O-ring head 4L0

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pdxjim
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O-ring head 4L0

#1 Post by pdxjim » Thu Jun 06, 2019 7:59 pm

Who’s done it?

What sealant do you use for the water jacket?
Wasting time on 2T forums since the dawn of the internet. RD350LC, TDR250, plated 300XCW. No four strokes.

tacky1
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Location: Pacifica,,

Re: O-ring head 4L0

#2 Post by tacky1 » Thu Jun 06, 2019 11:11 pm

I didn't do the 350, but both my 500s have O-Ringed heads, I didn't use any sealant, A little grease to hold the O-Rings in place and I let the rings do their job....
1985 RZv500
1984 RZ500 Hybrid
1986 RG500 Walter Wolf
1986 RG500 Skoal Bandit
1984 RZ350
1984 RZ350 Hybrid
1981 RD350LC
1981 RD350LC Hybrid
2009 CR500AF Supermoto 250X
2007 CR500AF 250X
1988 YSR50 (2)
1984 GPZ750 Turbo
1989 VFR750R RC30

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pdxjim
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Re: O-ring head 4L0

#3 Post by pdxjim » Thu Jun 06, 2019 11:22 pm

tacky1 wrote: Thu Jun 06, 2019 11:11 pm I didn't do the 350, but both my 500s have O-Ringed heads, I didn't use any sealant, A little grease to hold the O-Rings in place and I let the rings do their job....
So, are there O-rings for each of the openings at the water jacket?

Hard to describe, but the ones I've seen just have one big O-ring around the bore, and the water jacket is sealed with RTV or Threebond or something.
Wasting time on 2T forums since the dawn of the internet. RD350LC, TDR250, plated 300XCW. No four strokes.

tacky1
Posts: 950
Joined: Wed May 13, 2015 1:11 am
Location: Pacifica,,

Re: O-ring head 4L0

#4 Post by tacky1 » Fri Jun 07, 2019 2:27 am

Ah. The 500 heads have multiple o-rings. Every opening is covered.
1985 RZv500
1984 RZ500 Hybrid
1986 RG500 Walter Wolf
1986 RG500 Skoal Bandit
1984 RZ350
1984 RZ350 Hybrid
1981 RD350LC
1981 RD350LC Hybrid
2009 CR500AF Supermoto 250X
2007 CR500AF 250X
1988 YSR50 (2)
1984 GPZ750 Turbo
1989 VFR750R RC30

tacky1
Posts: 950
Joined: Wed May 13, 2015 1:11 am
Location: Pacifica,,

Re: O-ring head 4L0

#5 Post by tacky1 » Fri Jun 07, 2019 2:31 am

Found a few pics of the 500 heads.



Image

Image

Image

Image
1985 RZv500
1984 RZ500 Hybrid
1986 RG500 Walter Wolf
1986 RG500 Skoal Bandit
1984 RZ350
1984 RZ350 Hybrid
1981 RD350LC
1981 RD350LC Hybrid
2009 CR500AF Supermoto 250X
2007 CR500AF 250X
1988 YSR50 (2)
1984 GPZ750 Turbo
1989 VFR750R RC30

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pdxjim
Posts: 196
Joined: Sun Dec 30, 2018 9:24 pm
Location: Portland, Oregon!

Re: O-ring head 4L0

#6 Post by pdxjim » Mon Jun 10, 2019 4:01 am

Fancy!
Wasting time on 2T forums since the dawn of the internet. RD350LC, TDR250, plated 300XCW. No four strokes.

Hooligan
Posts: 1966
Joined: Mon Aug 20, 2012 1:37 am
Location: Calgary, Alberta

Re: O-ring head 4L0

#7 Post by Hooligan » Sat Jun 22, 2019 2:52 pm

pdxjim wrote: Thu Jun 06, 2019 7:59 pm Who’s done it?

What sealant do you use for the water jacket?
I've got two O-ringed LC motors. I use grey Motoseal to seal up the water passages.

My setup is a little different as it is the barrels that have the O-ring grooves cut into them rather than the head.
'82 RD350LC in '81 colours, OEM pipes, UNI filters
'85 FZ750

robakun
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Joined: Tue Jan 09, 2007 5:46 pm
Location: Torrance CA

Re: O-ring head 4L0

#8 Post by robakun » Mon Jun 24, 2019 2:00 am

No need for o ring head for the LC. buy a stock LC head gasket. take it apart and use only one layer of the wigly gasket. use YAMABOND on both sides and torque a little bit more. walla. high compression and excelent squish using a stock head. got 2 done like that. NO FUCKIN PROBLEMS!
Official LC whore.

Hooligan
Posts: 1966
Joined: Mon Aug 20, 2012 1:37 am
Location: Calgary, Alberta

Re: O-ring head 4L0

#9 Post by Hooligan » Mon Jun 24, 2019 10:04 pm

I've got a bag of 50 O-rings for about $25. Which means it costs $1 to do a head reseal. Doesn't get any cheaper or more effective than that.
'82 RD350LC in '81 colours, OEM pipes, UNI filters
'85 FZ750

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pdxjim
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Re: O-ring head 4L0

#10 Post by pdxjim » Tue Jun 25, 2019 12:56 pm

I agree, last I looked OEMLC head gasket was close to $80.
Wasting time on 2T forums since the dawn of the internet. RD350LC, TDR250, plated 300XCW. No four strokes.

LC Cnd
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Re: O-ring head 4L0

#11 Post by LC Cnd » Fri Jun 28, 2019 10:47 pm

Hooli is there a template for the groving for the LC o-ring parttern I can access (print) that you'd recommend? Like to consult with a local machinist to see if he can do it. Also how deep is the grooving?

Hooligan
Posts: 1966
Joined: Mon Aug 20, 2012 1:37 am
Location: Calgary, Alberta

Re: O-ring head 4L0

#12 Post by Hooligan » Sat Jun 29, 2019 1:05 am

The groove entirely depends upon the O-ring that goes in it. This is the O-ring I use in my motors. It is a standardized size (040)

https://www.amazon.com/040-Viton-Ring-D ... op?ie=UTF8

I measured the groove in my barrel and it is:
OD 2.965"
ID 2.800"
Depth .050"

I was mistaken on the cost. They are $1 each delivered so it costs $2 to lift and reseal the head. :smt005
'82 RD350LC in '81 colours, OEM pipes, UNI filters
'85 FZ750

LC Cnd
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Re: O-ring head 4L0

#13 Post by LC Cnd » Sat Jun 29, 2019 11:38 am

Merci! Any advantage in grooving the barrels vs the head? Squish perhaps.

Hooligan
Posts: 1966
Joined: Mon Aug 20, 2012 1:37 am
Location: Calgary, Alberta

Re: O-ring head 4L0

#14 Post by Hooligan » Sat Jun 29, 2019 1:03 pm

Its way easier to do the work. The barrels get put up in a lathe and cutting the groove is super easy. Done on manual equipment.

Grooving the head is way harder. Require way more setup and work holding and requires a CNC mill.
'82 RD350LC in '81 colours, OEM pipes, UNI filters
'85 FZ750

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two-stroke-brit
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Re: O-ring head 4L0

#15 Post by two-stroke-brit » Thu Jul 04, 2019 2:41 pm

ImageIMG_2971 by mark.dobson, on Flickr
i did this to my 350LC head after slinger re profiled the chambers to set proper squish dims.
all done on a manual mill with a rotary table.
i used 0.094 (actually .103) orings and the groove dims were 0.105 WIDE AND 0.078 DEEP.
As per the Parker o-ring book
mark
but as the previous poster stated easier to do the barrels
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

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