Generation III Internal Engine 1997-2006 LS1 | LS6
Sponsored by:
Sponsored by:

Too much DCR?

Thread Tools
 
Search this Thread
 
Old 07-07-2006, 11:50 PM
  #21  
LS1 Tech Administrator
iTrader: (14)
 
Patrick G's Avatar
 
Join Date: Nov 2001
Location: Victoria, TX
Posts: 8,245
Likes: 0
Received 32 Likes on 28 Posts

Default

Originally Posted by Beast96Z
Which is still a guesstimation, correct?
You know it!
__________________

2013 Corvette Grand Sport A6 LME forged 416, Greg Good ported TFS 255 LS3 heads, 222/242 .629"/.604" 121LSA Pat G blower cam, ARH 1 7/8" headers, ESC Novi 1500 Supercharger w/8 rib direct drive conversion, 747rwhp/709rwtq on 93 octane, 801rwhp/735rwtq on race fuel, 10.1 @ 147.25mph 1/4 mile, 174.7mph Half Mile.
2016 Corvette Z51 M7 Magnuson Heartbeat 2300 supercharger, TSP LT headers, Pat G tuned, 667rwhp, 662rwtq, 191mph TX Mile.
2009.5 Pontiac G8 GT 6.0L, A6, AFR 230v2 heads. 506rwhp/442rwtq. 11.413 @ 121.29mph 1/4 mile, 168.7mph TX Mile
2000 Pewter Ram Air Trans Am M6 heads/cam 508 rwhp/445 rwtq SAE, 183.092 TX Mile
2022 Cadillac Escalade 6.2L A10 S&B CAI, Corsa catback.
2023 Corvette 3LT Z51 soon to be modified.
Custom LSX tuning in person or via email press here.

Old 07-10-2006, 12:10 PM
  #22  
Launching!
Thread Starter
 
exSSer's Avatar
 
Join Date: Feb 2006
Posts: 270
Likes: 0
Received 0 Likes on 0 Posts
Default

Originally Posted by Patrick G
That gets me back to my original post of 278/282.
Turns out you're pretty close, Patrick. I phoned Crane, and got this further info.
ADV duration @ .006 is 281* intake, and 285* ex. So plugging in the other parameters for a stock bottom end LS6 with 61cc heads, I get an SCR of 11.17, and a DCR of 8.31 which should be OK with 92 octane, n'es pas?
Old 07-10-2006, 01:13 PM
  #23  
TECH Senior Member
 
PREDATOR-Z's Avatar
 
Join Date: Mar 2004
Location: BFE
Posts: 14,620
Likes: 0
Received 16 Likes on 16 Posts

Default

Oui, oui C'est bon comme cela.
Old 07-10-2006, 01:25 PM
  #24  
TECH Fanatic
 
ringram's Avatar
 
Join Date: Aug 2005
Location: Sunny London, UK
Posts: 1,691
Received 1 Like on 1 Post

Default

Zut alors
Old 07-10-2006, 04:54 PM
  #25  
Launching!
Thread Starter
 
exSSer's Avatar
 
Join Date: Feb 2006
Posts: 270
Likes: 0
Received 0 Likes on 0 Posts
Default

Oh great! This calculating business sure is fun. I've found even more bad data that skews the final #s. Crane now tells me there's 5* advance ground in, which would move my ICL to 107*. Also, I was figuring a MLS (stock GM) at .052 compressed, and should be .060. So anyway, the new #s make the final (Keerist, I hope) SCR @ 10.94, and the DCR @ 8.5. Still OK for pump gas, methinks.

Hope this combo runs good, Crane sure doesn't tell you all the particulars upfront.
Old 07-11-2006, 06:27 AM
  #26  
TECH Addict
iTrader: (11)
 
No Juice's Avatar
 
Join Date: Jan 2003
Location: Minnesota Corn Fields
Posts: 2,452
Likes: 0
Received 10 Likes on 9 Posts

Default

I thought the Stock GM or MLS gasket was 0.053 compressed??? Are you sure its 0.060??
Old 07-11-2006, 08:10 AM
  #27  
12 Second Club
iTrader: (6)
 
Viper's Avatar
 
Join Date: Dec 2001
Location: Cleveland, OH
Posts: 4,909
Received 3 Likes on 3 Posts

Default

I thought it was .052 compressed, that's the figures I've been using in calcs.
Old 07-11-2006, 10:52 AM
  #28  
TECH Enthusiast
 
MNR-0's Avatar
 
Join Date: Mar 2004
Location: Australia
Posts: 647
Likes: 0
Received 0 Likes on 0 Posts
Default

Originally Posted by exSSer
Oh great! This calculating business sure is fun. I've found even more bad data that skews the final #s. Crane now tells me there's 5* advance ground in, which would move my ICL to 107*. Also, I was figuring a MLS (stock GM) at .052 compressed, and should be .060. So anyway, the new #s make the final (Keerist, I hope) SCR @ 10.94, and the DCR @ 8.5. Still OK for pump gas, methinks.

Hope this combo runs good, Crane sure doesn't tell you all the particulars upfront.
I run essentially the same combo you are building. 11.4:1SCR, 10.5:1 idle CR and 9.5:1 DCR running. 57cc chambers, 2.5cc valve reliefs. Crane 228-232-112+5. Install the cam retarded 2* though. Mines installed straight up and for track work 2* retarded has shown to hold 400rwhp+ from 6000-7000RPM, very broad. This combo makes over 300rwkw here in OZ, or 400rwhp through a 4000 stalled A4. Bolt that through an M6 and expect 440rwhp or more. My idle vacuum is 55kPa, very idle friendly at 860RPM and a killer idle.

Best times similar combo over here 11.4@120MPH heavy *** commodore full weight 3600lbs. Are we feeling better?
Old 07-11-2006, 11:20 AM
  #29  
Launching!
Thread Starter
 
exSSer's Avatar
 
Join Date: Feb 2006
Posts: 270
Likes: 0
Received 0 Likes on 0 Posts
Default

Originally Posted by Viper
I thought it was .052 compressed, that's the figures I've been using in calcs.

I've gone through lots of old posts doing searches, and that's the figure that keeps coming up. At .052 my #s translate to 11.17, and 8.69 DCR.
edit: I checked the calculator. The stock '02+ MLS gaskets ARE .060 compressed, because using this figure, my stock CR computes to 10.48:1, which is correct.



Thanks to our down under brother. I'd planned on installing the cam dot to dot, and haven't a clue how to degree the thing. Hope that I get lucky, I guess. It'll run through a 6 speed, and also will be equipped with a ported FAST/LS2 90, and since the car only weighs about 3100, should be plenty fast.

Last edited by exSSer; 07-11-2006 at 01:19 PM.




All times are GMT -5. The time now is 05:19 AM.