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How do I get 550-600 HP from my 454

45K views 23 replies 10 participants last post by  LevonH 
#1 ·
I have 2 sets of heads. some 781s with stage one porting work done on them. .219/.188. also have some .118 rectangular port heads. (.219/.188)

454 Motor.
561/561 lift cam.
11.1 Dome Pistons
850 Carb
RPM Performer Intake
371 Gears/ 10 bolt
400 Trans
'74 Nova- 3400 lbs.

Would like to get it in the mid to low 10s. any help would be great!
 
#4 · (Edited)
The link above is a good one. As far as my experience, below is a combo a friend of mine had built and dynoed.

461
cleaned up 2.19 1.88 valve 049's (flowed 290 max)
port matched victor Jr
242 248 @.050 .600 lift hyd roller
9.5:1 compression
950 carb

dynoed at 560 hp at 6100 RPM and 560 ft lbs.

I would go with the oval heads without any doubt. I beleive that they will make more average hp and probably more peak power also. The motor looks like it should do well but may not be quite 550 with the size of your cam. I think you would need something a little bigger. I guess your duration at .050 is somewhere is the high 230's to low 240's based on the lift. To get the hp you are after, I would look at something in the low to mid 250's @.050 duration and .600-.650 lift and a 3500-4000 stall being that you have 11:1 compression. One other thing to think about, 11:1 seems a little high for iron heads. Can you give the rest of the specs on your cam?

Another thing, even with the larger cam which might put you around 575 hp, I dont think that will be enough to get you the ET you are after by its self. The ET calculator below should give you an idea of what you need to get a mid to low 10.

Assuming 3400 lbs with the driver, in order to get a mid 10, you would need around 575 at the wheels. If you assume a 20% loss to the wheels, you would be looking at needing ~720 hp at the motor. As for a 10 flat, you would need around 675 at the wheels which would be around 850 at the motor. All this assumes that the car hooks and the chassis performs well. It takes a lot to get a mid to low 10.

I would guess that your motor would probably be in the ~530 range with the oval heads and the cam you currently have. This would be around 425 at the wheels assuming a 20% loss which comes out to a ~11.7 in the 1/4. If you went with the larger cam, 575 at the motor would be ~460 at the wheels and ~11.4 in the 1/4.

You could always run a 150 shot on the motor. That may get you closer to what you are after.

ET calculator
http://www.race-cars.net/calculators/et_calculator.html


Adam
 
#5 ·
I pull my heads they are 3856206 and I have flat top piston also one of my push rod was broken about one and half in. missing was not in the valley of the motor . if I put 990 heads on flat top pistons 30 over what would my comp/rato be cam 561/561 also what would hp be.
 
#8 ·
if I put 990 heads on flat top pistons 30 over what would my comp/rato be cam 561/561 also what would hp be.
Compression will be low,but it will still perform.
Have a friend with a 68 GTO powered by a 468 BBC with 990's and flat tops
He used a Chet Herbert solid roller and was running mid to high 11's w/slicks (he ran low 12's on street tires)
It was a budget motor.Most expensive parts where the 990's (bought used for $600) and the solid roller/lifters/springs (bought used for $200)
 
#6 ·
I can only assume that the chamber is 118cc. Using the calculator below with a .045 quench, you would be at around 8.0:1. This would really not be a good combo. The low compression with the large runners is not a really good match. I would estimate power to be around 450 at the motor.

http://www.angelfire.com/fl/procrastination/motor.html

Adam
 
#7 ·
Greg,

the -206 heads are '65 to very early '66 heads and the chambers should be around 96 CC's - give or take. From what I've read here they are decent heads and work pretty well on a flat top 454.

Dan
 
#10 ·
new strategy, Im going to put that flat top motor back together and use it in my 70 Monte Carlo as a street driver only, nothing hot. However i do have a 454 LS5 that came out of a 70 impala or monte carlo, the numbers are

heads: 3964290 (GMT5) (11-5-9)/ 3964290 (H89) (GM8T)
intake: 3855287
front of motor: TO929CGV (10D116942)

Im not trying to make a numbers matching car. The motor is standard bore, I could build this motor and use the 990 heads on it, but i would hate to use a good motor for what i am doing.
 
#11 ·
Adam,

I would love to have the horsepower and torque your friends combo provides.

The main difference between your friends combo and mine is the cam and a half point of compression. My engine is a real dog. While the ET is not too bad, it is pretty bad for a 2950 pound car (with driver).

More evidence that a bigger cam is not necessarily the answer to more power.
 
#12 ·
Sandy, I assume you are talking about the Beaumont. What are you running for a rear gear, converter and exhaust? Dont feel too bad, I am having trouble with my combo also. I have a 9.5:1 496 with fully ported 2.19 1.88 valve 049 heads and a 248 254 @.050 .600 lift solid flat tappet cam in a 1972 ventura that probably weighs around 3500-3600 lbs that is most likely no faster than your beaumont. (It ran a 7.98 in the 1/8th mile which is probably around a 12.5 in the 1/4) I am just trying to get the bugs worked out now.

Adam
 
#13 ·
Do what I did :yes:

Dyno proven: 619hp @ 6200 rpm, 570 lb/ft @ 4800 rpm

468 cid, 4 bolt main
AFR 305 heads (as cast)
Edelbrock Victor Jr. intake
QFT 850 cfm carb
Comp hyd. roller cam (.612” lift, 244* @ .050”)
Schubeck Roller X lifters (65 grams each)
Jesel shaft rockers
Jesel pushrods
SRP forged pistons w/ ceramic coated tops and DFL coated skirts (10.2:1 CR)
Total Seal rings
Scat Pro Comp 4340 light weight crank
Scat 6.385" H beam rods
ARP main, head, and oil pan studs
MSD e-curve distributor (timing set at 39* total)
6A ignition box
Blaster 3 coil
MSD 8.5mm Super Conductor wires
Denso plugs
Stahl custom stepped headers (2” to 2.25” primary pipes, 3.5” collectors)
3.5" exhaust w/ Dr. Gas X crossover and Spin Tech mufflers
 
#15 ·
Herb, how's the driveability w/that cam? Any vaccum @ idle #'s? Idle rpms?
 
#14 ·
Adam,

No I was referring to the engine in my lightweight race Chevy II.

I am pretty happy with the Beaumont. Three inch exhaust system, but just short pipes from the headers back to mufflers and then down dumps. Resonates like crazy in the car, need to do the extension over the back axles and dump them out at the rear corners like the stock ones. 4.1 gears and 2400 converter. 10.0 compression with hydraulic flat tappet and stock rockers. Like your car it weighs in around 3560 with me in it and a half tank gas. Using the TCI race calculator I calculate 360 horsepower to generate 12.4 at 109 in a 3550 pound car.

The engine I was referring to in my post above was the 454 in my Chevy II. The TCI calculator shows 440 hp. So 80 hp more and 600 pounds less I guess this is what you get (10.8 @ 124). But 440 hp is not even 1 hp per cube!

Herb, you got the 620 hp I could use! The main difference is my GM iron 049 heads vs your AFR 305's. My cam is just a bit bigger too which is probably not a good thing.

Herb, with 620 hp and 3600 pounds you should run 10.4 at 130 if you can hook it and make your shifts.
 
#16 ·
When you say that the calculator came up with 440 hp, is that the number it spits out or have you corrected it to flywheel hp? Most All those calculators that I have seen tell you rear wheel hp. If you are running 440 at the wheels, assuming a 20% loss to the wheels comes out to ~550 at the motor. For instance using the calculator below, at ~3600 lbs, you would need 360 hp at the wheels to get a 12.5. 360 at the wheels would be at least 450 at the motor.

http://www.race-cars.net/calculators/et_calculator.html

Adam
 
#19 ·
Thanks Herb, I was thinking about a ~240ish cam but based on what you told me, I think that would be too radical.
 
#21 ·
Adam, yup I tried the race calculator in your post also and it also gives 440 hp, so if you say that is at the wheels and if it is 20% driveline losses, the flywheel hp would be around 550. (Calculations for 2950 pound car with driver and 124 mph.)

Is that believable for a standard bore 10.2 compression 454 on pump gas?
 
#22 ·
I would think that 550 hp number is pretty reasonable when the motor in my first post on this thread is considered. What are the cam specs on that 454 and what has been done to the heads?

Adam
 
#24 ·
Hey Sandy, my 454 in the 3050 lb Camaro (driver included) runs 11.00 with a 10.2-1 CR.
Crane 304 cam with untouched square ports, GM intake and HP 830 Holley Carb. It even idles like a stocker :)
 
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