be looking at trouble if you leave the seals on.
I decided to assemble the crankshaft, timing gear and camshaft, awaiting the piston rings and completion. I would have gotten it together faster if I'd thought harder about the sequence of reassembly. It took two boltings of the front cover and three boltings of the bellhousing (rear cover) to get it right. To keep you from making the same mistakes, here is the assembly sequence:
1: After removing the seals from the front cam bearing, tap it into it's bore in the front of the block. Note that, before the camshaft, timing gear and front cover are in place, it can be pushed all the way through. If you forget this step until after the front cover is on and before the cam and gear are in place, the bearing can also be pushed into it's bore from the rear, although it's a little harder to do from the back.
2: Get all of the mating surfaces clean and put silicone compound on them. Also put a thin film of compound on the bore in the front cover to keep oil from getting past the O.D. of the bearing. I rubbed a little oil on the exposed iron of the cover between the bearing and the outside world to keep rust at bay. Lay the gaskets in place and get the bolts and lockwashers ready. Put the front cover and the bolts where you can easily reach them.
3: With the main bearings in place on the crankshaft (sealed side out), put the oiled felt washers on the ends of the shaft. Do NOT put the counterweights on at this time!
4: Slip the crankshaft into the block from the center, working the counterweight studs on one end of the crankshaft through one of the main bearing bores in the block. When the shaft can be lowered to the other main bearing bore, move the crankshaft until it is roughly centered in the block.
5: Now, hold up the crankshaft and guide the front cover into place and secure it with the bolts.
6: Oil the valve tappets and put them in place.
7: Lay the cam gear in the block and slide the camshaft (with the woodruff key in place) in from the rear. Before tapping the camshaft into the keyway in the gear, align the timing marks. The timing marks consist of one chamfered tooth on the front of the crank gear and two chamfered teeth on the front of the cam gear. While holding the gears aligned, turn the camshaft so the keyway lines up and tap the camshaft onto the front cam bearing.
8: Put a thin coat of silicone sealer on the inside of the rear main bearing bore in rear cover (the bell housing). As with the front cover, put a little oil on the bare iron between the bearing and the outside world. Install the the bellhousing and the counterweights.
Once the pistons are in, the engine can be bolted to the oil sump/base. Don't forget to put the dipper trough, the oil pump plunger and spring in before hand. It'd be a good idea to leave the flywheel off until the engine is on the base. It's pretty tippy when it's upside-down even without the flywheel on at this point.
1-10-04........The block went on the base and I cleaned up some more bolts and nuts.
1-11-04........Today the head, manifold, flywheel and front pulley went back on. I learned something else, too. At least on this engine, the tappet cover won't go back on with the magneto in place. The stud is too long. I had to take off the magneto cap to get the cover on the stud.
The muffler is not original. It's a real affordable way to cut some of the racket. This one is for a Kohler engine and I got it at my local hardware store.
Ain't it about as cute as a speckled pup!
While I'm waiting for the silicone rubberized fabric for the fuel pump, I'll rebuild the carburetor and get it attached. The fan and bracket have yet to be cleaned-up and painted, too. Since I don't have a radiator shell, I've worked-up some brackets to hold the radiator in place. That has to wait 'til I get the fuel pump back on.
1-15-04........The silicone rubberized fabric came in today. Just to be sure, I cut-off a little corner of the material and dropped it in a can with a little gasoline. A couple of hours later, I went back and found that the 'rubber' had gotten crumbly. Drat!! Now, I'm checking on a neoprene material to see if it will be okay.
After looking at the pictures of the breather that Vic sent, I rooted through my junkpile then went to my friendly hardware store and got some stuff to 'roll my own'.
I ended-up not using the rubber washer and added a short stub of schedule 40 PVC pipe that pressed into the nipple. I cut most of the threads off one end of the nipple, leaving just just enough thread to be able to get it a turn or two into the coupling. I pressed the about 1" piece of PVC flush into the short thread end of the nipple to make a seat for the check valve washer shown at the upper right in the picture. Before screwing the short end into the coupling, I squared-off the short thread end to make the seat work better.
I drilled a hole through the middle a 1/4-20 thread coupling (also not shown) just slightly smaller than the diameter of the long bolt. After cutting off the head of the bolt, I pressed it into the coupling and peined over the end to keep it in place. This now looked like a "T" shaped thingy. I then drilled a 1/4" hole across the nipple just below the PVC insert and deeply countersinked both ends. I used the two flat head screws to hold the thread coupling inside the nipple. In place on the engine, the thread coupling is horizontal and the bolt sticks up, the threaded end eventually used to hold the cap (the large washer in the picture above) down.
To make the check valve (so the breather can blow out but not suck air in), the smaller washer was drilled to a slip fit over the bolt and the O.D. was ground so it fit with about 1/8" clearance inside the coupling. The spring was stretched and a piece was cut to slide down the bolt to just barely hold the valve washer against the seat when the large washer (the top) is bolted down.
You wonder about the color?....... I decided to paint the non-Stover parts (except the muffler) red so anyone looking at the engine will have no doubt as to the authenticity of the parts. When a correct breather is found, it will be painted green like the rest of the engine and the red one will be relegated back to the junkpile to await morphing into something else..
1-17-04........It's a-gettin' cuter all the time!!!
Today, I got the fan and bracket, the carb, the home made radiator brackets and the fuel pump on (minus the diaphragm - I'm still waiting for the correct diaphragm material). I've made a mounting bracket for the non-original gas tank that you can see a part of in the picture. The tank bracket mounts on a pad on the back of the block. Because the tank is pretty close to the exhaust pipe and muffler, I shortened the pipe and used a 45 degree elbow and close nipple to move it out of the way.
Since we don't have the radiator shell, we had to fabricate brackets and a couple of adapters to get the radiator mounted. I've still got to make some measurements and drill the bracket before I can mount the radiator and hook it up.
Today, while I was cranking it over, I leaned my arm against a plug and got a surprise. I hope the mag's hot enough for it to run. If it doesn't I'll probably have to get a new coil. Everything else in the magneto checks out okay and, since I believe these mags have Alnico magnets in them, they ought to be fine.
1-19-04........Today, after breaking off the top radiator connection and having to have a radiator shop re-solder it, I finally heard the engine run. I didn't have the fuel pump diaphragm material but, since it was ready, I hooked a temporary gravity tank to the carb line and, after a half dozen cranks, it started and ran strong. I may have to work some more on the carburetor because it is running a little rich.
Here it is, going like a champ. The governor hunts a little and there's no way to adjust the sensitivity to make it stop that bad habit. I found that if I adjusted the fuel mixture just so and held the throttle shaft a little, it would run fine for a few minutes before something upset it and it started hunting again. I ran it about a half an hour today.
1-20-04........When I first worked over the carburetor, I thought that I shouldn't try to tap the brass float pin out of the diecast carb housing. I figured it would be okay. It wasn't. If I left it sit for a while, the carb would drip a little so I took the carburetor apart and lapped the float valve and added a washer to the seat to lower the float level a little.. I was lucky to get it out and back in without any breakage.
That solved the drip problem but now the governor hunts worse so I have to run it with a little choke on. I'm certain that this is not the way it's supposed to be.
While tinkering, I shut it off and had a really hard time starting it again. Good spark to the plugs and gas in the cylinders so I think the plugs that came with the engine are going into the trash. I think I'll make a trip to AutoZone for a couple of those Autolite 216's and see if that makes it easier to start.
Here's a little better picture. Now, take note of the classy radiator cap made out of a spray paint cap. 'Ya can't say I don't do things first class!
01-22-04......Well, I put in the new plugs and it runs about the same. Another problem I thought would be fixed with new plugs is that I can't quarter turn the crank to start it. It won't fire even if I snap the crank over. If I spin it, after a couple of turns it'll start.
5-01-04........With the help of a fellow Stover DV-2 owner, Frank and I now have a correct breather. A picture if it is below. The only thing we need to do now is to make a new throttle shaft and ream the carburetor body to fit. This ought to solve the hard starting and rough running problem.
06-12-04.........Well - we made a new butterfly shaft and reamed out the carb body. The good news is that it fits really nice. The bad news is that I still have to spin it to start and it STILL hunts! My next theory is that, even though it doesn't try to kick back, the spark could be a little too advanced. I checked the timing and the mag impulse snaps REAL close to TDC so it should be all right.
Other than the cranking problem and hunting at no load, it sure runs good. Since there's no fine adjustment on the mounting of the magneto, the only way I can retard the spark is to move the mag gear one whole tooth. I think that may make it too slow but, some time when I'm over there and feel like fiddling with it, I'll give it a try. Who knows, it might work.
12-04-04........I did a swap with Arthur Southwell, a collector in southern Florida, for an old army surplus Leland 2,500 Watt 120 Volt AC generator head that runs at 1800 RPM. I think it will make a nice match to the little Stover. I see no reason I can't run the Stover at 1800 RPM forever. One of these days, I'll clean the Leland up and test it. If it works, I'll make a skid that I can bolt the skidded Stover and the generator to. Since the generator turns counterclockwise, I have to set them side-to-side and belt the Stover to it.
It'd be kinda nice to take it to shows with a string of lights and my Webster wire recorder playing 1950's Rock-n-Roll for evening entertainment.
10-12-05......Today, we belted the generator to an electric motor to see if it works. It generates fine but the commutator and slip rings are out of round. Since the brushes are perpendicular to the commutator and slip rings, it is possible to reverse rotation without damaging them. I tried reversing rotation but it wouldn't generate, even after I flashed it. Using the "What The Heck" scientific method, I reversed the exciter field wires, spun it up and flashed it again. Now it generates turning clockwise facing the shaft. We'll direct couple it to the Stover.
The only issue with turning it backwards from what the factory intended is that of the cooling fan. It's a squirrel cage and most likely won't move as much air when reversed. If the generator runs hot under load, we'll take it back apart and remove the squirrel cage, cut the cage from the spider and weld it back on reversed.
10-24-05.......We took the Leland generator apart and turned the commutator and slip rings. I guess they were turned out of round when the generator was manufactured. After cleaning it up, painting, re-insulating the field coils and replacing the bearings, it's back toghether. I still have to clean up and paint the brush cover.
The original outlets on the junction box were twist locks so, since we found that modern grounding outlets would fit perfectly, we replaced them. The generator was originally set-up for a floating (non-grounded) configuration so I grounded one side of the output to the generator frame then tied this lead to the neutral and ground lugs of the outlets. With this arrangement, there's less chance of a hair-raising experience.
We turned the stub shaft on the Stover for an Oldham coupling and are getting some 2 X 4 square steel tube to make a sub-frame for mounting the generator to the engine. When it's done, I think it'll make a nice circa 1940's genset.
I'm looking forward to seeing if the Stover will make enough power to generate the full 2,500 Watt output of the generator. We're gonna look through our collective junkboxes to see if we can find a 15-Amp AC Ammeter, a reed frequency meter and an AC Voltmeter. If we get lucky, we could make up a nice panel for the little genset......that is.....if the spirit moves us.
10-29-05......The frame for the genset is coming along. We got some 1-1/2 X 3 steel tube and here's Frank doing some artistic spark making.
In the next couple of days, we'll get the engine and generator mounted on the frame and do some testing. Now, I wonder how well the thermo-syphon cooling will work on the Stover. We'll find out.
11-01-05........Today, we finally got it all together and tested. The bands on the frame rails are holding the rubber feet 'til the glue dries.
The cord going through the doorway that's hooked to the light bulbs is for setting the engine speed so the generator puts out 60 cycle power. This is done by connecting the neutrals from commercial power and the generator together. Now, the hot from the generator is run through the two series connected 120 Volt bulbs (same wattage) to the hot of the commercial power. With the generator running, the governor is set so, with no load other than the lamps, the lamps fade in and out about twice a second on the fast side or about 62 cycles. Under overload conditions, the frequency is around 58 cycles or two fades per second.
We've been very interested in seeing how well the engine could pull the generator. The generator is rated at 2,500 Watts and the engine is rated at around 3-1/2 HP. Off the wall, we estimate that it takes about a horsepower to produce about 350 Watts from this particular generator. At this rate, the engine could produce enough power to make about 1,225 Watts. With these numbers in mind, we hooked a 500 Watt heat gun to the generator. This load only served to steady the governor that was hunting a little.
Next, we hooked a 1,500 Watt heater to the output, making the total load about 2,000 Watts and the engine picked up the load easily. Either the generator is more effecient than we thought or the Stover does better than 3-1/2 ponies. We ran it with this load for a few minutes to seat the rings and warm it up then we added another 1,500 Watt heater, bringing the total load to about 3,500 Watts. The little Stover was still game! The final straw was to replace the 500 Watt heat gun with a 1,500 Watt heat gun. Now, the load was 4,500 Watts and, although the throttle was wide open and the frequency was around 58 cycles, the voltage was still 115 and holding.
During the overload part of the test, I started smelling hot paint. That's when I noticed that the muffler was turning brown. Even after running for 5 minutes at 4,500 Watts, the radiator was just barely boiling. For a cooling system with no water pump, I think this is very good.
This leads us to the unmistakable conclusion that both the Stover and the generator are well under rated. If the generator does take one horse for 350 Watts, that means that the Stover is capable of producing 12.9 horsepower! Even at a horse for 500 Watts, the engine is doing about 9 horsepower. Not bad for such a cute little engine. Now, instead of this outfit being nice for show, it's also going to be a nice standby generator set.
Thanks to all who offered help and suggestions! Is this a great hobby or what??!!
10 September 2012:
Today, I got an email from Joe Cucuzza who has a Delco-Light power-plant type 15EC1. It is a 120VDC unit. He was asking if the engine for this neat little generator was a Stover DV-2. I think it is and, since it's in such good original condition, I thought (with Joe's permission) I'd post three photos of it.
Joe's Stover DV-2 powered Delco-Light generator.
(Click on the photos for the high-resolution version.)
Joe says that, as of this date, he hasn't had it running but it has compression and, with some cleaning-up, should run. Interestingly, the magneto is mounted on the end of the generator. Also note that the breather is returned to the carburetor air inlet and the governor is different. It has a choke stove mounted on the flat spot on top of the exhaust manifold. The DV-2 I restored had the same flat spot and I wondered what it was there for. Now I know.
The fan is driven directly off of the front of the crankshaft and it has no fan belt. Also, it is equipped with a water pump, driven by the governor gear.
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