NoGo

iTrader: (2)

I'm not an engine builder, but....

I think it comes down to how early you are making the power (ie torque) rather then overall HP. The heads seem to pick-up sooner on Nitrous and Turbo cars and not so much on Centri-S/C cars.

I think the technology is a little better now days but several years ago my rule of thumb was the heads come up around 800 HP.

Something else to keep in mind is alot of those folks making big HP on an LS6 head are picking the head up and pushing water, but either deal with it, or have other means to manage it.

I have almost 30k miles on a 700HP S/C setup LS6 head and no issues so far.

dschmittie1

iTrader: (64)

I just went 9.8@141mph with my ls6 heads last night

white01ss

iTrader: (37)

Congratulations on getting into the 9s! Nine second street cars are freaking sweet. Did you do it with the numbers in your sig?

dschmittie1

iTrader: (64)

Things have changed a little those number are from the stock 241 heads ls6 intake and 224 232 cam with the t56 still in it.

I have not dynoed it yet with the same forged 347 but with 243 heads that I ported 235/251 cam and Victor Jr intake. And it now has a TH400 That was my second full pass with the new setup and 1.54 60' (same blower pulley combo as last year)

The car has alot more in it with some more seat time and 60' work

fatmat80

^^nice results...the only thing better than a nine second street car is a m6 nine second street car...

white01ss

iTrader: (37)

Free set of ported LS6 heads to the next voter!!!!

Seriously, looks like the tide is turning to the 800+ range. Probably with head studs, right?

JAX04

iTrader: (17)

great thread white01ss, def some good info here

Rossko85

iTrader: (11)

oh my 243's are getting a nice lil stage 2 polish up in the fall and specked for RM cam and turbo...very good post! it helps the process!

black98ws6ta

iTrader: (77)

Stock heads do lift, so do aftermarket thicker deck heads. When the heads are going to lift has a ton of factors. How good of a tune, how much time at larger boost levels, what rpm the power adder makes full boost, head gasket, studs, ect , ect. I have had several cars at 800 rwhp or so with no leakage at all. I have had a few cars at 900 rwhp that showed some leakage at the bottom of the cylinders but no blown head gasket.

white01ss

iTrader: (37)

Spoken with the vagueness of a politician caught with an underage hooker... If I had a nickel for every time I heard "it's in the tune" I'd rent a movie or something. As a tuner myself, I'm interested in how a tune can make the head hold together, brother? I'd like to know because busting a head is going to cost me a few years worth of movies, not to mention months of downtime. Please share your secrets with the team and I ain't talking bout your grammy's crawfish etouffee recipe. Dan

If you want to be loved... be lovable. Damon Wayans

black98ws6ta

iTrader: (77)

I wouldn't call me sharing my years of experience being vague. Maybe I didn't go through this thread and answer every question but instead of looking online for my answer's, I've got a car on the dyno that needs to be tuned.

If you dont think the tune has to do with anything, highlight your timing table and add 15*. Then report back on how your pistons, bearings, plugs, and head gasket look. Your motors survival is without a doubt "in the tune".

Controlling cylinder pressure is how you keep a head down. You do that with the correct a/f ratio, the right amount of boost, and timing. There will be a point when you are going to excede the motor's mechanical limits but someone who has a clue will get much further safely.

white01ss

iTrader: (37)

I understand your time is valuable. And I don't want this thread to turn into a tuning how-to. Also, I didn't mean to diminish the connection between the tune and a head's ability to hold the power.

I never said that a tune wasn't important, what I was asking was what tuning techniques can help. Of course, running a jacked up tune is asking for trouble, but when I hear "it's in the tune" as an answer to why some folks break parts and other don't is very misleading. Other factors also come into play like: camshaft design, compression, type of fuel, driving style, weather, car weight, rev limit, auto/manual, etc.

Well said.

52172

iTrader: (2)

Power limits are limited by their ability to stay on the block because of the 4 bolts. People can reliably put down up to 1000 rwhp with oversize studs and o-ring job and the right gaskets. At the 1000 rwhp level its better to step up to 6 bolt heads with a thicker deck. I would even above 800 rwhp for added insurance.

LS1RedZ

iTrader: (19)

Any more people want to chime in on this? Can I max out a F1A with LS6 heads?

gpr

iTrader: (6)

I remember seeing a thread on here a few months back about someone making 1000hp with completely stock 317 heads. I can't remember the details, but i do remember they were completely stock unported heads.

Saying it is in the tune is very true. I think most piston failures, and blown head gaskets are due to other factors than simply pushing them past their limits. Small amounts of detonation, or excessive cylinder pressure because of poor timing setup will cause destruction quickly.

trav-tech

iTrader: (1)

I'm making 812rwhp 19psi gt4508r turbo arp head bolts (not studs) holding down home ported 243's via stock gaskets on a factory 5.3L shortblock with out pushing water.

+badss+

iTrader: (12)

Well I'm running stock 317 heads with upgraded springs and hit 9.95 @ 140 on soft tune if that helps race weight of 3800 lbs

LS1RedZ

iTrader: (19)

What size pulley do you have on the blower? You plan on making more power with those heads?

turbocamaro125

iTrader: (3)

Blackws666 is using ported 317's with 1/2 studs. 25-30psi on e85 and a gt5594 turbo. Prolly in the 1000-1100whp

+badss+

iTrader: (12)

Have a 3.90 making 16lbs making enough power for now
650rwhp on dyno but had lots of tire spin
3800 lb car doing 140 in 1/4 is 800+ rwhp and I can drive it anywhere not just track car