I have a 454 CID engine that originally was in a Camaro. I would like to build this Eng. to approx. 500 HP. From all the answers I have been given here, the heads are adequate enough to reach my goal.
My question now is...what are the "givens"?
Such as, in order to build a motor with that HP in mind,is it a "Given" that I will need a forged rotating assembly?
Looking to set up a proper budget before I dive into this.
As always, any help is greatly appreciated.
Mark

 

500hp??, Yes forged is required/Highly Suggested !
Heads are good enough?..
Heads are very Important ...what heads ?
Stock ? I don't think so.

 

Forged pistons would be a very good idea.
A forged crank is not necessary. The factory cast cranks can take 500+ hp easy.
All stock rods are forged and with ARP bolts are fine at that level.

 

The heads I have are numbered...336781. They have 2.190 intake valves and 1.880 exhaust valves. I believe these are open chamber and they have oval ex. ports.
The cam that was in it has the numbers Z024 above the centerline and I think E029P below. The best I can determine is that the cam lobes were 1.458 and 1.598. It also had multiple wiped lobes. It also has Comp Cam rockers. These appear to be forged,but I'm not sure. They are stamped with the numbers 1.72.
The cam dia. is 1.948 and the lifter dia is .842 with a 2.005 length. The lifters are currently flat tappet. I hope to go with hyd. rollers for the build, if concensus here says that will be adequate.
Never took a big block apart before, so I am learning as I go. Found out today that the ex. and int. push rods are of a different length. I did not expect that.

 

A solid or hydraulic roller in the 240-250 at .050 will get you there at the motor. With a decent intake manifold that is...

 

336781 was the last 454 head made introduced in 1974 and went out in early '75, an open chamber (113.06 cc) pass head had oval ports, 2.06/1.72 valves, application was Chevelle, Corvette, and Impala/Caprice/Estate Wagon.

Did someone work these over with larger valves?

The rockers are .02 oversized and would make your cam "look larger".

Is your body finished?

 

Yeah,I guess someone has been into these heads before, seeing that the valves are oversize. They seem to be good shape though. At least at this point. I see,however, that there are different amounts of shims under each spring. Not sure what that is about yet.
Body is finished and is going into primer real soon. Kevin(Vetts by Design) told me the other day that the body was tough to get right. He had to remove and reposition the entire front clip. And he did it by himself!!! Plus there was a problem with the "hairs" standing up. Real glad paint remover was used!!! At least I only used it on about half of the car. Fumes were killin' me.
I told him to take his time,seeing that this season is going fast. I sure do miss my ride though.
Going to a Harper Ave. cruise today and that is when I really wish I had it to show off. Oh well,there is always next year!!
Thanks for the e-mails...How ya' been??
Mark

 

Can anyone tell me what kind of lifters came stock in this eng.???
They are flat tappets at this time.
And would I be in the ballpark thinking I will be spending about $800.00 for forged 10:1 pistons?
Mark

 

I have been feeling much better. Thanks for asking.

I am fairly certain it was hydraulic flat tappet.

I would give a hydraulic roller serious consideration.

Welcome to the world of torque!

P.S. I have a dyno program if you want to play with some numbers.

 

Hyd. rollers are a given! I hope that they will be my largest expense. Oh wait...I have to buy a carb...and pistons...and new headers...and a cam...and intake!!! Oh well, it's only money...Go to work and make some more.

 

500 HP on a cast crank is OK if the crank is prepped and the rotating assembly is balanced. Forged pistons will only be required if you are thinking of any power adders. Although I personally use forged on anything I'm gonna beat on. You will be hard pressed to get 500 HP from stock oval port heads unless they have been ported by someone with a flow bench. The shims you speak of are used to adjust spring heights. You really need to determine what you want to do with the car. If it will be strictly street driven, the oval ports are the way to go for low end torque. But you will be limited in how many ponies you can get out of them.
Good luck, Dan

 

Street driven on weekends, mostly. I doubt that it will see 6000rpm's very often.
Mostly I want torque out of the hole for that "throw me into the seat" feeling.
And if the front wheels leave the ground...so be it! That is not my goal however,cuz I don't want to invest much in the drivetrain.

 

A general rule for calculating horsepower potential from a cylinder head, is intake port flow in cfm X 2.2.
Its obviously not exact, but its pretty close.
A bone stock open chamber oval port head will flow a little over 250cfm. That is original right down to the factory valve job.
With a little minor bowl clean up and a performance valve job, they will be 270+ cfm.
Well ported factory cast iron ovals with larger valves will flow around 340cfm.
All these numbers can vary by flow bench and fixtures, but they are pretty common.
They are capable of 500hp potential without ever touching them, and much more if you get someone good working on them.

 

Scat is a great option for a reasonably priced balanced rotating assembly for this application.

They have a cast STEEL crank which will support upwards of 700 hp, that combined with forged rods and pistons that they will supply, should be bullet proof for you. I've found their kits on auction for just a bit over 1000.00

Eagle has them too, but the Scat crank is a better quality at this level.

An Edelbrock RPM or RPM air gap will flow nicely up to mid 6000 rpm and won't choke your eng. out at 5000 like the Performer series.

You can find a performance re-man'd 3310-1 Holley that will actually flow close to 830 cfm on an internet auction for as little as 260 and that's a steal ... !!!

The 781 heads are the best you can do on a budget and under 6000 rpm they will absolutely out torque any rectangle port. You may want to consider an entry level set of Edelbrock Aluminium heads to bump the performance up ... and .... take 80 lbs off the front axle. In any event, you'll probably need to upgrade the valve springs etc., if you want to spend any time over 5000 rpm.

The core of the mods is the cam and you've already seen the Retro-Hydro- roller light, so that's great. An advertised duration of 285+/- and a lobe seperation angle of 110 to 112 and 4 degrees of installed advance will give you loads of tire smokin' mid range with no loss of top end.

Be patient and keep searches for everything you need on the auction site. If nothing else, you'll see what's out there... I just got a set of Sanderson BBC Block Huggers for Corvette for 150 ...brand new .... (I think they're 460. plus tax on the Sanderson site) .... some guy had them on the self for an uncompleted project for a year and blew them out (listed them) on a "Buy it now" at 1:00am when I happened to be up surfing.....

 

With a 454 block, you'll have to bore the cyclinders out 0.25 inches? Is there room there with a stock block?

 

Standard bore increments are usually @ 30, 60, 90 thou., the most common would probably be 60 thou over which would yield 468 cid. and is very well tolerated within the stock block.

There are some exceptions, but your engine person should be able to tell you by looking at your core. For instance, these blocks were bored using machine "registers" for locating devices during the machining processes. These "registers" are triangular shaped bosses or protrutions on the side of the block casting that you will see have machined slots in them. What happened was that in 97% those centering slots got properly machined, but there were some where the slots somehow got put in either too far forward or backward, so the finished cyl bores are actually off-center from the raw cyl. casting hole. This means that when you bore those off-center blocks one side is too thick and the opposite side is too thin, so those blocks will take less over-boring as the too thin side dictates how far you can go and still be safe.

You'll see vendors trying to promote "stroker" kits as the easy answer to more cubes, but rod angle becomes critical and more machine work will be necessary.

Many BBC engine builders will advise putting the cash into better heads before you do that.

 

related thread bump

 

So this is what i'm thinking...
Stock heads with the larger valves that are already there.
Stock crank and rods with new pistons to get to 10:1 compression
Cam is yet to be determined,but it will have hydrolic roller lifters....Car will not see much rpm's above 5000!!
I would like to use the rockers that came with the eng...Comp Cams,1.72:1
I want a car I can have fun with from a dead stop to 3rd gear.(I have a 5 speed) I have a 3.08 gear in the back.
Headers...Naturally. I have side pipes!
I would love to stick with a Q-Jet,if poss. The one on my small block performes flawlessly.(Large enough for a 454??????)Needs to have electric choke!
RPM Air gap intake

And as always...I'm open to all suggestions!
Thank you,my friends
Mark

 

If you really intend to limit yourself to 5000 rpm, you are probably not going to make 500 hp.
Also, the right cam to make that kind of power is not going to like 3.08 rear gears.
What transmission are you running? A nice low set of gears in there would really help out with that rear gear.

 

O'K., lets take it to 6000. I have a T5 trans with a 1st gear that will just about get me thru the intersection before I have to shift.
Like I said,I just want some good old fashioned "throw you into the back of the seat" acceleration!!! That was the only reason I limited myself to 5000rpm's
That and the fact that I plan on keeping the cast crank that is in there now,along with the stock forged connecting rods.
And I intend to get some forged pistons to take me to 10:1 compression with my almost stock(larger valves)heads.
Thank you for your input!
Mark