[T.Vick]

I saw an article in the new Hotrod mag earlier in the week that gave some of the numbers for the new LS1 heads from Air Flow Research. They seemed to flow pretty well and made decent power on the dyno but didn't seem any better than the numbers that I've seen for the Stage 2 Patriot heads. I looked up pricing on the ARF website and they seem very expensive too, about $2500 ported and assembled, $1800 as cast. I know they have a very good reputation, but they're about 50% more expensive than the Patriot heads in Summit.

Also, does anyone know where you could get a set of LS6 castings unassembled? The whole LS6 conversion is only about $1800 in Summit, the bare castings can't be too expensive.

 

[GMH GTO]

AFR heads are comming out soon for the 205cc version the 225 will come out later If I remember correctly they were dynoing 460hp with cam. And yeah fully ported AFRs are $2500 bucks, Patriot Stage IIs are $1795 probley best value.

Bare LS6 heads are P/N 12564825 $569
Assembled LS6 heads P/N 12564824 $676
prices from www.gmpartsdirect.com

 

[GMH GTO]

LG motorsport are going to have the AFR 205 heads in stock next week. They are going to have an introductory price below $2300 they say.

 

[speed_demon_freak]

http://store.summitracing.com/partdetail.asp?part=NAL-12564824

 

[LS1GURU]

507 hp with cam. you can LS6 castings from GM Performance parts. I dont remember part# or price but I can look it up.

 

[T.Vick]

Thanks for the link to GM Parts Direct. That seems like a very good price.

Does anyone have flow numbers for the CNC ported LS6 heads that are sold through GM Parts Direct? I would think the numbers must be pretty similar to the AFR heads. Also, what's the "ASA" cam that they mention?

Even the whole LS6 conversion is pretty tempting, but that cam just seems so small. It seems like a waste to do all the work and not go with something a little bigger.

 

[GMH GTO]

yeah i'm thinking the same thing tvick, but 405hp is pretty easy to live with, will probley not have to touch the clutch either. Stepping up to some AFRs or patriot stage IIs will require a better clutch.

ASA is american stock-car association, nascar style racing that few years ago turned to using LS1 engines a sealed crate motor made by lingenfelter (most cases). Of course switching to LS1s has better the racing lowered the cost, teams have gone two years (most go a season) with one engine at a 10 grand cost per motor. The ASA cam is long duration, big thumpy idle with average lift, its easier on valve springs I would only recommend it for its soul purpose, speedway oval track racing. Guys on LS1tech have put em in with stock tuning havn't seen any 1/4 mile numbers though.

I'd just wait for the moment and see how people react to the AFR heads, the 205 CNC ported heads are still smaller then the LS6 210cc. The 225 AFR may be interesting people are expecting head and cam swaps to yeild 500rwhp, that be the case I will be interested, thats considered MAX power on a LS1 bottom end.

This summer will be interesting at the track.

 

[EDC]

I'd just wait for the moment and see how people react to the AFR heads, the 205 CNC ported heads are still smaller then the LS6 210cc. The 225 AFR may be interesting people are expecting head and cam swaps to yeild 500rwhp, that be the case I will be interested, thats considered MAX power on a LS1 bottom end.

This summer will be interesting at the track.

There is a huge benefit to running the AFR head over any ported stocker.

PORT VELOCITY

Though it is critical in every combination to have the correct flow figures to match the desired horsepower wanted, to do this with a large port volume and cross section is extremely detrimental to velocity and real power.

The AFR 205 heads right out of the box, reach some very impressive levels of CFM all through the low lift numbers where they are needed most. No ported stocker, by any shop, could ever achieve this goal.

In almost any street car application and even in some racecar applications, this fact alone will create a faster"accelerating" car. And isn't this why we own such vehicles?

I'll be testing the "production" heads later this week and will be comparing these to the "pattern" heads from months ago. Shouldn't be that much different but I have to know..

Bottomlline: This new small runner head will be the ticket for the "faster" GTO's. Especially with it's 3600+ pound bulk...

Ed

 

[Old Goat]

Ports

Intake Velocity is what it's all about.
Small ports keep intake velocity up at low RPM and make torque low and mid, but start to roll off beyond.
Big ports are slow low and start to turn on as the RPM climbs into the midrange, making their power on the big end.
Nirvana would be a working marriage of the two.
JMHO

 

[GMH GTO]

LG motorsport dynoed a cammed LS6 motored vette ran 440rwhp with AFR 205 heads ran 485rwhp. So the 205 heads are definatly better then LS6 heads. Was still maintaining hp through 7000rpm, I don't think i'd like to try that for myself. More info on the vette and cam it had is on LS1tech.