ESE's works engine tuner

[TZ350]

These are hardened steel washers from a Suzuki RGV250. 0,010" side clearance (0,254mm). Very close slip fit on the pin and no appreciable grooving of the pin after hours of service. These washers are used to centralize the rod when no big end washers are being used. I have seen steel and hard anodized aluminium in Yamaha KT100 cart engines. I was not that impressed with the life of the alloy KT100 ones. I would think washers made out of any good quality steel would be fine. I don't think hardening would be all that necessary for a short run competition engine.

[peewee]

I'm not so sure about the nickel silver either now - i see its heavier (12%) than steel and not much stronger than mild steel . 4140/4340 with nitriding could be a likely candidate .
Titanium also but we need someone experienced with that to chime in ...

In my case no the wristpin was not damaged by running thrust washers. It was a very long time ago but I think there was reasonable clearance, in fact I was running them only as the piston was wider than stock so I had to contain the bearing.

These are hardened steel Suzuki RGV250. 0,010" side clearance (0,254mm). Very close slip fit on the pin and no appreciable grooving of the pin after hours of service. These washers are used to centralize the rod when no big end washers are being used. I have seen steel and hard anodized aluminium in Yamaha KT100 cart engines. I was not that impressed with the life of the alloy KT100 ones. I would think washers made out of any good quality steel would be fine. I don't think hardening would be all that necessary for a short run competition engine.

yes i only need washers to keep the small bearing centered as the piston is wider than standard. like you say, im sure most any steel would work for a short run engine. theres plenty of stainless steels that i can get and im sure they would be fine so thats probly what ill use. titanium grade 2 is cheap enough but i have no experience with it.

ive got 2mm total gap of the small bearing and piston. my plan is to use atleast .5mm washers so ill have 1mm total gap. .5mm each side of bearing. i could probly make even slightly thicker washers for .25mm gap on each side of the piston, which might be a better choice. thnks guys ill get the material ordered and not over think it

havent decided yet but might drill some oiling holes at the 2 and 10 oclock position on the rod small end. although maybe they arent needed for a short run engine

[Niels Abildgaard]

titanium grade 2 is cheap enough but i have no experience with it.

Titanium is NO bearing alloy.
It seizes on anything.
A bitch in heat.

[katinas]

Yes, titanium, without special coatings, is worst material (especially pure titanium grade 1 and 2) for sliding pairs.
Titanium is unique material, in vacuum and argon gas, friction is lower than cooper, Al and iron. But in a real environment, its opposite, because naturally the titanium outside oxide layer are very thin and broke easy at contact place. Then, very reactive under oxide metal layer quickly stick to other parts. Thermal conductivity is low and absolutely no adhesion with any oils, even more worsened things.

I try polyamide-imide Torlon 4301 for small end side washers and they work. But still needed more test. Torlon 4203 is little stronger, but without additional PTFE and graphite. Is less wear resistant, but with oil around no big difference.
On special pocketed piston with narrow inside, tested without any washers, so piston inner sides directly centered conrod. It works without any troubles.

[oldjohnno]

These are hardened steel Suzuki RGV250. 0,010" side clearance (0,254mm). Very close slip fit on the pin and no appreciable grooving of the pin after hours of service. These washers are used to centralize the rod when no big end washers are being used. I have seen steel and hard anodized aluminium in Yamaha KT100 cart engines. I was not that impressed with the life of the alloy KT100 ones. I would think washers made out of any good quality steel would be fine. I don't think hardening would be all that necessary for a short run competition engine.

I've had good results with steel washers as well. I machine them from some big socket head capscrews I have on hand, not super hard but very tough, grade 12.9 on the metric scale or around 170,000 psi in old speak. Once they're parted off I polish the sides on some fine wet and dry on a surface plate.

[TZ350]

yes i only need washers to keep the small bearing centered as the piston is wider than standard.

For that I would follow Oldjohnno's suggestion's and if you don't need to locate the rod then only make the washer diameter big enough for the L/E bearing so as to not restrict lubrication.

I've had good results with steel washers as well. I machine them from some big socket head capscrews I have on hand. Once they're parted off I polish the sides on some fine wet and dry on a surface plate.

[jbiplane]

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[mantonakakis]

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It has a clutch! Awesome!

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[mantonakakis]

We tested a winning Quad at Pikes Peak ,and the A/F was at 12.8:1 at the bottom, and 12.8:1 at the top - I couldn't believe it.

If you (or anyone else in this thread) ends up at Pikes Peak again, the beer (or other beverage of choice) is on me! I found exactly what I was looking for to fix my confusion re: carbs' circuits referred to mainly/only by throttle position and not engine speed.

[peewee]

preparing the pistons. all grinded surfaces i polished smooth

[oktrg500]

Hi,

I have been a daily lurker here since I discovered this thread a long time ago. A huge thanks to all for the knowledge being shared here.

Norway is a small country and there's not many dyno's around. As far as I'm aware, the only shop I would trust doing a two stroke dyno run is too far away for my budget. So, plug chops and seat of the pants dyno it is.

What buggers me a lot, is how to judge the smoke ring after WOT. I've always wanted to get to the bottom of this:
Quite a few people say you must look at both the width of the ring and the color of the ring.

I have experienced the color of the ring, and what the color looks like around the circumference of the porcelain is what I should pay attention to.

Is the width of the ring of any importance? If so, I'd like to understand how the color and the width relates to each other.

Attached is pics of a plug chop of my wifes scooter. I don't want to risk the wrath of my wife because the scooter seized. At the time this plug chop was done I think I could have used a smaller main jet and still be safe. Am I right thinking so?

[TZ350]

.
Welcome Octrg500

These are some earlier posts I found using the Google "site:" search option.

There may be other, better posts, cut and paste this into the search bar " plug reading site:https://www.kiwibiker.co.nz/forums/s...s-engine-tuner "

For the quotes below you will need to click through to the original posts to read the full story. Click on the little blue box that is after each posters ID.

Attachment 275922 Attachment 275923

B9 plug after Tokoroa.

B10 plug after Taumarunui

Attachment 275921 Attachment 275920

The B10 plug from Taumarunui after some hot laps and a proper plug chop before over rev deto set in. I would be interested in what Wob has to say about it.

Quite a bit on page 600 too.

Attachment 276053 Attachment 276054

Yes, Wob I would be very keen to know if the colour of the B10's fuel ring is more like you would expect.

a bit lean for unleaded fuel.

Is this still running AvGas??
For Av its a bit rich, for Unleaded its a bit lean.
The plug heat range appears good, and the mixture is on the rich side of correct for Av.

This plug reading stuff is very interesting I have always wondered how it was done. Cutting open a plug each time looks like a real dedicated way of doing it.

Attachment 276171 Attachment 276172 NGK B9 Plug

Attachment 276170 Attachment 276169 NGK B10 Plug

I know (because I asked) the B9 and B10 plugs were new and fitted into a hot (up to temperature) 2T engine after practice and plug chopped at the end of one race each so there is not much running time on them.

Is it because the ones below are 4T that there is no (oil ???) stain on the nose of the porcelain like you see on TeeZees plugs.

http://www.wallaceracing.com/plug-reading-lm.html

Attachment 276173 Attachment 276174

[TZ350]

.

NZ Cylinders trouble shooting page is worth a read. http://www.nzcylinders.com/Avoiding%20problems.html


Hi guys - actually its bloody obvious - when they say "under 30 dets in 3 laps" they mean it was 30 dets.
The Honda manual recomends 3 dets per Km MAX when ridden FULL OUT,tuned on the edge.
Thus to have 30 dets in 3 laps WHEN THEY SHOULD BE RUNNING THE NEWLY REBUILT TOP AND BOTTOM END IN, on part throttle, is simply irresponsible idiocy.
That many dets means it has WAY too much advance, or is WAY too lean on part throttle.
I have seen this before many times, on engines that are using the kit ignitions or the switchable ignitions that use lots of static advance on the stator.
They deto like hell when ridden slowly - as you do when running in, because so much extra advance is wound in down low to get good part throttle response when riding hard.
But whilst toodling round at part throttle, they will deto to self destruction in no time.
The deto counter is there to tell the rider something is wrong - to keep on shagging the engine with the deto counter rolling over in front of his eyes, when running in is just plain dumb.
Pull out some advance, lift the needle, and watch the deto counter, if it clicks over at all when running in - STOP.

[Frits Overmars]

NZ Cylinders trouble shooting page is worth a read. http://www.nzcylinders.com/Avoiding%20problems.html

Excellent site.

[TZ350]

preparing the pistons. all grinded surfaces I polished smooth

Great work Peewee on your pistons. When I raced RD's we cut the bottom part of that central rib away. It inevitably broke off in the inlet port otherwise.

TZ750 and a Vertex piston.