454 motor build Horsepower/torque Estimation

[71chevswb]

Currently building a 454 from the ground up. Below are the specs. What is an estimated horsepower and torque for this motor? Thanks!


454 2 bolt main block
0.030 bore over (All balanced )
1968 396 BBC oval port heads
PRW 1.7 aluminum roller rockers
Comp cams "Mutha thumpa" cam
Domed Pistons
About 9.4:1 compression
Weiand tunnel ram
2 Holley 450 cfm carbs
Sanderson headers

What more is needed to estimate horsepower and torque ratings?

[lwb82c10]

my build is about like your build i'm curious to know hp as well

454.060 68 396 oval port, 10.5 1 pistons, 561 lift in/ex

and i'm thinking about doing a tunnel ram with 450's as well

[Kyle@FTP]

What is the casting number on the head? any work done to them? Cam Specs?

Have you thought about a single plane and a single carb? build a little better torque at a lower RPM.

[71chevswb]

I had the casting number of the heads at one point and now the valve covers are on and I don't remember it. They are 109cc closed chamber and have been machined and cleaned. I am very aware I could get more power from a single carb and single carb intake. I have a hole in the hood and the tunnel ram is for looks.

Cam specs

Duration: 0.563"/ 0.536"
Lift: 283*/303*
Angle slope: 109*

[Kyle@FTP]

Originally Posted by 71chevswb

I had the casting number of the heads at one point and now the valve covers are on and I don't remember it. They are 109cc closed chamber and have been machined and cleaned. I am very aware I could get more power from a single carb and single carb intake. I have a hole in the hood and the tunnel ram is for looks.

Cam specs

Duration: 0.563"/ 0.536"
Lift: 283*/303*
Angle slope: 109*

Oh cool. That should look awesome! I would say its going to be a solid 400-450hp build. should be a blast on the street.

[71chevswb]

Originally Posted by Kyle@FTP

Oh cool. That should look awesome! I would say its going to be a solid 400-450hp build. should be a blast on the street.

Is that an estimation at the crank? What would I be running horsepower wise with a single carb with a single carb manifold?

[Kyle@FTP]

Yes, to the crank. I don't think it will make more power switching to a single plane intake and 1 carb but it will make a little more torque lower in the RPM range making it feel like it makes more power and it will also make it easier to drive. With that said there is a lot of power left on the table with the head cam combo. But that's where budget and goals come into play. 400HP on the street is a lot of fun!

[lyrikz]

Originally Posted by 71chevswb

Is that an estimation at the crank? What would I be running horsepower wise with a single carb with a single carb manifold?

My 454 build i did was similar. HIgher compression a bit. THe builder estimated 500hp and 500 torque. He said if i went with a set of aluminum heads that number would go up drastically.. It was a scary truck thats for sure.

[71chevswb]

My builder who is helping me estimated closer to 500hp but I wanted more opinions. Honestly it's just a number in my head, I won't hit the track much if at all. Just a grocery getter and fun truck to drive. The build has made me broke but it's been a blast putting it together and turning the bolts. This is my first motor build.

[ptc]

If your ever looking to take the next step up on your intake and staying with iron heads, Ive got the ticket for you.

Ive got some 088 Rect Port Heads off a 502 that will bolt right on, a hyd roller cam and lifter setup, rockers, pushrods, guides that would light that 454 right up. Just would need a gasket set.

[68c10owner]

what is the .050 duration of that camshaft? Did you degree it? What ICL?

"machined and cleaned", does that mean they are stock? No porting? stock valve size?

Also, you will make more power with a tunnel ram if the engine is built right but you need to pick the correct carbs and dial them in. Those 450 carbs are not great. No accelerator pump. Pick up a couple of 1850 600cfm carbs at the minimum. Some 660 center squirters would be ideal but they are not street friendly but can be modified to work well on the street.

There are much better camshafts out there than the Thumper series cams.

BTW, a domed piston with the early closed chamber oval heads will make much more than 9.4:1 compression. What is the piston part number? Honestly it sounds like a mismatch of parts. I would probably rethink some parts depending on your budget and what you are trying to do with this thing.

[WTF?]

Compression seems low. Also, what big mutha thumper cam?...there is a lot of them. It will bleed off even more cylinder pressure with a tight came like those further killing torque down low. Big cam, low compression and a tunnel ram...might not make as much as some think. It will need a lot of initial timing, probably a locked distributor, and a way to pull timing during cranking.

[71chevswb]

the motor is built/completely and in the truck. Had a professional builder decide what parts to use. I do not second guess his knowledge or decisions. Block was bored 0.030 over. All new internal parts used. Not mismatched parts, the heads were just what was laying around and got for free. Built for 9.4:1 compression to run on pump gas. Has a mother thumpr cam. They make a thumpr cam, a mother thumpr cam and a big mother thumpr. pretty sure I have the middle one, mother thumpr.

The motor wasnt built to make max horsepower for the amount spent. Motor was built to sound good, choppy idle and cruise around town. Tunnel ram is all for looks, I wasnt trying to add horsepower there. Not a track runner. I was simply curious what numbers it would produce if on a dyno.

And as far as carbs, i did tons of research and made some phone calls. 2 450's was what this motor needed. 600+ cfm is way too much IMO.

The truck rips, plenty of power. Enough for me. Hard to keep it straight.

[71chevswb]

cam specs:

http://www.compcams.com/Company/CC/c...?csid=486&sb=2

[ptc]

Your motor builder should be able to input all your build information into a computor program that is readily available online and come up with HP and Torque estimated value. Only your builder know the exact specs of all the setup he did during the build.

Its pretty typical to derate these values sometimes by as much as 30% depending upon the correction values that the software dictates.

Talk to your builder; he has all the info needed to find that information for you. Anybody on here is going to be GUESSING.....

[Ont67shortbox]

thinking maybe 450 hp/475 torque,nice street engine

[1quik70]

I've essentially got he same build in my truck, just finished it. I would agree with everyone else, 400-450 is about what my butt tells me. I had a dyne proven 500hp build in my last car and this one doesn't quite have the balls the last one did.