o ring heads...

mr_bungholeo · Post by **mr_bungholeo** » Fri Jun 22, 2007 6:13 pm

just found a place two doors down from my work that has a cnc machine...lathe etc...n he is putting o ring rockers on tr4/6 triumphs......he recons its easy to do it to my kr1s.....so.....

if i o ring the head the squish area is gonna change(cos its got no gasket in between) so do i put tz pistons in,sure i saw on mj's site that tz pistons r less hight from the crown to the small end pin... or raise the barrels(although wont that change port timing?)
wot do you guys do????

JanBros · Post by **JanBros** » Fri Jun 22, 2007 7:01 pm

the first KR I had, was already O-ringed, and since a couple of years, I do it myself.

the only thing that changes is that your compression is a little bit higher, just use standard pistons (I do

).

don't use ordinary O-rings, they van't cope with the temperature (only to about 100°C). you need special ones

best thing about O-rings is, you can re-use them quite a few times, so one can easily open up the top-end without having to buy a new headgasket

mr_bungholeo · Post by **mr_bungholeo** » Fri Jun 22, 2007 7:10 pm

thanx janbros....next question then...where do i get the o rings....???

JanBros · Post by **JanBros** » Fri Jun 22, 2007 11:56 pm

I got my first from Heiden Tuning in Holland, the guy that had tuned my first engine.

I've ordered some new ones at Peleman in Leuven, Belgium

if it exists in rubber, he can deliver

5euro for one.

find someone like that in Brittan

over here, the compound they are made off is called "vitton" .

if you can't find them, I'll order some more, but it can take up to 2 weeks before I get them.

mr_bungholeo · Post by **mr_bungholeo** » Mon Jun 25, 2007 7:19 pm

ok...ive found a company in the uk but what size do i need????

anyone from the uk that can help (come on elf/rc/mj etc)

thanx...

mr_bungholeo · Post by **mr_bungholeo** » Mon Jun 25, 2007 7:24 pm

just looked on wikipedia n it seems it was a vitton o ring that blew up the chalenger rocket.....lucky our bikes dont run on liquid nitrogen(well maybe mj will try it someday...

)

col · Post by **col** » Mon Jun 25, 2007 7:45 pm

try asking on www.rgv250.co.uk the o ring conversion is a common mod on the rgv and there is lots of advice on there about it.
they should be able to reccomend a supplier and help with your questions.
also have a at look "the tuning works" for o rings, dont know if sean does em but its a good place to start

mr_bungholeo · Post by **mr_bungholeo** » Mon Jun 25, 2007 7:58 pm

cheers col...

mgtkr1 · Post by **mgtkr1** » Mon Jun 25, 2007 8:44 pm

se tz250 o rings as there availible at a number of places such as padgetts, jim matthews, geoff greenham racing etc.

JanBros · Post by **JanBros** » Mon Jun 25, 2007 9:26 pm

you need a 2mm thick O-ring.

I've measured the diameters off my head :

inner : 61mm, outer : 65.5mm

If my memory is correct, it's the inner one that matters, so you'll need 61mm O-rings 2 mm thick

mr_bungholeo · Post by **mr_bungholeo** » Mon Jun 25, 2007 9:47 pm

top bloke...ive got tony at gibsons on the case(im only 20 mins away from em) n i was just about to post wot the sizes r....yet again...great info from great guys....

gonna take photo's of the project tomorrow..so watch this space..gonna keep one totally standard n the other is gonna get money thrown at it like tissue paper in a fire!!! ....

with all the info on modding on here i think itll cos a bomb..better give the bank manager a bj...

cheers guys..

ON-OFF · Post by **ON-OFF** » Sat Sep 15, 2007 9:42 pm

Greeting to everyone, I'm new here.

Question:
unlike the RGV, on the KR1 the exhaust valve are open to the top of the cylinder.
So you need two little o-rings to seal them, otherwise coolant may go in the valves...
Or do you use only one o-ring for the inner to resist the high pressure in the cylinder and glue the rest?

I used normal o-rings (vitton) on other engines (liquid cooled) and had no problem, cause the o-ring don't get hotter as the coolant

mgtkr1 · Post by **mgtkr1** » Sat Sep 15, 2007 10:48 pm

do you meran the seal for the powervalves? if so then the job for them is to stop residue (oil) from dribbling all over the front of the barrels. its a messy affair when they fail due to the gunk but nothing to worry about. there availible from kawasaki. any news on the o-ring mod bungholeo? couild do with hjaving some me self as there a must for a race bike. let us know when you have decided on which spec/size orings you end using, cheers mate.

mj43 · Post by **mj43** » Sat Sep 15, 2007 11:16 pm

from memory head gasket is 0.2mm thick so going over to o rings will close up the squish by that amount.

I use 2.364" x 0.070" viton o rings. Where I got them from wasn't cheap - I am sure you can do better.

Rest of head sealed using h***a 3 bond.