Got Me SOM

iTrader: (2)

These heads (2 included) were off of a 2003 Corvette Z06 and had 650 miles on them before being sent to CNC for porting. They have 2.05 Intake valves, 1.60 Exhaust valves,competition valve job, and competition cam 918 springs with titanium retainers

I can get these for 2 grand. Is it worth it?

Does CNC do good work?

Thanks in advance

Ragtop 99

iTrader: (7)

In terms of value received, it is a good deal. LS6 cores are expensive and new valves and springs and related porting add up. The question is how do they perform? Flow, port volume, and velocity when hooked up to the motor can not be judged on the basis of price.

Any performance data to back up the price? dyno, flow sheets, or track MPH?

thechef

iTrader: (13)

CnC does very good work and you will be happy with those <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" />

Got Me SOM

iTrader: (2)

I'm working on getting flow sheets. Apparently the head porter stamped his own number so he can recall what the head specs are. Supposedly the head work is similar to Nascar Winston Cup spec..

Don't think for a minute that I'm believing it.

for 2 grand i don't think its a bad deal.

The address of CNC the guy gave to me was in Florida does this sound correct?

robertbartsch

..you can get brand new CNC ported casting from SDPC for $980 per head...the port work is done by Linfelter and a neet spec sheet is included ...these come fully assembled and have new LS6 valves and springs...

...i think they flow 315 in the intake side at .550....

...my only problem is that the porting work has not been polished ...so i will do that myself/...

..so is your deal a great deal??? ...dont know but just compare it to this for a value test....

Got Me SOM

iTrader: (2)

keep in mind, this has 918 springs (better than ls6, good for up to .610 lift) and REV oversize valves plus its been ported. Flow numbers are in the 300's at the .570 lift range.

The guy that did the work works closely with NASCAR, ESP, and some other well known company.


Are these LS6 heads your talking about?

The port job alone is worth 2 grand alone. The heads well if you can find em cost about 8-1200 if you can find em.

THe only thing is these heads were setup for a blower car originally so the chambers were opened up a little but the guy told me he would angle mill them down to achieve a compression ratio of 11:1 which would be perfect for me.

Raughammer

Hell yea.

I8COBRA

iTrader: (56)

If he can provide flow #'s than get them, its a very good deal. Just one thing, I know that many guys here are big fans of the 918 valve springs but youre MUCH safer with the REV 1116 dual spring. I'm using smaller valves than most people, 2.00/1.55 and look at my #'s with LS6 heads <img border="0" alt="[cheers]" title="" src="graemlins/gr_cheers.gif" />


<img border="0" alt="[USA]" title="" src="graemlins/patriot.gif" /> <img border="0" alt="[USA]" title="" src="graemlins/patriot.gif" /> <img border="0" alt="[USA]" title="" src="graemlins/patriot.gif" /> <img border="0" alt="[USA]" title="" src="graemlins/patriot.gif" /> <img border="0" alt="[USA]" title="" src="graemlins/patriot.gif" />

<small>[ March 31, 2003, 06:52 PM: Message edited by: I8COBRA ]</small>

Got Me SOM

iTrader: (2)

Anybody foresee any p/v clearance problems with angle milling these heads to get the compression back since the chambers were opened up??

I'd like to know that I can run a cam as big as Lou's g5x2 and feel ok that I'm not gonna have a piston butchered by my valves.

Anyone have experience with CNC out of Florida?

Chicago Crew UnderBoss

iTrader: (1)

GOT ME SOM:

Nice meeting you neighbor at the dyno day at speed inc this past saturday. Welcome to the greater CHICAGOLAND AREA BROTHER!

I would talk to one of the tuners that you decide to do your install, but my educated guess would be that you are going to have to fly cut your pistons to run an awesome cam like the GX5-2 with is a very large agressive cam.

I say go for it man, you live once, the LS6 heads you reference above and the GX5-2 cam would make one awesome setup! Make sure you get the specs. on that cam and then match this up with a pro who can dial you with the perfect converter and you are looking at a low 11 sec everyday street machine! <img border="0" title="" alt="[Cool]" src="gr_images/icons/cool.gif" /> <img border="0" alt="[cheers]" title="" src="graemlins/gr_cheers.gif" />

MTI 427 C5 Roadster <img border="0" alt="[judgement]" title="" src="graemlins/gr_judge.gif" /> <img border="0" alt="[USA]" title="" src="graemlins/patriot.gif" />

robertbartsch

..the NEW SDPC ported castings I referred to earlier are LS6 castings...

...heads are new, fully assembled..but not polished only ported,,,,

....I'm not sure you can say that the porting is worth $2K alone ....like ...not to me if new SDPC ls6 heads are Lingfelter ported for $980 per head....

....do you have to give them your old LS1 heads too?

strokedls1

iTrader: (1)

CNC is a process of machine porting, not the name of a shop like I think you are inferring. I would not mill these down until you talk to Lou if the g5x2 cam is what you plan to run with it. Who knows better than the guy who sells them. No way that you are going to be able to run a .610 lift on those 918 springs. Get a set of the manley duals or the 1116 rev duals. Even if the outer spring breaks at some time, the inner spring will keep the valve from dropping. Cheap insurance in my opinion. I would expect a flow sheet before buying them. The SDPC ls6 heads are also a good deal.

Got Me SOM

iTrader: (2)

man i don't know.

here's the scoop: They were originally made for a blower car, which means they opened up the the chambers to lower the compression.

Well the owner then changed his mind and told the porter to "put it back to stock" which means he angle milled them to get back to 10.5:1 compression.

The porter suggested that I get em angle milled for 11:1 compression.

I'm worried with all this milling that I'm gonna have piston to valve clearance problems. The porter said there won't be any problem but I have a gut feeling that says don't do it..

I think I'm gonna pass on these. I hope I don't kick myself in the *** later for not buying these..

For 2 grand I can get my 12 bolt.

Got Me SOM

iTrader: (2)

o yea the Company that ported them is named CNC out of Tarpon Springs Fl.

No flow sheets can be provided....

Ragtop 99

iTrader: (7)

Who wrote the program for the CNC porting or gave them ported cores to measure? CNC will port to your specs.

BTW, if the heads were optimized for a blower, they are not optimized for NA.

Milling them down to counter having opened up combustion chambers may not be a good idea.

For $2k I would buy heads that I know were ported for NA. Several sponsors sell good heads, including double springs, for $2k.

Got Me SOM

iTrader: (2)

no core required. I'm buying them privately.