Yes I know "here we go again"

I am in the planning stage again to sort the issues with my 124"
I have read a number of times that setting Squish between .030 and .040' is desired.
 
Is .030" pushing things a bit much? I have 0.000' deck height, using a 030" HG I am wondering how that will go down the track with any carbon build up.
I am trying to come up with a chamber volume that will allow me to run different cams by swapping out head and or base gaskets.
 
My preference is to use .040" head gasket .000" deck and cut the heads to 88 cc and get 11.3:1 CP, With the 640's that should get me at 194 CCP.
If I can then change the base gasket to get -.010" deck height and .040" hg it should drop to 11:1 and let me run the 625's at 197 ccp
 
I like simple options.
 
So are there any real faults with what I am currently planning?
and
where can I get custom base gaskets made?
Cometic only has .010" and .020" for base and I would need .030 for this to work or a .050 HG
 

I run my 625 cams at 11.3/1 comp and they love it even with 91 octane fuel

if ya heads have external breathers and the tune is good then carbon build up isn't an issues

.030" HG would be my choices

Interesting, have you been able to do a ccp on it or are they easy starts? should be near 200 which I thought was a bit high. Mine is the best part of 100kgs more than yours also
Mine is ext breather but over time there will likely be some carbon build up I would think.

yep 200psi is correct

I sent an email recently to Scott Palmer (Hillside Cycles) verifying a quote he made in one of the yanky forums, that a good CR for the S&S 625s in a 113" would be 11.25:1 & could go more. I asked also what would be ideal for a 120" engine that I'm putting together, & his words were "Yes, that .625 will optimize right in those numbers on both engines." So your planned 11.3 CR would work for both cams, I would think. I'm with Ando on the HG choice. - Rob

setting the squish close is good but you will have to watch out for the piston clearance for & aft as it rocks over tdc ,  i use to shamfer my pistons down in this area , best do not rev her untill she is  hot so the barrel can grow & give more piston clearance to head clearance , @ high rev things change a little bit in that the crank will flex & the main & bigend bearings take up with load etc  eg a 498c.c motor could be 510 c.c or 520 c.c.  even  @ 7,000 rpm 

You can stack the base gaskets, or cometic will make you a custom size.

cheers guys, not to keen on stacking gaskets but I think I can get copper made to suite so I will look into that.
Hear you daddy on the tight squish .035 -.040 is my preference. I can get off the shelf .030", .040" and .043" and I guess copper any where else I decide.
Still think 200ccp is a bit much for a heavy bike like mine. sure might liven up the bottom end but would cause some heat issues as well and this thing already runs hot.

I will run the 625's as it is now and see how that turns out and then if necessary bump the CP 11.2 -11.3 and drop the 640'S back in. I will spin it and just tune full throttle and do the compares to see what is working best if the 625's don't change things enough.
Also got an elliptical 58mm HPI 2 piece throttle body for it to try out

cheers I will keep them in mind if I end up going that way.
It's called Annealing, do the same thing with copper washers on sump plugs

yes my spelling is not the best @ 1.30 am  when on pain killers 

no problem mate spelling isn't my best subject either.
I actually thought you just forgot what it was called.
I get that way some times I can't remember where I live.
About 6 months ago I was getting fuel and suddenly realized I had gone 1 1/2 hrs past home, no wonder I needed fuel. bitch to be getting on in years

I'm at 34 and 32 on my engine with james fiber gaskets also breathing to atmosphere with a good warm up before riding to let engine stretch and also warm up the forged CP slugs. No problems after 10.000 K's at 195 ccp 

Where's June thought she be here on this thread

She would be busy cleaning up the oil under the BSA and checking all the bolts haven't falling out after the last ride.

PM sent June