Thoughts on Cam given 9.5:1 (Lunati 10420704LK)

Thread Tools
 
Search this Thread
 
Old Mar 4, 2014 | 04:41 PM
  #1  
VinMichael's Avatar
Thread Starter
Registered User
 
Joined: Mar 2011
Posts: 558
Thoughts on Cam given 9.5:1 (Lunati 10420704LK)

455 around 9.5:1. ProComp heads. Running 91 octane. Want to run 12's but will drive it on the street a good amount as well.

RPM Range: 2000 - 6000
Lift with 1.6 Rocker: .522"/.539"
Duration @ .050": 233/241
Advertised Duration: 276/284
LSA: 110/106


It comes in 106 and 110 LSA

Lately I've been looking at intake duration @ .050 because from what I read it's detrimental:

I'm getting DCR at 8.0:1 with 106 LSA
I'm getting DCR at 7.8:1 with 110 LSA

7.5:1 - 8.5:1 being ideal DCR for 91 octane, erring on under 8.25:1 for less chance of knock.

But anyone know why it says it's for a 350 and how is "heavier vehicle" per 455 defined?

"Hot street or bracket cam for 350 c.i. engines or heavier 400-455 c.i. vehicles. Will need 9.5+ compression, 2800-3000 RPM stall converter and 3.42-3.73 gears. Likes up to 200 HP nitrous. Very rough idle quality."

Does this look good or would it be worth it to up static and therefore be able to run longer intake duration to reach my goals while staying within 7.5:1 - 8.5:1 dynamic?

Last edited by VinMichael; Mar 4, 2014 at 04:45 PM.
Old Mar 5, 2014 | 04:57 AM
  #2  
grampy's Avatar
Registered User
 
Joined: Sep 2013
Posts: 77
even if you had iron heads you could run 91 octane with 9.5 compression . I have a iron head 455 close to what you got 9.6 compression and it can run on 89 octane 230 @ 50 installed at 105 centerline. cranking compresstion 170 psi I pull 14 inches of vacume @750 rpm. That cam is on the edge of haveing good low end part throttle TQ. it will be fine for a 455 with 342 gear and a 2500 stall , but in a 350 it is a little too big and would be a little soggy down low and would need more gear more stall. the trick for me is you need a camshaft that gives at least 160 cranking psi (or it will be a lazy dog )and no more than 190 to 200 psi to run pump gas with a streatable camshaft . say with a camshaft with 240@ 50 max any bigger than that is not really street cam.

Last edited by grampy; Mar 5, 2014 at 06:19 AM.
Old Apr 6, 2014 | 01:10 PM
  #3  
VinMichael's Avatar
Thread Starter
Registered User
 
Joined: Mar 2011
Posts: 558
Originally Posted by grampy
even if you had iron heads you could run 91 octane with 9.5 compression . I have a iron head 455 close to what you got 9.6 compression and it can run on 89 octane 230 @ 50 installed at 105 centerline. cranking compresstion 170 psi I pull 14 inches of vacume @750 rpm. That cam is on the edge of haveing good low end part throttle TQ. it will be fine for a 455 with 342 gear and a 2500 stall , but in a 350 it is a little too big and would be a little soggy down low and would need more gear more stall. the trick for me is you need a camshaft that gives at least 160 cranking psi (or it will be a lazy dog )and no more than 190 to 200 psi to run pump gas with a streatable camshaft . say with a camshaft with 240@ 50 max any bigger than that is not really street cam.
Right on. I like your reference to personal experience regarding PSI in the cylinder. Trying to learn about this stuff; trying to put some meaning on these numbers.
Old Apr 6, 2014 | 01:38 PM
  #4  
70cutty's Avatar
Beer Connoisseur
 
Joined: Aug 2008
Posts: 2,092
From: Daly City, California
Ask Mark (Cutlassefi) to grind you a custom cam for your engine. The cost is about the same. He has helped many here, great guy to deal with.
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
bluecab
Parts For Sale
8
Nov 28, 2014 12:42 PM
nicks1966
Parts For Sale
0
Jan 1, 2013 04:51 PM
1971viking
Big Blocks
12
Nov 12, 2012 02:31 PM
64Rocket
Parts For Sale
5
Sep 22, 2012 03:00 PM
70oldscutlass
Parts For Sale
0
Apr 23, 2010 08:56 AM




All times are GMT -7. The time now is 02:06 PM.