ESE's works engine tuner

[ac3_snow]

But when Snow initially checked it.....

Much better said than I could manage. Engine runs a whole lot smoother now, still cracked the last exhaust but that was because it wasn't rubber mounted, more than the engine vibrating too much. New pipe is spring and rubber mounted now, holds up well. Might consider adding...or removing a little weight to see what happens.

Liquid flux I got is working ok, just need to soak it for a good few hours then it picks off fairly easy. Stuff I got is only 7.5% hydrochloric acid so takes a little while.

Interesting crank cases

[wobbly]

The oiling isnt an issue if you look at the SwissAuto and the kart engine, they simply have a hole - down from the case duct.The big end/washers are directly exposed to the incoming flow so no problem there.
I believe the hole simply allows the pulsing flows in the case to access the bearing from the crank side - if the bearing was in a blind pocket,there would be no reason for the suspended oil mix to flow into the closed cavity.
The SwissAuto is basically the same engine as was used by the Pulse Team,Bill Buckley owns one so I know all about the insides of those.
Case reed engines always used to have large volumes,and the RG when a 125 was too big anyway - so reducing the swept volume down to 100cc means we run into even more of an issue.
The latest engines like CR250 have a very small ,wide rectangular "window" from the reed box into the case,so I am trying to replicate something similar.
I will fill in the floor in front of the reed and continue this higher floor thru over the covers - next is some alloy plates screwed onto the crank,around the pin, to simulate a full circle web,and when the pistons arrive - do the balancing.
Using alloy will increase the crank inertia,good for drive out of corners and adds to overev power.

Edit - read here - interesting 2T developments http://www.european-2strokecup.com/

[husaberg]

Edit - read here - interesting 2T developments http://www.european-2strokecup.com/

Anyone remember the diehards eccentrics who used to race there outclassed 4 strokes in events such as the Thumper Nats.
How times have changed. not for the better I might add 2 strokes killed of in most forms of competition based on unfair rules and dubious science based on emissions .
It seems the two strokes are the eccentrics now.It's not fair.

[wobbly]

Dont call me eccentric - cheaky fucker - my hole is in the MIDDLE.

[husaberg]

Dont call me eccentric - cheaky fucker - my hole is in the MIDDLE.

When anyone quotes a claim posting of a pic of it is required. I say please no picture please Wob

Plus any more than 2 stroke's is Masturbation too.

re the coment below I read the entire thread it took a about a month but the thread tools option is certainly a good way to speed things up.You can also maximise the posts per page too speed things up ie less pages to look through.

[Grumph]

I haven't read the entire thread - I doubt anyone could - but balance factor discussion caught my eye.
The "conventional" factor of 50% plus works on upright cylinders - it makes them shake in the plane of the cylinder, ie up and down...this is generally the preferred direction as most frames are capable of damping vibrations in ths plane.
On horizontal cylinders an inverse balance factor is used. 25 - 28% works very well.This will make the motor shake at right angles to the plane of the cylinder...ie the preferred "up and down" direction...
FWIW I understand that parallel twin TZ's were around 33%....angled cylinders do make a difference.
It ain't simple....

[bucketracer]

From the twostrokeshop

I don't want to lapse into too much tech-babble here; suffice to say, a crank that is 'under-balanced', such as the YPVS/Banshee crank, tends to create oscillations/vibrations in the vertical plane. This, for anyone who has ever converted an LC or YPVS 250 to a 350, is exactly the type of stronger vibrations you feel when switching from the 250 to the 350.

A crank's Balance Factor is typically expressed as a percentage figure. Normally the balance factor on a twin such as the RD is set at 50% to 55% of the total reciprocating mass - in this case 342g - so this would need 171g for the 50% case and 188g for the 55% case.

More on crank balance here. http://www.twostrokeshop.com/RZRD350...fts.htm#sermon

Interesting look at TZ cranks. http://www.twostrokeshop.com/RZRD350...rankshafts.htm

And the different wear results of different B/E brg cages. http://www.twostrokeshop.com/peek_co...nd_bearing.htm

[bucketracer]

I think someone has posted this before, but I couldn't find it so here it is again.

http://www.saltmine.org.uk/shoeman/shoeman.html

Interesting read about tuning RD's.

[Yow Ling]

Heres an interesting crankcase pumped diesel. http://thekneeslider.com/archives/20...stroke-engine/

[Yow Ling]

Not much on TV tonight I found these on the net

[husaberg]

Not much on TV tonight I found these on the net

Seeing it is a slow news night have a look here some intersting stuff in the gudgeon pin stuffers and the scilencers and carbs etc.
http://www.villiers.info/Go to the tunning info bit on the left.

An excert of the gudeon pin stuffers are here.

As the piston descends and before the transfer ports are uncovered, a hollow gudgeon pin will bleed off some of the primary pressure that you have fought to create. The hollow pins should be plugged with an alloy slug or slugs which should have no more than a 1 thou clearance fit and be coated with Loctite or similar. Interference fits will swell the gudgeon pin causing fitment problems. The lack of interference fit is required to allow the Locktite to key and bond, a zero or interference fit will not allow the Locktite to work properly. At racing speeds, the difference in power can be measured on the dynamometer

Old school real deal Lab seals

When the Greeves Silverstone was first introduced it was recommended that the crank seals were changed after every meeting, as the wear rate was so high on the racing engine. The modern solution is to use Teflon coated oil seals. Before the times of Teflon coatings, Brian Woolley came up with an answer that not only worked but increased the time between servicing. His method entailed the use of Honda C50 piston rings to form labyrinth seals in place of the rubber seals. The rings were held in position by a steel sleeve which was a press fit into the crankcase, running in a slotted alloy carrier that rotated with the crank, the rings stopping any gas flow much in the same way that they do on the piston. As the seals on the standard 9E cases are smaller than the Greeves cases this modification may be a difficult one to embody without resorting to machining the seal housings, but for someone with machining know how it may be a feasible project. On the drive side the labyrinth seal can be located between the two bearings, the slotted carrier doubling as the bearing spacer. The original rubber seal can be left in position, and the outer bearing fed with lubricant from an external reservoir, or fed from the primary chaincase. The same technique can be employed on the timing side, if the 11E double bearing set up is used.

[ac3_snow]

And the different wear results of different B/E brg cages. http://www.twostrokeshop.com/peek_co...nd_bearing.htm

Thats quite interesting. does anyone use these, PEEK coated bearings, are they available as little end as well?
While on the topic of bearings.. Does any one use these 'cylindrical roller bearings' I realise that buckets obviously don't acheive any where near the high horse power they are refering to at twostrokeshop, but would they have an increased life over roller ball bearings?
taken from "http://www.twostrokeshop.com/RZRD350_Banshee_TSS_Crankshafts.htm"

An excert of the gudeon pin stuffers are here.

Also very interesting! Wonder if a bit of epoxy to fill in the ends would last a while.

[husaberg]

Also very interesting! Wonder if a bit of epoxy to fill in the ends would last a while.

F5 dave mentioned earlier teflon or similar buttons i think

[Kickaha]

F5 dave mentioned earlier teflon or similar buttons i think

Chocolate buttons?

[Yow Ling]

Chocolate buttons?

Would need to be matched with the chocolate valves in your GN