[napster]

Pontiaclars,

I'm running a 496 with the 4.5 inch stroke Scat crank. Details different from yours:
Carb is a Brawler 850 cfm
1.65 Harland Sharp roller rockers
compression is 9.9
cam is the same except lsa is 112
heads are cast iron SD heads bought with a bad port job only flow 260 cfm
HP 520, TQ 580

I would think you will do much better. If not 600 HP you will be knocking on the door. TQ will be north of 600.

Here is my thread:
https://forums.maxperformanceinc.com...d.php?t=834864

Here are two videos of the car running. First is the car is not finished and the second is when it is finished.
https://www.youtube.com/watch?v=LCVaZqP-PNo

https://www.youtube.com/watch?v=941I2R4IVzY

Good luck with the build.

[napster]

Originally Posted by PontiacLars

I am aiming for 550-600 hp. Would love to see close to 600, but I do not think my cylinder heads flow enough to achieve that. Heads are port matched to 1.18x2.35 port size gaskets and general touching up in bowls.
The camshaft is advertised as butlers 600+ camshaft, so hopefully the cam is radical enough.

If I'm not mistaken, I thought the Butler cam was for the 461 engines. My tech wanted me to go one step up with @.0500 numbers of 248/254 @ 110lsa. I'm the one that made him go one step under his recommendation.

[25stevem]

520 hp is not bad out of a iron head flowing 260 cfm and with under 10 to 1 compression and that Cam duration.
The most I would say you could get with flogging it for a few hours on a dyno is 537, so your not too far off.

[Formulajones]

Originally Posted by napster

If I'm not mistaken, I thought the Butler cam was for the 461 engines. My tech wanted me to go one step up with @.0500 numbers of 248/254 @ 110lsa. I'm the one that made him go one step under his recommendation.

That would be my thought on it. With a bigger engine I'd certainly go more on the camshaft. It's a nice fit for 450-ish cubes and very streetable, even with mine on a 110 lsa.

[Baron Von Zeppelin]

...but I do not think my cylinder heads flow enough to achieve that. Heads are port matched to 1.18x2.35 port size gaskets and general touching up in bowls.

Your heads were rated at 289cfm Intake at .600 lift ,,, 270cfm Intake at .500 lift
.540 lift would approx at 280cfm

Consider those test numbers just as the Best Port , not necessarily all 4 ports , and not a 4 port overall average.
We don't know those facts.

Might should deduct for the unknown and call it 270cfm overall average at .540 lift
Then maybe add another 5cfm for buttering them up a little.
275cfm should be pretty reasonable without going over board.

You have 550hp range pretty much locked in.
And possibly more with a super tuner testing it on a happy dyno.

Have you gotten to the point of mounting or test fitting the Intake Manifold yet ?
Mentions have been made of some intakes not sealing at top of port on ports that tall ,
and I believe they were referencing 2.20-2.25 range.
You are at 2.35
Just curious is the only reason I ask.

[PontiacLars]

Originally Posted by napster

Pontiaclars,

I'm running a 496 with the 4.5 inch stroke Scat crank. Details different from yours:
Carb is a Brawler 850 cfm
1.65 Harland Sharp roller rockers
compression is 9.9
cam is the same except lsa is 112
heads are cast iron SD heads bought with a bad port job only flow 260 cfm
HP 520, TQ 580

I would think you will do much better. If not 600 HP you will be knocking on the door. TQ will be north of 600.

Here is my thread:
https://forums.maxperformanceinc.com...d.php?t=834864

Here are two videos of the car running. First is the car is not finished and the second is when it is finished.
https://www.youtube.com/watch?v=LCVaZqP-PNo

https://www.youtube.com/watch?v=941I2R4IVzY

Good luck with the build.

Thanks!
Your engine sounds like a lot of fun. Good numbers! And very nice car you got!
I also have 1.65 rockers, so lift is a bit more than I wrote in the spec list.

[PontiacLars]

Originally Posted by Baron Von Zeppelin

Your heads were rated at 289cfm Intake at .600 lift ,,, 270cfm Intake at .500 lift
.540 lift would approx at 280cfm

Consider those test numbers just as the Best Port , not necessarily all 4 ports , and not a 4 port overall average.
We don't know those facts.

Might should deduct for the unknown and call it 270cfm overall average at .540 lift
Then maybe add another 5cfm for buttering them up a little.
275cfm should be pretty reasonable without going over board.

You have 550hp range pretty much locked in.
And possibly more with a super tuner testing it on a happy dyno.

Have you gotten to the point of mounting or test fitting the Intake Manifold yet ?
Mentions have been made of some intakes not sealing at top of port on ports that tall ,
and I believe they were referencing 2.20-2.25 range.
You are at 2.35
Just curious is the only reason I ask.

Sounds like I will be in the hp range i am shooting for.
No, test fitting of manifold yet. Will definetly keep that in mind though.

[JLMounce]

Originally Posted by PontiacLars

Ok, thanks.
I see that the Fitech throttlebody and 800hp fuel pump kit, comes with an6 fittings. The almigthy internet tells me an6 is good for 500 hp, an8 good for 800hp and so on,
Anyone know What an6 can support?

-6an will supply more than enough fuel for your needs. On a normally aspirated engine, you don't need much more line until you're getting close to or above 750ish hp. If this was a boosted application where there is more fuel demand, I'd start thinking about it in the 650hp range.

[65madgoat]

530hp and 575 tq all day unless you get more head flow

[Steve C.]

The KRE standard design Northwind 4150 intake is listed with a RA IV port match machined into the intake. That would be about a 2.200" tall port opening.


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