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the right cam  
mrhuntdwn
New User | Posts: 30 | Joined: 06/08
Posted: 06/08/08
03:52 PM

i have a 454 that came out of a rusted suburban. this is my first big block build. i plan on stuffing it in my 74 cheyenne pick up. im going to use the summit heads for the big block chevys. i plan on using the 200 shot of spray. the cam i want to use the nx274h or the n+ls6 nostalgia cam. both are by the comp and the 274 has a 113 and the ls6 has 112 lsa. question is if i use the nx274h will i make good power off the juice especially at the lower end? i'm looking at 9.3 to 9.5 to 1 with dish pistons. i need to know is running a nitrous cam in a daily driven application a strong choice. also has anybody ran both cams and were satisfied with performance? any advice is GREATLY appreciated  


 
GibTG
Moderator | Posts: 1334 | Joined: 10/03
Posted: 06/08/08
05:13 PM

A narrow lobe separation angle would benefit midrange torque production, but this would be at full throttle of course...

The difference in power between a 108° LSA and 112° may be less noticeable with the induction being restricted by a closed throttle.

Basically all OE vehicles have used very wide lobe separation angles on their cams for decades, so this is probably a fine idea for a ride that is frequently street driven.

Something is wrong with your compression ratio calculation I imagine. That sounds very high for a 454 with dished pistons.  


 
mrhuntdwn
New User | Posts: 30 | Joined: 06/08
Posted: 06/09/08
01:26 PM

the heads from summit have a 308 intake runner with 119cc chambers. so whats the CR then? will big block perform well with a 750 cfm carb or am i goin to go bigger?  


 
GibTG
Moderator | Posts: 1334 | Joined: 10/03
Posted: 06/09/08
02:53 PM

The intake runner does not affect static compression...

Head gasket volume, piston dome or dish volume, and piston to deck clearance affect compression most significantly.

A 750 carb should be alright for around a 400-425 horse engine.  


 
mrhuntdwn
New User | Posts: 30 | Joined: 06/08
Posted: 06/09/08
05:25 PM

ok gor the carb part. but using the 119cc with dished pistons with stock deck height and gasket thickness of .043 or .062. dont know about dish volume. can u help me out on that?  


 
GibTG
Moderator | Posts: 1334 | Joined: 10/03
Posted: 06/09/08
08:55 PM

The dish volume shouldn't be a difficult spec to find. Any aftermarket piston manufacturer almost has to give it. What pistons are you planning on using?  


 
mrhuntdwn
New User | Posts: 30 | Joined: 06/08
Posted: 06/12/08
06:59 PM

i plan on hrc dished pistons. forged of course  


 
GibTG
Moderator | Posts: 1334 | Joined: 10/03
Posted: 06/13/08
09:21 AM

A part number perhaps?  


 
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