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| discomog Member Since: 09 May 2015 Location: Notts/Lincs Border Posts: 2527   
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I have a spec sheet for the 4.2 but unfortunately does not give the CR. As you are probably aware the 4.2 is relatively rare compared with 3.9 or 4.6 and was only produced from 1994 to 1996. It unfortunately suffered from cylinder liner problems. Defender 90XS SW
Mini Countryman Cooper S Morgan Plus 8 |
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12th Jul 2018 8:48am |
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| LandRoverAnorak Member Since: 17 Jul 2011 Location: Surrey Posts: 11324
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A quick Google suggests that it's 8.94:1. This is the best reference that I found:
http://forums.roversnorth.com/showthread.p...-2-engines Darren 110 USW BUILD THREAD - EXPEDITION TRAILER - 200tdi 90 BUILD THREAD - SANKEY TRAILER - IG@landroveranorak "You came in that thing? You're braver than I thought!" - Princess Leia |
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12th Jul 2018 9:06am |
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| oneten110 Member Since: 02 Jul 2011 Location: Wish I was still in France Posts: 741
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Thank you gentlemen.
I have an early 4.2 in my One_Ten, from a scrapped RR Vogue LSE. No liner problems thus far, it uses hardly any oil or water and it works quite hard for its living. It is more economical than the previous 3.5  by about 2mpg |
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12th Jul 2018 6:04pm |
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| diesel_jim Member Since: 13 Oct 2008 Location: hiding Posts: 6093 
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Agree.... looking at the Russian EPC site at the 4.2 classic RR pistons (STC1191) then ending up at Turners website they state "STC 1191 Piston assembly including rings, gudgeon pin. 8.94:1CR " https://www.turnerengineering.co.uk/stc-11...2x20634396 |
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12th Jul 2018 7:29pm |
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| oneten110 Member Since: 02 Jul 2011 Location: Wish I was still in France Posts: 741
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Better take care of it then because crankshafts and real pistons are no longer available. Though apparently brit part do the pistons.
Lest anybody is wondering why the original question, I have just fitted a pair of late heads to the engine and used composite gaskets, I was wondering what difference it would make to the CR if I used original type tin gaskets |
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12th Jul 2018 7:58pm |
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| Devon-Rover Member Since: 22 Jan 2015 Location: South Devon Posts: 916 
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The difference would be marginal in terms of CR and it's effects Also can be found on Fb, Ytube, Insta & Twitter @4WDSouthwest
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12th Jul 2018 10:46pm |
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| oneten110 Member Since: 02 Jul 2011 Location: Wish I was still in France Posts: 741
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I am guessing that Land Rover reduced the size of the combustion chambers on the later heads (by 8cc) to compensate for the additional thickness of the composite gaskets?
If that is the case and with no additional factors, by my fairly basic reckoning changing from composite to tin gaskets would bump the CR from 8.94 to 11.03 |
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14th Jul 2018 6:35am |
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| discomog Member Since: 09 May 2015 Location: Notts/Lincs Border Posts: 2527
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oneten110, yes you're correct they reduced the volume from 36cc down to 28cc to compensate for using a composite gasket. I know on the 4.6 if you use a metal gasket it will increase the CR by 14% and on a 4.0 it will increase by 16% Defender 90XS SW
Mini Countryman Cooper S Morgan Plus 8 |
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14th Jul 2018 7:45am |
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