Cylinder head o ringing
Moderator: rztom
Cylinder head o ringing
Can anybody tell me some info on the cylinder sealing o ring mod?? I'm wanting to do this for my air cooled rd. Will they overheat and fail, can I use the ones designed for the banshee or would they be different. And what the spec for the trench. I've read up some but doent see info for the rd
Re: Cylinder head o ringing
You'd be better off using a copper headgasket and annealing it every time you take the head off.
Last edited by justind97 on Tue Feb 21, 2017 10:12 am, edited 1 time in total.
- two-stroke-brit
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Re: Cylinder head o ringing
a guy on the Kawi triple forum has a H2 which he o-ringed the heads many years ago and highly recommends it.
there is a guide by "parker" that supplies the info needed to cut the groove.
generally its 3/4 of the o-ring thickness deep.
mark
there is a guide by "parker" that supplies the info needed to cut the groove.
generally its 3/4 of the o-ring thickness deep.
mark
350LC,Athena 392 big bore,stock porting,swiss cheese air box,stock reeds,spec11 pipes.(now TSA big bore pipes)
She might not be pretty but she will always be a fun ride
1982 YAMA RD350LC
98KDX 220R
1967 TRIUMPH TIGER
2001 TRIUMPH TT600
She might not be pretty but she will always be a fun ride
1982 YAMA RD350LC
98KDX 220R
1967 TRIUMPH TIGER
2001 TRIUMPH TT600
Re: Cylinder head o ringing
I use them with the air cooled 250 350 and 400 engines
Re: Cylinder head o ringing
Oring'ing a head is a viable method of sealing, air-cooled or water cooled. Copper gaskets are definitely easier.
Be aware you are changing the compression ratio and squish by removing the head gasket.
For RD400s I mill a 2mm wide, 2mm deep, 75mm OD trench. Most cut the head on a lathe, I made a fixture for my rotary table... don't ask.
I suggest you get the oring (nitrile or better) THEN decide on the dimensions of the trench.
... if you go to the trouble of oring'ing the head; Install locating pins at the same time.
Be aware you are changing the compression ratio and squish by removing the head gasket.
For RD400s I mill a 2mm wide, 2mm deep, 75mm OD trench. Most cut the head on a lathe, I made a fixture for my rotary table... don't ask.
I suggest you get the oring (nitrile or better) THEN decide on the dimensions of the trench.
... if you go to the trouble of oring'ing the head; Install locating pins at the same time.
Re: Cylinder head o ringing
any 2-troke should be O-ringed (water and air), it's so much easier and you can open your engine anywhere/anytime as almost all the times the rings are re-usable.
O-rings can not be squeezed together, only deformed. therefore, the cross-section of the groove needs to be just a tiny bit bigger than the cross-section of the ring.
I always make the groove 20% less deep than the thinckness of the ring.
a 2mm ring has a cross section of 1x1xpi = 3.1415
so a 20% groove is 2x1.6 = 3.2mm²
and remember to use viton O-rings, they can handle the high temp's !
O-rings can not be squeezed together, only deformed. therefore, the cross-section of the groove needs to be just a tiny bit bigger than the cross-section of the ring.
I always make the groove 20% less deep than the thinckness of the ring.
a 2mm ring has a cross section of 1x1xpi = 3.1415
so a 20% groove is 2x1.6 = 3.2mm²
and remember to use viton O-rings, they can handle the high temp's !
if it runs, you can race it !
Re: Cylinder head o ringing
Where would be a good place to get o rings
Re: Cylinder head o ringing
I bought mine off evilbay. Pack of 25 for not much.
Dave
Dave
RZ 250 85 (Waiting)
RZ 250 85 (Parts)
RGV VJ21 250, Australian Speed Record Holder, MPS/G 250, 140.5 MPH
BMW R1100S 99 (Its Red)
BMW R1200GS (Its BIG)
http://www.dlra.org.au/index.htm" onclick="window.open(this.href);return false;
RZ 250 85 (Parts)
RGV VJ21 250, Australian Speed Record Holder, MPS/G 250, 140.5 MPH
BMW R1100S 99 (Its Red)
BMW R1200GS (Its BIG)
http://www.dlra.org.au/index.htm" onclick="window.open(this.href);return false;
- two-stroke-brit
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- Posts: 1701
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Re: Cylinder head o ringing
mc master carr has a tremendous selection .4cyl h2 wrote:Where would be a good place to get o rings
but may not ship to you depending on your secret location
350LC,Athena 392 big bore,stock porting,swiss cheese air box,stock reeds,spec11 pipes.(now TSA big bore pipes)
She might not be pretty but she will always be a fun ride
1982 YAMA RD350LC
98KDX 220R
1967 TRIUMPH TIGER
2001 TRIUMPH TT600
She might not be pretty but she will always be a fun ride
1982 YAMA RD350LC
98KDX 220R
1967 TRIUMPH TIGER
2001 TRIUMPH TT600
Re: Cylinder head o ringing
Most industrial supply houses also carry them, I got a bag of 50 locally for around $30.
Re: Cylinder head o ringing
Ok so what size should I be looking for and how smooth do the cylinder deck and head have to be ?
It's no problem for me to lathe the cylinder top and cut the groove but I also need specs for the o ring groove and don't know how smooth I can cut them
It's no problem for me to lathe the cylinder top and cut the groove but I also need specs for the o ring groove and don't know how smooth I can cut them
- two-stroke-brit
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- Posts: 1701
- Joined: Fri Nov 22, 2013 10:49 pm
- Location: Houston texas
Re: Cylinder head o ringing
i would think if the copper gasket is removed ,the chamber would need to be re profiled as well to get proper squish and compression.4cyl h2 wrote:Ok so what size should I be looking for and how smooth do the cylinder deck and head have to be ?
It's no problem for me to lathe the cylinder top and cut the groove but I also need specs for the o ring groove and don't know how smooth I can cut them
350LC,Athena 392 big bore,stock porting,swiss cheese air box,stock reeds,spec11 pipes.(now TSA big bore pipes)
She might not be pretty but she will always be a fun ride
1982 YAMA RD350LC
98KDX 220R
1967 TRIUMPH TIGER
2001 TRIUMPH TT600
She might not be pretty but she will always be a fun ride
1982 YAMA RD350LC
98KDX 220R
1967 TRIUMPH TIGER
2001 TRIUMPH TT600
Re: Cylinder head o ringing
Does it matter if the groove is put in the head or the top of the sleeve?
Re: Cylinder head o ringing
I did both and prefer the cylinder.
If you cut the head, there's always a risk of the ring falling out of the groove during engine assembly ...
If you cut the head, there's always a risk of the ring falling out of the groove during engine assembly ...
Bye
Martin
Martin
- two-stroke-brit
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- Posts: 1701
- Joined: Fri Nov 22, 2013 10:49 pm
- Location: Houston texas
Re: Cylinder head o ringing
if you have the choice the cylinder is preferable as martin saysMK wrote:I did both and prefer the cylinder.
If you cut the head, there's always a risk of the ring falling out of the groove during engine assembly ...
350LC,Athena 392 big bore,stock porting,swiss cheese air box,stock reeds,spec11 pipes.(now TSA big bore pipes)
She might not be pretty but she will always be a fun ride
1982 YAMA RD350LC
98KDX 220R
1967 TRIUMPH TIGER
2001 TRIUMPH TT600
She might not be pretty but she will always be a fun ride
1982 YAMA RD350LC
98KDX 220R
1967 TRIUMPH TIGER
2001 TRIUMPH TT600