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chevelle68malibu
11-05-2004, 12:35 AM
OK, so my friend has a 70 nova. He also has his 454 in the machine shop to be fully machined for a 4.25 crank and also is receiving 4 bolt splayed. I am working on this with him and we are to the point of buying EVERYTHING for this engine. This guy is doin’ pretty good in the money category (for being 19 years old and all, as am I) He is going to buy: an all forged rotating assembly (brand new), Hydraulic roller cam and lifters, needs an intake AND carb, headers and exhaust...and anything else I didn’t mention. Part numbers would be helpful!

The items he DOES have are: a pair of 781's ( oval port, 118cc chambers, 256cc intake, 114cc exhaust, not sure on valve sizes) .030 454 block. So pretty much working around those heads, what can you guys recommend for a combo that has a max RPM of 6500, PUMP gas, street strip, and is eventually going to use nitrous. He has nothing for a rear end or tranny now, so we will be building the car around the engine...

Any and ALL help will be GREATLY appreciated, so have at this poor engine, and let’s see what we can come up with! I'm talkin' what compression, cam, head gasket, zero deck… EVERY thing! :3gears: :fingersx: :cheers:

P.S. I will be lurkin’ here so if anyone has questions about something more specific, shoot away. Thanks.

TurboLark
11-05-2004, 07:12 AM
I would keep compreession to 9.5 or 10-1 max for the pump gas, especially if you will use the iron heads. But, personally, I would buy a nice set of aftermarket aluminum heads. You will spend just as much rebuilding and port/polishing the irons as it would cost for new heads(and you would still be making more power with the new ones).
Some numbers would be needed from you. You said 6500rpm, but what kind of HP you looking for?
For simplicity, you may want to look at the Edelbrock RPM Oval port kit. Would put you well over 500hp and tq.

Lowend
11-05-2004, 08:42 AM
What compression are you planning on running?
What are the cam specs?
Rearend & Torque Converter?

TurboLark
11-05-2004, 09:31 AM
What compression are you planning on running?
What are the cam specs?
Rearend & Torque Converter?
Did you read his post??
He is asking about compression, and said the rest of the car will be built to suit the specs of the motor.

chevelle68malibu
11-05-2004, 09:53 AM
Hey! thanks for the quick replies! What we want is the max power that can come out of a 6000-6500 max rpm, hydraulic roller, pump gas 496 with 781's. I was thinking something along the lines of a 950 HP series, 10.5:1, some porting, maybe valve jobs etc...(could use some tips on what to do with the heads also...) Would 2" primaries be too large for this motor? 3" duels? I have no idea on an intake to match...air gap or victor type? or is there a better alternative for this motor?

Yes we will be building the car around the motor, it just needs to be able to street ride every weekend or so...would also like LOW 11/ 10. e.t's....

again thanks for the help! greatly appreciated :cheers:

wendell
11-05-2004, 10:27 AM
Got to agree w/ Turbolark. Heads make horse power. Since you have such a blank slate, you would do well to post over at this board;
http://mikestarkcfm.proboards21.com/index.cgi
There's a ton of knowlege over there. Similar to this board, they changed hosts recently so you may want to mine the archives. Good luck.

TurboLark
11-05-2004, 11:16 AM
Hey! thanks for the quick replies! What we want is the max power that can come out of a 6000-6500 max rpm, hydraulic roller, pump gas 496 with 781's. I was thinking something along the lines of a 950 HP series, 10.5:1, some porting, maybe valve jobs etc...(could use some tips on what to do with the heads also...) Would 2" primaries be too large for this motor? 3" duels? I have no idea on an intake to match...air gap or victor type? or is there a better alternative for this motor?

Yes we will be building the car around the motor, it just needs to be able to street ride every weekend or so...would also like LOW 11/ 10. e.t's....

again thanks for the help! greatly appreciated :cheers:
You will severly limit your power with your heads. you will spend close to $1000(probably more) to get them in good shape to really make power, especially with 496cubes. Thats why I suggested aftermarket alumheads.along with the weight reduction or aluminum, you will have less problems with detonation at the 10.5 compression on pump gas.
Dual 3" exhaust if perfect. 2" headers should work well with the squeeze put to it. With that size motor you could get away with a single plane intake like the victor. I'd have to find my formula for calculating the carb cfm before i comment on it.

EDIT : found a formula. At 100%VE you will need 935cfm. At 85%(more realistic) you need 800cfm. So the 950 would be the largest with a 800 being minimum.

chevelle68malibu
11-05-2004, 05:19 PM
cool, thats kinda what i was thinkin, 950 HP 4150 series, victor....So new heads definately...how rare is a decent set of heads on ebay? and what heads would be good....(I'm not very knowledged on big block heads.)...what would you say for a cam to go with the 10.5:1? thanks again

p.s, I posted this over at team chevelle also, but they havent been too helpful

Lowend
11-05-2004, 07:31 PM
I read it wrong - I thought it said he already had the cam/heads ect

RatMalibu
11-05-2004, 08:27 PM
I'm running a stroked Rat myself that pretty close to what you're describing. Mine's a 489 (only went 0.030 over) and last year at test-n-tune it ran a 12.56 @ 110mph with a 2.2 60ft on Wal-Mart street tires......in a car set up for the drag strip I have no doubts it would turn 10's....mines way to stiff for weight transfer lol

anyway heres my combo

454 block 0.030 over
scat 4.25" crank
scat 6.385" h-beam rods
SRP small dome pistons (10.32:1 figured compression)
Comp XR288HR hydraulic roller/comp magnum hyd rollers
GM Performace signature series aluminum Oval port heads 2.25in/1.88ex (same ones used on the zz502)
Edelbrock Airgap RPM dualplane
Holley 3310 750 vacuum secondaries (mildly tweaked)
2" primary headers and full 3" exhaust

those times are with a TH-700R4, 3.42's in the rear. and 26" tall tires btw :woot:

oh yeah 15mpg on the highway and it has A/C too lol
It's one of those "I built way to much engine for my street car" kinda deals but it's really fun to drive :headbang:

chevelle68malibu
11-05-2004, 08:52 PM
thanks for adding that man, nice car btw. I do think that one could say your car is NOT set up for the strip, so with a 1.6 or so 60' I dont see why it wont run at least mid bottom 11's.

what did you pay for those heads?

TurboLark
11-05-2004, 09:57 PM
thanks for adding that man, nice car btw. I do think that one could say your car is NOT set up for the strip, so with a 1.6 or so 60' I dont see why it wont run at least mid bottom 11's.

what did you pay for those heads?
http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&rd=1&item=7932244335&category=33617
http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&rd=1&item=7932775720&category=33617
Just a couple I found on ebay. There are so many different ones to choose from. I personally have used AFR's for both small chevy and ford, and find the tend to have great flow in the midlifts, as well as almost always a killer exhaust port.

RatMalibu
11-06-2004, 10:04 AM
those Canfields are a good deal....if I recall right I gave right at $1800 for mine but it wsa 5 years ago....I have trouble remembering yesterday lol.....the ovals I'm running are a 290cc intake runner btw

yody
11-06-2004, 05:33 PM
I might consider the Brodix oval ports, or the AFR 305CC heads, if not the heads you have are good IF you port them and give them decent size valves, but you have to decide on the heads, because if you go aluminum you don't want 9-1 compression, also try to mill the heads down to get your compression up, try and stay away from big dome pistons. Also have fun getting to 6500rpm with a hydro roller in a BBC, the lifters are very heavy, you will need for sure a hydrarev kit. I would have him stick with a solid flat tappet for 6500rpms and he won't be missing and horsepower with it, a air gap rpm intake is a proven peformer. If you would like to kill some bottom end a vic jr. will work, 950 or 1000HP will work excellent, with the 496 wither 1 7/8 or 2" will work good. i would go with something in the high 280's to low 290's duration advertised for the cam. good luck

RatMalibu
11-06-2004, 07:29 PM
its not as hard as you think if you use the right parts......my car shifts at 6300rpm and I'm not using a rev kit.....my machine shop guy said it wouldn't be needed for what I wanted. the comp magnum hydraulic rollers are nice (at least mine are lol I've heard stories otherwise) and try to keep the valvetrain as light as possible otherwise

lol I get alot of crap for putting the car in "D" when I go to the strip........it revs up to quick to keep track of otherwise.....I'm not fast enough to keep it off the limiter :(

yody
11-06-2004, 09:52 PM
most people aren't as lucky as you, "normally" valve float is around 5800rpm. But like you said 6300 is possible. I think unless he wants to put a lot of street miles, and is looking for the super dependable never remove valve cover, go with the solid flat tappet....its also much cheaper....well if you don't wipe a lobe on the flat tappet :)