bence13_33

I really want to build a big block that will shut all of my friends up who are doubting me. I was wondering if anyone could give me a gross/net or rear wheel horsepower and torque estimate for my 454 that I'm building? I figure this way, if the numbers are low I can change some things to get those numbers up. Here's my setup:

454 (2 Bolt Mains)
Bored Over +.030
Hooker Header Side Pipes
Cast Crankshaft & Connecting Rods
Hyperuetic Pistons (9.5-10:1 Compression Ratio)
1973 454 Corvette Heads (110cc)[Pocket Ported & Polished]
Steel Shim Head Gaskets
2.06 Intake / 1.72 Exhaust Valves
Stock Stamped Steel Rocker Arms
Comp Cams XE274 Cam Kit (Hydraulic)
Hardened Push Rods
Edelbrock Torker II Aluminum Intake (Pocket Ported)
Holley 850CFM Double Pumper Carburetor
Holley Fuel Pump
GM Stock HEI Distributor
GM Stock Short Style Water Pump
Flex Fan w/ Fan Clutch

I'll also be using my Borg Warner Super T10 4 Speed. How much extra horsepower could I get by taking the muffler inserts out of the side pipes and running a straight header exhaust (obviously I wouldn't run it like that everywhere I go, only when I take it to the track)?

Any help is greatly appreciated.....the closer I get to 500 horsepower, the better :yesnod: .

Chris Fowler

Should be good for at least 100 at the flywheel. ;)

ZD75blue

more than me

oh well

Your base engine is out of a 73 l-36 if memory serves me... wasnt that 385 horse to start. Then you put pocket ported heads and high compression ratio cylinders. And free flowing exhaust, i wonder if you will have to many cubes for your side pipes? The sad part is that i'm not good at guesstimating

ZD


[Modified by ZD75blue, 7:41 PM 10/3/2001]

63Banshee

How much money do you have?

My advise, based on your previous postings and experience, would be to buy a create motor and add the additional needed parts that are recommended by the manufacturer.

… and don’t kill yourself… 500 HP in that car would make it a freak’n rocket!


[Modified by 63Banshee, 8:06 PM 10/3/2001]

bence13_33

63Banshee:

Whenever I first started this project everyone told me that I should just buy myself a crate motor. I would really like to take pride in this engine, which is why I would like to build it up myself. The completion of the project is set for this up and coming spring.

Does anyone have any guesses as to what this motor will be pushing?

63Banshee

There comes a time when the inexperienced should learn from the experienced without experiencing themselves.

BubbaJJ

Well, Bence, the 454 in my Camaro is 30 over, 9.5/1 compression, Comp cams EX280H, (cant remember exact specs), Edelbrock Performer RPM, long tube headers, stock oval port heads pocket ported with 2.19 valves installed, bore notched, with a Holley 750 vacuum secondary carb. Installed in a 72 camaro it runs 13.2 at 106. It doesnt have a posi unit so it will probably do 12's when I get the rear end. How much horsepower, Has to be about 400 gross, maybe 350RWHP. The one thing I have learned is that if you want to drive it dont go too nuts. My Camaro was fine until I put the 373 rear end in it. It's kind of a pain to drive any more. Mainly sits around waiting to go to the track.

427V8

With a .030 over 454 youve got what about 460+ inches?
If you have any cam in there at all you will get 460hp. Just look at my 434 small block it has a cam with about 239 degrees duration and .500 lift
It dynod at 460 hp and I ran a 12.9 in the quarter with crappy factory side exhaust and a messed up distributor! It should be able to run mid to low 12's

And remember, the cam is the main variable in the horsepower equation!
Compression is limited by the 92 octane gas, cubic inches is limited by the engine. Cam cam cam.
Spend MORE time on the cam selection! Understand cams! KNOW Cams! Live Cams! BE a CAM!

I would say if I were you to get a cam with about .6" lift 240-245 degrees duration and 110 degrees lobe seperation. then you should be on the 600hp side of 500 hp.

Flareside

Keith, how drivable is a .6 lift, 245 degree cam on the street? It doesn't sound like there would be much low end power with a cam like that. If you were driving along at 1000 rpm in second gear (with a normal 3.55 or 3.73 axle), what would happen if you punched the gas? Would it be able to spin the tires? Just curious...

Bence, I think it's great that you're building the motor yourself! Maybe things go perfectly, maybe they don't. This is a hobby, not rocket science, and it should be treated accordingly. There's only one way to become "experienced", and it's not by paying someone else.

-Joe


[Modified by Flareside, 8:30 AM 10/4/2001]

Rowdy Rat

Your goal of 500 horsepower can be reached quite easily with a 454.

A couple of things you may want to think about...

I'd stay away from steel shim gaskets unless you are building a restoration engine and want to be absolutely faithful to how the engine was originally built. Fel-Pro makes a great composition gasket that is superior to the original style steel shim gasket. I can post the Fel-Pro part number if you decide to go that route.

Cylinder heads... Good choice on staying with the oval port heads rather than the "high performance" rectangular port heads. I would definitely install 2.19"/1.88" valves in addition to your port work. The small valves that you currently intend to use will really choke airflow with the porting, headers, and the larger camshaft.

The 850 DP is a good carburetor for the strip, but I gather you intend to drive this car more on the street than on the track. You might consider a carburetor with vacuum secondaries which should help a bit with fuel economy. The big double pumper will certainly work for you though if you are so inclined.

Stay far away from flex fans... Go with a stock clutch fan or, if the budget allows, you can step up to electric fans. Either are a much better choice than a flex fan.

Considering the rest of your intended combination, I think that your camshaft choice is a good one for a street/strip car.

I'll be interested to hear what you finally decide on!

Regards,

72 Stingray

I think your combo appears to be pretty well thought out. Looks like you've avoided some of the huge mis-matches of parts people are commonly guilty of (myself included). You'll probably appreciate the response of the 850DP with a manual trans. I would say go with what you've got and 400 shouldn't be a problem. After you get it running, invest in some dyno time and tune yourself as close to 500 as possible. That way you can get a better idea where to spend any additional cash on parts. The things I would be most concerned about with your set-up are the longevity of the T-10 and the rest of the driveline if you ever got it to hook up at the track. I guess blowing up the trans or twisting the half-shafts in two would be proof enough for your friends that the motor is strong! :D

Flareside

Guys, how drivable is a .6 lift, 245 degree cam on the street? It doesn't sound like there would be much low end power with a cam like that. If you were driving along at 1000 rpm in second gear (with a normal 3.55 or 3.73 axle), what would happen if you punched the gas? Would it be able to spin the tires? Just curious...

-Joe

427V8

Well since I don't have that combination I don't know. I was guestimating .6" lift to break ( shatter ?) the 500 hp barrier.

I do know that my 434 with a .5" cam a single plane SUPERVICTOR can light up the tires nicely if I want to :D

And To expect any engine to be able to spin tires in second gear at 1000 RPM is asking a lot I think..
Now if you down shifted to first....

Monty

It can be very drivable if it matches the rest of your combination. I'm running a 256/264, .690"/.650" mechanical roller cam in my SBC427. It idels smoothly at 850 rpm, and pulls 12"-13" at idle. With 500+ ft lbs from 3000-7000rpm, peaking at 580@5100, there's torque everywhere. I don't know how much torque it makes at 1000rpm, since you typically don't start the engine dyno recorder that low, but at 2000rpm it makes 431 ft lbs. As for being able to smoke the tires in second gear form 1000rpm, the torque simply overwhelmes the car, tires, and drivetrain if you hammer it.

I would like to point out one thing though, most engine builders would probably say the heads are more important than the cam. Certainly, a well-matched combination is the best, but a set of very efficient heads with a mild cam will almost always make better power and torque than a set of crappy heads with a killer cam. When I was dyno testing my motor, I tried 4 different cams. The smallest cam was a freaky Dyno2000 'designed' 244/254, .648"/.623" cam and it still made 620hp/560ft lbs. Comparing that to the 256/264 cam I ended up staying with it's appearant that the high efficiency of the 18* heads I used made the difference.

A set of good heads with a small cam makes a low-mid rpm torque monster. A set of poor heads with a big cam makes a dog.

I also just finished helping a friend build another SBC427, based off of a Bill Mitchell Hardcore Motown SBC427 shortblock. He topped it off with a set of AFR 227 heads, a hyd roller with 248/254, .610"/.628", Victor Jr and Holley 750dp. He made 608hp@ 6100rpm and 598 ft lbs.@5200rpm.



[Modified by Monty, 11:30 AM 10/4/2001]

Turbo-Jet

OK! That's easy!

you might want to consider your intake manifold choice if you're running factory style sidpipes. the single plane is good with your 274 cam at high rpms, but will kill low end torque. are you using factory exhaust manifolds or headers? you should consider modifying a stock low-rise dual-plane intake or switching to a taller hood. this is what i'll be doing.

bence13_33

427V8:
With the Comp Cams XE274 Cam (.555" Lift ; 1800RPMs - 6000RPMs) do you think I'll be pushing 1 horsepower per cubic inch (460HP) ? Or do you think I should step it up a notch to the XE284 (.578" Lift ; 2300RPMs - 6500RPMs)? I only plan on running the big block up in between 5500RPMs - 6000RPMs....no higher.

Would it make sense to have a cam that pulls up to 6500RPMs, when your engine is never going to rev past 6000RPMs? I'm really lost when it comes to cams.... :confused:

My buddy with the Camaro has been giving me ideas as to what to get for the big block. I was originally going to run a Holley 750, but he said that it would be too small....he said to go with at least an 850 so I did.

"Over cammed and over carbureted" that's how the small block guys around my area build their engines. There's more to it than that right? The 318 Duster running around town has a 295 duration solid lifter cam and dual quads (Carters). The two carburetors aren't de-jetted either, it works out to be around 1000-1200CFM of carburetion for that 318. He also took the die-grinder to the heads and gave them a heavy port job.

Rowdy Rat:
If you could give me the number for those head gaskets, I would greatly appreciate it. I was going to run the steel shim head gaskets because I was told that you lose very little compression from them.

I guess I'll stay away from the flex-fan. I'll probably end up using the clutch fan setup and an electic fan. That way if I pull in somewhere and my engine starts running hot, I can crank the electric fans on and let it cool down.

72 Stingray:
I've actually spent a lot of time pondering my setup. The T10 and driveline components will be the week link for obvious reasons. Once I get the engine in, you will NOT find me doing clutch dumps or power shifting. If I do take it to the track, I'm going to launch it "soft". I'll drive it like that until I have enough money saved up to pay for the parts that it will break. If the transmission goes, I have a Turbo400 tranny laying around out of a '73 Corvette...I'll just use it. I really want the 4 speed tranny though :yesnod: . My buddy already told me that my half-shafts are going to be one of the first things to go. I guess I better start saving now

Turbo-Jet:
I'm ditching the side pipes that I currently have. I already have a set of Hooker Header Side Pipes painted and ready to bolt on. The headers have 2" primaries and 4" collectors. Whenever I take it drag racing, I'll probably pull the muffler inserts out of the side pipes and run a straight header exhaust.

I'm going with the Torker II intake. You are correct, it will take away from my low-end....which is what I want. I have a feeling that the big block will be pushing more than enough torque to get me moving (I will be running a 4 speed too, so that will also help). I also have a feeling that the big block will spin the tires with ease, so what good would a dual plane intake do for me other than cause me to lose more traction down low? I would rather lose that torque and add 10-20 horsepower up high where I can really put it to use. I went with the Torker II because it is only 1/4" higher than the stock cast iron manifold and I would like to keep my stock hood....for now until I have some more money.


[Modified by bence13_33, 12:25 PM 10/4/2001]

Flareside

Bence, don't be so sure that this engine will "spin the tires with ease". My 427 with 10.25 compression takes quite a bit of clutch and rpm to get the tires loose (unless you're at a dead stop). With the cam and intake you've chosen, I would expect no traction problems during normal street driving. How often will you hit 6000 rpms on the street (or even 5000 with a BB)? Your extra displacement should help some though. My next motor will definitely be 500+ cubes! It's all about low rpm torque for me.

I'm eager to hear how it turns out for you, since I'll be buying a BB cam soon.

Monty, that's some small block you've got there. I want a ride! What, exactly, is an 18 degree head? (probably expensive !)

I should probably have stated my question a little differently: How drivable will that cam be in a car like Bence's? Stock type iron heads, small valves, single plane intake, sidepipes and big cam. I'm asking because I'm planning changes to my stock 427/390, but can't decide which heads and cam to go with. People around here have commented that their mild BB cars felt over-cammed with less cam than Bence's.



[Modified by Flareside, 1:58 PM 10/4/2001]

bence13_33

I'm not for sure on this (don't take this is an attack) but a 454 and a 427 have the same bore size right (4.25")? The difference is that a 427 has a shorter stoke whereas the 454 has a 4.00" stroke (creates more torque). That's just my understanding.

In fact, my buddy with the 454 wants to build a 427 and get rid of his 454. He said that with the 427, he would have less traction problems but would still have the same bore size (slightly less displacement).

I'm not sure if what I just said is correct (I'm sure someone can correct me if I'm wrong).

427V8

Monty
I do have to agree about heads being very important I shouldn't have ignored that. I guess I have the opinion that you get the best heads you can afford and then try and match the cam to them. Personally I feel my engine has a horrible cam and really want to change it...But the heads are good

Bence
I cant even begin ( well I can begine as I have already demonstrated!) to guess what cam to use. I threw out the .5 and .6" numbers as ballpark figures, not as something I would recommend for a cam.
If I were you I would try and find some dyno tested combination simular to what you have and try and figure out the cam from there. Even then it's a swag.
BTW I have a small block 427 so my numbers will vary!!!

Monty

Keith,

I see your point. I guess I wasn't looking at it from the perspective of already having the heads, or from a cost perspective (heads vs. cams).