Compression Calculator
Thread Starter
Joined: Jun 2002
Posts: 4,281
Likes: 2
From: Colorado
Compression Calculator How accurate is this compression calculator?
http://www.rosspistons.com/CR%20Calculator.htm
For this setup, it gives a compression level of 12.42 <img border="0" title="" alt="[Eek!]" src="gr_eek2.gif" /> That seems very high.
Bore: 4.10
Stroke: 4.00
Head CC: 67
Head Gasket: 0.040 ( stock thickness )
Deck Height: 0.0001
Dish or Valve Pocket: 0.0
<small>[ September 23, 2002, 01:12 PM: Message edited by: ls1290 ]</small>
http://www.rosspistons.com/CR%20Calculator.htm
For this setup, it gives a compression level of 12.42 <img border="0" title="" alt="[Eek!]" src="gr_eek2.gif" /> That seems very high.
Bore: 4.10
Stroke: 4.00
Head CC: 67
Head Gasket: 0.040 ( stock thickness )
Deck Height: 0.0001
Dish or Valve Pocket: 0.0
<small>[ September 23, 2002, 01:12 PM: Message edited by: ls1290 ]</small>
On The Tree
Joined: Aug 2002
Posts: 149
Likes: 0
From: NorCal
Re: Compression Calculator Thread Starter
Joined: Jun 2002
Posts: 4,281
Likes: 2
From: Colorado
Re: Compression Calculator If this is true, are all the 422s out there running dish or inverted dome pistons? 12.4:1 compression would require at least 95 or 96 Octane gas if at sea level.
SSU Moderator
Joined: Nov 2001
Posts: 4,857
Likes: 0
From: Austin, TX
Re: Compression Calculator if you have vavle relief's (which you probably do) you have a 5cc dish. that alone is 11.73. the gasket is more like .047 or so after factoring in the negitive deck (.006) and the fact that stock gaskets are actually .053 as far as I know.
also, when i put 0cc relief, .047 for gasket, and stock ls1 measurements, surprise, i get 10.17 with a 68cc head. I have heard factory clearances as low at 67 and as high as 69cc's.
<small>[ September 23, 2002, 03:23 PM: Message edited by: Ryan ]</small>
also, when i put 0cc relief, .047 for gasket, and stock ls1 measurements, surprise, i get 10.17 with a 68cc head. I have heard factory clearances as low at 67 and as high as 69cc's.
<small>[ September 23, 2002, 03:23 PM: Message edited by: Ryan ]</small>
Launching!
Joined: Sep 2002
Posts: 297
Likes: 0
From: Clinton Twp. Mi
Re: Compression Calculator That is the correct compression ratio for the spec's that you have listed. Most guy's should be running a dish with the big inch LS1's, if they want to run it on pump gas. In another week we will be stocking 422 pistons for 6.125 rods and 4.000 stroke. In the following bores, 4.100, 4110, 4.120 and also 4.125. Let me know if you need anything.
Thanks,
Chris Gelineau
Diamond Pistons
877-552-2112 toll free
Thanks,
Chris Gelineau
Diamond Pistons
877-552-2112 toll free
