Cylinder head question

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Sitnlow4life
Posts: 60
Joined: Sat Mar 18, 2017 12:45 pm
Location: Detroit

Cylinder head question

#1 Post by Sitnlow4life » Sun Aug 06, 2017 3:54 pm

Ok I have a 1990 RZ350 so it has the 1UA cylinders and head.

I have heard nothing but good things about bumping the compression up on the 84-85 USA bikes .

The chamber on the USA bikes are 23cc stock and apparently going to 21cc makes a difference and you can still run pump gas.

Does anyone know the chamber size for the 1UA Canadian model bikes ?

I heard they are already smaller then the USA model , so will reducing it further help me at all ?

Any information is greatly appreciated as usual .

Thanks
Todd
Last edited by Sitnlow4life on Sun Aug 06, 2017 5:33 pm, edited 1 time in total.
1990 RZ350 with Toomey Pipes and Vforce Reeds

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

Re: Cylinder head question

#2 Post by Hooligan » Sun Aug 06, 2017 5:20 pm

O-ring the head and eliminate the head gasket. That will bump compression and narrow up the squish band, both of which are good.
'82 RD350LC in '81 colours, OEM pipes, UNI filters
'85 FZ750

hondaror
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Re: Cylinder head question

#3 Post by hondaror » Sun Aug 06, 2017 6:24 pm

You don't want more compression...unless of course you want to ride a grenade.
Rory
2 1984 RZ350s
1985 RZ350
9 1986-1990 RZ350s
2000 ST2
2005 749
2005 749 with 999 engine

Sitnlow4life
Posts: 60
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Location: Detroit

Re: Cylinder head question

#4 Post by Sitnlow4life » Sun Aug 06, 2017 9:44 pm

Hooligan wrote:O-ring the head and eliminate the head gasket. That will bump compression and narrow up the squish band, both of which are good.
So don't mess with the done area ? Just oring it and call it good ?

The difference in squish between gasket and no gasket will make it worth it ?

I have a Y3 head
1990 RZ350 with Toomey Pipes and Vforce Reeds

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T.RexRacing
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Re: Cylinder head question

#5 Post by T.RexRacing » Sun Aug 06, 2017 9:54 pm

I'd have the chamber cut for whatever fuel you'll be running even the swill referred to as Pump Gas. Klemm Vintage specializes in just that.
There is only one difference between a madman and me. The madman thinks he is sane. I know I am mad.
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Hooligan
Posts: 1966
Joined: Mon Aug 20, 2012 1:37 am
Location: Calgary, Alberta

Re: Cylinder head question

#6 Post by Hooligan » Mon Aug 07, 2017 3:08 pm

Sitnlow4life wrote:
Hooligan wrote:O-ring the head and eliminate the head gasket. That will bump compression and narrow up the squish band, both of which are good.
So don't mess with the done area ? Just oring it and call it good ?

The difference in squish between gasket and no gasket will make it worth it ?

I have a Y3 head
You will need to measure the squish during assembly to make sure it is not too tight. I have two motors that only had the O-ring installed and no dome work and they worked out perfectly.
'82 RD350LC in '81 colours, OEM pipes, UNI filters
'85 FZ750

Sitnlow4life
Posts: 60
Joined: Sat Mar 18, 2017 12:45 pm
Location: Detroit

Re: Cylinder head question

#7 Post by Sitnlow4life » Tue Aug 08, 2017 8:48 am

Hooligan wrote:
Sitnlow4life wrote:
Hooligan wrote:O-ring the head and eliminate the head gasket. That will bump compression and narrow up the squish band, both of which are good.
So don't mess with the done area ? Just oring it and call it good ?

The difference in squish between gasket and no gasket will make it worth it ?

I have a Y3 head
You will need to measure the squish during assembly to make sure it is not too tight. I have two motors that only had the O-ring installed and no dome work and they worked out perfectly.
That is what I was thinking ...

Just ditching the head gasket and going to an oring might get me what I want for pump gas .
1990 RZ350 with Toomey Pipes and Vforce Reeds

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