ESE's works engine tuner

[wobbly]

Finally off the meds enough to say something and be reasonably sure of not making myself a bigger dick.
The trailing axle as seen is also used with a huge amount of offset on the tripples.
Thus rake and trail are " normal " as we would define them, the actual position of the leg centre line is irrelevant - its the axle position in relation
to the steering axis that forms the trail number.
You could have a leading axle and very little offset - same geometry.

Re RS125 squish, 0.65mm is the number with around 50% SAR, a sharp bowl edge and toroidal chamber for a flat top, or bathtub for a domed piston.

[TZ350]

Good to see your back Wob.

[TZ350]

ok I understand the gluing bit, . . . -but how the heck do you 'screw' it in?

The stuffer plate is held down by screws through the exhaust port floor, the glue is only there to seal it.

[RomeuPT]

Welcome Back Wob.

My question got lost, not in a hurry but I really need to get the proper clearance.

Wob, I need your help.

I have a 9.7cc Honda RS head that I am not using, and now I have got some VHM domes, I am thinking in milling the 9.7cc head and fit the domes.

What tolerance should I use between the head and the outer diameter of the domes?

Thanks

[F5 Dave]

Ah, fairly thick plate Rob, well interesting.

Good to see you back Wob, hope Op went well.

[teriks]

Yes, TZ I too am considering placing a small transfer port in that front area below the exhaust port. In the new piece of " realestate" opened up by raising the bottom of the exhaust port. First need to confirm how high this " dam " can be? This could be very useful for helping to cool the front exhaust edge of the piston each cycle, the most dangerous area.

Here's an example, something on raised exhaust port floors from Jan Thiel on that same page too.
It seems that one have to click the link (arrow thingy to the right of "Frits Overmars") to see the picture..

Here it is: the MB40-6port. What is your link with MB40 engines, Teriks? Do you take part in F3D competition? If so, under which name?

Now, piston rings might not like that export witdth.

[FastFred]

Originally Posted by Jan Thiel
So that you might be able to raise the exhaust's 'floor'.This helps improve blowdown flow, as seen on a flowbench.In 2007 we started to raise the underside of the exhaust port.The first results were very promising!But at the end of 2007 I retired, so I could not finish what I started.The idea was to raise the exhaust underside as much as possible until power dropped.And then, with a smaller exhaust port underside it might have been possible to widen the A-ports more
without losing the fresh charge into the exhaust.

Even more radical things were tested I have been told, like an additional transfer port below the export floor.

Here it is: the MB40-6port.

Is this what TeeZee is up to and Jan was talking about, raising the exhaust port floor and maybe fitting an extra transfer there too?

[wobbly]

The inserts are a neat sliding fit into the head skull, the actual clearance is not important.
What is important is ensure the the insert face projects at least 0.05mm, so it is clamped onto the head face by the stud pressure.
I also make the skull face around the spark plug 0.1mm low, so that the top of the dome is pushed down by the head cover, and then the studs also pull the cover down over the inserts
outer flange as above.
Not all covers can be machined to do this, but it works well in adding strength to the insert at its weakest point - the middle of the chamber.

[TZ350]

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

Is this what TeeZee is up to and Jan was talking about, raising the exhaust port floor and maybe fitting an extra transfer there too?

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



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.



The alloy stuffer plate and Belzona glue.



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.

[wobbly]

To make the raised floor work as part of an overall plan that was seen all the way thru by Jan at Aprilia, the area reduction at the port should be extended all the
way to the flange.
Making this oval, and reducing the duct volume all the way to the exit then works with the 75% area guideline for T or tripple port duct exit geometry.

[Flettner]

How interesting is this, leading edge.
The real key is to get rid of the exhaust port altogether and just have transfers only around the cylinder. Exhaust needs to be in the roof, Uniflow scavenge. Tell me I'm wrong.

[teriks]

Is this what TeeZee is up to and Jan was talking about, raising the exhaust port floor and maybe fitting an extra transfer there too?

If you look at the original post, you'll see that the extra transfer port was mentioned only in the context of MB40 cylinders.
I.e. I have no idea if an additional port was tested at Aprilia.
I read what Jan wrote as his intention was to widen the existing transfers, not add another one.

[Yow Ling]

How interesting is this, leading edge.
The real key is to get rid of the exhaust port altogether and just have transfers only around the cylinder. Exhaust needs to be in the roof, Uniflow scavenge. Tell me I'm wrong.

Ahh Anton, kinda like this
http://www.kiwibiker.co.nz/forums/sh...post1130229157

but dont have to get all complicated like the uniflow, transfers for africa and a few exhausts as well

[Flettner]

So, how did it go? There must be some results by now? Casting the cylinder is not a problem. Transfer arrangement is not quite as simple as you might think. In my uniflow cylinder there are two transfer types one set after the other arranged around the cylinder wall, so they don't all eject ( I do mean this in a non pornographic way ) into each others stream.
I was thinking more along the lines of the Rolls Royce Crecy.

http://youtu.be/zPEbv3DlGh0

[Farmaken]

And a little boy waits .......