Birth of a new tool...

[kliff]

Sometimes I get PO'ed, sometimes I lose direction, sometimes I just need a change for a day or so.

This all started about 3 months back.....or so... Some guy had a whole bunch of 139QMB cylinder heads for sale on Ebay.....about 20 bux each. At a price that low, I figurred they had ro be QA rejects! But sometimes even a reject can serve a purpose. I bought one.

Today, I started taking it apart..... no, I mean APART!
As soon as I just started looking at the head, I saw a problem with the exhaust seat..... such as light, beteween the seat and the valve, at least 1/3rd it's circumference, and about .060" wide.
Had this head been installed as is, it never would have started.

So all the valve gear, including the guides, went into the parts box. All that stuff looked OK.

No to REALLY take it appart....whre's my bandsaw.







O man...what's with all those machinist set-up punches? Well sometimes you need to satrt some holes, directly in the center of an existing "pattern's" holes. Then you can sart making a fly cutter, similar to the one in the upper left of this photo...



Or, another veiw, like in this case...



Then when finished, the engine builder will have his store bought 60-65.5mm 157qmj BBK fly cutter, AND a homemeade baby brother for 139qmb 80-95cc BBK's

Anyway, I needed a little diversion today...this back is killing me, setting up appts is a PIA....yadayadayada should be done in a day or so, then back to Max.

[2strokd]

Great job Kliff, you are a heck off a machinist thats for sure. I have seen some of your other work too. Take care of that back, my dad has a bad back and over does it all the time then ends up in bed for 2 or 3 days.

[Rebel]

Most of us get back issues as we age, some like Kliff get real back problems. Get better guy, take care of that back you only get one.

[kliff]

Whoooooeeee, not much done this week on nuttin'! But this piece started off as a 4" dia X 5" long piece of steel.....since Monday it has sorta changed shape. Even had dad out there doing some turning for a couple of hours during the week.... slow but sure, metal removal like this, in steel just takes time...





A couple more hours here, then the arbor/ cutter holder, and it'll be done!

[kliff]

Getting there....slowly but surely. The store bought housing(150) is on the left, The homemade housing, (50), is on the right.... so far a 57mm piston is looking "doable" for a 50cc, if the crank bearing can be improved upon. But it would be a limitted life, race engine....don't even think street applications....to much crank and case stress, along with known bearing over loading, and heat is another factor that will show it's ugly head here.





But an Alky drag motor.....weeellllllll, now, that's a horse of a different color. How big would that be, 58mm by what, times who, when....huh.../

[Enviromoto]

hmmm the class would be 100c and under for the QMB, maybe we need a unlimited class for Kliff.

[kliff]

Jul 30, 2009 18:15:09 GMT -5 Enviromoto said:

hmmm the class would be 100c and under for the QMB, maybe we need a unlimited class for Kliff.

Oh I dunno.....what fun would racing yourself be? Maybe a transerance of some technology and machine work, for a few parts exchanges.... I could see where a mid-west meets south event, next summer could be fun, between a pair of alky burning "Big Bore Small Block QMB's"

;D

[Enviromoto]

sounds bitchin to me!

[Rebel]

So are you going to use top ends off a 150 to make these mighty mouses? Or is there any chance of the studs lining up, or would you just relocate them.

[kliff]

Jul 30, 2009 20:55:46 GMT -5 Rebel said:

So are you going to use top ends off a 150 to make these mighty mouses? Or is there any chance of the studs lining up, or would you just relocate them.

Nah....too easy. I'll bore out the stock cylinder to receive the largest sleeve I can press in, then bore out the case, get a final measurement on the smalles part of the new sleeve, which will be the tails, figure on a 1.5-2mm wall thickness, and size the piston form there. 58mm looks doable, though due to piston availability, we may settle on a 56, 57.25....it'll be interesting. Probably gonna need to make a head and case girdle to keep the top enf connected to the crankcase.... small alky motors tend to load up on liquid fuel during decel, sometime kicking compression to 20+:1 with liquid in the cylinder. Bad things can happen in the blink of an eye, if the top isn't reinforces..... or we could build for 104 Octane race gas, and for go the girdle....

decisions, decisions....

[kuzikood]

jeeze kliff i thought i had skillz , and im an arrogant jerk , but man you got me topped by so much i wanna be adopted by you ,.......... can i be your anakin and you be my palpitine show me the darkside of the force man come on'

[Rebel]

now don't give him a big head, his spine can't support the weight.

[Enviromoto]

lmfao! Good work kliff this is gonna be fun.. maybe