Conversion of 4 Cycle Utility Engine to Steam

[vtsteam]

Just found this link David -- pretty interesting. I'll also get the Smaalders links. Back in a bit.

http://books.google.com/books?id=PbxBAAAAYAAJ&pg=PA16&lpg=PA16

[DavidF]

now im thinking about airation and emulsifation...maybe skip the oil all together and replace it with graphite in the antifreeze???

[vtsteam]

Here are some links for Bart Smaalders and water in cranckase:

http://steamautomobile.com/phorum5214/read.php?1,20715,20715

His boat, engine, boiler with additional links:

http://smaalders.net/barts/boat.html

I believe he has used that engine on Otter since at least 1996.

[vtsteam]

I'm not going to go too far afield with this project. Oil is the lubricant, and if I can use it in the usual way, there won't be water or other substitutes in the sump. I think if I can bring th oil above 100C that condensation won't be a problem in the sump. If that doesn't work, then I may try the oil in water route. But I'll leave the antifreeze and graphite mix to you David! 

[DavidF]

LOL  yea im kinda grasping at straws, but sometime you have to say what you think to see what the reaction is....boy I bet the guys on the saca forum are going to have a ball with my last post....LOL   

[DavidA]

I'm following this build with great interest.  But I am having a bit of a problem with the basic concept.  I am not a steam man by nature,  even if I am building a steam loco.  But I have spent about half of my working life as a mechanic on internal combustion engines.

My problem is what I can't envisage how you will start a single cylinder, single action (steam only on one side of the piston) if the engine is in the bottom-dead-centre position. Or ,say, half way up on the exhaust stroke.

Do you have to initially turn it by hand ?

I can easily see how a twin will start. Or a single cylinder double action.  But not a single.

My apologies for appearing so thick.

Dave.

[vtsteam]

Hey DavidA,

I appreciate your questions so fire away!

It's true you can' just start from a stand still with a steam single if it is in the wrong position. You would have to rotate it a maximum of 180 degrees. You can do so at any speed, as long as you get there.

Not so with an IC gas engine. It needs to be turned over a maximum of 540 degrees under ideal condiitons, and at a speed fast enough to induct the fuel and air in the right mix and strike a spark, assuming it has a magneto. If fuel is not right at the jet in the right mixture, it will need to be turned over until that occurs. Also the mixture will need to be correct for the conditions of temperature and pressure. Hence the need for a choke, automatic, or manual, or fuel injection, often accompanied by a computer and associated programming.

I'm going to have to go outside shortly and start my snowblower. I'm sure that the above process will be demonstrated a few times over!   

[vtsteam]

Actually I didn't completely answer your question. Which was, does it have to be started by hand? You can start it by hand using the pull starter, or a crank, or take advantage of the ring gear on the flywheel and add a starter motor. Just like an IC engine. You could also rig something up clever to make the engine stop at he correct position for re-starting directly by steam.

I think this question comes up a lot because so many steam vehicles, cars and locos, did not use a clutch or transmission -- things that became commonplace after the IC engine came into favor because of its greater difficulty in starting, and its poor low speed torque curve.

[DavidA]

Thanks for that.  It is reassuring to me in that wasn't barking up the wrong tree.

Dave.

[vtsteam]

DavidF, new ideas and experiments are important. And I don't think anyone is laughing at different ideas. We all work on estimation and experience, but those can be altered by experiment if results show them to be incomplete.

I'm taking a pretty conservative path with this engine -- backwards almost -- with an eccentric and external valve gear. But when finished it will be a nice baseline to try a few ideas out on. And it will probably bring up problems to solve. Which is a good thing.

BTW, cast iron naturally has graphite in its makeup, and I plan to make a new CI head when the weather warms. Not that I expect the valve to run dry, but CI will run better than aluminum I believe.

I think antifreeze in the sump would be a problem because it would need to be drained fairly frequently and replaced as it got contaminated or diluted in a steam crankcase. It's expensive stuff, and environmentally problematic. Not saying it is impossible to maybe work some of the problems out. But it wouldn't be my first choice. Obviously auto water pumps work fine in that medium, so other mechanisms are feasible with it.

The old water and oil crankcase mix seems to depend on the oil separating readily from the water and floating on top, so the two can be drained separately if necessary. Easy to get rid of the excess water due to condensation with a bottom drain plug, while maintaining the lubricating oil in the sump.

The oils recommended for this are heavy weight and very specific -- not your usual automotive multigrade high detergent motor oil, which would quickly look like a milkshake emulsion if mixed with water in a crankcase.

So, I think the fact that antifreeze an graphite would combine with water, might be the actual problem, separation and layering seems to have an advantage.

[DavidF]

But if you used the straight antifreeze not the 50/50 mix stuff then it getting diluted by the condensate wouldnt really be a big deal.
   I would have to experiment some to get a better understanding of how the heavy steam oils work with a flooded crankcase. But thats for a later time, getting ready to start carving out a pattern for my enclosed  twin build, then its time to melt some Iron again 

[DavidA]

I was thinking about the cooling fins on the barrel.  As the idea would be to retain heat,  not get rid of it as with a petrol engine,  would it help to fill the gaps between the fins ?

Dave.

[vtsteam]

I was thinking about the cooling fins on the barrel.  As the idea would be to retain heat,  not get rid of it as with a petrol engine,  would it help to fill the gaps between the fins ?

Dave.

Yes it's been suggested before that rope type insulation between the fins would work as lagging. I might prefer to reduce their number as well. They do add stiffness to the cylinder -- the walls over the liner are relatively thin so I wouldn't take them all out. We'll see when I get to finishing details.

[vtsteam]

So I was drilling the head casting for the head bolts after marking out their locations and the location of the valve bore. Got 3 of them done and ran out of kerosene in my oilcan which I usually use on aluminum when drilling. Thought I'd just finish step drilling this first 3/32" pilot hole when ...snap! You guessed it, and I knew it, should never have done it. I knew better. 

Broken drill in 1" of cast aluminum. Tiny one, too. Nothing to grab onto and try to reverse twist out.

So I brought it inside and tried to recall all of the tricks people use to get the drill out.

It was in a boss so I heated that and tapped the head upside down -- maybe I could expand the hole with heat and it will just fall out.

No such luck.

Then I sat down for awhile and thought about drilling up from the bottom of the head to meet the broken piece, and then tap it out with a drift. Well maybe that would work, but tomorrow, as it was getting too dark to work in the shed.

Finally I wondered if I could get it out with a magnet. I have some really powerful magnets from a big old hard drive. So I found those -- I have two -- and pulled them apart -- which took considerable grunt. I rubbed one over the hole, and all of a sudden, chunks of drill bit came out! I probed around in the hole with the point of one of my daughter's school compasses -- the cheap pencil type, and I could still feel steel embedded down there. Then I realized I could stick the magnet on the compass, and it would become a magnetic probe. So I did that and scratched around in the bottom of the hole, and pulled out more bits and pieces. After about 15 minutes of this, I felt aluminum at the bottom of the hole!   

Well, I don't know if that method has been written up before, but it worked at least once for me, so thought I'd pass it along!

I'll be filling the oil can back up with kero tomorrow.

[DMIOM]

                  
What a good feeling that must be! - thanks for posting that

Dave

[tom osselton]

Hi just a shot in the dark but if you ran some steamlines through your oil would you have enough heat to evaporate the emusified water that could be vented out of the engine? I would think steam could create steam lol.

[vtsteam]

Tom, that's actually the plan A if there is a problem with condensation in the crankcase! 

Thanks DMIOM!! 


Today's tasks:

I completed drilling the head bolt holes, and they all line up. I must ]have removed all of the old pilot drill bit, because that hole drilled fine -- I did leave it until last, though.

Then I thought about drilling the valve bore. This is a tricky one since it is 6" long and should finish out to 1/2" in diameter. It goes straight through the casting from one boss to the other.

Having just recommended to someone else on the forum that they drill a long hole by coming in from both sides, before boring to final ID, I figured I'd better take my own medicine and do it that way, too.

My 1/4" drill bit was barely 3" long, and I planned to start with that. Since I'm also doing a thread about my Gingery lathe and the use of  faceplate and angle plates to do a lot of work, I decided to do the same thing here to drill the hole. I have a Sears/Atlas 12"x36" lathe now that is somewhat accessible in an unheated storage shed. The Gingery lathe is packed away.

I used some of my Gingery lathe angle plates to set up  the drilling operation on the Atlas, just as I would have in the past. The head casting was bolted to one angle plate, and a reference line squared to that. Then the angle plate was bolted to the faceplate (off the lathe and in my much warmer home). Then a short trip to the brisk machine shop atmosphere of the shed carrying the faceplate setup. Metal sure gets cold fast!

Once the faceplate was mounted, I brought the tailstock up to the casting with the dead center in place, loosened the angle plate/faceplate bolt slightly and tapped with a soft hammer until the casting drill mark was just touching the point of the dead center. I already knew the casting valve center line was square to the faceplate. I just tightened the angle plate bolt, and was good to go.

I had also mounted a second angle plate to the face plate as a balance weight. I engaged the back gears and set the belts to a speed of about 60 rpm. I first checked that I had clearance all around by swinging the lathe by hand before switching on, and also did a last check of the squareness of the valve centerline with the faceplate. To start the hole I faced the boss, center drilled it, then mounted the 1/4" drill bit for the first hole. Everything went well, and I made sure to clear the drill frequently.

After I drilled right up to the end of the flutes on the 1/4" drill, I switched to a 3/8" drill to open it out more. This went quickly.

Then I unbolted the casting, turned it around, remounted it as before, and drilled from the other side.

[vtsteam]

The result? The holes lined up almost perfectly. I couldn't even feel a ridge with a piece of drill rod I sent down there.   

I unscrewed the faceplate and brought it into the warm house to think about my next move. The holes lined up so well, I'm even thinking of welding an extension onto a 1/2" drill and sending it all the way through, rather than boring. Then either reaming or lapping that. It might come out a little oversized, but I can turn the valve body to suit. Otherwise it will be tough to bore out a a small hole like this one (3/8" x 6" starting) -- since it will require a very small, and therefore flexible boring tool. I could do it, but it will be very slow going.

Anyway, looking at it and thinking about it.

[DavidF]

My advice would be drill it another 64th then decide.

[DavidF]

You know, after thinking for a minute, you don't really need a seal across the whole 6". Just where it counts, like maybe the length of the drill bit???

[vtsteam]

Thanks David for your ideas. I guess I do want bearing support near the ends and want a true bore all the way. I can't count on the fact that the holes seem to have met up well. It needs to be a true hole.

I read up on D bits in Hasluck -- the old style machinist's handbook. I've also made stationary boring bar bits out of 1/4" drill rod in the past -pseudo D bits, by flattening the end, hardening and tempering and grinding. But these are fairly flexible for even a 4" cut, and cut slowly.

After thinking about it for awhile and looking at a wood spade drill bit, I think I'm going to modify one of those into a boring bit. They are a little shy of 6" total length if you grind off the end spike, so I'll add to the other end -- it doesn't have to be tool steel there.

Probably I will end drill a piece of 3/8" square keystock and braze the spade bit end into the keystock to lengthen it. That square stock should fit in my lathe tool holder and provide good stiffness and support.

I'll turn the corners of the keystock round near the bit shank so part of the keystock can enter the drilled hole.

For the bit material I'll maybe use a 3/8" spade bit -- convenient for this size. It will be ground to a boring profile -- the back side of the flat will be ground away so it doesn't contact the hole sidewall. A cutting tooth will be ground on the contact side. Interestingly, the clearances of the end and side are already correct, so I can leave those.

I think spade bits will work well because they are a lot stiffer than the drill rod boring bits I've made -- I measured the shank of one I have in front of me now and it is .28" -- a little heavier than 1/4". And it must be hardened in a way to give it some extra rigidity, by comparison.

So basically I will be boring the hole to size, not drilling. I'll just be modifying a wood drill bit to do it.

Pictures tomorrow when I make it. Fingers crossed it will work out......

[DavidF]

you can get some pretty long masonary bits as well, plus they are carbide tipped 
  I have some concerns about boring 6 inches with the tool only supported on one end. Were you going to bore then ream to final size?
  Maybe you should make a trial run in something to test it out???

[vtsteam]

A likely looking boring bar! I believe I found this one on the side of the road a couple years ago. Not a 3/8" but you get what you pay for, I guess.

[vtsteam]

A little cleanup and marking out what I want to grind off.

[vtsteam]

Finished implement of destruction -- drill bit brazed to a piece of key stock. Not pretty, but effective.

I drilled the hole out to 15/32" and 5 passes with the new "boring bar" got me to 1/1000th undersize. I didn't do the final pass because I was well frozen by then. It takes about 20 minutes per pass at the slow speed I'm turning the faceplate, and light cuts I was taking. Standing there in 35 degree temps watching the lathe go around eventually lost its charm and I headed up to the house to warm up and eat dinner.

But progress!!!!