Stock LS1 head

Or

AFR 23 degree head with 200 cc runners

The AFRs do. Check out Chevy Hi Performance's website. They have a cylinder head data base.
-Paul

As a general rule....the LS1 is a great engine because the 15 degree heads allow it to flow more air than a traditional 23 degree head....

But I've always had to wonderif the best of the best 23 degree heads such as AFR's could flow the same if not more than a stock 15 degree head?

The afrs flow better, but the ls1s just seem to make a lot of power, plus you can get over 300cfm out of a stock casting ls1 for $1000

Stock LS1 heads flow 230-240s at best...
(but have plenty potential for 300+)
Good 23deg 200cc heads will flow 280-300cfm.
But flow # aint everything

If flow isn't everything then what is?

Last I heard all engines are air pumps, the more air it intakes/exhales the more power it made.....??? Is that not where most of the engine efficiency comes from?

I'd like to throw on a set of AFR's on a 400 sbc and see how much power it makes as opposed to the average LS1. :)

If flow isn't everything then what is?

Last I heard all engines are air pumps, the more air it intakes/exhales the more power it made.....??? Is that not where most of the engine efficiency comes from?

I'd like to throw on a set of AFR's on a 400 sbc and see how much power it makes as opposed to the average LS1. :)


JYD, I went with a aftermarket 200cc steel head (2.05/1.6) and am 1.0 faster and 7mph over the stock home ported 400 heads (1.94/1.6). I can't say they'll all do this or how it compares to a LS1, but I still have a smile.

Also CHP did a build off with set limits between a 406 23* gen 1 block and a gen 4 LS 402. both made 586?HP or there abouts, but they did say the LS was streetable and the 23* wasn't too street friendly.
Now also remember it's a magazine build.

If flow isn't everything then what is?

Last I heard all engines are air pumps, the more air it intakes/exhales the more power it made.....??? Is that not where most of the engine efficiency comes from?

I'd like to throw on a set of AFR's on a 400 sbc and see how much power it makes as opposed to the average LS1. :)

I'm very far from an expert, but I do know velocity is a critical component when it comes to a head making good power. So is chamber design and probably a number of other items that hopefully the more knowledgable people here will chime in on.

I'd like to throw on a set of AFR's on a 400 sbc and see how much power it makes as opposed to the average LS1.

Throw a set of AFR "Mongoose" street (205cc) heads on a 396ci LSX and then compare it to the 23* 400.

Scot

If flow isn't everything then what is?



ET & MPH at the track. It lets you bypass all those silly 23* v. 15* and streetable v. non-streetable arguments. :-)

ET & MPH at the track. It lets you bypass all those silly 23* v. 15* and streetable v. non-streetable arguments.

I saw a late model LSX Camaro running 11.20's at Cedar Falls Raceway this past summer. The car appeared totally stock. A couple of hours after we left, this same car passed me (pulling my trailer) on I-35 near Ames (about 100 miles away). I was bought and sold on the driveability issue.

Scot

Swirl, combustion efficiency, chamber design, spark plug location, port shape, port location, the minimum area in the port (smallest section of the port), velocity....

Flow is but one thing in MANY.

I think SlowPoke70 summed it up very nicely. Flow is only one variable in the equation and too much flow can be a bad thing if other elements are missing. As an extreme example, if you had 4 inch sewer pipes for runners on a 350 chevy, they would certainly flow a lot more than 200cc runners, but guess which one is going to get down the track quicker.

Here is an excellent thread on head flow and why many top engine builders are getting sick of it being used as a bench mark for performance:
http://www.speedtalk.com/forum/viewtopic.php?t=4696

Also CHP did a build off with set limits between a 406 23* gen 1 block and a gen 4 LS 402. both made 586?HP or there abouts, but they did say the LS was streetable and the 23* wasn't too street friendly.
Now also remember it's a magazine build.

Yeah I saw that article, pretty impressive on both engines. Not sure how you describe "unfriendly" other than the LS2 had a smooth idle while the 406 had a lope....plus the 406 had to be rowled up a little to make the same numbers.