ESE's works engine tuner

[F5 Dave]

Well it's pretty simple to check. you obviously measured the top sticking out of the clamps & you can measure the btm of clamps to the dust seals. if out then damper rod 'issue', perhaps hanging up, or someone has been swaping bits before. if measure the same them something is on the piss.

As Henk sez loosening the clamp & spinning the tube will give the drunken axle wobble. I assume the axle is straight?

[TZ350]

.

Bucket was given the job of sorting the forks out. He found a collection of small errors that had all combined on one side.

In centralising the damper rod piston the rods had been unevenly shortened, the springs were slightly different and the new alloy pistons were unevenly pressed onto the damper rods.

All small errors but they added up.

Bucket corrected what he could and selectivly re-assembled everything else so the forks finished up the same length.

The axel was found to be ok and the tripple clamps were parallel.

The forks were turned until a sweet spot found and the wheel could drop easily under its own weight.

As always the fork caps tried to escape when Chambers was re-fitting them.

[TZ350]

.

A good day at Mt Welly. My first real ride in a year, tried my best to beat the guy coming last but failed miserably, still the 50 was lots of fun.

Avalon was peddling Chambers FZR-GP100 until it lost power, the culprit was a ring locating pin coming lose in the piston.

The exhaust port is 69% although not to wide it possibly was not easing the ring back gently/evenly but rather slamming one end of the ring against its locating pin.

When the pin came out the ring turned and the ring end chewed away at the side of the exhaust port.

Still the bike was going well enough to finish the race and even restarted and limped through the next one........brave little barsteds these 2-smokers

[Henk]

Hard on kit team ESE.

[Yow Ling]

Yea you guys are rough, I havnt blown up an engine since Friday !!!!

[Buckets4Me]

.

A good day at Mt Welly. My first real ride in a year, tried my best to beat the guy coming last but failed miserably, still the 50 was lots of fun.

so that was Keith Biddle you where trying to stay infrount of ?

.Avalon was peddling Chambers FZR-GP100 until it lost power, the culprit was a ring locating pin coming lose in the piston.


When the pin came out the ring turned and the ring end chewed away at the side of the exhaust port.

Still the bike was going well enough to finish the race and even restarted and limped through the next one........brave little barsteds these 2-smokers

So i should not have told her to ring its neck till the end and not worry about the clattering sounds coming form the bike

[SS90]

.


Avalon was peddling Chambers FZR-GP100 until it lost power, the culprit was a ring locating pin coming lose in the piston.

The exhaust port is 69% although not to wide it possibly was not easing the ring back gently/evenly but rather slamming one end of the ring against its locating pin.

When the pin came out the ring turned and the ring end chewed away at the side of the exhaust port.

Still the bike was going well enough to finish the race and even restarted and limped through the next one........brave little barsteds these 2-smokers

I like the transfer divider made out of devcon, it should help with the short circuiting on the odd rear transfer/Boost port set up the GP engines have, as well as increasing cylinder filling at high RPM.

Certainly better than nothing.

I can't help but notice the streaks coming up from the top of the exhaust port, almost like that port is too wide (hard to tell from just one image), do you measure the exhaust port width against the chord, or bore width alone?

My experience with that sort of streaking is "right on the limit" as far as width goes, and with the thin modern rings and piston you are using, normally up to 70% is quite safe, Plents of tuners with go more, but the chamfering on such cylinders is much much more than what I can see in the pictures.

I can't quite see the chamfering on the port though (perhaps the damage did away with all that).

It could also be that the somewhat square shape of the exhaust port makes with such as this too extreme.... perhaps the only slightly arched top edge, combined with the square sides is just too much for it all...... It certainly looks as though one side of the ring pushed against the pin causing the damage....my money is on the square sides of the port causing the problem.

If the problem persists, the 100% solution is to make a new liner, and include an exhaust bridge (among other things)

I also find that chamfering the rings grooves in the piston with a triangle port file helps alot too.

[Chambers]

Brought this to make a F5 racer, it has all the fruit like 2.5 and 3.5 X 17 wheels an aprilia engine that you can get good aftermarket chambers and bits for, only done 2.6K and registered. Paid $2.6k, its real fun to ride, and in the end I could not bring myself to convert it into a bucket, who could?...what was I thinking???? currently for sale on Kiwi Trader.........offers...pm me.

[Chambers]

Ok...another good idea that wasn't, an SDR200 runner, but not registered, VINed or road legal. Was going to have an engine transplant and run in F4, paid $1000, great looking frame and smart sporty looks, uses TZR 2.15F and 2.5R x 17" rims possibly good fun cheep trackday bike or fit a Lonkin 150 4-stroke for buckets, use the SDR200 engine in a go-cart. For sale on Kiwi Trader...........offers..pm me.

[TZ350]

Getting the best out of current setup Calliper Pistons must be un-seized, sliding pins free with high temp grease. Old setups should have pistons pumped out & seals carefully removed with a pick or small screwdriver down the edge but not skewering it. Clean out gunk behind pistons & white build-up in seal grooves (read up how to get them out). Clean totally. Inspect seals. Largely the main inner seals if undamaged will be fine if square in section. Outer Dust seals are less important, but if deformed can pull or jam the pistons causing excessive lever travel or dragging respectively. Replace as required. Corrosion damage to the pistons or the ally bores can often be dressed gently with pot scourer, but at some point are irretrievable.

F5Daves post on brakes is timely as we are cleaning up the brakes on my new FZR bucket. Check out his post as there is plenty of good info there…..we did.

After dismantling, the gunk is scraped out of the piston seal groves and from the back and sides of the piston seals themselves and the pistons cleaned up. Hot water or Meths washes out brake fluid and cleans up rubber parts and Kero or the like can be used to clean road gunk of the metal parts.

As the rubber used in brake systems swells and or rots when in contact with mineral oil or solvents like kero once everything is scraped and washed off it all needs to get a good rinse in hot soapy water to get rid of any oily residue and then rinsed again under the hot tap, then thoroughly dried.

Once every thing is clean it can be re-assembled using proper brake grease or brake fluid..….”but NOT Ordinary Grease or Oil”....... as anything mineral will ruin all the rubber parts in the brake system.

We have found that most times we are able to re-cycle the old rubber piston seals and you know if you got it all perfect when the piston seals suck the pistons back a few thou after you pull the brake on hard then release it.

Stripping and cleaning the brake system on any new project is pretty much a must. Even a lightly dragging brake, can easily have you off in a corner especially if its the front and its wet.

A champher around the edges of the brake pads makes it easy to get the disk back in when changing wheels.

[TZ350]

.

New front caliper mount for the bigger disk and progress on the new chamber that Chambers and Bucket are kindly helping me with. Bucket cut it out and rolled the cones and Chambers is welding it up, I get to hammer and dress up the welds, its not as good looking as those real nifty chambers that you see, but the internal shape and finish is pretty good.

[bucketracer]

Chambers and I are getting there with the new pipe for TeeZee. Chambers has welded it all up and it looks real good. Test fitting it, it has sufficent clearance from the front wheel when it is fully compressed and it fits under the engine as planned.

[bucketracer]

Crankcase Compression Ratios Revisited

Primary or crankcase compression ratio is determined by dividing the full crankcase volume including transfers with the piston at TDC by the crankcase clearance volume with the piston at BDC.

For a 125 the ratio will probably be some where between 1.3:1 and 1.5:1, also according to Blair it is very difficult to get a 50 above 1.4:1 and a 500 below 1.55:1.

Pic-01 the good old Suzuki GP125

Pic-02 I found greasing the piston crown and around the piston in the exhaust port then plugging it with paper towels sealed it up OK with out any leaks.

Pic-03 I used anti freeze and a measuring cylinder to measure the crankcase volume. After pouring the anti freeze in through the inlet port and wriggling the engine to get all the air out I found the full crankcase volume with the piston at TDC to be 470cc.

Pic-04 The engine simulation package Mota requires the crankcase clearance volume below the piston crown when the piston is at bottom dead center (BDC), excluding transfer duct volumes. From the bore and stroke and the transfer duct area of the engine being simulated and it works out the full crankcase volume for itself.

Crankcase compression ratio (Primary Compression Ratio).

Terms
Full crankcase Volume = FV
Crankcase Clearance Volume = CCV
Primary Compression Ratio = PCR
Engine Capacity = CC

Formula
FV/CCV = PCR

As
CCV = FV-CC

Then the formula becomes
FV/(FV-CC)=PCR

Then for the GP125 the primary compression ratio is…….

470/(470-125)=1.36

The Suzuki GP125 has a crankcase compression ratio or primary compression ratio of 1.36:1

[bucketracer]

I have found the MOTA Engine Simulation package very useful in giving us direction in engine development. Once you have measured and entered all the relevant dimensions of the engine the simulation package will give you an idea of the affect on the motor of any changes you make to port timing, pipe, carb etc.

Pic-01 A simulation of the GP engine with its restrictive 24mm carb at 1.3 (blue line) and 1.5:1 (red line) primary compression ratio showing the better overall crankcase delivery ratio for 1.5:1 with the original 24mm carb.

Pic-02 A simulation of the GP engine with a larger 28mm carb and 1.3:1 primary compression ratio and better delivery ratio with improved crankcase filling compared to the 24mm carb and 1.5:1

Pic-03 A MOTA simulation of the GP125 compared to a real dyno graph of the same motor. There is a difference in power and torque as the dyno is reading RWHP which is less than MOTA’s simulated crank HP. Also if the MOTA graph was stretched out more it would look more like the dyno graph but it is good enough to see that the shape of the curves are pretty close and the simulation is not a bad representation of the real thing.

So the moral of the story is, run a 100cc engine with a big carb or for a 125, a 24mm carb and plenum chamber like the one TeeZee is working on.

Sorry the pictures aren't in any sensible order, even when they are selected in order Kiwi Biker seems to load them randomly and I have had to change the order of the text to suit the pictures.

[SS90]

So the moral of the story is, run a 100cc engine with a plenum chamber like the one TeeZee is working on.

I almost forgot about that, how is that coming along?........