ESE's works engine tuner

**dinamik2t** · 18th February 2012, 09:52

I run through the last few posts very quickly, thanks for the heads up Wob!

Just wanted to add a link with several interesting info, here:

http://www.redline-ci.com/

I liked particularly the explanation on powerjet carbs : http://www.redline-ci.com/Technical%...S125R-250R.htm

It also has lots of RS and TZ manuals -like anyone here would need those.. anyway.

Some info on the deto counter that Wod mentioned too on the quest for power: http://www.redline-ci.com/Technical%...20COUNTERS.htm

AH, and here's mr Neels webpage : http://www.vannik.co.za/index.htm

**Yow Ling** · 18th February 2012, 10:19

Hey TZ you should ask Neels to put your bucket on his examples page then there will be 4 out of 4 kiwi developers on there

**wobbly** · 18th February 2012, 13:23

Two types of asymmetric chambers have been tried, one by Doc Erlich who worked for OMC etc and sold the patent to Yamaha, simply moved the whole chamber back ,over the boost port.
This was supposed to help the loop stay attached,maybe it did but it also made the squish velocity go thru the roof on the opposite side, and it detoed its tits off.
Yamaha used it once then dropped it, maybe useful down at 7 bar bmep in an outboard, not at 12+.
The other I have seen was a teardrop shape front to rear, with wide squish on the sides - same shit, different shape.
More than happy to CAD and CNC something else if anyone comes up with something.

**richban** · 18th February 2012, 14:22

I recently read a little piece on pipe design that got me thinking. One bit in particular spoke of badly matched pipes to ports. It said that any anomaly at the port end was a bigger problem than if say you had a dent further down the pipe. Due to greater force and speed at the port pipe juncture. Resulting in, as he put it ghost waves created. reversion I suppose. How important is it to have the transition seamless. I would imagine its very important. I know on my 4 stroke single the exhaust port is D shaped and does not match the header very well. I am thinking I should fix this now. Is this something you guys pay a lot of attention to?

**husaberg** · 18th February 2012, 15:05

Originally Posted by richban

. I know on my 4 stroke single the exhaust port is D shaped and does not match the header very well. I am thinking I should fix this now. Is this something you guys pay a lot of attention to?

4 strokes, i think you are right. i don't think most people pay attention to them

I doubt they will catch on, Unless someone changes the rules to give them an advantage in capacity then bans 2 strokes all together.

Originally Posted by wobbly

Two types of asymmetric chambers have been tried, one by Doc Erlich who worked for OMC etc and sold the patent to Yamaha, simply moved the whole chamber back ,over the boost port.
This was supposed to help the loop stay attached,maybe it did but it also made the squish velocity go thru the roof on the opposite side, and it detoed its tits off.
Yamaha used it once then dropped it, maybe useful down at 7 bar bmep in an outboard, not at 12+.
The other I have seen was a teardrop shape front to rear, with wide squish on the sides - same shit, different shape.
More than happy to CAD and CNC something else if anyone comes up with something.

DKW ran them prewar MZ postwar in the 60's.
I would hazard a guess Dr Joe got his idea from them a long with a complete engine or two.
Suzuki ran them on the 60's GP bikes as well i think.
I do remember some others in the late 70s maber 125 gp bikes euro type Motobelli or such like.

here is the DKW and The MZ.

As Wob says above there was a total elliptical shaped one basically oval buggered if i can remember what had it though.

Bear in mind that the book these came from is from the 1960's so it might as well be 50 years old

ps have a look at the crankcase finning and the plug

**speedpro** · 18th February 2012, 15:16

4-strokes

I'm pretty sure the D shape is just as important to 4-strokes as the the transition 2-strokes have between port and pipe. I would not get rid of it. I have seen that d-shaped port to round pipe transition on some serious high horsepower v8s. Ask your brother before getting the grinder out.

**richban** · 18th February 2012, 15:57

Originally Posted by speedpro

4-strokes

I'm pretty sure the D shape is just as important to 4-strokes as the the transition 2-strokes have between port and pipe. I would not get rid of it. I have seen that d-shaped port to round pipe transition on some serious high horsepower v8s. Ask your brother before getting the grinder out.

I was not meaning the port shape. D shaped ports I think are supposed to help with reversion. I was meaning after the port and the transition to the pipe.

**wobbly** · 18th February 2012, 16:31

D ports in a 4T are there to speed the flow up on the short turn radius, and prevent serious reversion in the area of least flow velocity,the port floor.
In a 2T we use the step at the manifold to reduce the Ex duct volume - also keeping the velocity high, and also preventing the reverse plugging wave from buggering the powerband
even more than it usually does when the pipe is too short for the rpm.
When they are designed correctly both are a useful tuning tool.
STEP AWAY FROM THE GRINDER.

**speedpro** · 18th February 2012, 17:59

Originally Posted by richban

I was not meaning the port shape. D shaped ports I think are supposed to help with reversion. I was meaning after the port and the transition to the pipe.

The V8s had the flat floor of the D port right to the gasket surface where the headers bolted up. The shape of the port at the outlet was a D and the pipe that bolted on was an O. I wonder if there wouldn't be some advantage in a CNC oval or D to round transition like has been discussed earlier in this thread. Wondering about that sort of stuff really is for another thread.

**wobbly** · 18th February 2012, 19:16

In a 4T there is very little mass flow on the port bottom,due to the tight short turn, the flat face of the 1/2 moon formed where the header bolts on, is to help prevent reverse flow
overcoming the slow velocity exiting the port at that junction.
Making a smooth transition there, would fuck the whole idea, and the power.
The Britten made a heap more power when Tim made a new pipe to my design with two reversion steps, plus one at the gasket face.

It had no problem with short turn flow, but the steps also produce a depression reflection every time you step up in dia, and if the steps are in the right place, they can reflect at peak torque and peak Hp rpm - helping to spread the usable power.
Its a similar situation with a 2T but the dynamics are way different - as is the detail of the Devil, or God, depending upon your predilections.

**richban** · 18th February 2012, 19:26

Originally Posted by wobbly

In a 4T there is very little mass flow on the port bottom,due to the tight short turn, the flat face of the 1/2 moon formed where the header bolts on, is to help prevent reverse flow
overcoming the slow velocity exiting the port at that junction.
Making a smooth transition there, would fuck the whole idea, and the power.
The Britten made a heap more power when Tim made a new pipe to my design with two reversion steps, plus one at the gasket face.

It had no problem with short turn flow, but the steps also produce a depression reflection every time you step up in dia, and if the steps are in the right place, they can reflect at peak torque and peak Hp rpm - helping to spread the usable power.
Its a similar situation with a 2T but the dynamics are way different - as is the detail of the Devil, or God, depending upon your predilections.

Cool. That means we are in the ball park for sure. There is one at the gasket face from mr suzuki and I have two more steps at 100mm intervals.

**dmcca** · 18th February 2012, 21:56

Originally Posted by wobbly

Two types of asymmetric chambers have been tried, one by Doc Erlich who worked for OMC etc and sold the patent to Yamaha, simply moved the whole chamber back ,over the boost port.
This was supposed to help the loop stay attached,maybe it did but it also made the squish velocity go thru the roof on the opposite side, and it detoed its tits off.
Yamaha used it once then dropped it, maybe useful down at 7 bar bmep in an outboard, not at 12+.
The other I have seen was a teardrop shape front to rear, with wide squish on the sides - same shit, different shape.
More than happy to CAD and CNC something else if anyone comes up with something.

Speaking of head profiles...

Is there a definitive answer as to whether or not a toroid is better than a bath tub shape? I believe that the RSA has a bath tub shape?? but i have heard that the toroid is good/better. Ive tried toroid shapes and they seem fine, defintiely seem to detonate less with high comp and lean mixtures, but im not testing the peak of performance like others here are, so i cant really tell too much difference.

What do others here run?