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What do I have here?
Posted: Sat May 04, 2013 2:00 pm
by nogger
I'm rebuilding my H2b but on closer inspection I seem to have a head I don't recognise. What's it off, I've never seen the engine run it came knackered. I'm assuming it won't make any difference.
The top is the one I've not seen?
The single ring is stamped 4 and multi rings is stamped 3.
Posted: Sat May 04, 2013 2:04 pm
by Tartan Triple
that looks to be re profiled so i would not use it
Posted: Sat May 04, 2013 2:20 pm
by nogger
Yeah!!! thanks for that Tartan I didn't notice that it has been skimmed as there is a difference in the height profile. It's the first time I 've had good look at everything as I just stripped it engine and sent it to get blasted. Even so they aren't a pair as the head dome is a different profile?
Posted: Sat May 04, 2013 7:13 pm
by Tartan Triple
looks like you need to find another head to make the set
Posted: Sat May 04, 2013 8:25 pm
by nogger
Yeah I guess I'll have to, anybody have spare outer head? So does anyone know what this might be off?
Posted: Sat May 04, 2013 8:42 pm
by Tartan Triple
looks like h2 but been worked on,multiple grooves on gasket face seem to be an attempt to seal the head.as for the profile of the head,it would be intresting if you had three the same,as some one has taken the time to re profile.
speak to scouse and leaon about head profile.
i :smt023
Posted: Sat May 04, 2013 9:14 pm
by Hal
The modified head has a double squish squish band. It is a common mod to increase performance and looks like the one that came with my FBG stage 111. Tthough I can't remember if that also had the multiple small grooves. You would likely have stratospheric compression if you tried to use it with cylinder having a standard exhaust port.
Posted: Sat May 04, 2013 9:18 pm
by Tartan Triple
+1
Posted: Sun May 05, 2013 4:46 pm
by scouse
not sure about the compression, I have double squish heads, which actually lower compression
Gary T
Posted: Sun May 05, 2013 7:17 pm
by Hal
How do you work that out then Gary? If it is skimmed and re-profiled properly the cc's left in the combustion chamber will be reduced, not increased.
Posted: Sun May 05, 2013 7:20 pm
by scouse
dunno, Leo did mine
but deffo easier to kick over than a standard H2
Gary T
m
Posted: Mon May 06, 2013 6:35 am
by downpipe3
leo re cuts his heads deeper to 29cc after squish bands are cut in
that head that nogger has looks like FBG as Hal said its probably 24cc and to add more to it if you rebore your heads should be recut to match the bore due to higher swept volume being compressed in the head
Re: m
Posted: Mon May 06, 2013 8:10 am
by scouse
downpipe3 wrote:leo re cuts his heads deeper to 29cc after squish bands are cut in
that head that nogger has looks like FBG as Hal said its probably 24cc and to add more to it if you rebore your heads should be recut to match the bore due to higher swept volume being compressed in the head
Always learning :smt023
Gary T
