1fastxz

iTrader: (16)

Form what iv heard, the intake ports are in a diffident location, they said that This heads where not meant for anything but a carb hight rise intake
the intake runner size is well over 300cc's

Think you could get Beck to make you up a intake, but don't think there is a chance they will work with a FAST

O.N.

yeah but if you get the unported dr heads and even add material to them if needed to make the port locations right.

LS6427

iTrader: (2)

FAST 102 will choke those heads big time.

ITB.....................
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Stang's Bane

iTrader: (22)

Any available itb intake out now will choke these heads. Big single plane or sheetmetal is what's needed

LS6427

iTrader: (2)

Like to see someone try this one out: they should have their LSx versions out by now.
new intake

They get 850 hp out of their 441ci LSX with the old Hogan sheet metal intake and lesser flowing heads than those 430cfm LSXr's.....14:1 cr engine, but still, thats a ton of power for a Hogan.

.

O.N.

but it would probably still be an improvement over the LSX LS7 ported heads im running now.
Currently im making 597HP at the wheels mainline aussie dyno our figuers on this dyno are about 640HP on the ones you guys use.

I think the heada are flowing about 390cfm @ 700 lift the dr's flow 435cfm????

HNK

Is that NA rwhp? what is your package?

O.N.

Yeah rwhp on a mainline aussie dyno our dyno's give numbers lower than your usa ones, and yeah N/A.

LSX454 Crate motor
LSXR 102mm intake
102mm throttle body
DUS speed OTR
heads cnc ported and shaved 20 thou compression now 11.6.1
fast 50lb fuel injectors
mafless dyno tune.
2in 4into 1 extractors
twin 3in exhaust
custom comp cam over 660lift.

video here:
[youtube]BSj6ecmlYh0[/youtube]

Beau@SDPC

iTrader: (14)

It appears to me you need way more injector. My wheel of death shows at least a 65lb based on fuel pressure that is.

It appears what you call a "mainline" dyno is probably a loaded dyno, such as a mustang that uses an eddy current. Yes, they do have a tendency to show lower numbers.

O.N.

nah injectors are fine, we can see what they were flowing at when tuning the are right on the money no need to go any bigger.

i was told on a usa dyno the figures would have been 638rwhp.

So whats your thoughts on modifiying the lsx dr head to suit the fast 120mm intake worth it? make more power? manifold be too much restriction?

Bill00Formula

iTrader: (4)

Do you have quarter mile tracks in your country? If you make that much power you would trap close to 138 or more in decent weather at full weight.

HNK

John

Are these the heads you were talking about to use on a 454?

HNK

Did u try to work the runners to improve the flow for your motor?

O.N.

Yeah we have 1/4 mile tracks...lol we are not some tiny little country...lol
Im waiting on a gforce1320 CF drive shaft before i goto the track.
Mine is still manual 6 speed which will bring the time down a little. But yeah the MPH would be about that if not more, the car has alot of torque you can see the dyno print out at the end of the youtube video.

Nah left them they way they came. Shortening will make slight improvements but the more top end you gain with the runners the more bottom and mid range you lose so no point just leave em stock.

Beau@SDPC

iTrader: (14)

No. GM is going to use them on a 454R but they are a bit from being complete. They are rather pricey, plus take quite a few different parts that make the cost go up more. Plus, I am not sure that the entire setup would fit under most factory hoods.

Eddie2011

I just got mine yesterday. Took pics but not on the computer yet. They will not work with a fast intake no matter what you do. The only manifolds I know available right now are the carb one mentioned above or custom.

I am building my manifold with an integral air/water intercooler. Haven't nailed the design down yet since I gotta get the heads on the motor and see what kinda room I am going to have.

chop_runoou

hi i am building a n/a 427 ci stroker motor and am amaized of how many different types of heads you can get for the ls engines now . i am still learning a lot to do with heads at the moment ,and realising the big is not always best . but my car is not an every day driver , i dont care bout fuel consumption or surging in traffic. would these heads be to big as we are looking at running around 12.5 to 13.1 compression and we want to run at 750 thou lift on the springs . what i am worried about is air speed ? is the runner to big and would i loose to much air speed . would i be better going for a ct version of these heads or can some one recomend a head that would suit what i am after . as for intakes i was looking at a sheet metal tunnel ram with twin throttle bodies. . i cant tell anybody cam specs at this time as we can not do anything till we decide on what heads to go with .

Stang's Bane

iTrader: (22)

Your build is exactly what these heads were designed for. Make sure they will fit with your bore size and let it rip. They should shine in your application. They should make 800++ crank HP.

commy

mast heads.

chop_runoou

my bore size is 4.125 its a darton sleeved ls block.

je pistons , scat rods and callies crank.

thanks for your help