Need help with 396 build. - Team Camaro Tech
Engine General Engine Discussion.

 
LinkBack Thread Tools Display Modes
post #1 of 12 (permalink) Old Jan 17th, 05, 09:11 AM Thread Starter
 
Join Date: Jan 2005
Posts: 45
Post

Hey guys long time lurker, first post. I am wanting to build a 396 to put in a 69 camaro. My goal is to get between 350 and 400 hp. Want it to be basically stock with good streetability. I have a 1969 block, bored .30 over with the original crank. Block numbers are 3955272. The heads are the original heads I think and are oval port, open head with 112 cc chambers. Head numbers are 3933148. The heads have been rebuilt to stock specs years ago and have been in storage for the last 15 years with the block.
I am a sbc man so i dont really know what i have or need to reach my hp goals. I could use some advice on component selection such as pistons, cam and lifters, intake, carb, that sort of stuff. Thanks for replying.

[ 01-18-2005, 08:42 PM: Message edited by: rkw1969 ]
rkw1969 is offline  
Sponsored Links
Advertisement
 
post #2 of 12 (permalink) Old Jan 17th, 05, 05:30 PM
Senior Tech
 
Join Date: Feb 2003
Location: KC
Posts: 266
Post

Are the heads you have peanut port (small oval ports) or large oval port? In looking at mortec it looks like they're truck heads so I figured they're peanut port heads. If so you need to get some large oval ports like 063 if you want a closed chamber or 049 or 781 if you want open chamber heads. Get the heads nailed and then let's talk about the other items. Did the car have a big block in it? If not you'll need to change some other items also. Ted
rpol78 is offline  
post #3 of 12 (permalink) Old Jan 17th, 05, 05:33 PM Thread Starter
 
Join Date: Jan 2005
Posts: 45
Post

Man i have no idea what they look like as far as size on the ports. How can you tell? With them being truck heads is that bad?
rkw1969 is offline  
 
post #4 of 12 (permalink) Old Jan 17th, 05, 05:49 PM
Senior Tech
 
Join Date: Feb 2003
Location: KC
Posts: 266
Post

Look at the difference in the intake ports of these heads and compare them to what you have.

Peanut port Heads

Large Oval Port Head
rpol78 is offline  
post #5 of 12 (permalink) Old Jan 17th, 05, 07:17 PM Thread Starter
 
Join Date: Jan 2005
Posts: 45
Post

im fixin to go on duty and will run down to the shop and check.
rkw1969 is offline  
post #6 of 12 (permalink) Old Jan 18th, 05, 06:00 AM Thread Starter
 
Join Date: Jan 2005
Posts: 45
Post

Man they look like large oval port compared to the picture.
rkw1969 is offline  
post #7 of 12 (permalink) Old Jan 18th, 05, 03:43 PM
Senior Tech
 
Join Date: Feb 2003
Location: KC
Posts: 266
Post

I'm not familiar with the castings and I don't have flow numbers for them so I'll make the best calls I can. Unfortunately there's not alot of hypereutectic pistons that I've seen available for the 396. With 112cc heads something like the L78 pistons would be ideal from a compression standpoint. They are a little spendy though since they're forged pistons. They would put you around 10.25:1 static compression given that TRW shows them at 10.58 with 109.4cc heads. Since the heads were reworked to stock configuration they probably have the original size valves in them which are probably 2.06 intake and 1.72 exhaust. Also if you put a larger cam in you're probably going to need to replace the springs at a minimum.

What tranny and rear gears are you running? What do you plan on doing with the car (street, street/strip, strip)? I'm assuming you want to run it on 91/92 premium unleaded, is this correct? Was the block decked?
rpol78 is offline  
post #8 of 12 (permalink) Old Jan 18th, 05, 06:42 PM Thread Starter
 
Join Date: Jan 2005
Posts: 45
Post

Im thinkin 400T on tranny, possibnle 3:73 gears in the rear. This will be a street car only, wife and kids may drive it one of these days (when i trust em and not much and not by themselves. Hahah) needs to be reliable, may take it on 100 to 200 mile cruises. Im starting to think that maybe i need to build along the lines of the old 396/375 horse. i believe that would be plenty of hp for me. where could i get specs on that build? i have looked everywhere and am not getting anything.
rkw1969 is offline  
post #9 of 12 (permalink) Old Jan 18th, 05, 06:45 PM Thread Starter
 
Join Date: Jan 2005
Posts: 45
Post

oH by the way the block is not bored over yet and has not had any machine work done to it. that was a different motor that was bored after talking to my brother. he started to rebuild this one years ago, got the heads reworked and never did another thing to it. he told me last night the rest of the motor is in the barn if i can find it. thanks little bro.
rkw1969 is offline  
post #10 of 12 (permalink) Old Jan 18th, 05, 07:23 PM
 
Join Date: Oct 2004
Posts: 56
Post

If you want to go with "the old 396/375" you`re going to want a pair of #3964291 closed chamber rect. port sweethearts. Get ready to live with that .520 lift solid cam too. If it were me(and it was at one point)I would try to match the power but do it differently. Unfortunately I never listen to my own advice, so I`m living with something more resembling an L88 than an L78. Definately keep the 396 though. It`s a stout piece that doesn`t seem to get that much press. -----Scott
Mod396 is offline  
post #11 of 12 (permalink) Old Jan 19th, 05, 06:38 AM Thread Starter
 
Join Date: Jan 2005
Posts: 45
Post

good advice Mod396. i will keep that in mind. man i didnt think building a motor was as complicated. hell when i was doin this 20 years ago we just built em and usually got good results. i guess when your 15 or 16 and the motor you built seems really fast, but really isnt. i guess ya never really think about what you did to make it run.
rkw1969 is offline  
post #12 of 12 (permalink) Old Jan 19th, 05, 06:48 AM
Senior Tech
 
Join Date: Feb 2003
Location: KC
Posts: 266
Post

If you want to go to an L78 configuration, for 69 they had either a 3955272 or 3969854 block with 4 bolt mains, 3856223 forged steel crank, 3/8 dimple rods, equivalent to L2242 TRW Forged pistons, 3919840 or 3964291 heads (both are closed chamber rect. port), 3933163 aluminum intake, 4346 - 780 CFM vacuum sec. Holley, 1111499 distributor, solid cam with 316*int./302*exh. and .520/.520 lift crane and compcams make a reproduction.

If you haven't spent the $$$ on the machine work, don't care about "matching numbers", don't currently have an L78, and want reliable HP there's a couple of routes to go. One would be to get a 454 from a donor and build it. "There's no replacement for displacement" and there's some good combinations (i.e. the BSE 454) that make decent reliable HP/Torque for less $. If you have the 396 and want to use it. I'd look at aftermarket items such as heads, cam, ignition and you'll end up making more streetable HP for about the same or less $.

My '69 currently has a 70 2 bolt 402 bored .060 to a 414, 063 heads with hardened seats, a CompCams XE274 cam, TRW forged L2240 pistons, 6223 steel crank, 3/8 dimple rods with ARP bolts, 750 holley, stock distributor with accel coil, stock exhaust. The rotating assy was balanced. My car is has a 4 speed and a 3.55 posi. The engine has less than 10K miles on it. It runs pretty strong and a better exhaust system would help it out a bunch. I am willing to sell the engine since I am building a matching numbers L78 for the car. It has lots of torque, is in the HP range you're looking at, is reliable, and runs good on 91 octane unleaded. It also has enough vacuum to run power brakes and vacuum headlights. If you're intested email me off line.
rpol78 is offline  
Sponsored Links
Advertisement
 
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Team Camaro 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 we receive a lot of registrations with bad email addresses. IF you do not receive your confirmation email you will not be able to post. contact support and we will try and help.
Be sure you enter a valid email address and check your spam folder as well.



Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



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
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome