skid2964

My Feedback: (5)

Does anyone know where I can get Diesel heads for the old Veco 19? I have 7 of these little engines and would love run a few(maybe all) as diesels.

Thanks

gcb

All of my Veco .19's are baffle engines. Although it can be done, you would have to "pin" the contra so it wouldn't rotate and mill a baffle into the contra. Perhaps you could mill the baffle off the piston...don't know what that would do to the engine balance.

This is just one opinion, perhaps someone has done it.

George

skid2964

My Feedback: (5)

Ahh ...I didnt realize they were baffled ... I wonder if milling the baffle off of the piston would do it? Or is the baffle hollow?

AMB

I would leave it the way it is besides balance, due to the porting of these engines you would upset the incoming charge and believe
really have a breathing problem

AndyW

My Feedback: (1)

There is a way that entails milling the head down to where you have virtually no combustion chamber volume left. Then, you add shims till the engine fires. This basically gives you a fixed compression head. The next item is to make up a secondary chamber that screws into your original glow plug socket. You screw this device, in and out to fine tune the combustion chamber volume.

For the moment, the concept is only a visualization. May give it a try this winter and report back.

On the other hand, milling off the baffle and making up the usual diesel head may work just fine. After all, diesel depends on compression for combustion and doesn't the whole charge ignite all at once? Unlike glow with a specific ignition point, (the element) and a flame front. Or, as suggested, the incoming charge, without the baffle might just go right on through the exhaust port before the piston has a chance to close and trap the fresh fuel charge.

Hmmm, maybe another winter project.

Say Skid, you say you have 7 of those .19s? I've owned four in the last 15 years, two are still NIB. Despite being steel and not schneurle, they make an awful lot of power for their weight. AND they're twin ball bearings. Great little engines, well built and bullet proof.

skid2964

My Feedback: (5)

The first suggestion sounds like it may work and milling the piston would be easier but, as mentioned above, how would you go about rebalancing the engine with the lighter weight piston?

I love these little engines due to thier great power output. I would love to see what they would do as a diesel.

Jim Thomerson

This is of the "I think" variety as I have never seen one or a photo. The OS 15 diesel has a baffled piston. The contrapiston has a slot for the baffle and is pinned so that it cannot rotate. As said, I think.

Get you some diesel fuel and see if you can get your Veco 19's to run on it. Put a battery to the glow plug to get it started and leave the glow plug connected for maybe 30 seconds. I have run two different K&B 4011's on diesel fuel, one ran fine, the other undercompressed, I suspect the undercompressed one had a thicker head gasket, but have never checked. It would run fine with the glow plug connected. Interestingly, both engines turned an APC 11 x 5 at 9,700, both glow and diesel. The needle screwed in a turn and a half for the diesel.

Jim

ajcoholic

My Feedback: (10)

I personally have tried to run Fox 35's as diesel by milling off the baffle. I know the Fox 35's had light pistons and this may not apply to the Veco... but I had actually CAVED IN the top of the fox piston after a few minutes run time! The engine seized up and the piston was obviously distorted and the top covcave.

Just a thought...

AJC

AndyW

My Feedback: (1)

Skid,

Now that I've dug up my Veco stuff, I see that my first suggestion won't work. Not enough meat in the original head. [] It looks like the best way is to make up a head with a contra piston that has clearance for the piston baffle. Looks like it could be done and I suspect that the piston baffle serves a very useful function that you might want to retain.

As far as rebalancing for a lighter weight piston, I'd bet that a lighter piston in ANY engine can only be a plus. Most aren't fully balanced, particulalry those with steel pistons, such as the Veco.

dennis

My Feedback: (90)

Milling some of the baffle from the piston is a trick that some C/L flyers used to get a 4-2-4 break in the motor. Be advised though that in many motors removing the baffle completely would make leaning out the motor impossible.

Motorboy

Milling of baffle can be risk since you can damage piston to example use milling vise to hold the piston.

You can remove baffle of piston with grindingwheel (better with Dremel), but first the piston must be protected agains grinding particles. Apply electro tape around the piston then grind off baffle. Wash piston clean and remove electro tape and wash piston again before use.

Jens Eirik

gcb

Skid,

If you are really going to do this, why not remove the piston altogether and mill a new one with a flat top and make the crown thicker to compensate for the weight of the baffle?

George

Edit: Another thought would be to find another engine with the same bore and use the piston.
Personal opinion: The Veco .19 is an EXCELLENT engine as-is. I would suggest just running it as...shudder...a glow.

skid2964

My Feedback: (5)

My original question was asked not knowing about the difficulties in converting this engine. With all the trouble it would require. I will leave them alone, They are excellent little glow engines .....

Jim Thomerson

On thinking about it on another forum, a keyed contapiston does not seem too hard. If the contrapiston extends above the cylinder liner, you could cut a vertical slot in the upper part of the contrapiston and then insert a rollpin through the side of the head to key the contrapiston. Alternatively, you might drill a hole in the top of the contrapiston and insert a rollpin. This rollpin would extend up into a hole drilled through the head. Probably you engineers and machinists can suggest other better ways.

Jim

maxtenet

Here is my conversion of an Enya .19 baffle piston engine.


For some reason the damn pictures won't upload. Anyway, I shaved off the baffle and made a new head. I also rotated the cylinder a few degrees and drilled an upward facing hole next to the bypass port ala O.S. Max FP series. The fresh charge comes in and up and hits the opposite wall somewhat instead of going out the exhaust. Granted, the exhaust port is smaller, but this thing runs like a champ and idles very well.

Anyway, maybe I can figure out how to get these pictures on this site.

Max

Hobbsy

My Feedback: (102)

Max, I put mine in My Documents sub My Pictures and get them from there.

AndyW

My Feedback: (1)

Skid,

Well, to answer your question about dieselizing the Veco .19. It CAN be done and the engine will run, but only briefly. Some concern was expressed about milling off the baffle and upsetting the balance. Well, along with the piston and rod, the assembly still needs way more counterbalance so milling off the baffle can only help.

The engine was run at just above freezing temps and ran real well. Sounded great, swung that big prop with gusto. However, that only lasted some 5 minutes. Didn't even have a chance to check throttle response or tach it. Unfortunately, the crank is just too weak for diesel combustion. Also, as the rod is bent, it wouldn't surprise me if that happened during the run.

At the same time, I discovered that The K & B .21 uses the same crank except that the web and counterbalance is much bigger. This takes the crank pin further back so a thinner bearing is needed but no one makes them. So, I'll be making a bushing the right size to replace the rear bearing.

Otherwise, the head I made worked. Will try again with the .21 crank.

gcb

Andy,

Someone posted on another board that MECOA has produced a new run of Veco .19's so you might be able to get parts.

Good luck.

George

AndyW

My Feedback: (1)

George,

Yes, and thanks. Also, Frank Bowman advertised on RCU some years ago that he had a bunch of original Veco parts for sale. I've actually got a reverse crank, the .21 crank and some other bits on order from him. Amazing what a simple search on Google can get you.

I should mention that on the original head, while all of the "hemi" portion was eliminated, I made the grove for the baffle a little too wide and deep and this created just enough combustion volume to take the contra-piston uncomfortable close to the piston. IF the rod bent, say on the first start up, and while there seems to be no evidence, it could be that the contra-piston was banging against the piston ever so lightly. This would have contributed to the destruction. A new head has been made by doing the grove a little tight and then lapping the piston to it for a squeaky close fit. A job for CNC for sure.

When the engine ran, it really didn't seem to be winding up, even if it DID have a biggish prop. An email to Davis yielded the fact that he'd been there and done that. He didn't seem enthused about baffled engines so there may be a serious issue about running them as diesel. Fun trying anyway.

maxtenet

seems to be working now? please refer to earlier post. Max

AndyW

My Feedback: (1)

Neato Max,

Can you give some performance numbers? Prop size, RPM etc. As mentioned, the Veco didn't seem to be winding up but maybe I'm just expecting what I saw when it was glow. It sure did howl on an 8 X 6. Also, it looks like the Enya's crank is more robust.

AndyW

My Feedback: (1)

Finally, K&B .21 crank installed into the Veco .19. All dimensions same except the crank web is much thicker and this takes up a lot of room where the bearing sits. So, the bearing is eliminated and a brass bushing takes up the remaining space. A new, bushed rod was also made. This one had to be dressed down several times to eliminate banging against various edges inside the crankcase and even the cylinder.

Compression feels very good, with the proper snap over when the prop is flipped. A new piston was installed, courtesy of Frank Bowman. I hope to be able to hand start it. It'll be broken in on glow and then run as diesel. It will also be interesting to see how the new crank affects glow operation. MUCH better counterbalance may allow for more power. Testing waits for the weather.

First picture shows the stock crank, the reverse crank and the .21 crank.

Second shows the differences between the two cranks more clearly.

Third shows a later, machined rod with the original cast rod and the much more robust, custom rod.

Last shows a trick for power boost along with the brass bushing. The new crank has also had JB Weld added to the intake port to smooth the flow of the fuel charge. Norvels done this way allow for a free 500 rpm. Dressing the crank web with the groove is credited to Larry Driskill and the JB idea is my own taking example from the way the CS crank is made.

AndyW

My Feedback: (1)

How to make a stronger rod with only a drill press. If you have good aluminum, and don't need brass bushings, you can make your own rods with just a drill press and hand tools.

It's important to drill both rod ends at the same time to make sure that both are square to each other. Taking it out of the vise and replacing it, no matter how careful you are, may not guarantee the holes will be exactly in line. Also, drill with the vise in the same orientation. Its important to sneak up on the final drill size. The final drill bit acts more like a reamer than a bit. If you drill with the final drill starting with just a small pilot hole, or none at all, this will guarantee a sloppy fit.

While I used a milling attachment to trim the stem of the rod, this could be done with small files while the rod is held on edge in a vise. Just file down to the face of the vise. This doesn't have to be perfect or cosmetic, it just needs to provide clearance for all the internal edges that need to be cleared.

The final rod is shown in the last picture. Not evident is that the stem is much thicker than stock.

AndyW

My Feedback: (1)

More pics.

1: The head in closer detail.
2: All the bits and pieces.
3 &4: The final result.

The throttle is from the Sportster .19 and so is the muffler. As glow, I usually use the Sportster .28 throttle. No problem with fuel draw and with the larger barrel bore, I get more power. The muffler is VERY effective without a great loss of power. As diesel, it has the smaller, Sportster .20 throttle. If that works well, I'll try the bigger throttle just to see if we get more power despite the convention that diesels use smaller carbs. Never know till you try.

Final detail is that, as the crankweb is thicker, the crank needs to sit a bit deeper and the rear bushing is cut to allow this. If you look carefully, the front bearing sits protruding a bit instead of the other way around. A bushing was installed in back of the front bearing to accomplish this and the prop drive washer had a backing ring installed to take up the slack. Glued on with JB Weld, of course. Love that stuff.

Final, final detail is that the rear brass bushing is inserted into a larger, aluminum bushing that is the same OD as the original bearing.

ddd

Hi Andy,

Over 35 years ago when we had finished the Cox .049 conversion we moved on to the next most numerical seller the K&B 40 a baffled piston engine. All efforts to make it an efffective diesel were abanded after the pre-ignition problem could not be corrected, off-set piston, keyed contra you name it; the baffle sitting up there would get too hot and cause pre-ignition just as it did as a glow engine our Super tigre 35 on diesel would out run it by 1000 rpm. OS 15 diesel egged out the their upper rods from this problem.

Bob Davis
DDD