CNC - Off Shelf Parts Engine and Other ?'s

[RogerAS]

Hey all,

Would it be possible (remotely practical) to use available parts from other engines, like sleeves, pistons etc along with some CNC laser cut parts to build a Lister-like engine? Perhaps a hybrid of fabricated parts and available replacement parts.

I know welding a crankcase together might be a nightmare for alignment, but is such even possible? Couldn't a crank case be milled after welding it up to true the bearing journals areas?

Could a crank, and or cam, from a production engine of another design be machined into a workable model, or would it be better to mill parts and fab the crank/cam? I read about cam experiments were being done in TN right now, and that made me think of these questions.

For that matter couldn't these engine blocks be cast from aluminum/alloy, or milled from billet parts?

Why can't a slow speed diesel pass the EPA rules? Is it the unregulated direct fuel injection that gives them fits? How can we clean up one of these engines so that the EPA will allow them?

Sorry if there's just too many questions, but I'm curious as to what others think.

R

[vdubnut62]

I think that I have been lying awake at night struggling with the same questions.   Modifying an old tractor engine? Casting an aluminum crankcase
and fabbing a crank to use a Cummins piston, rod and liner with a listeroid injector and pump?
Ah, the many questions that will drive a man mad!
Ron

[Crofter]

Fabricating a Lister style crankcase by welding up steel plate would not be difficult for a one off proof of concept situation but it would be much more expensive than casting for actual production.  After welding a stress removal heat treatment would be necessary to prevent distortion as final machining progresses. Almost as much energy needed for that alone as in melting the iron for a casting. I think trying to lose weight by going aluminum would result in even more trouble with vibration.

For sure an existing cylinder, head and valve gear, piston and rod assy from a segmented engine such as Cummins, deutz etc. would get you longer fiddle free run time.

[Crofter]

Ron, the listeroid injection system parts are cheap compared to most anything else. I think trying to make that style engine compliant though needs much more elaborate control of variability of valve timing, injection timing, higher spray pressures, throttling for idle and low speed etc., etc. Another issue is unburn hydrocarbons from the space above top ring, valve guide oi leakage etc. Really hard to retro engineer and the pounds of material to horsepower ratio is never going to be good. Intense vs relaxed combustion puts efficiency and power pulse issues in opposition. Light pistons and less reciprocating and rotary mass are more efficient at absorbing energy from the burning charge but that only works if multiple cylinders spread out the pulses. Smaller cylinders burning the same fuel at higher rpm but lower torque can deliver much more and smoother power from a fraction of the engine weight. The Listeroids beauty is in its raw simplicity. Make it complicated and you destroy most of its reason for being.

[mobile_bob]

i will throw in my .02

if i were to do it, i would use an 855 cummins head, which covers two cylinders and make a twin

there are many examples over time of welded steel crankcases, and i see no reason why one could not be made.

but at what cost?  i guess if you have the large milling machines, line boring capability, make up the patterns and have
the plates laser cut (which would probably save a lot of time and money), and have a rather heavy duty mig welder
(although a stick welder would do very well, the mig would be faster and cleaner for most all but a professional welder)
then by all means get after it.

using the cummins head would allow for a cummins fuel system, and one could also use other parts of the same family of engine
cylinder kits, con rod, part of the cam (if you can tolerate a really odd fire, think harley "rumpty, rump")

failing that one could build a really large single using the cummins KT series parts, the heads cover only one cylinder
which would make using a bunch of parts really easy, however

it would have a 6" bore and about the same in stroke, iirc

that would be a really large single cylinder engine.

bob g

[RogerAS]

Ok, good posts so far.

With good steel, a CNC driven laser, accurate fabrication, post welding heat treating and machining we could get a usable block/lower end/mains.

Is it possible to rework, shorten to reflect a single, a factory cast crank so that flywheel(s) could be attached. Would a machined crank be possible for a 6" throw?

If the crank were made of machined parts one would need both ends where mains and flywheels run and seal areas, key way for cam gearing and flywheels  counterbalanced throw connectors and the lower connecting rod shaft. That's only 5 parts and the ends and rod connector are just shafts, all of which could be bolted in the proper register. The throws/counterbalances would require the most work. Oil passages would be fairly simple drilling, as even the counterbalances could have the passages plugged after assembly. Roller bearings could be employed everywhere except the connecting rod area.

What about the timing gears, cam and lifters? Would a cog belt driven overhead cam, like in my 92 ranger 2.3 work? Racer Walsh has some cam pulleys with timing slot adjustments (+-15°), which would come in handy in a large single diesel!

So a 6X6 engine is possible with all the upper end (sans pushrods) from off the shelf parts. All we need to do is connect the lower and upper end. I think this is doable.

Any more, BETTER, thoughts?

What about a much smaller version of the Lister. Are there small engine parts, less than 2 HP, that we could make work as a diesel? Water cooled motorcycle cylinders? Heck, a 1K diesel, or less, from oddball parts sounds like fun to me, but a 6X6 would be a real thumper!

R

[Crofter]

A 5 piece crankshaft can be made up of standard shafting and the bells (throws) could be made up from flame cut and bored plate. Heat and cold interference fit cranks have been made from ounces to tons in size. Possible but not practical. There are many existing engines that are close to those specs. like perhaps the Witte. Unless you could find the suitable engine parts on somebodys scrap pile I bet they would be too expensive.

An external dry cogged timing belt and modding an overhead cam for the listeroid would be a good project just by itself. The present valve train has warts for sure. Just a bit of work to the rod bearing setup and getting filtration and pressure lube would make the bottom end OK.

[vdubnut62]

Having owned an interference designed OHC diesel vw, timing belts are the DEVIL!!!!!!!!!!!!!
I figure use a cam from tractor or some such with angle cut timing gears and cut the shaft to length.
Square hay balers ( Especially New Holland and Massey-Ferguson) have nice heavy USA cast flywheels of a couple hundred pounds, and they are rated for 540 rpm out of the box, so 600 should not be a problem.
And I would not be very worried about EPA compliance, at least in the development phase. A horizontally opposed twin would be nice too, since it would be in balance by it's very nature.
Still losing sleep and thinking...........
Ron

[rl71459]

I found these on e-bay... I dont even know if they are useable together... Thought iot might spark start some discussion.  Sorry about that "spark" slip up.

Cummins 3081070-RX OEM Diesel Cylinder Head 4 Valve*

Item number: 230512293048   US $165.50
_________________________________________________________
Connecting Rod - USED CUMMINS 6B

Item number: 370220167851   US $50.00
_________________________________________________________
Cummins Pistons for a 903 or 555, part # 3010178

Item number: 160469486297   US $55.00
_________________________________________________________
CUMMINS KV 3022157WS/3007525 CYLINDER SLEEVE KIT OEM

Item number: 380255688411  US $39.93


Rob

[Crofter]

Hey Vdubnutnut, how about we just put a big jug on the baler in place of the packer plate and chamber and we have a horizontal one cylinder engine on our hands!

Yes the timing belts on the VWs are a pain but not so bad if you change them before they crash. Have done mine three times now. A single cylinder engine is hell on gear trains; I wonder if a built in harmonic balancer effect would work. Space is an issue.

If you started with a clean slate perhaps an opposed piston ported two stroke with two pistons per cylinder might be worth visiting. No valves or valve train, no balance issues.

[vdubnut62]

Hey Vdubnutnut, how about we just put a big jug on the baler in place of the packer plate and chamber and we have a horizontal one cylinder engine on our hands!

Yes the timing belts on the VWs are a pain but not so bad if you change them before they crash. Have done mine three times now. A single cylinder engine is hell on gear trains; I wonder if a built in harmonic balancer effect would work. Space is an issue.

If you started with a clean slate perhaps an opposed piston ported two stroke with two pistons per cylinder might be worth visiting. No valves or valve train, no balance issues.

Yes (sigh) I am a nutnut- landed on my head too many times!
Yep, a baler might make an engine, if you could live with about 15 power strokes a minute, and a  stroke of about 16-20 inches, and the conrod bearing would take the stress, then you would have the gear train that the flywheel is connected to to contend with.... if I tried it, it would explode, spectacularly.
Be a lot of fun while it lasted!!!
Now that  opposed two stroke idea... Hmmm.
Ron