[6pack] TOO MUCH COMPRESSION

[Mark Hooper]

Hi John:

Just to note that there are quite a few high-compression standard engines out
there today. I have a 2006 DTS with a Northstar V8. The standard compression
ratio is between 10:1 and 10.3:1. Following the introduction of the
coil-on-plug model in 2000 premium fuel was no longer required. However, my
TR6 used to run on awfully unless I put at least 90 octane fuel in the tank.
It has a slightly shaved head, but I don't think it is over 9:1 CR. So the
fuel octane requirement seems to be more related to specific engine
construction than any precise compression ratio.

Cheers,

Mark


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From: 6pack-bounces at autox.team.net [6pack-bounces at autox.team.net] On Behalf Of
John Mc  [john.mcmaster at netspeed.com.au]
Sent: July 5, 2010 9:03 PM
To: 6pack at autox.team.net
Subject: Re: [6pack] TOO MUCH COMPRESSION

Thanks for all the input into my dilema!  From most of the comments, I think I
should be OK with it as is.
Definitely not going to use two gaskets!  The compression is closer to 9.8:1
(averaged across all cylinders
after a re-measure) and given that we have 98 RON premium petrol here, it's
probably not going to cause too
many detonation issues. Worst case, I'll have to run some octane booster!
Thanks again,

John Mc
'71 TR6 PI
'76 Dolomite 1850
'76 Dolomite Sprint
'64 2000 Estate
"Fast is First"
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