Can anyone tell me about getting a head "o" ringed? I'm a machinist and could easily do it myself but concerns about increased compression!! I tried a search but came up empty. Would the inside ring burn up do to being so close to the edge? THX

 

i really can't tell you about getting one o ringed, but the head on my 250R came to me already o-ringed, I'm a machinist too and i'll have my certification next year once i graduate, but it sucks though cause no one will give me a job yet even for co-op, i bored a few engines and did a couple heads but never o ringed one. sorry i can't help. later

 

There are a few ways to do it. One is if you have a mill you can bolt the head to a indexing head and cut it that way. Another way is to make a fixture to bolt the head to and chuck it up in a lathe. If the head is an odd shape (Polygon) then you are going to have to get a CNC mill and program the shape into it.
I don't understand your concern. O-ringing your head won't increase your compression at all.
Again I don't understand the problem? What ring?

O-ringing the cylinder is a ton easier. Some places will sell you the fixture to do it by hand I believe for less than $100.00. I know for less than $200.00. I don't know how small they go though?

Are you sure your not talking about milling the head?

 

I've been a machinist for 20 yrs...I KNOW HOW TO HOLD IT....an o ringed head DOES increase your compression. Your stock head gasket is roughly .040" thick but an o ringed head will sit very close if not directly on the cylinder so that would be like milling the head .040". That will increase compression dramatically. The o ring that could get toast is the one that sits on the inside near the piston (and could be in direct contact with combustion) not the one that is near the outside near the.....outside!!!! Plus I have to o ring all bolt hole so coolant doesn't come up around the stud.
I need someone that has had a head o ringed or can help me with valuable ideas. THX

 

Ha ha ha, when I O-ring a head I DON"T remove the gasket. I use the O-ring to bit into and build a fire ring into the gasket. On a well clamped head I can build over 25 PSI boost without any gasket worries.

That is WHY you keep the gasket in place, for the stock fire ring. If you want to do it without a gasket, knock yourself out.

 

ATK /cannondalescome from the factory with an o-ring cyllinder without a fire ring and Ive never heard of one burning out. You have to be sure the area you mill out is the correct depth to get the correct squish. To small and you can damage the cyllinder. To big and it will leak.

 

Norm, I'll share what little knowledge I have with you.

First of all, if you are wanting to O-ring a stock head, the .040" - .050" you'll gain by removing the gasket is still pretty insignificant. Yes, it will increase your compression, but not enough to be worthy of mentioning.

I just did my first O-ring head, and milled .080" off before machining the grooves... now that's some increase in compression!
I've always ran a gasket, and usually milled around .120" off the stock head to get the static comp. up to 185# (I'm at 7000 ft above sealevel... lowlanders will need less removed)

When removing that much material, the dome area needs some adjusting too. IMHO the stock configuration is pathetic. These motors need a faster squish velocity and higher compression to help curb a really bad detonation problem that was never corrected by suzuki.

A decent setup for a stock or close to stock build would be set the squish band at 15-16 degrees, beginning at .5mm larger than the bore diameter and blending into the dome with a nice radius.

Back to the O-rings... The inner ring MUST be Viton! Any other material cannot handle the hostile environment. Now I have yet to run my setup, but it works great on my 250R.... I've heard some really high compression motors still have issues blowing past the inner ring, so some folks are using a stainless steel 'crush' ring... The jury is still out for me on that one.
I use another larger ring on the outside to seal the coolant, and likewise, a small ring for each stud to seal them up.

Hope this helps...

 

that's exactly how my 250R head is setup and i never burned the inner o ring yet. i have copper rings around each of my studs.

 

OK duneaddict. Can you tell me more about your squish angle. More preciselly what your changes are? And what the changes do to performance? Will it increase rpm or torque? I still what a reliable machine. I can do all the changes on my lathe at work.....THX.

 

lathe would work if that's all you had, but a mill with about an 1/16 or 1/8 ball end mill and get that nice radius inside there. Acurite CNC controls are awesome for doing these kinds of things