Ok so i know there probebly the best head out there right now or so i heard i was wanting to run them on my turbo 396 setup ive been looking and what size would be the best for that perticular setup (havent worked on finding a blower cam yet to fit my need but im guessing a custom grind would best suite that) But ive been seeing the use of alot of 210 lt4 AFR's any suggestions?

 

since you're going boosted alot of the usual head size stuff goes out the window right off the bat. 210 would be a great size... if you were staying n/a. but on my boosted stuff i tend to err on the large side. imo you'd probably do nothing but gain by going up to a 220 or possible even a 227, depending on how tight you aim to wind it up.

 

The bigger castings offset the valve further and further. You "should" run shaft mounts, or you can just buy adjustable guidplates but that starts to get iffy after a certain point

 

Im looking at getting the most poer i can and spooling up as fast as i can in other words id like a good blance of the two

 

what do you plan to use the car for?? power goals?


i had a 400ci lt1 with afr 215RRheads and i was going to use a 88mmturbo on her. if you go with a 215 or 227 its going to need offset stuff like the other guy mentioned.

you can make plenty of power (probably more than whatever your goal is) with a hyd setup and 210s, with a 76mm turbo.

brook

 

the offset rockers is a good point on the larger stuff. but in a build like this i dont even consider a stud mounted rocker. by the time you get a set of stainless rockers and adjustable guideplates set up with a stud girdle, you've already pretty much spent the green for a decent shaft setup.

 

i wanted to get 700ish rwhp what do you thin the 210's could max it out too? The more i can get out of em the better....I want to show up a freind who has approximaty 500-500 rwhp ls1 n/a he said there is no way the lt1 could beat him id like to show him otherwise and do it on pump gas as well

 

Why do you believe the AFRs are so good? Everyone says this but I see more that contradicts it than backs it up?????

 

Its from what ive seen on peoples cars around me and what its done for them and ive heard nothing but good things about them?

 

From what I have seen the people who use them have thrown so much money at the car it would be hard NOT to make power. Take at least a look at the Trickflows if you feel you have to have an aftermarket head. These seem to be becoming a favorite among some of the LT1 specialists.

IMO AFR earned a good rep years back when OEMs had crap for heads and have just skated along on that rep since then. Many of the guys I see using them have mediocre results that could have been duplicated with stock castings competently ported.
Also consider more often than not people will defend a large purchase like that even if it turns out to be a mistake, pride an all . Seen A LOT of guys blindly defend their AFRs even after the next guy makes more power with ported stock castings or LT4s ported. I don't think AFR is wholely bad just that people are WAY too fast to hop on that bandwagon and not objective enough in looking at what they might actually offer.

AI, Lloyd, CM all do great things with a stock casting and I know they all like the Trickflows. CM currently has the fastest LT1 b-body 28psi boosted stroked consistently a 9 second car at elevation in the desert, weighs 4240lbs., they run the Trickflows. If someone tells you that is too small a head you might want to think twice before listening.

 

Ported TFS would be a better choice with a blower and a 396. They can flow 310+CFM where an AFR has a tough time with that much flow even from a 227.
The combustion chambers are 62CC's, better for the blower.

 

The key to a blower motor is not boost pressure, it's CFM put in the motor from the blower. Boost pressure is actually just backpressure.

Larger cross sectional area heads are going to help you more flow at lower restriction so you make more power with less boost.

Dwayne, last time I looked over at B-body land Mr Elliot seems to have some of the fastest rides out there in their classes. ;-)

Bret

 

When ya are showing a LOT of boost,that means it ain't going in the engine to be used.
Like I said larger flow numbers in the heads and intake will net ya more HP,just like Bret said.
If ya want more boost get a bigger blower. If ya want HP get bigger heads and cam to compliment the blower.

 

so what heads do you think would he;p me reach the 700 mark like i said dont feel afraid to give me suggestions im always looking to get more then my goal out of things what is the mos i could get out of the 210's or comparable head? also what would be a good reason for going with a bigger head? I just want to figure out which one would work best for me

 

Going only from watching someone else, George Baxter made close to 1,000 flywheelHP (383 LT1, Vortech S/C) with a set of LPE CNC LT4 heads. They had some additional work in them, beyond what they left LPE with. He looked at every head available at the time (we're talking late 90's), and tried and rejected the AFR's - couldn't unload them fast enough. Could not get the power he wanted out of them. The LT4's worked fine at that level. When he bumped it up to 1,125HP, he took a set of Canfields, and totally reworked them. They are no longer available. I'm not sure what the AFR mystique is.