AFR 195cc LT4 . . . fully ported flow #'s @ .28 In. 2.02 / 1.60 valves. Actual volume is ~203cc intake and ~67cc exhaust.

Lift Intake Exhaust
0.10..... 61.9 ..... 53.5
0.20..... 132.6..... 113.3
0.30..... 198.8..... 168.9
0.40..... 240.2..... 186.6
0.50..... 268.5..... 199.4
0.55..... 273.3..... 202.5
0.60..... 280.1..... 205.9
0.70..... 281.3..... 207.7

After all the work I have into them, I'm a little disappointed. I wanted to hit 300cfm, but without going to bigger valves that looks like a pipe dream. And I can't raise the runner any more without having to manufacture my OWN intake manifold (the LT4 manifold is getting pretty thin). From what I've seen, these numbers are on par with standard ported LT4 heads. I'm beginning to wish I'd went with some AFR 210's or 220's.

As you can see, going solid-roller would be a waste of time & spring life. The heads are pretty much stalled out after .57 - .58. My goal is to break 400rwhp with these heads on a stock LT1 shortblock, which, hopefully, will be going back together this coming weekend.

 

are those AFR numbers? or numbers after you had some work done to them?

i would think in competent hands those heads should have more potential then what the numbers are showing...

fyi, my heads ( GM LT1's ) arent much under the numbers you have up there, with smaller valves...

with a well matched camshaft and valvetrain tho, i would think 400+ to the wheels would be easy

 

Good numbers, what kind of experience do you have porting?

 

You should make 420 to the tires with the right cam and 11.5 to 1 compression and all the right bolt ons, I see no problem doing it.

David

 

The gentleman who ported them usually works on Mopar stuff (he has a 571ci HEMI with a 1471 blower on it). AFR's #'s are about the same for these heads as what he's gotten out of them, actually.

400hp at the wheels may not prove as easy as it might sound. I have a Ford 9" with some 17X11's. No electric WP, no underdrives.

I'm running a 233/239 .569/.577 cam. Depending on how I do on the dyno, I may go bigger with the cam and get it matched to the heads. Was thinking of something like a 242/248 @ .5.

 

You will be close to 400rwhp with good tuning and that cam IMO, but I dont see 420rwhp.

 

The combo I had in my car previously was not as good as what he has and made around 380 rwhp, was never dynoed, but the formula's say for a 3740 lb car to run 90 mph in the 1/8 takes 380 rwhp, and the fact I outran a buddies car from a roll on twice that made slightly better than 400 rwhp, I would say it was close to that mark. My heads only flowed 257 cfm@.600, had a 224/228@.050 cam, 1 5/8 shorty headers, slp 2OTL ex fully capped, no pullies, no electric water pump, through a 9 inch with 4.11 gears. I still think with his six speed, right cam and compression 420 can be done.

David

 

I agree. I dont think he has the right cam though... Its all speculation anyway.

 

Are you racing peak flow #s with other people?
Peak flow really doesnt matter that much in regards to flow #s and power, you have nice low/mid lift and that's what counts.

 

Ken, think his car is capable of 420rwhp with a different cam and 11 or 11.5 to 1 compression? And the right combo of bolt ons?

David

 

I hate guessing at other people's setup on what i think they will do because i do not know every little detail of their car. And one little detail can make or break a setup. But in general if he does everything well (when I say well I mean like how i'd do it ) yeh i think he could do 420rwhp.

 

FYI: I had the heads milled so final compression will be around 11.5:1. I intend to have it dyno-tuned on a Mustang dyno (AP Engineering). I know they dyno low, but they're supposed to be better for tuning and drivability b/c they can put a load on the drivetrain.

As far as peak flow #'s go, I was hoping for better, but, obviously, the heads are going on the car now one way or another.

To help you guys out a little with details: I have hooker longtubes, stainless "catless" y-pipe, Corsa catback, MSD6AL, new opti (sad that I have to list that as a mod), LS1 nose & airlid w/ K&N, ported 58mm throttle body, gasket matched intake, !EGR.

 

What cam would you reccommend?

 

i'd let a professional 'spec' a cam for you
one comes to mind is Bret Bauer e-mail... Bret@bauer-racing.com

 

Yup.