ESE's works engine tuner

**jonny quest** · 7th August 2021, 09:26

I thought you could base mill cylinder to tighten up squish and compression, just looked and that's part of case too.

Best bet is make a longer rod.

**lohring** · 8th August 2021, 01:45

Originally Posted by jonny quest

I thought you could base mill cylinder to tighten up squish and compression, just looked and that's part of case too.

Best bet is make a longer rod.

What do the transfer passages and head look like. It might be easier to increase the stroke to tighten the squish if there is a squish area. Otherwise the pipe with high enough exhaust port timing will be the easiest. Rpm equals easy power. The limit will be crankshaft flex and the big end bearing. it looks like the crankshaft isn't an overhung design, so that should hold up.

Lohring Miller

**Muhr** · 9th August 2021, 08:52

Thanks guys for the suggestions!
The problem i se with an engine like this, which relies on crankcase compression the more port time the less compression. Together with the fact that it has a piston-controlled intake, it makes a bit of a Catch 22 without a proper exhaust.
It has both a traditional piston-controlled intake port and a port through grooves in the piston to the transfer ports (which I have never seen before, perhaps common in these applications)
I tried porting a bit and I can not say that I noticed any big difference. It is 1 mm in squish so you could do a little there, but it is not a quick fix to stroke it or make a new connecting rod ...

**lohring** · 9th August 2021, 14:56

My articles on what we do to our industrial 26 to 30 cc piston port, race engines are here:

http://namba.com/content/library/pro...015/October/#6
http://namba.com/content/library/pro...2016/April/#5/

Lohring Miller

**SwePatrick** · 10th August 2021, 03:48

Originally Posted by Muhr

, but it is not a quick fix to stroke it or make a new connecting rod ...

Make new lower plate that holds the crank, offsetbore the mainbearings to alter to desired squish.

**husaberg** · 10th August 2021, 14:31

Get rid of crap cylinder replace with noncrap one.
later on, realise i should have just brought a bigger saw.
Divorce wife get a younger girlfriend and central heating.
give saw to wife in the settlement.

**Pursang** · 11th August 2021, 00:29

**TZ350** · 11th August 2021, 21:42

.
I just love that chain saw.

2Stroke Stuffing. Includes a brief run with the 24/7 on the dyno. Sounds much better with the longer inlet tract. Progress.

**Joshua_** · 12th August 2021, 22:18

Kia ora,

I am wonder where I should go to read up on some modern 2T theory. I have read the performance tuning graham bell & tuners handbook but they seem mighty old - one suggested I buy a fancy scientific calculator.
I've been following Alex on 2T stuffing youtube channel for years.

**Frits Overmars** · 12th August 2021, 23:41

Originally Posted by Joshua_

Kia ora,
I am wonder where I should go to read up on some modern 2T theory.

Kia ora to you too, Joshua.
HERE would be a good start.
I can also recommend http://www.pit-lane.biz/t117p246-gp1...es-aprilia-rsa. It's a French forum, but the Aprilia-thread is largely English-spoken (Maori not so much, yet)

**lohring** · 13th August 2021, 02:10

I've written many articles on high performance two strokes, especially for our small racing two strokes. One series is below:

Lohring Miller
PS The links in these articles don't work any more.

Click image for larger version.

Name: High Power Two Stroke Design.pdf
Views: 133
Size: 1.36 MB
ID: 349459

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Name: High Power Two Stroke Design.pdf
Views: 133
Size: 562.1 KB
ID: 349456

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Name: High Power Two Stroke Design Part 2.pdf
Views: 86
Size: 371.4 KB
ID: 349457

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Name: High Power Two Stroke Design Part 3.pdf
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Size: 895.4 KB
ID: 349458

**Joshua_** · 13th August 2021, 10:39

Originally Posted by lohring

I've written many articles on high performance two strokes, especially for our small racing two strokes. One series is below:

Lohring Miller
PS The links in these articles don't work any more.

Thank you very much - I'll read over these today :> I really appreciate the help. I accidentally asked the same question in a facebook group called moped army. I had seen a heap of cool projects on there but no one seemed to have much in depth theory going on. More bolt on go fast parts.