ESE's works engine tuner

[peewee]

22x53 is what i bought. i know its a 22mm diam but i couldnt get my calipers in there to check the length so i guessed (crank is still assembled). ill go see if i can find someway to measure the length and report back if these pins are the right ones

i swear i thought frits said not to have any holes, voids, cavities in the crankshaft assembly. something to do with harmonics maybe ? or bad frequencies ? hell i cant remember. ive noticed some hollow pins use caps, thats why i was asking if its better to keep the solid pins. i have some 22x55 hollow pins i can cut down but they dont have caps on the ends

[wobbly]

If the crank was designed correctly for hollow pins then solids will be real tight on the press fit.
Frits is right about cavities, but he is talking about large balance holes etc being hollow - the small volume created by a pin hole would be insignificant
unless you are wanting to win Moto GP.

[Flettner]

Any thoughts? piston 2 is fine, piston one? sudden advance! There is a story that goes with this picture, as you could imagine!

[Neal]

Pre ignition ?

[Tim Ey]

Thanks a lot wobbly!

Have you tried a 6-Petal reed instead?
My guess my Problem with a 6-Petal reed would be the flow not to be separeted once but twice.
On your reed you are free to ad a straight divider in the middle and be safe. Your area distribution can be made by your stuffer.
At a 6 Petal reed these dividers will have to be curved to get a constant area from outside to inside... You see an attempt to do so on Vforce2 + 3 reeds quite often...
Am I thinking right?
cheers!
Tim

Edith: Just found a YZ250 Reed in my spare box which fits perfectly into the screw-on box - with 4 petals :-)

By the way? How did you put your reed on a flow-bench? Just simply let air flow through it statically on a classical flow bench and take a look at the Cd's and how the plates open? Or did you build yourself some oszillating-flow bench?

[Frits Overmars]

Any thoughts?

Yes, about golf: hole in one.

[peewee]

If the crank was designed correctly for hollow pins then solids will be real tight on the press fit.
Frits is right about cavities, but he is talking about large balance holes etc being hollow - the small volume created by a pin hole would be insignificant
unless you are wanting to win Moto GP.

naw the crank originally used solid pins. gonna pull it apart and use different rods. ill use these new solid pins as well i guess

[seattle smitty]

I see Chambers has a few V8 side valves. Not one of Chambers engines, just posted here because we like it. We would love to run one at Bonneville.

I have a 1941 Lincoln Continental V12 coupe. An engine with all of the faults of the Ford flathead X 1.5, sad piece of junk that most Connie owners replaced by the early Fifties with Cadillac V8s, as mine has. In the interest of having an actual V12 in the car, I'll eventually replace the Cad with a Jaguar sedan V12 if I live so long.

Flettner, that's a curious failure, got so hot the crown finally collapsed, melted out and not blasted out, yet from what I can see of the skirt, it didn't try to seize and skid there . . . so it would seem to me that the piston was made with plenty of taper and had good lubrication. Did you get an air-leak lean-out?

[Flettner]

Re the pistons, first there was the ignitec, two lobes and one sensor with one lobe having a slot so the ignition can tell cylinder two from cylinder one. This set up had a clear timing light signal on cylinder one but always cylinder two seemed " goasted". this set up had the engine running rough and within a short time a holed piston! So I took the ignition out and fitted the whole thing to my CNC mill spindle so as to run it up to 10000 rpm and watch what was happening. Cylinder one smooth and perfect advance and retard, cylinder two timing was all over the place, no wonder it holed a piston.
Next setup I decided to use my old home made CDI with no advance retard, single sensor, two pins on the flywheel with wasted spark. Engine runs smooth ( best ever ) and can hold it at 6500 under load for as long as you want, no problems at all. I ran the engine like this for a while but it was time to get the engine flying so I didn't want this home made ( and rough at that ) ignition in the sky, highly likely to fail.
So I fit the ignitec again but this time with two pickups ( 180 degrees apart ) and a single flywheel pin. I watch the timing on cylinder one and two with the light ( up to about 4500 rpm ), all is well if perhaps a little advanced ( due to me not understanding how the base timing works ) but not advanced enough to case massive failure ( as in the picture ). I run the engine up watching temps and am happy all is well, no problem, no detonation, 6000 rpm suddenly ( instantly ) the engine coughs and stops, first time up to 6000 rpm with this setup.
After some thought ( and some bad words ) I come to the conclustion that the cylinder one pickup probably should not have been placed right next to the bob weight. Seems the bob weight ( steel ) as it speeds up will start to cause fluctuations in the magnetic core in the pickup to a point where it becomes enough to trigger the ignitec, at a point way in advance of where ignition should be. Bugger, see what happens when you only know enough to be dangerous.
The new engines will have the pickups placed somewhere completly inert to outside influences.

[wobbly]

I wasnt going to say anything as we had already discussed the issue but there are two things going on that need description to help others.
Firstly is the Ignitech, until you actually think long and hard about what the Base Timing does it may NOT be intuitive, but is perfectly logical, that when
you INCREASE the base advance number YOU ARE RETARDING THE ACTUAL FIRING POINT.
Thus if its firing advanced ( that is the rotor reference line is still ahead of the stator line ) when the strobe fires - you must INCREASE the base advance to get the lines to align.
So if say you have 10* in base and a pair of lines marked at 10* on the rotor/stator, and you see that the rotor line is 5* ahead of the stator line, then the actual firing point is 15*.
To tell the computer exactly where the firing point is in reality, you need to add 5* to the base advance to retard the timing back to where it should be.
Thus in this case you increase the base to retard the timing.


The second point re the two pistons.
A hole like that can be created by 2 things, too much advance and or too lean A/F ratio.
But the actual cause of the hole is that the plug body is being overheated, and there is local detonation due to preignition of the combustion being initiated by a red hot earth or centre electrode.
This points to the plug being too hot to start with, or the cooling around the threads is insufficient.
If you somehow run too much advance, or run too lean, the piston as a whole should overheat and seize and or the end gases in the squish detonate and kill the piston edge.
The hole is a symptom of a secondary plug issue - the excessive advance just highlighted the fact you have a problem there that is lurking, in even a normal running engine.

EDIT - only just saw the comment - there is no such thing as an air leak lean out.
If here is a leak anywhere in the case of a 2T it will run rich, the only place a leak can cause leanness is between the carb and a reed, where extra air is sucked into the stream that already has fuel.

[Flettner]

The second point re the two pistons.
A hole like that can be created by 2 things, too much advance and or too lean A/F ratio.
But the actual cause of the hole is that the plug body is being overheated, and there is local detonation due to preignition of the combustion being initiated by a red hot earth or centre electrode.
This points to the plug being too hot to start with, or the cooling around the threads is insufficient.
If you somehow run too much advance, or run too lean, the piston as a whole should overheat and seize and or the end gases in the squish detonate and kill the piston edge.
The hole is a symptom of a secondary plug issue - the excessive advance just highlighted the fact you have a problem there that is lurking, in even a normal running engine.

Even if the timing goes to 60 degrees advance, instantly at 6000 rpm. ( only on this one cylinder )

[RAW]

I wasnt going to say anything as we had already discussed the issue but there are two things going on that need description to help others.
Firstly is the Ignitech, until you actually think long and hard about what the Base Timing does it may NOT be intuitive, but is perfectly logical, that when
you INCREASE the base advance number YOU ARE RETARDING THE ACTUAL FIRING POINT.
Thus if its firing advanced ( that is the rotor reference line is still ahead of the stator line ) when the strobe fires - you must INCREASE the base advance to get the lines to align.
So if say you have 10* in base and a pair of lines marked at 10* on the rotor/stator, and you see that the rotor line is 5* ahead of the stator line, then the actual firing point is 15*.
To tell the computer exactly where the firing point is in reality, you need to add 5* to the base advance to retard the timing back to where it should be.
Thus in this case you increase the base to retard the timing.


The second point re the two pistons.
A hole like that can be created by 2 things, too much advance and or too lean A/F ratio.
But the actual cause of the hole is that the plug body is being overheated, and there is local detonation due to preignition of the combustion being initiated by a red hot earth or centre electrode.
This points to the plug being too hot to start with, or the cooling around the threads is insufficient.
If you somehow run too much advance, or run too lean, the piston as a whole should overheat and seize and or the end gases in the squish detonate and kill the piston edge.
The hole is a symptom of a secondary plug issue - the excessive advance just highlighted the fact you have a problem there that is lurking, in even a normal running engine.

EDIT - only just saw the comment - there is no such thing as an air leak lean out.
If here is a leak anywhere in the case of a 2T it will run rich, the only place a leak can cause leanness is between the carb and a reed, where extra air is sucked into the stream that already has fuel.

Would you please explain how having a air leak in the casses causes a rich mixture & how this differs to a leak behind the carb

[wobbly]

Simple explanation - in the case with a leak there is a much reduced compression phase caused by the piston dropping, thus this uncompressed volume in the case
doesnt assist flow into the transfers.
In the area between the carb and the reed this volume has a trap door separating it from the case during the compression phase - the reed petals.
Thus extra air is sucked in by the depression in the case when the reeds are open and this lean mixture gets all the way into the cylinder, when the reeds are closed.
With the case leak like a broken gasket or faulty seal,some reduced amount of A/F mixture makes it into the case, but very little ends up in the cylinder.
This progressively gets worse and the engine exhibits all the 4 stroking symptoms of smoke out the back etc, so of course your clever tuning buddy leans it down
and - bang - it siezes.
Hard to get your head around I know - but after 40 + years of seeing this so many times and explaining it time and again ,no one believes me.
Go try it, lift your cylinder and cut away a 1mm slot of gasket material - bolt it up and start it.
If it aint as rich as a dogs arse, then another offer of free blowys is on the table.

[TZ350]

My little supercharger turned up today, nice unit. AMR 300.

This could be a handy little project for the AMR300.



Although being CVT the engine would be pretty much constant revs so turbocharging may be better. Its 150cc so would need de stroking and boring to 100cc.

The scooter is a CPI GPR150 150cc water cooled 4T, 2.5x17" front wheel 3.5?x16" rear, fairly good CVT transmission, possibly good for 40hp.

If the rules allowed, I would love to turbocharge a 2T CVT special.

What about adding air cooled 100cc 2T turbocharged to the current F4 mix, would that be to outrageous?.

[speedpro]

I am going to claim I was thinking something like what Wobbly said regarding the cause of that piston failure. Not helped of course by the erratic timing. That holed piston "looks" to have some erosion on the exhaust port side which in my limited experience is usually heat related detonation. That heat also could cause(?) the hot plug as per Wobbly which could cause preignition. That preignition could cause a shock that displaces the boundary layer locally exposing the piston crown to exceedingly hot gases and successive shocks, eventually blasting the hole we see. It would be interesting to see if the squish band outer edge on the exhaust port side has a slight roughness.

Could you fit a steel disc behind the pickups to isolate effects from the balance weight?