PICTURES ENCLOSED... This is how I closed up the squish band clearance the simple way

[best]

Re: PICTURES ENCLOSED... This is how I closed up the squish band clearance the simple

BEST...

My timing is stock. It runs perfect where its at. I was expecting more also.

I inspect the bore each and everytime the head is off. The top end looks perfect and has 10 hours on it.
When I was doing the compression test's, I did it multiple times,and also shot oil through the spark plug hole (a healthy ammount) and got the exact same readings (maybe 1 pound difference).

I was stumped,so I re installed my old head and got the same reads (130 psi which is what this head had),did the oil thing,and the same readings appeared.

The "MAC" tools compression gauge works perfectly! When I kick over the kick starter,they feel the same too.
Hmmmmmm:-/

The engine runs beyond awesome with either head,phenominally actually,and ther is ZERO DETONATION!

I have seen the same thing Joe, nice clean (nikasil) bore, no problems with the rings I can see, low compression reading.
New rings bring it up for a while, but soon low again. Engine works great. I put it to unknown bore issues.

 

[joeak47]

Re: PICTURES ENCLOSED... This is how I closed up the squish band clearance the simple

Best...

The bore is strait and true! Taper is within .0005 (half thou) ,and the same goes for the bore being round .0005 (half thou).

 

[best]

Re: PICTURES ENCLOSED... This is how I closed up the squish band clearance the simple

No, I don't really know but I think it is either a bore surface finish thing, or a ring wear issue, at least in my case. Rings are quite low tension. Remember I have the low cranking compression issue on KTM nikasil bores. Diameter is not generally an issue on these, end gap good. New rings fix it up, boost cranking compression for a dozen hours, then it drops again. I suspected overly polished bore (from use) but scuffing up the bore to give it new cross hatching didn't help. I have a couple 125 cylinders like this and my 250 in my Blaster was like this too, but it had other issues too. No big deal, still works great on top end, gives up some power on bottom end. Just had the 250 replated and am dropping it into the Blaster now, but not much time to work on it.

Also bought a Trail Tech TTO pyrometer to get an idea of Triplecrown's head temperature and on my KZ1000. Unfortunately Triplecrown has been busy too and no time for us to get together and install the new head. He'd like me there for setting up the squish distance.

Steve Best

 

[joeak47]

Re: PICTURES ENCLOSED... This is how I closed up the squish band clearance the simple

BEST... I'm cutting a "step cut" on this head too ,so I can close up the squish band clearance by setting the copper head gasket into the head,which gets the squish band closer to the piston. That is where the power is coming from!

I'm going to start cutting head #3 today. This one will have a really small chamber,and 50% band. We'll see if it up's compression.

 

[sicivicdude]

Re: PICTURES ENCLOSED... This is how I closed up the squish band clearance the simple

So Joe, when are you going to make a blasty head that looks like this?

 

[mud runner]

Re: PICTURES ENCLOSED... This is how I closed up the squish band clearance the simple

So Joe, when are you going to make a blasty head that looks like this?

i have 1 queston how mutch comperestion are you running with that head

 

[sicivicdude]

Re: PICTURES ENCLOSED... This is how I closed up the squish band clearance the simple

i have 1 queston how mutch comperestion are you running with that head

It's high, but not THAT high, nitromethane does this funky thing when you compress and heat it..... it tends to explode violently (more so than gasoline or even methanol) with quite the force. You physically can't move it too fast or get it too hot or localized predetonation will spall aluminum on contact.