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Little Louis
Field Plougher
Joined: February 8th, 2009, 12:07 am Posts: 2357
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 8.5:1 and 9:1
Where's the difference, the piston, barrel or both?
Fanks
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April 24th, 2011, 8:27 pm |
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Russell
Firing on two.
Joined: November 29th, 2008, 10:05 pm Posts: 9259 Location: West Sussex, U.K.
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 Re: 8.5:1 and 9:1
Piston. Barrels are all the same.
_________________
samfieldhouse wrote: What I like about I2F is that there is no pretence of democracy.
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April 24th, 2011, 8:28 pm |
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Little Louis
Field Plougher
Joined: February 8th, 2009, 12:07 am Posts: 2357
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 Re: 8.5:1 and 9:1
Awesome, thanks Russ 
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April 24th, 2011, 8:34 pm |
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andyx
2CV Fan
Joined: March 31st, 2011, 3:09 pm Posts: 45 Location: Basildon
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 Re: 8.5:1 and 9:1
So if your barrels are ok all you need are a set of pistons and rings for a cheap upgrade or am I missing something?
_________________ Life begins at the end of your comfort zone
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April 24th, 2011, 10:02 pm |
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Russell
Firing on two.
Joined: November 29th, 2008, 10:05 pm Posts: 9259 Location: West Sussex, U.K.
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 Re: 8.5:1 and 9:1
Yes, although if you're buying a set of new pistons and rings you might aswell buy barrels too. I don't think it's much more expensive.
_________________
samfieldhouse wrote: What I like about I2F is that there is no pretence of democracy.
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April 24th, 2011, 10:05 pm |
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ken
Agony Aunt - You have a car problem? Speak to Ken
Joined: March 6th, 2009, 1:40 am Posts: 3675
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 Re: 8.5:1 and 9:1
Yep, if your 8.5:1 pistons and the barrels are in good condition, machining 0.25mm off the top of the barrels will increase the effective CR to close to 9.0:1... ken andyx wrote: So if your barrels are ok all you need are a set of pistons and rings for a cheap upgrade or am I missing something?
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April 24th, 2011, 10:35 pm |
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Jonathan
Firing on two.
Joined: January 1st, 2009, 7:37 pm Posts: 4708 Location: Disunited Kingdom
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 Re: 8.5:1 and 9:1
I'll be looking to replace the barrels and pistons on my 2CV soon, but will keep with 8.5:1 as the bottom end would still have done over 205 thousand miles and I wouldn't want to put too much extra stress on it.
_________________ 1988 built (1989 F-registered) Citroën 2CV-Six 2013 (63-Plate) VW Golf SE 1.4TSI BMT DSG7 1932 Morris Minor Open Two-Seater (The £100 car).

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April 24th, 2011, 10:44 pm |
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Devils Advocate
Firing on two.
Joined: July 26th, 2009, 3:36 pm Posts: 1019
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 Re: 8.5:1 and 9:1
What increase in power are we talking about - 3 or 4 bhp? (I'd have thought that would be 'noticeable'?)
Will it still be as **cough** 'smooth' at tick-over?
Thanks.
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April 25th, 2011, 1:31 pm |
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Nelsthebass
Firing on two.
Joined: October 5th, 2009, 8:22 pm Posts: 1415 Location: Stone, Staffs
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 Re: 8.5:1 and 9:1
Dont think you will notice any difference in tick-over smoothness - even if you put 8.5's on you will notice a big difference over an old tired engine and rings
_________________ 1987 2CV Special 2014 Suzuki Swift Sport 2015 Lexus NX300h 1966 Ami Break
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April 25th, 2011, 1:40 pm |
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spanners
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 Re: 8.5:1 and 9:1
^^^ What he said^^^
Even just taking the heads off the Ami and "lapping" them back in has made a massive difference!
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April 25th, 2011, 1:42 pm |
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