Making fast go fast with a 323 Big Bore Stroker

01yellerCobra

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Just when I decide to get rid of my big bore block you're going to make want to build it.

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05stroker

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Just when I decide to get rid of my big bore block you're going to make want to build it.

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No, you dont need to do that, just sell it to me at .50 on dollar shipped. We all know these blocks are junk anyways.
 

JoshK

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Good luck Billy. Fwiw, I have been to 23-24lbs peak on my BBS so far. I have stock main caps with arp everything, Kellogg 3.800 crank and Manley I beams. I actually just sprayed the wet kit on it for the first time a couple weeks ago as well
 

01yellerCobra

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Good luck Billy. Fwiw, I have been to 23-24lbs peak on my BBS so far. I have stock main caps with arp everything, Kellogg 3.800 crank and Manley I beams. I actually just sprayed the wet kit on it for the first time a couple weeks ago as well
What kind of numbers are you making?

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05stroker

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Well the SB is together! Deck height​ came in at .007 so with my 48cc heads that will put me at 322.56 CI and 9.97 CR. We will call it a 323" with 10:1 CR.

Now to decide, do I use my heads I ported or the Foxlake heads i pucked up and had gone though?

Mine are port matched to my JPC intake and ARH headers. The Foxlake heads have a better looking combustion chamber though. I also do not know the cc of the Foxlake heads though. I will check them.

Do I flow them both and use the one with the best numbers on the same bench?

If the Foxlake heads flow better do I match the intake ports to my intake or just leave them alone?

Even if one flows better, will it nessearly flow the best at 24 psi?
 

travelers

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I would flow the Foxlake heads to make a comparison between the two first. If you decide to go with the Foxlake heads then port match them.

As for the question of flow at 24psi, that's a good one. Can a flow bench test at positive psi? I know they usually check at different valve opening but never heard of a positive psi test.
 

05stroker

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I would flow the Foxlake heads to make a comparison between the two first. If you decide to go with the Foxlake heads then port match them.

As for the question of flow at 24psi, that's a good one. Can a flow bench test at positive psi? I know they usually check at different valve opening but never heard of a positive psi test.

Not that Im aware of, thats why I was wondering if anything changes when the incoming air is under pressure.
 

travelers

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Not that Im aware of, thats why I was wondering if anything changes when the incoming air is under pressure.

I would think that with the volume of the runner at WOT or 24psi the volume of air at different valve opening would flow at a higher speed. The only restriction or slowing of the air, would be the opening and closing of the valve.

I would ask the shop there take on it. It may be irrelevant to air flow.
 

RocketcarX

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Kaase had to make a similar decision when he did the 409 CI mod motor for Engine Masters sans boost, he choose the big valve heads but lamented that he thought they would have done about the same.
 

Department Of Boost

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A tidbit of "theory". A Centri blower is a true "blower", not a compressor like a PD blower is. So a Centri blower is far more sensitive to airflow efficiency.

If you go with big heads, big cams, big exhaust, big displacement, etc with a PD blower you will see a small increase in power because it will have less parasitic drag (less boost = less parasitic loss). But mostly what you will see is a decrease in boost. Consequently if you go the other direction you will see an increase in boost and a slight decrease in power.

If you go with big heads, big cams, big exhaust, big displacement, etc with a Centri blower you will increase the efficiency of the actual blower unit because it has less restriction to "blow" through. Again, not a compressor.

In simple terms I think you want to use the best flowing heads/best combustion chambers and then port match them to the intake/exhaust. The less restriction you have, the better your blower will work.
 

05stroker

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A tidbit of "theory". A Centri blower is a true "blower", not a compressor like a PD blower is. So a Centri blower is far more sensitive to airflow efficiency.

If you go with big heads, big cams, big exhaust, big displacement, etc with a PD blower you will see a small increase in power because it will have less parasitic drag (less boost = less parasitic loss). But mostly what you will see is a decrease in boost. Consequently if you go the other direction you will see an increase in boost and a slight decrease in power.

If you go with big heads, big cams, big exhaust, big displacement, etc with a Centri blower you will increase the efficiency of the actual blower unit because it has less restriction to "blow" through. Again, not a compressor.

In simple terms I think you want to use the best flowing heads/best combustion chambers and then port match them to the intake/exhaust. The less restriction you have, the better your blower will work.
This was my thinking as well when I gutted my heads. Im hoping to flow them on Saturday. If I reuse mine, I will most likely upgrade to 2" headers since I'm being told I have left power and scavenging on the table by port matching my exhaust ports to my headers. If I use the Folxlake heads, I will port match the intake ports to the JPC intake and ported delete plates and leave the exhaust ports alone.
 

05stroker

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I dropped the heads off last Friday, I should have some numbers by the end of the week.

Sunday I went to work on the kids new 302 stroker. It has Manley billet I beam lightweight rods, Scat 3.75 stroker crank and Manley pistons.

Most dont know yet, but he totaled the white car over a month ago. 45* into a concrete bridge and guard rail at speed, the car is done. We are looking for a replacement as we speak.

Plan is to swap everything from his old car to the new one. Problem is, this is effecting mine getting back up and running. Good news is everyone is okay and its making me take my time with mine. I went ahead and rebuilt my blower as well while waiting. I now have a fresh trans, converter, rear end, ds, blower, and soon to be motor with more CI then Ive ever had.
 

01yellerCobra

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Sorry to hear about the car, but glad your son is ok. The F1A with a BB/S is as awesome combo.

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