ESE's works engine tuner

[TZ350]

Bucket has found himself distracted by other interests.



So Darren fearing I might try to weld up the Wobbly Piranna myself offered to help.



After a weld Darren hammered the bead flat and rounded the join into a nice curve.



And yep the sections are still hot.

[TZ350]

Page 450 ....

EngMod2T

For something different Page 400 is going to be the basic info for building a 30+hp Suzuki GP125 taken from the EngMod2T simulation files.

Attachment 254400 Crank HP. Simulated Dyno Graph from EngMod2T using an early RS125 pipe.

Attachment 254399 EngMod2T's main screen for developing the model.

Attachment 254401 Basic engine dimensions.

Attachment 254402 Exhaust port dimensions.

Attachment 254403 Transfer port and duct dimensions.

Attachment 254404 Transfer port cylinder entry design and angles.

EngMod2T

Attachment 254407 Inlet port and disk timing info.

Attachment 254408 Early RS125 chamber layout.

Attachment 254409 24mm pumper carb and inlet tract model.

Attachment 254410 Combustion data for a flat top piston.

Attachment 254411 Air cool temp data.

Attachment 254406 STA's or Specific Time Areas.

[husaberg]

Combustion chamber effects
I was going back reordering some of the attachments i had previously posted. Yes i have finally figured how to do it now. shame they shut out the editing after about a month.

I came across this one as i was hoping some of the more learned types amongst the thread might pick up on what Cameron mentioned with the combustion and elaborate on it for the less academically gifted.
Wob mentioned at the time that Yamaha had their own ideas relating to squish and comp but didn't elaborate.
esp how the shapes and comp and squish clearance effect engine characteristics like acceleration.

Also what is the modern take (ie Aprilia) I am talking for high lead or low lead to if anyone wishes to expand on the subject.

Keihin carb on late RS125/250
Wob also mentioned the RS125 late model carb (i think he called it the.. sx?pic 2 below i guess is it) can anyone explain how it differs in detail from the earlier Keihins PWK's and the Electric PJ Keihins fitted to MX bikes? It looks like it can possibly deal with greater downdraft as well.

Splitters wings etc
Also i was hoping someone would have had some experience using one of the splitters power wings etc. My understanding is it seems that any obstruction upstream can effect the jetting on a two stroke to .........(bugger can't find my notes (Added below from the source a little latter) Where as an obstruction down stream..... (see attachment below from Robinson)
I have seen a few write up where these wings and similar clean up low speed carbuartion so are they a band aid for incorrect jetting? or just a new shinny bit for the Magpies.

Ceramic bearings
Someone (possibly Bert) regarding ceramic bearings a while back i said i had something to suggest that a lot of MX teams don't use them as they change their bearing too often to justify their use. this was the exert I was talking about.

I found this from one Retailer.

How do you get that Factory-Race bike advantage? One of the secrets is ceramic bearings that are used in nearly every AMA superbike, World Superbike, MotoGP, and Professional Drag Race Motors around the world! Less Weight, less friction and less surface wear equals more horsepower in your motor, simple as that.

Reduced Rotating Mass
The ceramic balls in these hybrid bearings are over 60% lighter than their steel counterparts resulting in faster acceleration and reduced inertial loads.

Low Friction - Less Vibration
The coefficient of friction for the ceramic balls is an average of 3x's lower than steel. When you combine this with the high tolerances for roundness you get a bearing that dramatically lowers vibration levels and produces more horsepower.
Preservation
Due to the unique properties of the ceramic balls these bearings have vastly reduced surface wear when compared to steel balls. The reduction in wear eliminates a large portion of the oil contaminates, thus prolonging lubricant life.

http://www.woodcraft-cfm.com/cgi-bin...&category=CBH3
But the price wow that would hurt even with the conversion rate of the current US peso.
Maybe the wheel bearings are Cheaper? What gains could you realistically expect from the engine would it be measurable? or from friction losses from the wheels.
I realise at the competition classes this sort of excess is common while chasing the last nano of performance.ESP when all the other bike are essentially the same as in 125 classes etc.

[wobbly]

The SPJ carb is sort of what is says , a Short version of the old PJ.
But there are a few imprtant detail changes, apart from the obvious power jet solenoid and TPS.
The emulsion tube has a short extension to the main jet that allows fitting different diameters, entering the tube after the main.
This changes the rate of change of the fuel curve and works a little like a bigger or smaller air corrector.
Bigger volume allows more fuel to enter the tubes well,at initial snap open of the slide, helping riders who like to get on it early.
But for gradual, smooth riders, it goes "fluffy" so no free lunch.

Ceramic bearings do exactly as they say - I have always used Micro Blue versions so can only speak about those.
A 50 Hp 125 will make around another 1.5 to 2 Hp with a full set, they last forever and work a treat.
In wheel bearings, a bike or kart will roll easily twice as far in neutral, after a plug chop.
Riders love not having to push back to the pit, and I love plug chops.
One thing I would like to try is to Micro Blue the surface of the sleeves where the seals run.
Seal friction is probably way bigger than the balls rolling friction, so this could be useful too.

Squish configuration is now set in stone, be it race gas or ULP.
As long as you have the tuning aids to overcome the natural effects.
50% SAR, combined with a vertical height that allows the piston to clip in the overev is the baseline.
This gives a VERY close optimum setup, be it domed or flat top piston, combined with a toroid chamber.
The domes like a bathtub ( confirmed by Frits ) and Yamaha factory bikes.
A flat top likes a re - entrant dropped plug shape, confirmed by HRC and me, many times.
Wide, close squish will always give great acceleration, but will restrict overev if you havnt got a digital ignition to pull out timing, and a solenoid powerjet to turn off the fuel past peak torque.
Without the tuning aids you have to juggle com,static timing and squish height, to get back the overev, if its needed for the application.

[dinamik2t]

50% SAR, combined with a vertical height that allows the piston to clip in the overev is the baseline.

Wob -and Frits-, you have our gratidute for sharing and explaining heaps of different stuff!
Troubling you a little more, could you use a different expression for that one? It must be a metaphor, but being in english, I didn't catch it. Would you mean 'to almost touch'?
Furthermore, an air-cooled engine can handle the same amount of msv with a water-cooled one? So far, my readings about MSV said that it shouldn't be higher than what the fuel octane can handle, otherwise extra-needless(?) heat would be created.

[F5 Dave]

he means, I believe. to touch or appear to touch its that close. On my 50 I have had it so close that it will totally clean surface of piston & head squish (0.5mm on the RG) but if I reuse the base gaskets (2 of) too many times you can actually hear it tinkle a bit on overrev. That is probably a bit too close so I change the gaskets, or rather don't reuse them more than twice.

[2T Institute]

One thing I would like to try is to Micro Blue the surface of the sleeves where the seals run.
Seal friction is probably way bigger than the balls rolling friction, so this could be useful too.

Hey Wob, looks like finaly found that one thing you haven't heard about.

http://sharkshifter.com/zc/index.php...roducts_id=810

Most seal manufacturers can make them, seal friction is very high these make a massive difference

[bucketracer]

Troubling you a little more, could you use a different expression for that one? It must be a metaphor, but being in english, I didn't catch it. Would you mean 'to almost touch'?

This is what it looks like, pictures of TeeZees piston and head, he can shim the barrell so the piston just touches, kisses, clips or skims the head on over run.

The carbin on the squish area of the pistion is polished, more so on the back where it rocks over TDC, the little pock marks are made by ingested dirt being trapped between the piston squish band and head and leaving little craters.

When TeeZee is setting it up he allows about 0.5mm for rod stretch on overrun at max rpm and he talks about static and dynamic squish clearance.

[husaberg]

This is what it looks like, pictures of TeeZees piston and head, he can shim the barrell so the piston just touches, kisses, or skims the head on over run.

Kisses metaphor probably isn't helping either Bucket?

Kisses,Touches. skims ,head on over. TZ said you were a little distracted.

Bucket has found himself distracted by other interests.

The SPJ carb is sort of what is says , a Short version of the old PJ.......
Ceramic bearings do exactly as they say - .......
Squish configuration is now set in stone, be it race gas or ULP.A........

Thanks Wob

So you would use them in preference to phenolic bearings
do you have a pic of the extension tube in the carb also do they allow more downdraft i believe some KTM and the KX125 99ish reputably ran the shorty version as well but with differing PJ outlet and possibly(likely) other changes no doubt.?


So that just leaves the Powerwing Splitter anyone?


Re seals
I am pretty sure i posted the Greeves solution to the seals a while back Std Honda Parts too.(only used on Works bikes and factory supported racer mind you.)
I can't remember what they were worth in HP.... something along the lines of 1.5-2 HP out of 30 i think. Lasted forever as well though.
This was pre admittedly telflon days though.

http://www.lortim.demon.co.uk/vsih/cranksha.htmWhen 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.

Grumph or one of our Euro contributers will have a pic or diagram of them i am guessing but the explanation is pretty simple, the fitting into a modern engine less so.looks like this only less rings


Teflon ones from 2tinsitutes site he found include
HS_30
Seal crank clutch side R/H Honda 125 Carbon Teflon
Honda CR 125 right hand crank seal Carbon / Teflon 30x45x7mm low drag best seals available
$10.00

HS_22
Seal crank clutch side R/H Honda CR80 / 85 Carbon Teflon
Honda cr 80/85 right hand crank seal Carbon / Teflon 22x40x7 mm low drag best seals available
$10.00

HS-20
Seal Crank Ignition side L/H CR 125 & 80/85 Carbon Teflon
Seal Crank Ignition side L/H CR 125 & 80/85 Carbon Teflon 20x32x7mm best seals low drag available not legal in spec stock moto
$10.00

HS-17
Seal output shaft CR 80 & 85 Honda Teflon Carbon
Honda CR 80 / 85 counter shaft seal 17x28x6mm Teflon carbon best seal available low drag
$10.00

HS-26
Seal output shaft 99 CR 125 Honda Teflon Carbon
Honda CR 125 counter shaft seal 90 to 06 motors 26x37x6mm Teflon carbon best seal available low drag not spec stock legal
$12.00

You can't argue with the price i guess.Cheaper than std Honda

But doesn't seem useful for a MB100 or even a Nsr125 such as Vanessa.bugger


RS125 oil seal and crankcase seals sizes attached below
forgive any errors it bloody late Wob.
Source they have all sorts of parts manuals and service manuals etc.
http://www.rscycles.com/pdf_partsbooks.htm
I do not part centre code 166 is CR80 the air cooled of around 1980 which shares parts with the MB5 and MB100 series.

[wobbly]

The carbs of the MX bikes with the Powerjet and TPS all have the air guides in the bellmouth in front of the slide.
This kills a heap of flow compared to an SPJ, but does give good response down low ( worth a couple of Hp on a RS125 in the top end for example ).
The flow thing isnt really an issue for a bucket motor as they are only made in 36 and 38mm - so plenty big enough to get the flow back with area.
The SPJ will handle more downdraft due to the Powerjet fuel pickup point in the bowl.
The MX ones have an issue with this as the suction point is right at the back of the bowl and would not be under water if tipped up too far.
I posted a pic of the fix a while ago.

Are the teflon seals for the RS125 kit, available in a range of sizes ie where do they come from.

You dont want the piston hitting during normal running,just short of a hit is whats needed at the peak rpm you would normally see on track - often when idiot riders bash the shift pedal on the overun into corners,
with no dynamic com pressure at work.

Saw an amazing ride in the weekend.
A 70+ guy now holds the lap record for post classic pre 82 Junior at Pukekohe,on a C model TZ350.
Im sure the toroids made a difference,but even with Dual Carbon pads you have to know how to go down inside 4 bikes at a time into the hairpin.
Poetry in motion on a bike - makes all the hard work seem easy.

[teriks]

While on the topic of seals, I'm thinking the SKF speedi-sleeve might be useful in bucket racing.
Anyone tried these yet?

http://www.skf.com/portal/skf/home/p...&newlink=4_5_3

SKF SPEEDI-SLEEVE

This thin-walled sleeve [0,28 mm (0.011 in.)], developed by SKF, is simply pushed in position over the worn area, providing a counterface surface that is optimized for radial shaft seals.
There is no shaft disassembly or machining involved and costly downtime is minimized. Since the same sized seal as the original can be used, there is no need to search for other seals, or keep a stock of different sizes.
No special equipment is required since the installation tool is supplied with the sleeve. A mallet and a pair of pliers are all that is needed for the installation.

Features
The new generation SKF SPEEDI-SLEEVE uses a proprietary stainless steel material and manufacturing process, resulting in an optimized seal counterface surface that minimizes wear on both sleeve and sealing lip. The proprietary material provides increased strength and excellent ductil ity properties of the sleeve. Imperceptible lubricant pockets enable the lubricant to reside on the sleeve and thereby prevent dry running of the sealing lip that otherwise can create excessive wear. The contact surface is wear resistant and machined to minimize directionality (0° ±0,05) with a finish of Ra 0,25 to 0,5 µm (10 to 20 µin.). This is, in fact, a better counterface surface than can often be achieved on a shaft.

SKF SPEEDI-SLEEVE has a removable flange to simplify installation (fig). The flange can most often be left intact, but in applications where the flange will interfere with other system components, it should be removed so as not to cause friction heat and wear debris. The flange should also be removed in applications where it may reduce the supply of lubricant to the seal. This would reduce the cooling effect of the lubricant, resulting in elevated underlip temperatures and premature ageing of the seal material.

If the flange is to be removed, it should be cut from the outside diameter into the radius in one location prior to installation. The flange can then be twisted and raised up after installation and grasped with a pair of long-nosed pliers and twisted into a coil.

Size range
The standard size range covers sleeves for shaft diameters from 11,99 to 203,33 mm (0.472 to 8 in.). Depending on production quantities, non-standard sizes can be manufactured. Each sleeve is designed to fit a specific shaft diameter range, usually above and below the nominal shaft diameter. This permits some flexibility to accommodate variations in the actual shaft diameter.

Also available in a coated version, gold indicates TiN.

SKF SPEEDI-SLEEVE Gold (fig) is an enhanced version of standard SKF SPEEDI-SLEEVE, offering improved resistance to abrasive wear. Designed for applications where extended sealing system life is needed, SKF SPEEDI-SLEEVE Gold bridges the performance gap between the standard sleeve and expensive custom shaft treatments. A thin, metallic coating applied to the base stainless steel imparts a gold colour and significantly increases durability. SKF SPEEDI-SLEEVE Gold is particularly effective in environments where there are abrasive contaminants, especially when combined with a seal manufactured from the SKF fluoro rubber material, SKF Duralife.

The installation procedure is identical to that of standard SKF SPEEDI-SLEEVE and the original seal size can still be used.

Test results
SKF SPEEDI-SLEEVE Gold has been thoroughly tested to establish its level of abrasion resistance in severely contaminated environments using both coarse and fine sand (diagram). The tests were carried out at temperatures up to 110 °C (225 °F) and at shaft speeds up to 8,6 m/s (1 700 ft/min). Under these conditions, seals on SKF SPEEDI-SLEEVE Gold ran for an average of 2 500 hours.

Size range and availability
SKF SPEEDI-SLEEVE Gold is available in the same sizes as standard SKF SPEEDI-SLEEVE.

[F5 Dave]

. . .
The SPJ will handle more downdraft due to the Powerjet fuel pickup point in the bowl.
The MX ones have an issue with this as the suction point is right at the back of the bowl and would not be under water if tipped up too far.
. . .

But will the excessive lean cause the pilot cct to flood?

[F5 Dave]

While on the topic of seals, I'm thinking the SKF speedi-sleeve might be useful in bucket racing.
Anyone tried these yet?

Also available in a coated version, gold indicates TiN.

Sounds interesting although low friction isn't being heavily pushed as an advantage. One may consider on small shaft sizes you would have considerably more spring pressure as the thin sleeve is a larger percentage of the dia than on a bigger shaft.

If the sizes were available you could machine your shaft & press fit the sleeve on. . . .Actually having said that I have a crank that has a goove in it currently. Mind you the thread end is a bit mullered so I was going to use another crank next build anyway.

[wobbly]

You cant run as much down angle as a Lectron or FCR type ( RGV250 carbs are good ) but the SPJ will run with alot more than most carbs without flooding via the idle circuit.
They cost a bloody fortune though.

[teriks]

Sounds interesting although low friction isn't being heavily pushed as an advantage. One may consider on small shaft sizes you would have considerably more spring pressure as the thin sleeve is a larger percentage of the dia than on a bigger shaft.

If the sizes were available you could machine your shaft & press fit the sleeve on. . . .Actually having said that I have a crank that has a goove in it currently. Mind you the thread end is a bit mullered so I was going to use another crank next build anyway.

Salvaging grooved shafts was indeed my main thought, any increase in seal life and/or reduced friction could be a side benefit.