Overbore

QldRobbo · tinkerer Joined: 11 Apr 2002 Posts: 455

G'day,
Anyone know whats the maximum you can bore out a 1600? How many mm or thou can you add to the bore of this motor? I have a friend of a friend who says he bored a 1600 out by 10mm to make the capacity 2L without changing the stroke. That sounds a little much to me... is there really over a cm of spare metal on the cylinder walls?!

motoboy · tinkerer Joined: 19 May 2002 Posts: 152

my gems 1.6 is 60 thou over n i heard that was about the most u can go or the walls get to thin, i think 60 thou gets close to a 1.8 im not sure but thats my two cents
cheers

MR_GEMI · Posted: Mon Jul 08, 2002 3:46 pm Post subject: Re: Overbore

hahaha if 60 thou is as far as they go then im well over my water jackets.
i have a 216 thou overbore making it a total capacity of 1803cc.
A 60 thou overbore leaves total capacity of 1643cc.

hope that helps...

cheers,
kev
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TXcoupe · petrol head Joined: 05 Oct 2001 Posts: 1675

u can go on a 1600 up safely is 120 thou or 3mm and i think u might be able to go bigger on the 1800 and i think the 2L is the only one to be able to go 60 thou

and mark m,y bros G200 was sleeved and his cap was about 2.3

Ben Wight · backyard mechanic Joined: 04 Oct 2001 Posts: 946

a gemini bore is 82mm, a 2 litre bore is 87mm, so you can safely bore about 1.5mm past that, thats 6.5mm total.

The only problem is the 2 litre pistons have different pin heights, so you need different rods.

Ben Wight

QldRobbo · tinkerer Joined: 11 Apr 2002 Posts: 455

Yeah, thanks Ben, that's actually what I thought myself, don't know what these other guys are talking about.

So for anyone else who can't do the maths, a 1600 bored out to the max, which would be 88.5, and without modifying the stroke/crank actually makes 1844cc.

Robbo