ESE's works engine tuner

[TZ350]

Making progress with the six speed Suzuki GP110cc engine. Spent my evenings after work for the last couple of weeks test assembling everything to make sure that they fit and the clearances are correct. Lots and lots of detail work has been required to get things right.



Micro polished gear-set courtesy of Morgan Engineering.



Lots of port area. Exhaust opens 80 atdc transfers open 114-116-117 atdc and inlet opens 145 btdc and closes 80 atdc. No porting work has been done on the cylinder at all. The port timing has been obtained by adjusting the cylinder up and down with a spacer plate and shims until I got the timing that EngMod suggests as being optimal.

Between the variable timing of the exhaust port power valve and a pressure reducing valve in the expansion chamber I hope to get a wide spread of useful power.

The inlet tract is a nominal 30mm with a short 24mm venture restriction at the engine end of the carb to satisfy class regulations. From previous experience, I am not expecting the venture restriction to have much real effect on power output.



Major crankcase volume, it will be interesting to see how that goes. Slow speed injector port on the right hand side. The injector port is angled so the injection stream fires directly into the face of the incoming inlet air stream. The timing of the injection squirt can be adjusted in the EFI software for best effect.



The top of the cylinder was skimmed 2mm and the head insert also protrudes into the cylinder 2mm. The insert itself is a blank that can be machined to what ever combustion chamber you like.

The beauty of reducing the stroke on a 2T motor is that even without any porting on the cylinder, the exhaust blowdown time area is automatically increased.

I was unsure about the legality of using a VHM head but no where on the paperwork does VHM call it a racing part. It is clearly labeled as being for a NSR250 which is a class legal non competition engine.

[peewee]

Engines with crap transfer ducts need the ratio up closer to 1.4.

mines barely over 1.3 with vf4 which seems to be some of the thinest petals ive seen. any predictions how it will turn out since it isnt running yet ? incase it doesnt go well ive got plan B which is higher wristpin pistons

[mr bucketracer]

Making progress with the six speed Suzuki GP110cc engine. Spent my evenings after work for the last couple of weeks test assembling everything to make sure that they fit and the clearances are correct. Lots and lots of detail work has been required to get things right.



Micro polished gear-set courtesy of Morgan Engineering.



Lots of port area. Exhaust opens 80 atdc transfers open 114-116-117 atdc and inlet opens 145 btdc and closes 80 atdc. No porting work has been done on the cylinder at all. The port timing has been obtained by adjusting the cylinder up and down with a spacer plate and shims until I got the timing that EngMod suggests as being optimal.

Between the variable timing of the exhaust port power valve and a pressure reducing valve in the expansion chamber I hope to get a wide spread of useful power.

The inlet tract is a nominal 30mm with a short 24mm venture restriction at the engine end of the carb to satisfy class regulations. From previous experience, I am not expecting the venture restriction to have much real effect on power output.



Major crankcase volume, it will be interesting to see how that goes. Slow speed injector port on the right hand side. The injector port is angled so the injection stream fires directly into the face of the incoming inlet air stream. The timing of the injection squirt can be adjusted in the EFI software for best effect.



The top of the cylinder was skimmed 2mm and the head insert also protrudes into the cylinder 2mm. The insert itself is a blank that can be machined to what ever combustion chamber you like.

The beauty of reducing the stroke on a 2T motor is that even without any porting on the cylinder, the exhaust blowdown time area is automatically increased.

I was unsure about the legality of using a VHM head but no where on the paperwork does VHM call it a racing part. It is clearly labeled as being for a NSR250 which is a class legal non competition engine.

whats with this buying heads .gpr boys make them

[TZ350]

whats with this buying heads .gpr boys make them

Yea I know, buying one, totally piss poor of me ... ... your head work looks great, very impressive.

[jonny quest]

Curious, why did you use a NSR barrel TZ?

[2T Institute]

135/90 disc timing will make better mid range and top end

[jasonu]

Curious, why did you use a NSR barrel TZ?

My guess is because he already had one in a box somewhere...

[SwePatrick]

About HCCI ignition(i think)
I have built a new engine(not fully complete yet)
Test started it this weekend.

It´s an Kawasaki KX250 downstroked to 211.9cc(due to regulations in swedish dragracing)
However, i was so eager to hear the engine spin even though the pipe isn´t ready yet.
So i started it anyway.
And note, the exhaustvalves wasn´t in place, the guillotine therefor left a big hole downwards in exhaustport(no lid on either)

Engine started nicely but started to rev out of control almost directly.
Tried to stop it, pulled the cord to the stop button, nothing happened.
Placed hand onto the carburetor, nothing happened.
With hand still on carb and full throttle engine lowered the speed.
Had to shut off fuel to get it to stop.

Later, put back all exhaustports and started engine with no other adjustment.
It ran nicely on idle.

Quite interesting experiance

I figure the exhaustpulses drew fresh air into cylinder through guillotineport.
And even though i had hand on carb it still drew fuel enough to get a burnable mixture.
But, interesting is that what i think it almost directly triggered HCCI.

Rgds.

[TZ350]

Curious, why did you use a NSR barrel TZ?

My guess is because he already had one in a box somewhere...

Pretty much true …. like all good Bucket racers, plenty of junk in a box under the bench.

Curious, why did you use a NSR barrel TZ?

The F4 F5 (Buckets) is a formula road racing class with a mix of small capacity four and two strokes where the engine/gearbox components have to be sourced from a non-competition engine, no road racing or MX allowed except for a few specific exceptions like piston and ignition.

It used to be in F4 that a water cooled two stroke could only be 104cc max oversize but to make things easier/cheaper for themselves some bright spark got the re-bore allowance increased to 110cc but restricted to a 24mm carb.

Here in New Zealand the RGV250 and NSR250 were popular road bikes. Some people sleeved the 56mm RGV cylinder down to get their 104cc, I guess because it had easily modified power valves to suit the smaller bore.

But now that 110 is allowed using an old re-bored (re-plated) cylinder and de-stroking is an easier to meet the class rule. So I have recycled my old GP100 bottom end and shortened it’s 50mm stroke to 48mm and fitted a re-plated (re bored) 54mm NSR250 cylinder. That way, at 110cc I still have the same bore/stroke ratio as I had with my original Suzuki GP125 air cooled motor. Not ideal, square would be ideal but at least workable.

135/90 disc timing will make better mid range and top end

Yes, this temps me because, on the dyno I have seen the air/fuel mixture bouncing back of the closed rotary valve at 80 and 85 deg atdc so maybe 90 will allow a bit more to be squeezed in (TZ’s were 90/90) and I agree opening 135 btdc is more the norm than 145.

[jonny quest]

I didn't realize you couldn't use MX cylinders. Surprised at that. They're popular, and would be a cost effective means.

That's why I asked TZ. The NSR cylinder is decent, but CR is better.

[TZ350]

I didn't realize you couldn't use MX cylinders. Surprised at that. They're popular, and would be a cost effective means. The NSR cylinder is decent, but CR is better.

Agreed a CR125 cylinder or complete engine would be much better and possibly cheaper (in time anyway) but the Bucket non competition thing is a deliberate self inflicted inconvenience for the sake of keeping things relatively cheap for racing with the spin off of learning something about engine tuning and engineering in general.

An objective of the Bucket racing rules is to oblige you to earn your competition hp by building something clever out of non competition engine bits, and to prevent you from taking the easy way out by buying factory made hp, there are other racing classes for that.

[lodgernz]

Agreed a CR125 cylinder or complete engine would be much better and possibly cheaper (in time anyway) but the Bucket non competition thing is a deliberate self inflicted inconvenience for the sake of keeping things relatively cheap for racing with the spin off of learning something about engine tuning and engineering in general.

One of the Bucket objectives is to oblige you to earn your competition hp by building something clever out of non competition engine bits, and not to take the easy way out of buying factory made hp, there are other racing classes for that.

Beautifully and succinctly put TeeZee.

[Frits Overmars]

Agreed a CR125 cylinder or complete engine would be much better and possibly cheaper (in time anyway) but the Bucket non competition thing is a deliberate self inflicted inconvenience for the sake of keeping things relatively cheap for racing with the spin off of learning something about engine tuning and engineering in general.
An objective of the Bucket racing rules is to oblige you to earn your competition hp by building something clever out of non competition engine bits, and to prevent you from taking the easy way out by buying factory made hp, there are other racing classes for that.

Beautifully and succinctly put TeeZee.

Same here. I like both the Bucket philosophy and the way you described it Rob.

[jonny quest]

http://www.greencarcongress.com/2016...-anltribo.html


Researchers at Argonne National Laboratory have discovered an ultra-durable, self-lubricating tribofilm that regenerates in the presence of oil, heat, and pressure—meaning that it will not wear away over the life of an engine. The film, reported yesterday in the journal Nature, develops when a new catalytic coating that can be applied to engine parts interacts with lubricating oil to create an extremely tough coating that almost eliminates wear.

Tests revealed the diamond-like carbon (DLC) tribofilm reduced friction by 25-40% and that wear was reduced to unmeasurable values. The discovery could have implications for the efficiency and durability of future engines and other moving metal parts that can be made to develop self-healing DLC tribofilms.

This is a very unique discovery, and one that was a little unexpected. We have developed many types of diamond-like carbon coatings of our own, but we’ve never found one that generates itself by breaking down the molecules of the lubricating oil and can actually regenerate the tribofilm as it is worn away

[2T Institute]

Agreed a CR125 cylinder or complete engine would be much better and possibly cheaper (in time anyway) but the Bucket non competition thing is a deliberate self inflicted inconvenience for the sake of keeping things relatively cheap for racing with the spin off of learning something about engine tuning and engineering in general.

An objective of the Bucket racing rules is to oblige you to earn your competition hp by building something clever out of non competition engine bits, and to prevent you from taking the easy way out by buying factory made hp, there are other racing classes for that.

Only problem is that the pile of broken/discarded bits is twice the cost of a competition engine and still fragile at the limit. You do learn a lot that is true but taking an an already highly tuned and developed engine and increasing it's output is much steeper learning curve than hotting up a mudbug.