Hi Guys what would a 396 with 10.25 to 1,closed chamber heads and headers.
And a factory cast iron semi high rise manifold and comp cams flat tappet XE 268 cam have for HP Thanks for any help

In the car? Fully equipped with accessories? Full stock exhaust system? Using underhood air?

It has cowl Induction which is fully functional.I guess I am looking for a desk top dyno hp number.I know rear wheel hp is much less Thanks

I'd guess 275hp at the rear wheels.

You didn't state the carb, so I ran it with 750 cfm any brand.

I was suprised, but here's what dynosim came up with 386 HP @ 5000 and 459 TQ @ 3500. It seemed to really like that compression. Here is the VooDoo 268 (I forget the part # 60203?) for comparison, 392 HP @ 5000 and 467 TQ @ 3500.

My personal guess was going to be around 350 HP and 430 TQ, plus dynosim doesn't really like big blocks, so you should have a good combo there.

Hi 396 combo is basically the same as mine and someone here in t/chevelle desk dyno'd it for me and got the following hp/trq which i thought was realistic & below that is my motor setup so you can see what it was to compair to yours.

But either way you will have a very nice spunky street motor but you may have to run octain booster in it. My static cranking comp with the comp 268 cam i used is approx 210-220 psi and thats high for most pump gas to handle. My car doesn't ping under normal driving cond but when its real hot and i get into it there is some ping at times But not always its right on the edge with todays 93 oct fuel. I only go thorugh approx 5-6 tanks of fuel a yr so i now run some real booster that increases the octain in FULL PT'S (not tenth's of a point like most boosters) just to be safe,it also gives it more kick with the real booster. So be listening for any detonation after you get the cam broken in and go for some rides to fine tunes the motor and complete breaking it in.

Scott

================================================== ========

Desktop dyno results:

365HP+ @ 5,300 RPMS
437LBS TORQUE @ 3,500 RPMS
(407-400 LBS TORQUE FROM 2,000-4,500 RPMS.)


MY 396 MOTOR SETUP :

* BORE = .030 OVERSIZE FROM 4.094 TO 4.125
* DECK PLATE & HONE BLOCK
* STROKE = 3.76
* CRANK = NODULAR IRON (MAINS .010 UNDER/RODS STD SIZE/MAGGED NO CRACKS FOUND/OIL HOLES CHAMFERED & CRANK BALLANCED/CLEANED/POLISHED)
* CLEVITE H/D & H/PERF NASCAR SERIES MAIN/ROD/CAM BEARINGS
* RODS = STOCK 3/8 BOLTS (RODS MAGGED FOR CRACKS(NONE FOUND) & RESIZED TO NEW SPECS WITH NEW ARP WAVELOCK BOLTS & BALLANCED)
* 063 CLOSED CHAMBERED LRG OVAL PORT HEADS = 99-100CC CHAMBERS POST DECKING
* MATCHED TO CAM COMP SPRINGS
* TITANIUM VALVE SPRING RETAINERS & KEEPERS
* MANLEY UNDERCUT SWIRL POLISHED RACE FLOW VALVES FOR INCREASED AIR FLOW
* COMPLETE VALVE JOB INCLUDING INSTALLING NEW HARDENED EXHAUST VALVE SEATS FOR UNLEADED FUEL.
* COMP MAGNUM ROLLER TIP ROCKERS
* COMP MATCHED MAGNUM PUSHRODS
* L2240NF.030 SPEED PRO FORGED PISTONS
* DOME HEIGHT = .182
* DOME VOLUME = 21
* WIEGHT = 720 GRAMS
* BORE CLEARANCE .0015
* APPROX 9:8-10:0 COMP (BLOCK & HEADS WERE DECKED)
* CAM = COMP SPECIAL PURPOSE 268 HYD FLAT TAPPET
* CAM SPECS = 222/226 DUR @ .05,.525/.525 LIFT,112 DEG LSA
* LIFTERS = HYD
* CLOYES DBL ROW TIMING CHAIN & GEARS
* MELINGS STD BBC M77 OIL PUMP * NEW PICKUP SCREED TACK WELDED ON
* STOCK GM CAST IRON 067 (SEMI HIGH RISE INTAKE)
* STOCK 750 CFM GM 7029201 Q-JET TWEAKED WITH LARGER .035 NEEDLE & SEAT(MORE FUEL FLOW)/LARGER 73 PRIM JETS(71'S WERE STOCK) & 45B PRIM RODS/RICHER AX SEC RODS
* STOCK GM L78 TYPE OPEN ELEMENT AIR CLEANER WITH K & N FILTER FOR INCREASED AIRFLOW
* STOCK EXHAUST MANIFOLDS EXTRUDED HONED FOR INCREASED FLOW
* 2.5 INCH PIPES FRONT TO BACK WITH 50 SERIES FLOWMASTERS
* HOTTER STOCK SIZE/APPEARING 40K VOLT COIL
* H/PERF POINTS WITH H/D 32OZ SPRING TO ELIMINATE HIGH RPM POINT BOUNCE
* H/PERF DIST CAP & ROTOR WITH HIGH DIELETRIC MATERIAL & BRASS/COPPER CONTACTS WITH LESS RESISTANCE FOR INCREASED CURRENT FLOW.
* SPIRAL CORE IGN WIRES FOR LOWER RESISTANCE & INCREASED CURRENT FLOW.
* SPLIT FIRE PLUGS WITH FORKED GROUND ELECTRODE FOR ENHANCED SPARK KERNAL EXPOSURE TO COMBUSTION CHAMBER /BETTER BURN.
* TIMING CURVE ,18 INITIAL/36 TOTAL IN BY 2,800 RPM & VAC ADV
* OIL PRESSURE = 36-38@ 925-950 RPM IDLE & 50-52 @ 2,500 RPM CRUISE WITH 20W-50 OIL & MOTOR HOT @ FULL OPERATING TEMP
================================================== ========

Thanks for the info guys.I forgot to say what type of carb it has.It has a Sean Murphy Stage 2 quadrajet.I do have a little ping if its really hot out.But she does run real strong.The combo seems to work real well with the turbo 400 stock converter and 331 posi.Sounds like a solid lifter setup to with that sewing machine noise in the back ground.Got to love that comp cams fast valve seating

Hi 396 combo is basically the same as mine and someone here in t/chevelle desk dyno'd it for me and got the following hp/trq which i thought was realistic & below that is my motor setup so you can see what it was to compair to yours.

But either way you will have a very nice spunky street motor but you may have to run octain booster in it. My static cranking comp with the comp 268 cam i used is approx 210-220 psi and thats high for most pump gas to handle. My car doesn't ping under normal driving cond but when its real hot and i get into it there is some ping at times But not always its right on the edge with todays 93 oct fuel. I only go thorugh approx 5-6 tanks of fuel a yr so i now run some real booster that increases the octain in FULL PT'S (not tenth's of a point like most boosters) just to be safe,it also gives it more kick with the real booster. So be listening for any detonation after you get the cam broken in and go for some rides to fine tunes the motor and complete breaking it in.

Scott

================================================== ========

Desktop dyno results:

365HP+ @ 5,300 RPMS
437LBS TORQUE @ 3,500 RPMS
(407-400 LBS TORQUE FROM 2,000-4,500 RPMS.)


MY 396 MOTOR SETUP :

* BORE = .030 OVERSIZE FROM 4.094 TO 4.125
* DECK PLATE & HONE BLOCK
* STROKE = 3.76
* CRANK = NODULAR IRON (MAINS .010 UNDER/RODS STD SIZE/MAGGED NO CRACKS FOUND/OIL HOLES CHAMFERED & CRANK BALLANCED/CLEANED/POLISHED)
* CLEVITE H/D & H/PERF NASCAR SERIES MAIN/ROD/CAM BEARINGS
* RODS = STOCK 3/8 BOLTS (RODS MAGGED FOR CRACKS(NONE FOUND) & RESIZED TO NEW SPECS WITH NEW ARP WAVELOCK BOLTS & BALLANCED)
* 063 CLOSED CHAMBERED LRG OVAL PORT HEADS = 99-100CC CHAMBERS POST DECKING
* MATCHED TO CAM COMP SPRINGS
* TITANIUM VALVE SPRING RETAINERS & KEEPERS
* MANLEY UNDERCUT SWIRL POLISHED RACE FLOW VALVES FOR INCREASED AIR FLOW
* COMPLETE VALVE JOB INCLUDING INSTALLING NEW HARDENED EXHAUST VALVE SEATS FOR UNLEADED FUEL.
* COMP MAGNUM ROLLER TIP ROCKERS
* COMP MATCHED MAGNUM PUSHRODS
* L2240NF.030 SPEED PRO FORGED PISTONS
* DOME HEIGHT = .182
* DOME VOLUME = 21
* WIEGHT = 720 GRAMS
* BORE CLEARANCE .0015
* APPROX 9:8-10:0 COMP (BLOCK & HEADS WERE DECKED)
* CAM = COMP SPECIAL PURPOSE 268 HYD FLAT TAPPET
* CAM SPECS = 222/226 DUR @ .05,.525/.525 LIFT,112 DEG LSA
* LIFTERS = HYD
* CLOYES DBL ROW TIMING CHAIN & GEARS
* MELINGS STD BBC M77 OIL PUMP * NEW PICKUP SCREED TACK WELDED ON
* STOCK GM CAST IRON 067 (SEMI HIGH RISE INTAKE)
* STOCK 750 CFM GM 7029201 Q-JET TWEAKED WITH LARGER .035 NEEDLE & SEAT(MORE FUEL FLOW)/LARGER 73 PRIM JETS(71'S WERE STOCK) & 45B PRIM RODS/RICHER AX SEC RODS
* STOCK GM L78 TYPE OPEN ELEMENT AIR CLEANER WITH K & N FILTER FOR INCREASED AIRFLOW
* STOCK EXHAUST MANIFOLDS EXTRUDED HONED FOR INCREASED FLOW
* 2.5 INCH PIPES FRONT TO BACK WITH 50 SERIES FLOWMASTERS
* HOTTER STOCK SIZE/APPEARING 40K VOLT COIL
* H/PERF POINTS WITH H/D 32OZ SPRING TO ELIMINATE HIGH RPM POINT BOUNCE
* H/PERF DIST CAP & ROTOR WITH HIGH DIELETRIC MATERIAL & BRASS/COPPER CONTACTS WITH LESS RESISTANCE FOR INCREASED CURRENT FLOW.
* SPIRAL CORE IGN WIRES FOR LOWER RESISTANCE & INCREASED CURRENT FLOW.
* SPLIT FIRE PLUGS WITH FORKED GROUND ELECTRODE FOR ENHANCED SPARK KERNAL EXPOSURE TO COMBUSTION CHAMBER /BETTER BURN.
* TIMING CURVE ,18 INITIAL/36 TOTAL IN BY 2,800 RPM & VAC ADV
* OIL PRESSURE = 36-38@ 925-950 RPM IDLE & 50-52 @ 2,500 RPM CRUISE WITH 20W-50 OIL & MOTOR HOT @ FULL OPERATING TEMP
================================================== ========

Hey Scott I have been trying to figure out my compression raito on my 396 and I have the same pistons @30 over with oval closed port heads.It says in the how to rebulid a chevy bb engine that the heads I have #3904390 have a closed chamber and 96.4cc combustion chamber.Do I have less or more commpression???

Kevin,that depends on the deck hieght 7 how much material has been removed from the heads prior to install.

But off the top of my head i would say yes you should have a little more comp then me since your heads have slightly smaller chambers.

scott

Thanks for the quick response. The guy I bought the car from had the engine built for him and he told me that it had low commpression for pump gas.But with my resurch it seems to have more than I had thought.Maybe to him 10:0 to 1 is low?He was only running a 510 lift cam with a 670 Steet Avenger carb.It ran good but it seems to me that there is alot more power in there with that compression ratio.He also told me with this combo it dynoed at 408 HP on an engine dyno.