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Bore size

Posted: Fri Jan 01, 2021 1:17 pm
by Gray
I have just roughly gauged the bores of my s block and it is reading about 72mm so does anybody know what size overbore that could equate to? Cheers Graeme

Re: Bore size

Posted: Fri Jan 01, 2021 1:23 pm
by steve1071
Standard S bore is 70.6mm, every 10 thou of an inch extra is plus 0.254mm. Plus 60 would give you just over 72mm

Re: Bore size

Posted: Fri Jan 01, 2021 3:12 pm
by whistler
According to the pdf file I have +0.060" is 72.17mm. How does that compare?

Re: Bore size

Posted: Fri Jan 01, 2021 4:33 pm
by Fanfaniracing
Same for me.

72mm with +60

Re: Bore size

Posted: Fri Jan 01, 2021 4:53 pm
by 251 ENG
72mm is 2.8347"

+60 is 2.840 "

Re: Bore size

Posted: Fri Jan 01, 2021 6:35 pm
by Gray
Cheers for the replies so it looks to be + 60 does that leave room for sleeving and if so what is the going rate?

Re: Bore size

Posted: Sat Jan 02, 2021 12:07 am
by CooperTune
I had a .060 Cooper S block under the bench for 20 years. I located a set of 73 mm pistons out of OZ. Have been running it since. Steve (CTR)

Re: Bore size

Posted: Sat Jan 02, 2021 11:59 pm
by steve1071
Pretty sure Keith Calver sells the Oz 73mm pistons

Re: Bore size

Posted: Sun Jan 03, 2021 12:49 pm
by LuisM
Keith Calver used to have a 72.5mm Piston, this would leave room for another rebore at 73mm .

cheers
Luis

Re: Bore size

Posted: Sun Jan 03, 2021 2:17 pm
by Fanfaniracing
Here you can have almost every possible and impossible piston size custom made:

https://wahl-spezialkolben.de/

I heard a lot from this enterprise and if i remember right, whe got our piston-rings for my 998 Cooper engine from there...

Re: Bore size

Posted: Sun Jan 03, 2021 3:58 pm
by wantafaster1
Calver ST also does 72.5 which would be an excellent save for +.060

Re: Bore size

Posted: Sun Jan 03, 2021 9:01 pm
by Gray
Cheers for all the input I will nip along to Spamspeed for him to cast an eye on it.