RE: compression

[Geordie Smith]

But isn't normal air pressure 1 bar or 14.7psi So your taking 14.7psi of regular air, compressing it with the piston to 150psi so that gives you a squish ratio.   150psi / 14.7psi would equal 10.2:1 compression ratio.   How many cranks of the engine do you do to get 150psi tho? You can't tell me that each crank gives you 150psi. Nor can you say that *ALL* the air is expelled between cranks, hence a regular compression gauge gives you somewhat of a build-up of pressure by cranking the engine over 4 or 5 turns to get your 150psi.       -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]]On Behalf Of CM510 Sent: Wednesday, 16 January 2002 10:05 PM To: [EMAIL PROTECTED] Subject: Re: compression Don't think you can do it that way mate, cam timing and valve overlap play a part in the actual cranking psi, ie. wild cam equals low psi due to both inlet and exhaust valves over-lapping.   Just for the record, my sr20det is 150psi.   Cheers,   Cam CM510 www.sprite.com.au/cm510 ----- Original Message ----- From: FJ510 To: [EMAIL PROTECTED] Sent: Wednesday, January 16, 2002 10:01 PM Subject: Re: compression when i said compression relating to PSI i meant when you do a comp test..   i.e.  160psi on all 4 cylinders (what does that equate to) or can't you work it out from just that?   what is the calculation, i saw it somewhere the other day but forgot to save the email (or webpage) ----- Original Message ----- From: FJ510 To: [EMAIL PROTECTED] Sent: Wednesday, January 16, 2002 6:52 PM Subject: Re: compression sorry, also the intercooled and non-intercooled skylines had different CR's i'm told the intercooled used a "taller piston" (maybe flatter) and the non-intercooled a lower compression piston.  this is from a guy at nissan who imports genuine nissan pistons all the time and has the parts microfiche with all the different specs for pistons.     ----- Original Message ----- From: Terry Rudd To: [EMAIL PROTECTED] Sent: Wednesday, January 16, 2002 6:37 PM Subject: RE: compression Early Gazelle CR is 8.0:1 Late Skyline CR is 8.5:1 and came in intercooled and non-intercooled.   There isn't a direct relationship between CR and boost levels as such but the theory is that you can you higher boost on lower CR engines with everything else being equal.   regards Terry -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]]On Behalf Of FJ510 Sent: Wednesday, 16 January 2002 7:37 PM To: [EMAIL PROTECTED] Subject: compression anyone know the standard compression ratios for   1)        FJ20 Turbo (non-intercooled)         2)        FJ20 Turbo (intercooled)     ??     and also is their a direct conversion for compression ratio to psi and vice versa?     --membersozdat------------------------------------------------------- OZDAT Mailing List Please Note:- Send (un)subscribe requests to [EMAIL PROTECTED] Send submissions to [EMAIL PROTECTED] No unauthorised redistribution of this email http://www.ozdat.com/ozdatonline/index.htm http://www.ozdat.com/ozdatonline/listindex.html http://www.mail-archive.com/membersozdat@datascribe.com.au/ --------------------------------------------------------------------- --membersozdat------------------------------------------------------- OZDAT Mailing List Please Note:- Send (un)subscribe requests to [EMAIL PROTECTED] Send submissions to [EMAIL PROTECTED] No unauthorised redistribution of this email http://www.ozdat.com/ozdatonline/index.htm http://www.ozdat.com/ozdatonline/listindex.html http://www.mail-archive.com/membersozdat@datascribe.com.au/ --------------------------------------------------------------------- --membersozdat------------------------------------------------------- OZDAT Mailing List Please Note:- Send (un)subscribe requests to [EMAIL PROTECTED] Send submissions to [EMAIL PROTECTED] No unauthorised redistribution of this email http://www.ozdat.com/ozdatonline/index.htm http://www.ozdat.com/ozdatonline/listindex.html http://www.mail-archive.com/membersozdat@datascribe.com.au/ --------------------------------------------------------------------- --membersozdat------------------------------------------------------- OZDAT Mailing List Please Note:- Send (un)subscribe requests to [EMAIL PROTECTED] Send submissions to [EMAIL PROTECTED] No unauthorised redistribution of this email http://www.ozdat.com/ozdatonline/index.htm http://www.ozdat.com/ozdatonline/listindex.html http://www.mail-archive.com/membersozdat@datascribe.com.au/ --------------------------------------------------------------------- --membersozdat------------------------------------------------------- OZDAT Mailing List Please Note:- Send (un)subscribe requests to [EMAIL PROTECTED] Send submissions to [EMAIL PROTECTED] No unauthorised redistribution of this email http://www.ozdat.com/ozdatonline/index.htm http://www.ozdat.com/ozdatonline/listindex.html http://www.mail-archive.com/membersozdat@datascribe.com.au/ --------------------------------------------------------------------- --membersozdat------------------------------------------------------- OZDAT Mailing List Please Note:- Send (un)subscribe requests to [EMAIL PROTECTED] Send submissions to [EMAIL PROTECTED] No unauthorised redistribution of this email http://www.ozdat.com/ozdatonline/index.htm http://www.ozdat.com/ozdatonline/listindex.html http://www.mail-archive.com/membersozdat@datascribe.com.au/ ---------------------------------------------------------------------