Sporty-X

hello,

i plan building a 454 block for my second car, and use it as an occasional driver and use it at the track sometimes.

I juts want to have a nice enjoyable car. My first car stays my 96 camaro.

So my question is :

I already have :

454 block
cast crank and standard rods
Keith Black pistons KB207 with -25.5 dome
stock heads (large oval)

i plan to be in the 500 to 600 hp mark with an engine not reving higher than 6000 RPM.

First question is : is this possible with what i already have or is there already limitations from them ?

If not, i planned to get and Edelbrock Performer RPM Air gap manifold, and wonder which cam would be the best for such a setup ?

Every suggestion would be appreciate.

Thanks

rskrause

Where you need to concentrate is the heads. You are going to need high quality porting to approach your hp goals. Which specific heads do you have? Runner size differs quite a bit on the different castings and this may be the ultimate limit on how much airflow you can get out of them and thus be the limiting factor in hp. The better the head you start with, the less time consuming and costly the porting needed to achieve the desired flow. With your hp goals, do not use a dual plane manifold. A small runner single plane is much more compatible with a 6,500rpm mostly track engine.

Rich

angel71rs

KB hypereutectic pistons have a rep for breaking at the top ring lands. The high silicon percentage and the heat treat makes them very wear resistant and stiff, but they will break instead of bend. KB will blame it on insufficient ring gaps (they call for wider than normal gaps). On a computer controlled engine, not as big an issue; the computer will pull back timing if knock is detected. With traditional distributor/carb... don't make any mistakes on the tune.

I've seen guys make 500 engine hp with big oval heads reworked with larger valves/mild port, flat solid cam ~ 240*, 750-850 Holley, and either the Perform RPM Air Gap or small single plane. I'd go with the RPM intake if you want it to feel strong on the street, single plane if peak hp at the track is more important.

You might want to price what it will cost you to rework the stock heads vs the price of aftermarket heads. Keep in mind some aftermarket heads require extras like specific head bolts. Roller cam will make more hp, but for a lot more $$$. Not needed to make the lower end of your target hp.

Rice Killer87

I had a 79 Z with a .060 454 10.0:1,781 oval port heads,single plane intake w/ a flowed 850 Holley and a 244/244 .550/.550 Comp Cam (Magnum 292 cam actually....came w/ the motor). It went 11.0's in the 1/4 which make it right around 500 HP and was very streetable w/ only a 3,000 stall and 4.10 gears. And it was only a hydraulic camshaft so I only went through the valves 2 or 3 times the whole time.

So thats about what you need/asking for as I shifted it at 6,000.

Im actually still using the bottom end in the 86 race car....except it has 990 casting rect. port heads and a .714 lift solid roller in it...different intake and 1050 dominator. It WILL be faster this season that whats in my sig. It had 5.43 gears in it and we just put 4.56's in.

Sporty-X

which single plane manifold you suggest ?

Stephen 87 IROC

Victor

Sporty-X

oky , i will look at noon at which casting i have, so i can let you know.

I have also a friend building another engine with flat top Fel-Pro hypereutectic piston.
He has small oval heads. He plan to change them for aftermaket ones, but not now and he wonders the limited HP he can get from these heads. Any idea about it ?

Sporty-X

i looked at my heads : casting number is 353049.

i made a search about opinions on them and it seems good heads.

rskrause

Victor Jr. 454-O #2904 850CFM carb.

Rich

Stephen 87 IROC

The 049 and 781 castings are some of the more common and better oval port heads. Get some 2.19/1.88 valves installed and do some port and polishing to help them breath a bit better.

For your HP goals, find a cam in the .600-.650 lift range that's considered a street cam since you're not building a track only car.

rskrause

BTW: I prefer vacuum secondary carbs for the street. You need a cam with a fairly narrow LSA (108-110) and duration in the 240-245 degree @ 50 range.

Rich

byrons1502

have a 454 with kb 207 pistons,.039 head gasket,large oval ports. 049 heads, 2.19/1.88 valves. heads were ported on the exhaust side,bowl hogged. victor jr, custom solid cam with 224-229 at 050 with a tad over 560 lift. edebrock 600 carb,stock fuel pump ls7. stock hei. hooker headers. made 383 rwhp in full size truck on 87 octane.
with the 207 pistons and stock heads,.039 gasket,block not decked the compression will be around 9.5 to 1. not the 10.1 to 1. you need to zero deck the block and mill a little off the heads to reach the 10 to 1 spot. i just dropped it off tonight for a refresh and planning to install a comp 292 with a 950e85 carb and shooting for 570-600 hp.
the cost to do heads is going to run about the same as a decent merlin head. run the merlins,comp 280-290ish extreme performer rpm air gap, 850 carb, put wavre loc rod bolts in. keep it under 6300 rpm and have fun. you should be in the 550-600 hp range

Sporty-X

thanks for the last post. I didn't remembered the zero deck would help so much on compression ratio.

I already bought wave loc bolts.

I plan to start with my heads and not spend so much money on them, so i can change someday and see what i can have with them.

What about valvetrain ?

Chrome383Z

I've never jumped into the old school big block world; but for those horsepower numbers and the rpms you will be turning I wouldn't neglect the bottom end. I don't know what they can handle factory, but for a reliable engine i'd at least upgrade to a forged crank and ARP rod bolts. Forged rods if you can swing it.

rskrause

The stock Gen IV stuff is stout. There is many a 500hp bracket car making pass after pass with 2-bolt block and stock crank and rods. Nearly all the cranks were forged, most of the blocks are 4-bolt, all the rods are forged (though there a couple of different designs). The best of the stock parts are certainly good enough for 700hp, maybe more. The motor in my bracket car uses a stock crank (one of the good ones) and is reliably over 700rwhp.

Rich