[slowbird]

Got a qiestion about LS heads that maybe someone can answer, what's the csa of the rectangle port heads? I saw someone mention they're big, so just how big are they?

[Scott Roberts]

Originally Posted by slowbird

Got a qiestion about LS heads that maybe someone can answer, what's the csa of the rectangle port heads? I saw someone mention they're big, so just how big are they?

Big enough to skull drag a pump gas Pontiac down the track....so I hear.��
Actually, it around 3.2 at the opening I believe..

[pastry_chef]

Not factory but the AFR LS3 260 cc are stated to have min CSA - 2.875 sq. in.

https://www.airflowresearch.com/260c...cylinder-head/

[Scott Roberts]

Originally Posted by pastry_chef

Not factory but the AFR LS3 260 cc are stated to have min CSA - 2.875 sq. in.

https://www.airflowresearch.com/260c...cylinder-head/

Oh..you he ment those little heads..lol

[pastry_chef]

Originally Posted by Scott Roberts

Oh..you he ment those little heads..lol

Mini me heads.

The AFR LS3 260 heads would be interesting dyno comparison on the engine in post 1. The AFR's have a substantially better intake flow curve, a sliver less exhaust flow.

Image of Trick Flow GenX 245 , cathedral ports.

[242177P]

Speaking of LS rectangle ports, the LS7 heads aren't as-cast. Factory CNC'd.
Worth noting the valve sizes, 2.2 and 1.6. Titanium valves. They also sit atop
a 4.125 bore and 4.00 stroke, why does that sound so familiar?

Also worth noting that the 5.3 (325 CID) has a bore of just 3.780 inches. And
they LOVE sticking turbos on them. Our tree fiddy is 3.875.

[Scott Roberts]

Originally Posted by 242177P

Speaking of LS rectangle ports, the LS7 heads aren't as-cast. Factory CNC'd.
Worth noting the valve sizes, 2.2 and 1.6. Titanium valves. They also sit atop
a 4.125 bore and 4.00 stroke, why does that sound so familiar?

Also worth noting that the 5.3 (325 CID) has a bore of just 3.780 inches. And
they LOVE sticking turbos on them. Our tree fiddy is 3.875.

Go ahead and slap a turbo on a stock 350 pontiac and let me know how that works out

[242177P]

Originally Posted by Scott Roberts

Go ahead and slap a turbo on a stock 350 pontiac and let me know how that works out

Other than pistons, I don't see what you're afraid of. You get stupid enough
with anything and it'll fail. If someone's going to spend money on a 350P, I'd
rather see some moderate boost than a 4.25 stroke. 7 PSI. No intercooler. Low
RPM.

Slap a 8-71 on an LS4 and let me know how it works out?

[PAUL K]

Eleven pages later and LS engines are still easy to beat 🤔

[Scott Roberts]

Originally Posted by PAUL K

Eleven pages later and LS engines are still easy to beat 🤔

Best post out of all 11 pages..lmao🤣

[FrankieT/A]

Originally Posted by 242177P

Other than pistons, I don't see what you're afraid of. You get stupid enough
with anything and it'll fail. If someone's going to spend money on a 350P, I'd
rather see some moderate boost than a 4.25 stroke. 7 PSI. No intercooler. Low
RPM.

Slap a 8-71 on an LS4 and let me know how it works out?

These guys buy junk yard 5.3's and 4.8's and without doing a thing turbo them run 10's on a stock bottom end. Blow them up after about 10 runs, go back to the junk yard buy another $500 engine and by the end of the weekend they are ready to go 10's again.

Hard to beat that!!!

[PAUL K]

Originally Posted by FrankieT/A

These guys buy junk yard 5.3's and 4.8's and without doing a thing turbo them run 10's on a stock bottom end. Blow them up after about 10 runs, go back to the junk yard buy another $500 engine and by the end of the weekend they are ready to go 10's again.

Hard to beat that!!!

..... and sometimes have the balancer fly off and go through folks skulls causing lifetime injuries and sometimes death. Please figure that cost into the purchase of the $500 5.3 and report back.

["QUICK-SILVER"]

Originally Posted by FrankieT/A

These guys buy junk yard 5.3's and 4.8's and without doing a thing turbo them run 10's on a stock bottom end. Blow them up after about 10 runs, go back to the junk yard buy another $500 engine and by the end of the weekend they are ready to go 10's again.

Hard to beat that!!!

So for $500 you can get an engine that will go 2.5 miles under power?

That's one heck of a deal
Clay

[FrankieT/A]

Originally Posted by FrankieT/A

These guys buy junk yard 5.3's and 4.8's and without doing a thing turbo them run 10's on a stock bottom end. Blow them up after about 10 runs, go back to the junk yard buy another $500 engine and by the end of the weekend they are ready to go 10's again.

Hard to beat that!!!

Here's the actual quote...