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Cam selection for my 402

 
bobj_70
I love my Chevy Chevette!
Posts: 9
Joined: 12/09
Posted: 12/04/09 10:10 PM

I have a 396 in the shop, being bored .030 to 402 and need some help with picking a cam. The heads i have for it are a set of #-360 peanut port 454 open chamber heads. Now because of this, my compression will be low, around 8.7:1. It will be 90% street, 10% track.

I'm looking for a lopey idle and most power made early (street car) but have no idea what to go with for a cam. I've been directed to get a high lift, low duration cam with a 108LSA, such as the Lunati 07201 to make up for the lower compression.

Is this a good choice?? PLEASE, feel free to recommend something!  

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tuffnuff
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Posts: 7841
Joined: 12/09
Posted: 12/04/09 11:18 PM

Hmmm,,,
I'm just bolting together my 454 +.030 (same heads and compression as your 396 for available gas) and I'm not sure if you really want a 108 LSA.
The tighter you go in LSA,,, the more radical and lopey the idle becomes.
Furthermore, at 8.5 compression, you can't afford any bleed off because of overlap (both ex. and in. valves open at same time)
The cam I chose is the old 450 horse 454 cam of 1970 vintage,,, with new hi-tech improvements. This cam is very similar to the old 375 horse 396 or 425 horse 427 of the late 60's muscle car era.
The cam specs are as follows:
Comp Cams 11-671-4
Int. dur. 276
Ex. dur. 283
Lobe sep 112 Deg.
Int lift .544
Ex. lift .539
I ran a simulation on my Dyno and the results are great,,, lots of torque
This is a solid lifter cam and if you prefer a hydraulic stick, anything close to these specs will give you the sound and lope you are looking for.
What is the casting number on those heads cuz I can cross reference the cc's.
Smile  
When The Flag Drops.,.

tuffnuff

The Bull ***t Stops.,.
tuffnuff

P. Engineer, Engine Builder

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Pontiacman2
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Posts: 8956
Joined: 09/08
Posted: 12/05/09 05:53 AM

I would recommend the lunati P#60201LK it should work well on the street  
Pontiacman2
Pontiacman2

Professional Hi-performance engine builder

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gettnlarge01
I mow my lawn and find Chevys
Posts: 3330
Joined: 09/09
Posted: 12/05/09 07:08 AM

+1  
luck is when skill and opportunity meet

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tuffnuff
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Joined: 12/09
Posted: 12/05/09 08:33 AM

Pontiac, that Lunati Is a good choice, a little less cam but probably better for the smaller 396
.515/.530 lift
256/262 duration
Hydraulic and good to 5500  
When The Flag Drops.,.

tuffnuff

The Bull ***t Stops.,.
tuffnuff

P. Engineer, Engine Builder

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Pontiacman2
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Posts: 8956
Joined: 09/08
Posted: 12/05/09 09:07 AM

Thanks, I figured it will make a great street cam for the small cubic inch big block and build the power where it is most usable on the street.  
Pontiacman2
Pontiacman2

Professional Hi-performance engine builder

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bobj_70
I love my Chevy Chevette!
Posts: 9
Joined: 12/09
Posted: 12/05/09 10:59 AM

the heads are also at the shop so i dont have the full number. the last three are -360, mid 80's 454 heads.

And i am looking for a radical/lopey idle  

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tuffnuff
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Posts: 7841
Joined: 12/09
Posted: 12/05/09 11:34 AM

Go with the smaller cam as suggested by 'pontiac'. Brand isn't nearly as important as LSA, Lift and of course, duration.

It is almost identical overall as your original 375 horse 396 was in the late '60's which had .519'' lift,,, only diff is the original was a solid and the Lunati is hydraulic.
Those heads are 113.0 cc, intakes are 2.06'' and exhaust are 1.77''
Again,,, don't go overboard with lift or duration,,, at least not with 8 to 1 comp.

14092360 1985-89 454 Open Chamber  "Truck" <-- this is what you have.

These have real small ports, BUT, you will have tremendues runner velocity at the bottom end and midrange.
Porting wakes these heads up,,, but as usual, this depends on the competence level of the porter
Smile  
When The Flag Drops.,.

tuffnuff

The Bull ***t Stops.,.
tuffnuff

P. Engineer, Engine Builder

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Pontiacman2
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Posted: 12/05/09 12:49 PM

Over caming a engine with low compression will make a slug out of it and the low end torque will suffer.  
Pontiacman2
Pontiacman2

Professional Hi-performance engine builder

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gettnlarge01
I mow my lawn and find Chevys
Posts: 3330
Joined: 09/09
Posted: 12/06/09 06:45 AM

+1 Pontman. Most people dont know this fact and then refuse to accept it when told by someone trying to save them some problems and headaches. This goes with the running to big of a carb too  
luck is when skill and opportunity meet

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bobj_70
I love my Chevy Chevette!
Posts: 9
Joined: 12/09
Posted: 01/17/10 10:04 AM

i checked out the lunati P#60201LK  that Pontiac dude recommended, but the LSA is what gets me. I don't want a 112 because i want that scary muscle car choppy rumble. The cam in my 350 is a 112 and it sounds too smooth, almost like a brand new Chevy truck.

I'd like something with a 110 or 108 as in my original post. And yes i understand that the LSA is more than just an idle maker, lol.

Any help??  

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bobj_70
I love my Chevy Chevette!
Posts: 9
Joined: 12/09
Posted: 01/17/10 10:05 AM

i checked out the lunati P#60201LK  that Pontiac dude recommended, but the LSA is what gets me. I don't want a 112 because i want that scary muscle car choppy rumble. The cam in my 350 is a 112 and it sounds too smooth, almost like a brand new Chevy truck.

I'd like something with a 110 or 108 as in my original post. And yes i understand that the LSA is more than just an idle maker, lol.

Any help??  

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1976Skylark
My first time was in a Chevy
Posts: 127
Joined: 12/09
Posted: 01/17/10 10:46 AM

we all understand wanting the racecar sound,but being outrun sucks.your spending money on pseudo performance.(not real)you have to get the car moving. i'm the kind that the more power I have the less I want others to know.  

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idrivejunk
I mow my lawn and find Chevys
Posts: 5119
Joined: 12/09
Posted: 01/17/10 10:51 AM

Grin  
idrivejunk

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Pontiacman2
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Posts: 8956
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Posted: 01/17/10 10:55 AM

I mentioned that cam because of that really low CR the engine has running a bigger cam and mismatching parts is a great way to totally kill performance.
I here this all the time from some of my costumers and all they say or know is they want a choppy cam and that is it and do not realize that you have to match up the components of a engine for it to perform well.  
Pontiacman2
Pontiacman2

Professional Hi-performance engine builder

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