GPZ750/810 racer running....

x

We have one. Use it mainly to check thread profiles, keeper angels, etc

ok injected, see now what you mean by a 10X, we actually have one of these at my work place. will give it a try.

before the welding i did a plasticine cast and sliced it to get the radius of the spherical chamber. traced from that a small carton template, so sounds like we are on the same page after all.


grazie mille

TG

turboguzzi wrote:

before the welding i did a plasticine cast and sliced it to get the radius of the spherical chamber. traced from that a small carton template, so sounds like we are on the same page after all.

Yes... that was a good idea.

Here is that tool I made up... picture is a little fuzzy because it was -2C this morning taken before my coffie!

I am based in milano, where are you? by the way you spell coffie it sounds like netherlands

nice tool, would be great to see how your chambers look like now.

Larry, did a bit of homework and sounds like pressure recovery is what i call the diffuser effect when the gases enter the chamber past the valve. So yes, i am aware of a possible downside, in any case. Still want to keep a good squish band, with the current welding i should get something like 28% squished area. really worked for me in the past.

What i might do, time permitting, is play with plasticine and thread streamers in a spare head to see if there's any point in chamfering only the area near the inlet valve for a bit of a diffuser effect.

TG

I am missing the point on the tool (pun intended!) where is the cutting edge? What are you trying to cut? I believe you are cutting a deeper (or new) squish band, but how do you cut it without the tool beating up the cumbustion chamber dome?

x

Awesome... Injected you are a cool cat! It has been a long while since I actually learned something on this forum.

In shop class we spent all our tume rebuilding lawn mower engines... i only used the mill and lathe for maybe 2 class periods in my 4 years. Damn shame the shop teacher was a perfectionist and machinest by trade and basically he hated to see the sloppy work we would turn out. Great guy, not so great teacher.

So when would recomend doing something like this? What compression ratio would require it? Could this be at all benificial for a street machine? It sounds like there is a risk of messing with the heads flow (diffuser effect?) so it this something best left to the professionals?

::EDIT:: Sorry for the hijack and thank you (injected and turboguzzi) for the info!

x

I had a feeling it was a race motor only thing... but cool as hell to hear about. I doubt it will be something I ever need to do to one of my motors but cool to hear about anyways.

hei injected,

might have to do something similar as i already discovered quite a marked difference in chamber volume, so in order to equalize cc's in all the chambers, this might be the best way.

TG

Yes... if you make a tool to do the chamber edge every one will be exactly the same volume - doing it by hand they could get close, but not every one the same.