Another "How much will it make?" Project "Special Needs"

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CGT
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Another "How much will it make?" Project "Special Needs"

Post by CGT »

Building a sbc currently that will find its home in my 65 Malibu SS as a fun street cruiser, 5spd man.. Will hang it on the dyno this winter before going in the car. Looking for hp and tq guesses, input, advice etc. and advice. The parts list is as follows:

4.040 x 3.5 stroke
Srp Pro flat top pistons 1.2 1.5 3mm rings
Napier second ring
5.7 Rod length
Morel hyd roller lifters
Stock oil pan....Z28 windage tray
Hex adjust Cover and gear set
12496822 GMPP Single Plane Manifold
Ported BV heads 206cc 64cc chamber
Crower 1.6 1.5 stud mount rockers
Manley 221438-16 Nextek Springs
Will try different carb sizes but will start out with a 850 Demon carb
.035 piston to head.

Have not purchased a camshaft yet...would like some opinions on that and/or anything else. And of course power predictions. Would like to not spin it higher than 7000rpm(hyd lifters). Projects need names and this ones named "Special Needs" for various reasons.

Thanks
Chad
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Re: Another "How much will it make?" Project "Special Needs"

Post by Orr89rocz »

If heads flow decent, something around 230/236 .050 and .550-.570" 108-110 should make steam carry to 6500-6800 and shift 6800 ish
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Re: Another "How much will it make?" Project "Special Needs"

Post by mag2555 »

Post up a level of hp you would like to see and then folks can give you much more focused picks on Cams to get there and the needed head flow and port area to get there!
You say the heads are ported, so what CCs are they at now , and what is there peak flow @28"?
Not many of us here have the needed Crystal ball to nail down a complete reply as you have posted this!
You can cut a man's tongue from his mouth, but that does not mean he’s a liar, it just shows that you fear the truth he might speak about you!
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Re: Another "How much will it make?" Project "Special Needs"

Post by CGT »

mag2555 wrote:Post up a level of hp you would like to see and then folks can give you much more focused picks on Cams to get there and the needed head flow and port area to get there!You say the heads are ported, so what CCs are they at now , and what is there peak flow @28"?
I want to make 550hp and 490ftlbs. But more is always welcome. :lol: Peak flow is 290cfm.
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Re: Another "How much will it make?" Project "Special Needs"

Post by mag2555 »

Ok then, you will need to run enough valve lift to tap 270 cfm out of those heads and I would want to see atleast 10.75 to 1 up to 11.2 comp.
The Intake manifold chosen needs to pass that full 270 cfm@28" with no drop off also .
You can cut a man's tongue from his mouth, but that does not mean he’s a liar, it just shows that you fear the truth he might speak about you!
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Re: Another "How much will it make?" Project "Special Needs"

Post by CGT »

mag2555 wrote:Ok then, you will need to run enough valve lift to tap 270 cfm out of those heads and I would want to see atleast 10.75 to 1 up to 11.2 comp.The Intake manifold chosen needs to pass that full 270 cfm@28" with no drop off also .
That should be doable.
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Re: Another "How much will it make?" Project "Special Needs"

Post by mag2555 »

Yup, no magic needed!
You can cut a man's tongue from his mouth, but that does not mean he’s a liar, it just shows that you fear the truth he might speak about you!
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Re: Another "How much will it make?" Project "Special Needs"

Post by zums »

That intake is going to need some work, on a head that flowed 280cfm the #3 runner tested dropped to 230, so get your burrs out
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Re: Another "How much will it make?" Project "Special Needs"

Post by randy331 »

CGT wrote:
mag2555 wrote: I want to make 550hp and 490ftlbs. But more is always welcome. :lol: Peak flow is 290cfm.
Your goal doesn't seem outta line. With a max 7000 rpm limit, 6500 rpm would be a reasonable target rpm for peak HP. To make 550 HP at 6500 rpm it takes 445 LBs of TQ to do that. The decent engines I've seen seem to loose about %10 of their peak TQ number by peak HP rpm. So 445 x 1.1 = 489.5. pretty close to your TQ goal. So if you can make 490 LBs at 5000 rpm or so, it should make 550 HP at 6500 rpm. 490 Lbs is 1.36 pounds/cubes. Good for a low comp not real serious street engine, but doable.

The 290 cfm through a 206cc vortec port would be close to 300 FPS average port speed on the bench, so that part sounds in line.

228*/252*-112* for a cam get you close.

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Re: Another "How much will it make?" Project "Special Needs"

Post by CGT »

randy331 wrote: 228*/252*-112* for a cam get you close.
Interesting cam choice. Looks like an early EVO for that rpm range.
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Re: Another "How much will it make?" Project "Special Needs"

Post by CGT »

62 deg bbdc @50. Couldnt that be a torque killer?
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Re: Another "How much will it make?" Project "Special Needs"

Post by zums »

Ported BV heads 206cc 64cc chamber

so did you port the 183s or epoxy the 223s, valve size?
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Re: Another "How much will it make?" Project "Special Needs"

Post by CGT »

zums wrote:Ported BV heads 206cc 64cc chamber

so did you port the 183s or epoxy the 223s, valve size?
Large Port BV epoxied down. 2.08 1.56
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Re: Another "How much will it make?" Project "Special Needs"

Post by Rick360 »

FLOWZ?
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Re: Another "How much will it make?" Project "Special Needs"

Post by CGT »

Rick360 wrote:FLOWZ?
Ill have to obtain the flowz!
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