The

Homebrew Hvid

Engine

Part 3

Part Four - Getting It Running!

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26 February 2009:

I got the head-end header drilled and tapped for the studs and have the jacket and liner drilled and tapped for the water inlet and outlet and the oiler.

  

              Header with studs installed.                            Test fit of head, header, rockers and fuel valve.

While I was about it, I used the dremel and a carbide burr to open up the air inlet holes to get around the restriction that the valve spring poses.

 

Test fit of oiler.

All I've got left to do to the liner is to turn an outside chamfer on the end shown to facilitate welding.

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12 March 2009:

A couple of days ago, I found out that the guy who does my welding is going to be out of state for about six weeks.  He's got a job doing a rebuild at a power plant.  That means that I've got some time to get the rear header done and maybe the crankshaft.

 

Today, I worked up the fuel valve actuator.

    

The fuel valve actuator setup.

Since the fuel valve operates off the intake valve, I made an offset socket, bolted to the intake rocker.  It engages a pushrod that goes up to the fuel valve rocker arm.  Adjustment is by way of the 6-32 machine screw on the fuel valve rocker.

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17 March 2009:

Went to Panama City today and paid a visit to a scrap yard.  

On the left, the 1-1/2" thick piece and on the right, the 1/2" thick piece

 

The 1/2" steel plate was easy to find but I couldn't find any 1-1/4" steel anywhere in the heap so I had to settle for 1-1/2" stuff.  I think I can modify the design of the crankshaft to accomodate the extra 1/4" of thickness in the cheeks.  If not, I can always flycut the pieces down to 1-1/4".  Anyway, they'll look nice machined all over.

 

The 1/2" plate is the blank for the crankshaft end cylinder header.  Both pieces need to be cleaned of torch slag and scale before starting the shaping process.

 

The piece on the left will be cut roughly in half along the faint soapstone line then cut so I can fit it into the mill and turn the blanks round before cutting out the crank-end sides.

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3 April 2009:

A few days ago, I cut out the crankshaft end header and got a good start at finishing it.  I did goof when I drilled the holes for temporarily mounting the header prior to welding.  I forgot that I'd already drilled four holes in the side plates so I have a few "extra" holes.

 

The tappet guide holes and the liner hole still need to be done

Semi-complete crankshaft end cylinder header.

 

I got back to the crankshaft today and, after cutting the 1-1/2" piece into two with the bandsaw then laying out the circles, I began to cut off the excess material.  NOW, I know not to tackle an engine as big as this one is with the small machine tools I have.  I tried three ways to trim off the excess and none of them is easy.

 

The first thing I tried was the bandsaw.  I hogged-off two pieces this way and it took a LONG time.  It's also hard on blades.

Using a roughing mill to remove chunks of excess metal.

The next thing I tried was a roughing mill.  This, too, was slow and puts quite a bit of wear on the milling cutter.

Drilling removal holes.

Finally, I decided to just drill a line of 1/4" holes then use the band saw to cut along the "dotted" line.

Cutting along the "dotted" line.

 

Here are the blanks along with the stuff that was removed the hard way.

Phew!  I'm glad that part of the work is done!  It took the better part of the day to get the material hogged-off.  Next will be to set the blanks up on the mill and bore the holes for the main pins.  I will then make a pin with a 1.5" (-) diameter for a light press fit into the cheeks then turn the other end to 7/8" to fit into a collet in the mill.

 

With both of the cheeks mounted together on the mandrel and in the mill, I can use the big carbide turning tool in the vise to turn the O.D. of the cheeks.  I figure that will take at least another day of work.

 

We had to make a quick trip back to Kentucky for a little family problem and I took that opportunity to haul the 12" diameter by 2" thick back to my friend who will use his CNC mill to whittle out the flywheels.  He's mentoring a Junior Robotics competition team and will let the kids program the mill and machine the wheels.

 

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5 April 2009:

I've been a-whittlin' on the crankshaft cheeks and I've changed the way they will be machined.

  

     Drilling 1/2" drawbolt hole.                                            Centering blank on face plate.

The first "aw-shoot" of the day was finding out that the mill is about two inches shy of being able to flycut the faces.  I cogitated on it a bit (after the cussin') and found that the blanks will just barely swing in the lathe.  Okay - I'll drill out the centering hole in the blanks to 1/2" so I can use a hunk of 1/2-13 all thread to draw the blanks to the face plate.

 

Since I'd previously drawn a circle on each blank to aid in trimming off the extra steel, I used a tool to roughly center the blank.

  

    Partially turning O.D.                                                       Facing one side.

When I had the blank centered, I used a big moose of a carbide tool to partially turn the O.D. for centering after flipping.  The blanks were taken from a scrap that had been sheared on one edge.  The shearing caused the steel to be smeared away from the surface.  Because of this, I first mounted the blanks with the "bad" or "smeared" side against the face plate.  The "smeared" area was almost 1/8".

 

A cleaning cut was then taken, just removing enough material so that side of blank was flat.

  

Centering after facing one side.                                              Faced to thickness dimension.                       

After getting the "good" side faced, I flipped the blank so the "bad" side could be faced.  Using a dial indicator, the blank was centered back up. 

 

The original design called for 1-1/4" plate for the cheeks but when I visited the scrap yard, all I could get was 1-1/2" plate.  

 

It is good that I had to get the thicker plate and I modified the crankshaft and rod bearing design so the cheeks could be 1.328" thick, facing off more than enough to eliminate the smeared areas.  

 

I would have liked for the cheeks to face a little prettier but I was lucky that the lathe is just beefy enough to get the job done.

 

Note the step-turned shaft with the bolt and washer in the photo of the crank cheeks.  Since they will now swing fine in the lathe, I've decided to temporarily bore the center holes to 1.25" and lightly press both cheeks onto the mandrel which can be chucked in the lathe for turning the O.D. to dimension.

 

After this is done and leaving the mandrel in place, the cheeks will again be mounted in the mill and bored to approximately 1.500"(-) for a press fit to the main and rod pins.  I hope to press them in tight enough that I won't need to weld or pin them.

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7 April 2009:

More progress on the crankshaft.

   

            Boring center holes for mandrel.                           Turning mandrel diameter to fit crank cheeks.

Yesterday, I got my spray mist coolant system and today, I hooked it up.  I was surprised at how much better the machined finishes are using mist and soluble oil.  I guessed at the ratio of water to oil at about 8 parts of water to one part of oil.  It looks kinda weak to me but seems to work all right.

 

A couple of days ago, I made the mandrel for turning the O.D. of the cheeks.  Today, after boring the cheeks to approximately 1.250", I finished turning the mandrel so the cheeks would be a snug (not tight) fit.

 

   

       Starting O.D. turning.                                                   O.D. turning nearly complete.

The cheeks were shoved onto the mandrel and a 3/8 bolt threaded into the end of the mandrel and a washer held everything firmly.

 

THEN, I spent the rest of the day making LOTS of shavings.  About five hours worth!  I did learn something.  My little lathe just doesn't have the horsepower to handle stuff this big and take any kind of cuts.  

 

Well......It did do 0.010" cuts at fast feed until the surface became less interrupted.  Then the flywheel effect went away and the torque to pull the bit through the metal was too much.  I ended up slowing the feed then I had to reduce the cuts to 0.005".  Finally, I was taking 0.003 cuts at the slowest feed.  In any case, I'm almost done with this step and the finish is nice.

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9 April 2009:

I spent a boring day boring out the rod and main pin holes in the crank cheeks.  What fun!

  

Gauge pin sitting on cheeks.                                                  Gauge pin in rod hole.    

After consulting with the experts on Smokstak, I came to the conclusion that the press fit of the pins into the crank cheeks should be between 0.0015" and 0.002".  To be sure I got it right, I took the remains of the piece of shafting I cut the main and rod pins from and and made a gauge pin  out of it by turning three steps on it.  In the left picture, the lowest step (identified by a magic marker line) is 0.003" undersize.  The next step up is 0.002" under and the third step is 0.001" under.

 

I then proceeded to bore the holes until the gauge pin would allllllllmost go in at the 0.002" step.  I can now make a pretty good guess that the fit is somewhere in the range of 0.002" and 0.003".

 

Also, per a suggestion from one of the Smokstak guys, I'm going to see if I can find someone who has liquid nitrogen.  If the pins are taken -300 degrees F or so, they should shrink enough to drop into place and that would make the assembly a LOT easier, although it would have to be done really quickly or the parts will stick before positioning is complete.

 

[Using my 1908 Electrical Engineer's handbook, I see that the coeffecient of linear expansion of mild steel is 0.00000599 per degree Farenheit.  I don't remember exactly how cold liquid nitrogen is but it's at least -300 degrees Farenheit.  Since the cheeks will be at room temperature, about 70F, the difference in temperature between the pins and the cheeks will be about 370 degrees F.  Multiplying 0.000006 times 370 degrees gives a total coeffecient of 0.0022.  That times the diameter which ended up being 1.495" gives 0.0332" of shrinkage which should work.]

 

I have to make another scrap yard run for another length of 1-1/2" shafting to make the alignment pin out of.  I underestimated the amount of shafting I would need because I hadn't thought about the alignment pin idea for making sure the crank was true when pressed (shrunk) together.

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11 April 2009:

The crankshaft cheeks are almost done!

   

Using end mill to remove material.                                                First cheek done.          

Now, this job took all day, too!  It was very tedious removing that excess material and took about six hours to get the job done.  Ask me if I've got sore arms from all that cranking.

   

Top Cheek removed with temporary clamps in place.                         Working on second cheek.  

After I'd milled down past the first cheek and removed the pieces, I temporarily clamped the cheeks at the points where the excess would be taken from the second cheek.  I did this so I could remove the clamps holding the top cheek without disturbing the position of the second cheek.  I then removed the first cheek, replaced the clamps and removed the temporary clamps.       

All done but the deburring.

Tomorrow, I will debur the cheeks and prep them for pressing in the pins.  I've decided to do this at room temperature because it is the simpler method and only requires the use of a press.

 

I may have an "aw shoot!" with the bores in the cheeks.  Before I trimmed them, I made the alignment pin and found that the bores are tapered!  I don't know why this happened except that the quill in the mill is a bit loose and even setting the drag almost tight, it moved a little while running the boring tool.  Tomorrow, I'll do some test fits and see how bad it is.  I may have to resort to welding the pins to the cheeks then I'm sure it will be necessary to grind it true.

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20 April 2009:

I went to a machine shop in Panama City today and we pressed the crankshaft together.  I dunno perzackly how tight the fits were but the 50 ton press was groaning while pushing the last main pin in.

  

     Crank with rod pin press into place.                         Finished crankshaft ready for trip home.

When I walked into the shop, they were water jet cutting some shapes in 1" steel.  Wow!  Had I known the shop had that capability, I would have driven the scrap piece directly there and let them rough it out.  That would have saved about four days of work on my part!

 

Not shown in the left photo above is the alignment pin that was a light press fit through both main bores.  This was hammered into place to assure alignment of the cheeks before the rod pin was pressed in.

Crankshaft in lathe being checked for straightness.

After I got the crankshaft back, I put it in the lathe and checked it for straightness.  The main shafts have about 0.012" runout maximum so it's not good enough to use as-is.  I would be able to turn it true on my lathe except for the fact that I can't get the carriage under it.  It looks like I will be taking it to a crankshaft grinding shop.  

 

As it is, I can have them grind the mains to as small as 1.975" and the bearings will fit because I haven't finished the I.D.'s of them and they are about 1.976" rough.  The crank pin just needs to be cleaned up and I can't let it get much smaller than 1.995" or so or I will be removing shims from the bearing.

 

After I get the crankshaft sorted out, I'll start thinking of getting the frame welded up.

 

Just hefting the crankshaft makes me think that I may have over-engineered the engine a bit!  It must weigh at least 30 lbs!  Kinda big for an engine with a 2" bore and 4" stroke even if it is compression ignition.  Ah,well, I guess that the more rotating mass there is, the smoother the engine will run.

 

I've been thinking about what to do with the engine if it runs well.  Maybe I will make an Algore GREEN hybrid butt buggy.  I can use the engine (running constant speed) to run a generator that charges a battery that powers an electric motor to propel the buggy.  Whaddya think?

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21 April 2009:

Before the crank goes to the shop for grinding, I figured to get the crankshaft as straight as I could so I measured the distance between the cheeks at the counterweight end and at the rod end.  It measured about 0.013" wider at the rod end than at the counterweight end.

Using the Redneck Method of straightening the crankshaft.

I used a couple of pieces of plywood, a big chisel and a large watchmaker's hammer to spread the cheeks of the crankshaft.  I found that I had to go about 0.020" over where I needed to be to allow for spring-back.  NOW, it can go to the grinder.

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21 April 2009:

The cylinder's about done except for final honing.

Cylinder, head and oiler set in place.

I got ahold of an old Sears Roebuck AC welder and, after cleaning it up and replacing the cooling fan, I decided to see if I could actually do decent arc welds.  Thanks to the advice of the guys on Smokstak.com, I got some 1/8" 7014 rod and, after practicing on some scraps, did the deed.  Not the best looking welds but I think they'll stay together and might even hold water.

 

I'll have to give the project a bit of a vacation while I get some other things taken care of then it's back to the home stretch.

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4 May 2009:

I took the crankshaft to the shop to have it ground and found out that they can't grind it to the ends of the mainshafts.  DRAT!

 

Sooooooo......I hauled it back home and made do with my little lathe.

My crank turning outfit.

Since I'd previously put centers into the ends of the main shafts, I used them to support the crank in the lathe.  Then, with a piece of 1/2-13 all-thread hooked to the faceplate to act as a dog, I spun it and turned the short end.  After that end was done, I unshipped the crank and reversed it so I could turn the long end.

 

The finish isn't as good as I'd like but, with some finish filing and then going over it with emery paper, I think it will do just fine, especially after I lap the bearings to it.  I've left the rod journal alone because I have no way to offset the crank.......AND my little lathe won't swing it.

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6 May 2009:

Today, I welded the frame together.

  

Parts laid together for welding.                                                Welding complete.       

I'm really not a very good arc welder.  For some reason, the eye-hand coordination is not there and my welds tend to wander all over the place.  Anyhow, I've never had a weld fail so I guess it's only the appearance that makes me a little ill.

 

After laying up the mains with the crank, rod and piston mounted and in place as an alignment jig, the welding was done.  After finishing the welding and letting the frame cool, I again assembled the crank and main bearings.  There was a little warpage but it appears to be within the amount I allowed for lapping the bearings.

 

If the flywheels aren't here by next week, I'll make a temporary pulley out of a piece of 2X8 so I can start motoring it to seat the bearings and, after the bearings are done, the rings.

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10 May 2009:

I got the keyways milled in the crankshaft and assembled the timing chain, governor, camshaft and chain tensioner.

  

               Timing chain in place.                               Showing camshaft, tappets and governor. 

Some of the dimensions had to be adjusted to get the chain and all the sprockets to line up.  I had to narrow the timing-side main bearing so I could get the crankshaft sprocket close enough to the frame for everything to line up.  When I made the main bearing inserts, I left them a bit on the wide side, figuring that, with bearings, more length is better........EXCEPT when it throws something off.

 

Frank says that one of the flywheels is nearly done and he will ship it as soon as it's finished so I can begin motoring the engine.  I plan to use the far-side flywheel as a pulley.  I'll probably use a piece of 2 X 6 for a temporary skid and so I can mount the motor.

 

Just about the only parts I have to make now are the valve pushrods, head gasket, cooling system and some bits for the governor linkage.

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12 May 2009:

The temporary (maybe) skid is done and the engine is mounted on it.  I've also been doing some of the "fiddly bits" as our Brit friends say.

Most of the mechanical parts are finished and hooked-up.

Among the things I did today were to make the pushrods and the governor linkage.  

 

It took a bit of "creative engineering" to come up with the head-end bearing mount for the governor but it seems to be in the ballpark except for some tightness in the bearings.  I'll have to do a little tweaking to get it to move freely.  The lever ratios of the linkage allow the fuel metering valve to completely close well before the governor weights are all the way out.

 

With the valves adjusted to 0.012" clearance, the compression release keeps the exhaust valve open by a few thousandths so that ought to work okay.

 

Tomorrow, I'll go to the local hardware store and get some 1/4" pipe and fittings and get going on the cooling system.

 

I'd like to make the fuel tank out of copper or brass but am not sure if there will be a chemical reaction with Diesel fuel or kerosene (parrafin).  I think not because I ran my Dieselized '50 Chevy with copper fuel supply and return lines for over 20 years and 200,000 miles with no problems.

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15 May 2009:

First thing today, I worked on the governor linkage and took out about 0.001" from the head-end bushing and it now works freely enough.  I figure it will loosen-up with wear.

 

Then, I spent the rest of the day making the fuel tank and getting the fuel line fittings organized.

  

Fuel tank.

I just got the tank bolted to the engine and will have to put in some braces to stiffen up the mount.

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16 May 2009:

I made the cooling tank out of a couple of naphtha cans soldered together end-to-end.  Classy!  At least that should give me some idea of how much cooling I will need before making the permanent tank.

Fuel tank brace in place and fuel plumbing done.

I soldered-in an adapter to 1/4" pipe on the bottom of the tank.  I still have to put the top nipple in the tank but can't do that until the motor is in place and I know just where it's going to be.  Note that I put the cheap fuel can on the bottom of the cooling stack.  

 

All I have to do now is wait for the first flywheel to arrive so I can figure placement of the variable speed DC motor.  Then I can make the plywood platform for the motor and cooling tank.

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19 May 2009:

Since I've been running out of stuff to do while waiting for the first flywheel to arrive, I decided to go ahead and lap the bearings.

Plywood pulley for motoring.

I used a hunk of scrap 1" plywood to make a 12" diameter pulley (the same diameter as the flywheels).  The hub is made from part of the scrapped piston, epoxied into the plywood circle.  I made a mandrel consisting of a stub shaft and a bar that I clamped on the drill press table.  Using a coarse rotary file in the drill press, I rotated the plywood wheel while trimming it.  It ended-up a near-perfect circle. 

 

Set screwed into the keyway, it works well to spin the crankshaft.

 

  

       Timing side main bearing after lapping.                  Off-timing side main bearing after lapping.

It took most of the afternoon and four disassembly/clean/reassembly steps using lapping compound to get the bearings fitted.  As you can see, I've got nearly 100% contact on the timing side bearing and 80-90% on the off-side bearing.  Right now, they are stiff with the bolts drawn-up tight so I will add the grease cups and run it with light grease for a couple of more hours to work-off most of the tightness.

 

At that point, I will align the rod and run it ringless for a while to get most of the roughness out of the cylinder and break-in the wrist pin bushing.  Then the rings go on and it gets run more to seat them.  I don't think I can spin it under compression until I get at least one of the flywheels mounted, so I'll run it with the compression off.

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20 May 2009:

Except for the flywheels, I'm ready to start fuel tests.

Motoring with engine completely assembled.

After running the main bearings for a few hours with oil, I hooked up the rod and piston without rings and ran it some more 'til the rod bearing lost it's tightness.  Then I put in the grease cups and ran it for a while with grease.

 

When it was running with the ringless piston, I could run the motor at maximum speed (about 500 RPM on the engine and throw in the compression and it would still turn but had a LOT of blowby (natch!).  After running the ringless piston for an hour or so, I took it out and checked for unusual wear marks and found none so the piston is running true in the bore.

 

I installed the rings and re-assembled the piston and rod and motored it again to seat the rings.  This time, when I flipped the compression release off, the motor couldn't turn it.  With the flywheels mounted, they will store enough energy to force it over compression.

 

I filled the cooling system and found one small leak, a blow hole in a weld.  This was patched with J.B. Weld.

 

Data plate.

While awaiting the first flywheel (maybe enough to start fuel tests), I will motor it to be sure the rings are seated.

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Part Four - Getting It Running!

If you have any questions or comments, please email me at:  [email protected]