Return to Thunderdome, the Saga Continues

[Stainless1]

Well folks, most of you know how Mad Max fared last year, for those that don't you should read this thread

http://www.landracing.com/forum/index.php/topic,3908.0.html

Well the Kansas Bad Man is back in business, sure he said last year might be the last, but like most of us, he has unfinished business with the salt.... 

I've been over to Max's several times since the races, Max cleaned and painted the shop... and then got back to work

The body came off and the motors came out, Max took them apart to inspect their condition.  The blower was also removed to replace the broken blower drive shaft. 

Max started by solving his broken blower drive, in the mix was also the problem with 2 broken blower belts this year.  The belts, like the shaft, were just not heavy duty enough to drive the blower.  Max rarely has a problem finding the weak link in his machine.  So he employed his basic Navy engineering principles... if it broke, build it bigger and tougher the next time. 

1 The broken shaft and the replacement
2 Stacked back together, you see the new one is longer, it will drive a wider pulley
3 The old and new belts and pulleys

[sabat]

Very nice, good luck this year. -Dean

[Stainless1]

Yes, Max made the blower drive shaft, it is bigger and make from better steel than the original..
The pulleys, yes he made those also, although the teeth were machined at a friends machine shop, needed the CNC to do that the first time, Max made the cutter have the correct tooth profile.  The first picture shows the drive pulley is not finished yet, but you see a better shot of the difference in the belts.

The second picture shows the new blower shaft and pulley assembled

The last picture is the crankshaft drive pulleys, the old and yet to be finished new...

[narider]

How freaking cool is that!!!

Bob, all aspects concerning fabrication and assembly of Max' project have overly impressed me every time I've read about it (to the point I couldn't even comment on it), especially pics in his shop, before and after shots, troubleshooting items, and etc. etc.... man has he got me envious and excited that I have a good bit of time ahead of me to learn a little of this stuff. And of course anything that impresses you sure gets my eyes opened up, so it was cool to see you be the one to bring this portion of the project/repair up.

It took me about 18 views of looking at those dual plugged Vincent heads in the background before I saw there was pulleys and shafts in the foreground by the way.

Any chance that "tapering/blending" the keyslot back into the shaft would be less stressful, as opposed to where it's squared off at now. I might be missing it, but it looks like the the end of the key slot is where the last one gave up the goat maybe?

Miss being on here... this stuff is just too cool to check out to not comment on at least once so I can find it easier later.

Go get 'em Max,
Todd

[Stainless1]

Todd, I don't know if blending will help but it might, and I'm sure it won't hurt.  I was planning to show head work later, but since you brought them up, I'll show what Max is doing to them first.  The intake pressure tubes have had a little alignment problem in the past, Max is fixing that and while he is at it doing a little port work...  The one on the right is about 1.5 the one on the left is 1.6 ish.  More to come on these as things progress, but here is a peek

Here is a look down the old

And them the ported

[narider]

Just a thought on the shaft... just hate seeing shear or rotational areas have square edges at the areas designed ot hold the stress. Then again I know just barely enough to be dangerous to myself and those foolish enough to listen to me.

Very nice on the heads , love seeing that cast polished like that and am very familiar with just how nasty and how much work that is
Were the vanes an oem item on those heads, or did he weld those up earlier? Either way I really like them and their placement. Would love to see floor pics from chamber side (seat to port blend area), they look nice and shallow.
Todd

[Stainless1]

Luckily I just happen to know several mechanical engineers, and I will check with them to see if Max needs to blend the bottom of the round key slot. 

OK while we are looking at engine stuff I should mention that I went over to Max's to help him pick up his motors from the machine shop.  Last year I showed you the gear train between the motors.  The backlash was set during the manufacturing process by drilling the holes for the pins in the correct location.  Max did that very well on his little home mill/drill.  But when he took the motors apart there was a problem with the gears and some galling on the pins.  Max spent a while figuring out that when the machine shop that EDMd the holes in the quick change gears missed the center of 1 by .005 so he had a tight spot.  New gears, re-EDM the holes, and re-machine the cases for a larger pin had to be done.  Max figured the assembled cases would not fit in his mill/drill, so he was going to borrow a mill from a friend.  Well, the motors needed a big mill, so he borrowed a CNC from his friend Dick at Machine Services Inc in Wichita. 
The first picture is Max and Dick with the motor on the mill.

The second is a little closer look before we loaded up the motor, the 3 pins between the cranks were located to set the backlash for the gear train between the cranks to about a little over a degree.   

Hi Honey, I'm home... we brought the motor back to the Thunderdome...

[Stainless1]

We hauled it in the shop and Max decided he had almost enough fun for the day.  We were going to pull the gear cover off and take a few more pictures, but that will be another day
Here it is on the floor
The gears beneath the plate will be revealed later.... but they look just like last years with a bigger pin. 

[Queeziryder]

Hi Stainless,
On behalf of those of us who help Max, from the other side of the pond, please keep this up

Max tries to keep us informed, but when he's working in the shop, he doesnt have much time left

Cheers
Neil

Vincent owner, and part time salt crew

[saltwheels262]

 looks like quite a bit has been going on
in ks. it will be another great build to
watch & read.

franey

[Kansas Bad Man]

Just a thought on the shaft... just hate seeing shear or rotational areas have square edges at the areas designed ot hold the stress. Then again I know just barely enough to be dangerous to myself and those foolish enough to listen to me.

Very nice on the heads , love seeing that cast polished like that and am very familiar with just how nasty and how much work that is
Were the vanes an oem item on those heads, or did he weld those up earlier? Either way I really like them and their placement. Would love to see floor pics from chamber side (seat to port blend area), they look nice and shallow.
Todd

Hey Todd,

Thanks for asking.

The blower drive shaft wasn't finished when the picture was taken.  I had to scrounge up a ball end mill to finish the keyway.  Got the mill, will finish it today.  All of the welding was done on the heads, and then heat treated.  I'll ask Stainless to take some pictures of the combustion chamber side. 

On another message board that I frequent, a fellow asked me why the key, and said there are other ways to mount the pulley to the shaft.  I can only think of three ways--a taper fit, (I don't
particularly like that method) a spline shaft and pulley, (which weakens the shaft) and a keyway.  I prefer a round keyway rather than a square.  There's no shear per se on a round keyway.  A square keyway lends itself to shear.  The best way to explain this: a square keyway resembles a metal shear.  You certainly wouldn't want to try to build a metal shear with the shear edges round. 

                                        Max

[Dean Los Angeles]

The straight shaft places the entire drive load on the key. Even the round key is in shear.

The tapered shaft places the drive load on the taper with a very large amount of contact to distribute the load.

When I first started building two cycle engines I questioned a buddy and said that the nut was holding the flywheel on the taper. He said no, the nut drives it on the taper and the taper holds it. He then removed the nut and fired up the engine.

Where you see a tapered shaft with a key, the key is to locate the flywheel or gear.

[Kansas Bad Man]

The straight shaft places the entire drive load on the key. Even the round key is in shear.

The tapered shaft places the drive load on the taper with a very large amount of contact to distribute the load.

When I first started building two cycle engines I questioned a buddy and said that the nut was holding the flywheel on the taper. He said no, the nut drives it on the taper and the taper holds it. He then removed the nut and fired up the engine.

Where you see a tapered shaft with a key, the key is to locate the flywheel or gear.

Hi Dean,

I agree.  The round pin is in shear, but far less than a square keyway. 

When I was about 16 years old and screwing with the rear axles on my Ford, if I remember correctly, the rear wheel hubs were on a tapered shaft with a keyway.  I can't tell you how many times I replaced sheared keys.  The taper didn't prevent this from happening. 

                                             Max

[Indianken]

   Here we have something that is easy to use; capable of high torque loads;
 no stress risers; and off the shelf.

    http://www.fennerdrives.com/catalogs/keyless_bushings.pdf

  Worth a look.

   Ken Smith

[Stainless1]

Ready for more?  Too bad, here it comes....
Max expected to find some traces of "black death" on a couple of piston skirts and cylinder walls.  The motor has oiling issues for the cylinders so Max has some ideas he has been tossing around with Dave Matson, another fast and should be famous Bonneville Vincent rider.  Dave runs a little extra oil in the sump for the crank to catch and sling, neither of the guys are too concerned about windage issues.... They would rather loose a couple of HP to that than seize up a washed down wall.  Max is thinking about drilling the crank counterweight to help catch more oil to sling. 
Max is also doing a little work to the pistons to help them catch and hold a little more oil.  He has also changed rings, this year he will have a chrome top, a gapless middle and a low tension oil ring.

Here are some piston comparison pictures, the unmodified ones are obvious...    Nice looking slugs Nick...