ESE's works engine tuner

[richban]

Looking good, but what about the outer o-ring? What squish, compression and fuel did you decide on? Is the piston flush with the top of the barell? As I alluded to before we had to machine the barell to pick up the required squish but this caused the chrome to flake off.
We have a couple of RGV heads which need modifying, looks like Glenn's the man

.75 machined Squish. The piston will be flush and Avgas. Compression, I will get back to yah when I measure everything. 14:1 I hope. I had to make a few concessions with what I was working with. Outer o-ring will come later maybe. Glue will do for now.

Next will be stock heads converted to take inserts so I can really get things dialled.

I am really doing this quick and dirty and will try a few things but for me its about getting the bloody thing going and on the track.

[richban]

If you find an outfit in the States you want to use I would be happy to act as middle man/shipping agent.

Thanks Man will be in touch if need be.

[wobbly]

Rich, ya know how to cc toroids properly??

[richban]

Rich, ya know how to cc toroids properly??

I made a solid of the of the cylinder and then read the Volume of the file. Then just subtracted it form another solid to get the the cylinder working file for CNC.


But real world CC with engine built I would think it would need to be almost upside-down. Whats the trick master?

[F5 Dave]

Ooh there's a trap I hadn't thought about.

[F5 Dave]

. . .Outer o-ring will come later maybe. Glue will do for now.
. ..

My 50 has an inner ring & Loctite red Hi temp goop for outer seal. Never had a leak in. . .erm, 3 different cylinders & 15 years.

[TZ350]

Making progress, its starting to go back together again with the Boost Bottle and Ball Valve fitted for the EFI setup.



This is the dyno graph of the single exhaust port cylinder when it was last run (with a carburetor) it also ran reliably at Taumuranui.

I am going to use it for the EFI tests, so there is something of a base line to compare the boost bottle and EFI with. At some point I will plug the boost bottle pipe near the inlet to see what difference the boost bottle is realy making.

[Drew]

I have to be honest. At 28 horses reliably, I'd be leaving the thing alone from there. Or at least that set up with injection.

Now you're just being greedy!

[wobbly]

Measure the cc with piston at TDC to the top of the plug hole.
Stop about 5mm from the top of the threads and rock the piston to get exactly the highest level.
Then fill flush to the top.
If you have 1mm of a 10 plug protruding then 2.2cc = the plug vol.
Take the head off and turn upside down LEVEL on the bench.
Fill the recessed toroid with fluid till it just creeps over the edge to the flat around the plug.
Take the original cc less 2.2 then add the extra fluid that represents the trapped air pocket within the head.
Remember with all these measurements, leave the burette sitting for 10mins to allow the clinging fluid on the glass walls to drop down and give accurate readings.

[TZ350]

I have to be honest. At 28 horses reliably, I'd be leaving the thing alone from there. Or at least that set up with injection. Now you're just being greedy!

Yes you are right, I will leave this cylinder alone other than the EFI bit and you right again, I am greedy and will make another cylinder with the aim of low 30's and the same spread of power, and in the end, like Wob I think 36 at the rear wheel is possible.

OK it might be a big ask for an air cooled 125 with a 24mm carb equivalent but EFI should give me better control over the fueling and if things start detoing then I can have it chuck in more fuel to save myself. And the programmable ignition with a few gubbons like switching on forced air cooling at the right time, and an ATAC valve might be a help too.

[Drew]

Yes you are right, I will leave this cylinder alone other than the EFI bit and you right again, I am greedy and will make another cylinder with the aim of low 30's and the same spread of power, and in the end, like Wob I think 36 at the rear wheel is possible.

OK it might be a big ask for an air cooled 125 with a 24mm carb equivalent but EFI should give me better control over the fueling and if things start detoing then I can have it chuck in more fuel and save myself. And the programmable ignition with a few gubbons like switching on forced air cooling at the right time, and an ATAC valve might be a help too.

I am envious of course. I just don't have the patience to learn all the shit to do it. Or the brains to be able to apply it.

[TZ350]

I would be very interested in the roof angle of the 6th transfer port thats under exhaust.



This is where I have got to tonight, cylinder prepped and ready to go.

Attachment 284574

The floor of the exhaust port is higher than BDC. I have no idea how high the exhaust port floor could be and I would dearly love to know more about it and what sort of angle a 6th transfer port there should be.

Attachment 284575Attachment 284576

The alloy stuffer plate and Belzona glue.

Attachment 284573

All assembled, and compression tested OK so ready for a run up on the dyno, hopefully tomorrow night.

I want to get a good base run with the carb setup then switch to fuel injection. I have no idea how long the stuffer plate and Belzona will last, I guess we will find out soon enough.

The glued and screwed in port floor dam held up OK and the dyno results were better.

Attachment 285043Attachment 285044Attachment 285045

Raised port floor Blue line.

Attachment 285042

But I wouldn't read to much into it as this triple exhaust port cylinder made much better power before I "improved" it.

Attachment 285046

All I did was tidy up around the inside of the main exhaust port area where the side ports converge and after I had finished that I found that some of the horses had bolted.

What was a stable of 29 became less than 20 ??????? ...

Originally the the exhaust timing was 203 degrees duration, lowering the cylinder to 200 exposed the bottom of the exhaust port, the floor dam fixed that.

I was also going to try a power valve like piece in the top of the port but in the end a glued solution was not going to be satisfactory in the long run.

Messing with this has held me up so I have switched to working on fuel injecting a known good single exhaust port cylinder. I will try making another triple exhaust later.

Thanks Drew, but I am not sure about the brains bit.



I initialy thought the triple exhaust port cylinder was not performing because there was so little piston skirt left to seal the exhaust port floor at TDC.



And it improved when I put in the exhaust port dam but now I think that improvement is a red hearing. It may not have been leaking there after all and the improvement is due to exhaust port dams being a good idea and not a lack of sealing there.



The ports on a Suzuki GP are not on the center line, they are rotated a bit relative to the piston and when you look at the side exhaust ports you can see one of them extends back past the piston center line.



And these pro-light pistons with the side cutaways, when at TDC the piston cutaway would allow the side exhaust port to communicate directly with the transfer port and crank case.

I am sure it was pointed out to me as a possibility but I just didn't pick up on it.

So not so smart....

I have another piston that does not have the sides cut away, I guess the old triple exhaust port cylinder is worth another try.

[Kickaha]

but I am not sure about the brains bit.

No Drew was right,he doesn't have any

[F5 Dave]

Thanks wob. Was lying awake last night and thought just flat clear plate the bugger (with drill hole for burette) , use that tech to machine sometimes having gotten the full measurement on engine, but with flat top piston could be added to deck height with no crazy math. Never had flat pistons on an engine I'm running yet.

rob yeah those suzi engines can be crazy like that, the VJ23 is like that too!

[TZ350]

Original Suzuki GP 125 100mm rod on the right, the RGV250 105mm rod I currently use and the RD400 115 rod on the left that I am going to use in my new engine.



Interestingly these 1986-88 YZ125 pistons both have the same Wiseco part number stamped on top. I think the one on the left was connecting the side exhaust port to the crankcase, I am going to try the one on the right in the triple ex port cylinder next.