Commando Crankshaft Porn

How 'bout eliminating or reducing the central flywheel and make the side cheek bigger and run the pin across/through all 3. If the flywheel was kept a circle its rim could be kept somewhat in line from the jump rope by placing sacrificial bearing blocks set around the DS crank case so after 9,000 rpm or so the flywheel collides with the blocks which then deform to take some load, then melt then vaporize then turn into atomic plasma explosion that repells flywheel back to center plus reduces friction and allows some time as insane rpm till renewing the blocks for next excess. Oil interface as the translation speed of flywheel rim on any surface would simply burn it up in microseconds.

There is another way w/o above drama just no engine examples just Spirograph plastic drawing toy that draws a perfect line not curves.

Ludwig's comment about flywheels and trains had me thinking, although in a different context about the size of the flywheels they use to manufacture railroad wheel sets. They heat the wheel to a fair temperature and turn it by means of a massive flywheel. The axle is inserted and pressed into the center hole of the wheel and the two pieces are effectively welded into a single piece once the wheel has cooled. Talk about a big flywheel.

On the really big locomotive wheel or even bigger crank shafts, they found they must heat the hole area first so heat expands outward to rim as heating rim first compressed the bore and crank would bind before seated. Very fine polished mated surfaces also self weld when pressed together tightly.

And to add another story, my Caterpillar road grader done a drive hub (out in the middle of nowhere), solid cast and a 2 man lift job! To install another, hub was heated with gas cooker till to too hot to touch, then lifted onto drive shaft (with steel bars). The taperd hub went on further than original and hasnt moved since. Apparently these are normally done with a huge press, not to be found out here! FWIW

Foxy

I got my crank pieces back from having it shot peened and cryro treated. I static balanced it to 62% dry or around 55% wet. I also added a couple bolts and a tube through the big end to hopefully help keep it from breaking since it has been offset ground .100 to increase the stroke by 2mm.
Here are some pictures. Jim

Wow that looks really nice Jim. What's the deal with the recessed radius?

Hortons Norton said:

Wow that looks really nice Jim. What's the deal with the recessed radius?

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Norton cranks have a habit of cracking at the sharp corner there. It's common practice to cut a larger radius there to relieve the stress riser on a motor that may be used hard. Jim

Porno delight. What will this crank be put into to stress it?

It is going into the new 914 cc motor to replace the worn out 880 in my fuelie bike. 45000 miles now and it is sounding kinda loose. Jim

comnoz said:

It is going into the new 914 cc motor to replace the worn out 880 in my fuelie bike. 45000 miles now and it is sounding kinda loose. Jim

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And what kind of rods are those?

Carillo?

Hortons Norton said:

Carillo?

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Yes they are Carrillos from several sets I had made up for my racebike years ago. They are .5 over stock length and go with short pistons. Jim

Is there bushings in the small ends of those rods?

914 sroker fuel injected super duper everything else, hm, yum, that'd fast shove you into hinged handling on nice sweepers, I'd highly recommend while deep into it to put your talents on rump rod and see if it don't make you crazy as me never looking back, as no one going be passing you when there's any leaning involved. My guesimate is 66 lbft , 87 hp.
What redline are you going to respect?

Your flywheel is similar to Peel's. That round rim just begs to be a load bearing jump rope resisting surface. Alas surface translation speeds eliminate normal rotating elements like rollers or bushes, oil vaporizes so fast it pressurized the gap and diesel explodes and metal to metal contact returns the alloys to elemental states beyond gas phase straight into plasma phase of matter with the electrons all striped off. Air/gas bearings can/t take the flex shock loads of big twin hits, it ain't no turbine. If sacrificial babbit material was in close relation to the flywheel the exploding softer/lower melt pt. metal would repel and greatly resist crank jump rope, for a time at some excessive rpm. Maybe with Norton head only a boosted engine could flow to those rpms.

There is another way with no metal surface translations nor central bearing via planetary/elliptic gears messing in pure linear to rotory motion. Forked big end rods required.

RennieK said:

Is there bushings in the small ends of those rods?

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They are copper [?] plated small ends. Done before plain ends with DLC coated pins were common. I will be using DLC coated pins also. Jim

Splatt, This is going in the new motor I am building. Yes I have been concerned about weakening the crank by it's offset grind. To try and make up for some of what I have removed I installed 2 1/2 inch bolts and a heavy walled tube through the journals. Time will tell if that is going to hold. The counterweights are bolted to the crank with 3/8 inch flathead screws. Rather than posting more pictures I will just give you the link to my photobucket. Look in the projects folder and you will see all the crank pictures I have. Jim

http://s658.photobucket.com/albums/uu31 ... 2QQtppZZ20

What VW engines are these special cranks taken out of?
How does the engine sprocket attach to the PTO part of the crank?
How would the crankcases be modified to utilise a centre bearing?

pouchy750 said:

What VW engines are these special cranks taken out of?
How does the engine sprocket attach to the PTO part of the crank?
How would the crankcases be modified to utilise a centre bearing?

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The cranks were made from 1/2 of a 1.6 liter Volkswagon Rabbit diesel crank. The drive sprocket is attached by a ring of 5- 5/16 inch bolts.
For the center support I built a 3/4 inch thick aluminum plate that was split horizontally with 4 bolts to hold it together over the center main.
In my first design, it was attached with bolts run radially from the outside of the case after machining and welding in bosses.
The second design had the center plate sandwiched between the two case halves after removing the correct amount from the flange.
The first design worked better but required too much welding which weakened the cases resulting in cracks.
There were also two long studs that run from the center support through the barrel with nuts in countersinks under the head gasket.
This is a picture of one of the cranks installed in a second design support. The cases in this picture were cut from billet but I also used a similar support in stock cases. You can also see the crank pulley. Jim

[video]http://www.youtube.com/watch?v=qmaLhV2__qU&feature=related[/video]

More - http://www.youtube.com/watch?v=qAQuljp- ... re=related