decking engine cases

[nickh]

I have seen "decking" the cases mentioned here and there. am I right in thinking that the reason for it is so that the deck is true and that it will also allow a bit more flexibility in raising and lowering cylinders to get everything spot on. how much do you take off? I am thinking of changing from my procup 3 to the ET7 cylinder and think I need to machine off part of the flywheel volute so it would make sense to deck the engine at the same time.
cheers
Nick 

[henri]

its mostly done to get a bigger an safer gasket area ,aswell as adjusting squish . a et7 barrel can be matched to transfers on undecked cases with care an still have a 2-3mm gasket face . but recently all the et7 iron barrels ive had give a 1.6-1.7 squish out the box without a gasket . so been taking 1mm off the base an using a .5mm gasket .giving a 1.2mm squish at the end .H

[nickh]

Cheers H, any machine shops in the south east you can recommend that have done the work previously?
thanks
Nick 

[henri]

i use southern rebore ,there not cheap but are very good ,http://www.southern-rebore.com/ . they will need clean cases ,without bearings in an bolted together .an also do hot washing an aqua blasting .H

[jonnysnatchsniffer]

if you have the money the sip cases have already been done, as unlees you get it done for beer money, ive been quoted over 400 quid for this work and then found someone to do it for
£15, which then turned into 25 later when i had cases coming out my ears to get it done 4 peeps on here.
what kit and crank are you using as with a 105mm rod, a 110mm rod may be better tho. you can make a packer so as not to need the case gasket face to be milled
this can also be used to get port times where you want, but maybe not time area, really ther isnt much to be gained from making
the transfers on the case and barrel big as fuck, granted it give you more volume in the crankcase which could be good
looking at the et7 cylinder how do the aux ex ports miss the studs? what is et7 a copy of? it does have a lot of ports but oversquare
what does this kit do? as a rotary its gonna need a big carb around 220 dgrees of inlet and a fucking good crank

[nickh]

I don't know what it is a copy of. the procup is a copy of a quatrini I think. The transfers were blended to match the procup which it turns out are the same on the ET7 but the ET7 cylinder needs the bit of the casing next to the cylinder removing so the cylinder fits. I have a choice of carbs, I was going to start with a PHBH 26 and take it from there. David at on small wheels suggested a BGM crank.

[henri]

the procup started out as a quatt m1 56 mk1 copy ,but is on its 3rd version now an quite different .the et7 isnt a copy at all ,an needs top of stator surround removing .an also a lightened flywheel if using stock ignition to not rub .H

[jonnysnatchsniffer]

if it makes more than 20hp the bgm will struggle to stay inline unless you weld and loctite it, not many good cranks for standard cases, maybe 3, the falc, the fabrizi and possibly the sip bell cranks