69 396(325HP)cam recommendation - Chevelle Tech
Chevelle Tech join team chevelle as a supporting member  
Chevelle Parts at SS396.com      
GROUND UP & SS396.com         
Official Sponsor of Team Chevelle
     

Auto Insurance

Chevelles.com is the premier Chevrolet Chevelle Forum on the internet. Registered Users do not see the above ads.
Engine AdvertisementGeneral Engine Discussion.

Reply
 
Thread Tools Search this Thread Display Modes
  #1  
Old Dec 9th, 12, 1:55 AM
socalss socalss is offline
Tech Team
Rob
 
Join Date: Oct 2012
Location: Southern California
Posts: 58
Default 69 396(325HP)cam recommendation

Stock 325 hp engine(.60 over), original heads with stock valve train, intake, carb, etc. automatic. Looking for a cam recommendation for rebuild. Looking for some increased initial acceleration while maintaining close to stock idle.

Thanks....
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #2  
Old Dec 9th, 12, 3:53 AM
z27 z27 is offline
Tech Team
alex
 
Join Date: Nov 2010
Location: boston ma.
Posts: 401
Default Re: 69 396(325HP)cam recommendation

Well Rob! It looks like you wan,t your cake and wan,t to eat it too.You are asking for quick acceleration {throttle response} and wan,t a near stock idle. The two don,t go hand in hand .I think what you are looking for is {seat of the pants when you pour the coals to it ,that,s torque} for that you would need a cam on a 110 or 108 lobe separation. That will not give you a stock type idle, it will be a little lumpy but if you don,t go crazy on duration the idle will be noticable but livable. On the other hand you could use a cam that,s on a 112or 114 separation angle and that will smoothen the idle out and spread the torque over a wider band but that will negate the seat of the pants feeling when you nail it.I hope this helps you and that i understood your question correctly. Alex
Reply With Quote Quick reply to this message
  #3  
Old Dec 9th, 12, 9:42 AM
mr mr is offline
Senior Tech Team
Don
 
Join Date: Oct 2004
Location: USArkansas
Posts: 1,499
Default Re: 69 396 (325HP) cam recommendation

Quote:
Originally Posted by cstraub View Post
In no way,
will an OEM headed BBC engine, ever be optimized, by an single pattern cam if the heads have been untouched.
Quote:
Originally Posted by cstraub View Post
The 2.065" valve has enough area to feed 430 CID to 6200 rpm...
Quote:
Originally Posted by cstraub View Post
Heads and cam, are the power of the engine.

You need to decide what you want out of the engine, and then move forward on selecting parts.
Quote:
Originally Posted by cstraub View Post
The cams job is to do the thinking for the engine.
............... The cam controls the air/fuel going in-and-the exhaust going out.
1) it has to know what size the engine is ...
2) what rpm it needs to go to in order to make power ...
3) how much heads can flow in and out ...

Knowing all 3 of the above, camshaft selection is black and white ...
Without knowing what the heads airflow is your guess at a cam is as good as anyone on this board.
Quote:
Originally Posted by cstraub View Post
Duration is the ability to make power/sustain power at a given rpm range.

.......... Added duration that is not needed makes an engine peaky, narrows the powerband.
Quote:
Originally Posted by cstraub View Post
At low rpm's you need to open the valve sooner, and get the air in since the head, does not have velocity at low rpm.

As the rpm grows the intake valve can be opened later, as the velocity is there.
Quote:
Originally Posted by cstraub View Post
At the point we open the exhaust valve, it is under extreme pressure, so as soon as the valve leaves the seat the exhaust leaves the cylinder.
The exhaust gas velocity is at it greatest at this point, much like a bullet leaving the barrel.

Holding the exhaust valve open longer just blows torque out the pipe.
I'd recommend a cam with moderately high lift [in the .550" range] & a moderate amount of duration [225/235@.050]

Something similar to the [quote] cams listed below, for a stock type 396 BBC.
Quote:
Comp Cams Xtreme Marine, XM 270H-12 [11-236-4] XM270H 270 286 [226/236 .544/.547 112]

Comp Cams Xtreme 4X4 profile, X4 270H-11 [11-239-3] X4 270H 270 278 [226/234 .544/.564 111]
http://www.chevelles.com/forums/show...ic+roller+test

http://www.corvettefever.com/techart...g/viewall.html
__________________
__________________________________________________
....... "drag racers do it , till their rubber smokes" .....
Reply With Quote Quick reply to this message
  #4  
Old Dec 9th, 12, 10:03 AM
OLDED OLDED is offline
Team Member
Ed
 
Join Date: Feb 2003
Location: Marietta, Ga.,USA
Posts: 2,650
Default Re: 69 396(325HP)cam recommendation

Put in a Lunati 60202 flat tappet hydraulic and new stock or slightly stronger valve springs and don't look back. It will have a nice idle with a bit of pop to it and all the stock parts will remain compatible. The stockish springs will assure a drama free break in and reliability. Ask for the hardened lifters from Lunati. This will wake up the 325 without making it radical. It will rev nicely to near 6,000 and will be a fun ride all around. Basically, it will put it into a direct comparison to a stock 360 HP. Of the day. FWIW, Ed.
__________________
OLDED - It's STOCK if it's marked GM and it fits!

*65 Elky, Gen VI 496 BBC, TH400
*59 Vette, 283/270 hp. 4 spd.,
*Harley - Street Bob
*Life Member - Team Chevelle & Team ElCamino
*Peach State Chevelle Member
****Retired June 1, 2014****
Reply With Quote Quick reply to this message
  #5  
Old Dec 9th, 12, 11:37 AM
Bob's66396 Bob's66396 is offline
Lifetime Premium Member
Bob
 
Join Date: Nov 2008
Location: Towson,Md
Posts: 958
Default Re: 69 396(325HP)cam recommendation

I understand what you are looking for. You might want to look at the cam I have in my 1966 396/325. It is an Isky 270 Megacam,(HFT),and I had it ground on a 112 lsa. The cam come on a 108 lsa,too choppy for me,and I wanted to keep the vacuum up. I used all Isky though out the whole valvetrain. I am very happy with it...Bob
__________________
MCC#826
T/C#4889
A.C.E.S#08597
Baltimore-06C
1966 SS 396/325,M-21,P/S,P/B,.331 Posi.
Marina Blue,White Interior,Wood Steering Wheel
'66 AM/FM Delco,Knee Knocker Tachometer
Boyd Coddington 17" Magneatos
Rotisserie Restored-Matching Numbers
95% Original Chevrolet-5% Original Bob
http://www.chevelles.com/forums/album.php?albumid=201
Reply With Quote Quick reply to this message
  #6  
Old Dec 9th, 12, 1:18 PM
mr mr is offline
Senior Tech Team
Don
 
Join Date: Oct 2004
Location: USArkansas
Posts: 1,499
Thumbs up Re: 69 396(325HP)cam recommendation

Quote:
Originally Posted by OLDED View Post
Put in a Lunati 60202 flat tappet hydraulic and new stock or slightly stronger valve springs and don't look back.
It will have a nice idle with a bit of pop to it and all the stock parts will remain compatible.
The stockish springs will assure a drama free break in and reliability. Ask for the hardened lifters from Lunati.
This will wake up the 325 without making it radical. It will rev nicely to near 6,000 and will be a fun ride all around.
Basically, it will put it into a direct comparison to a stock 360 HP.

=Advertised Duration (Int/Exh): 262/268-Lunati #60202
Duration @ .050 (Int/Exh): 219/227
Gross Valve Lift (Int/Exh): .530"/.542"
LSA/ICL: 112/108
Quote:
Originally Posted by Bob's66396 View Post
I understand what you are looking for. You might want to look at the cam I have in my 1966 396/325.
It is an Isky 270 Megacam, (HFT), I had it ground on a 112 lsa. The cam come on a 108 lsa, too choppy for me, and I wanted to keep the vacuum up. I used all Isky though out the whole valvetrain. I am very happy with it.

=Advertised Duration (Int/Exh): 270/270-Isky 270 Megacam
Duration @ .050 (Int/Exh): 221/221
Gross Valve Lift (Int/Exh): .542"/.542"
LSA/ICL: 112/108
Quote:
Originally Posted by badrad View Post
My favorite cam for this type of build is the Isky Mega 270/280, same as the Isky listed above but with more exhaust duration for better breathing. It has mild manners on the street and makes really good TQ.

=Advertised Duration (Int/Exh): 270/280-MEGA
Duration @ .050 (Int/Exh): 221/232
Gross Valve Lift (Int/Exh): .542"/.565"
LC: 114
All the cams mentioned above, should be provide major power improvements, to your 396 ...

Quote:
L-35 specs: 396 CID produced 325 hp, from 1965-thru-1969, had 10.25:1 compression, Q-jet carburetor, hydraulic lifters, oval port closed chamber heads, and two-bolt main caps.
I believe these are the camshaft specs, for your stock 1969 Chevrolet 396 325 hp/L35.
Camshaft number = #3874872
Camshaft Intake duration @ .050" == 196
Camshaft Exhaust duration @ .050" = 196
Camshaft lift - Intake == 0.398"
Camshaft lift - Exhaust = 0.398"
@ 114 LSA

1969 Chevrolet 396 w/L35 engine.
C.R. = 10.25:1
Horsepower = 325 @ 4000
Torque = 410 @ 3200
__________________________________________

I believe these would be the correct camshaft specs, for a 1970 Chevrolet 402 w/L34.
The duration figures, which are taken at .008-inch lift are 268 int./ 274 exh.
Camshaft number = #3883986
Camshaft Intake duration @ .050" == 214
Camshaft Exhaust duration @ .050" = 218
Camshaft lift - Intake == 0.461"
Camshaft lift - Exhaust = 0.480"
@ 115 LSA

1970 Chevrolet 402 w/L34 engine.
C.R. = 10.25:1
Horsepower = 350 @ 5200
Torque = 415 @ 3400
__________________________________________

I believe these are the correct "solid lifter camshaft specs", for a 1969 Chevrolet 396 w/L78.
Camshaft number = #3863148
Camshaft Intake duration @ .050" == 242
Camshaft Exhaust duration @ .050" = 242
Camshaft lift - Intake == 0.520"
Camshaft lift - Exhaust = 0.520"
@ 114 LSA

1969 Chevrolet 396 w/L78 engine.
C.R. = 11.25:1
Horsepower = 375 @ 5600
Torque = 415 @ 3600

NOTE: there is supposedly an -8 duration difference, between the specs on a "hydraulic cam" & a "solid lifter camshaft".
* take this 1969 L78 solid camshaft, if it were a hydraulic lifter camshaft, duration would be approximately 234 @.050"
Quote:
Originally Posted by cstraub View Post
Duration split ... You can manipulate the valve events and duration split to achieve vacuum.
I do a ton of vacuum rule cams in both circle track and truck pull.

Street cars worry about brakes, sanctioning bodies use vacuum rules to limit camshafts.

Pulling 15" vacuum @ 1000 rpm is doable with a 240 range camshaft on a 106 or 107.
__________________
__________________________________________________
....... "drag racers do it , till their rubber smokes" .....

Last edited by mr; Dec 9th, 12 at 4:32 PM.
Reply With Quote Quick reply to this message
  #7  
Old Dec 9th, 12, 1:29 PM
socalss socalss is offline
Tech Team
Rob
 
Join Date: Oct 2012
Location: Southern California
Posts: 58
Default Re: 69 396(325HP)cam recommendation

Quote:
Originally Posted by OLDED View Post
Put in a Lunati 60202 flat tappet hydraulic and new stock or slightly stronger valve springs and don't look back. It will have a nice idle with a bit of pop to it and all the stock parts will remain compatible. The stockish springs will assure a drama free break in and reliability. Ask for the hardened lifters from Lunati. This will wake up the 325 without making it radical. It will rev nicely to near 6,000 and will be a fun ride all around. Basically, it will put it into a direct comparison to a stock 360 HP. Of the day. FWIW, Ed.
That sounds like a nice, simple solution to what I'm looking for. I think I will either do as you suggested, or build it to 69 396 350hp specs, which if I undestand correctly, only differed in the cam and possibly the carb jetting. Sounds like either direction will give me what I'm looking for.

Thanks.....
Reply With Quote Quick reply to this message
  #8  
Old Dec 9th, 12, 3:13 PM
badrad badrad is offline
Lifetime Premium Member
jimmyradford
 
Join Date: Oct 2007
Location: Escondido, CA
Posts: 2,305
Default Re: 69 396(325HP)cam recommendation

My favorite cam for this type of build is the Isky Mega 270/280, same as the Isky listed above but with more exhaust duration for better breathing. It has mild manners on the street and makes really good TQ. What part of SoCal are you in?
__________________
TC Member # 4431
'04 Ram Quad-That thing has a Hemi in it!
'93 F350 Centurion-I needed something big to haul my ego.
'67 Hell Camino-BB 427/TH400/???
'65 Elky-327/TH350/3.08 peg leg
'55 BelAir 2 door post-327, in progress/TH-400/4.10
"Good people sleep peacefully in their beds at night only because rough men stand ready to do violence on their behalf."-Orsen Wells
Reply With Quote Quick reply to this message
  #9  
Old Dec 9th, 12, 4:05 PM
Stokerboats Stokerboats is online now
Lifetime Premium Member
Dan
 
Join Date: Aug 2007
Location: orange county
Posts: 6,578
Default Re: 69 396(325HP)cam recommendation

X2 on the Isky stuff. Call Isky, ask for Rod, tell him what you are trying to achieve and he will hook you up or call Mike at Wolfplace, he sell's Isky part's.
__________________
66SS 499.5 in BBC TH400 4.11 12bolt posi
Best ET 6.263 @ 108.40 Isky flat tappet
nos top shot. 3800 lbs
Reply With Quote Quick reply to this message
  #10  
Old Dec 10th, 12, 6:38 PM
kettbo kettbo is online now
Lifetime Premium Member
George
 
Join Date: Mar 2006
Location: Lakewood, WA
Posts: 10,541
Default Re: 69 396(325HP)cam recommendation

Quote:
Originally Posted by socalss View Post
That sounds like a nice, simple solution to what I'm looking for. I think I will either do as you suggested, or build it to 69 396 350hp specs, which if I undestand correctly, only differed in the cam and possibly the carb jetting. Sounds like either direction will give me what I'm looking for.

Thanks.....

the 325 cam is a loser
the 350 horse cam is next to last place...

lots of modern cams out there that will do for you what needs doing
__________________
George Kettler
o 70 Elky 496 build continues #074 AL heads
$2000 low buck 454 is broken, ran well for a 3995# all-up wt.
1.631 11.727 113.37 91.47 midtrack 1.647 11.729 113.49 91.58 mph mid track
Bests 1.620 60 ft 91.60 best mph


o 68 Vette 427/M-20/3.36 23 year owner
http://public.fotki.com/kettbo/gearhead/
o 68 Camaro Vert 327 project, painted, assembly stage http://www.camaros.net/forums/showth...183654&page=55
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
Reply
Chevelle Tech > Mechanical > Engine      Current Topic: 69 396(325HP)cam recommendation
Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the Chevelle Tech forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address. Note, you will be sent a confirmation request to this address.
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.



Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -4. The time now is 2:13 AM.


Is there a site like this for?    El Caminos Camaros Novas Impalas GTO Chevy Punch All Chevys

2009 Team Chevelle - AutoForums