</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by Terry Burger:
<strong>Pat is that how you ran those 12.50s on the stock motor? <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" /> </strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Hehehe.... Naw, if I was cheating, I'd certainly do a better job than mid 12's.

But it does give me ideas for the new car....

 

Cary from SDPC told me that Ryan.

I'm sure the price is $1800 each.

LS6 cores are $1100 for a pair shipped FWIW. <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />

 

then tell cary to change the website.

 

Gmpartsdirect has them listed at $906.50 each...

 

has anyone flowed these heads? is there any info out there on these bad boys? they look pretty good esp with forced induction!

 

One thing that I find funny is that the ported LS1 heads are actually more expensive... I wonder how they compare. As for the lack of power on the LPE packages... you have to remember... Lingenfelter tries to capitalize on driveability.. his packages use relatively small cams. His two standard LS1 cams are a 205/212 116.5 LSA and a 218/219 113 LSA. The bigger numbers we see from MTI/ARE/Cartek/MMS etc. are usually from comparatively larger cams. Also, these are stage 1 heads... once again... not the greatest for a high peak HP #... but you'll have better throttle response and torque... So, I wouldn't say that Lingenfelter is an inferior head porter... just that he has a different objective.

 

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by Ryan:
<strong>i think the GT2 is the C5R. cant remember. just because John says LPE ports them doesnt make them law. Ask Joseph who works at SDPC or SDPC themselves. Sorry John.</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">The CNC LS1 and LS6 heads both have LPE stampings on them with LPE machining tags, although still having a regular GM part number. The ones I have looked at had springs spec'd for .530" lift and had combustion chamber work unshrouding the intake valve in addition to an undercut stock intake valves.

I don't work for SDPC though <img border="0" title="" alt="[Sad]" src="gr_sad.gif" /> , but I do work a few feet away from them <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" /> I'll try to have Cary post some more details if he has access to them.

 

With the heads being milled .050 from GM, is it possible to run a 230/230 .578 lift cam without any piston to valve clearance problems ? What size pushrods would you use ? And last but not least has anyone bolted these heads on yet ?

John

 

you would have to replace the valve springs. i dont think the springs will handle lift near .600 though. this seems most interesting to me~!

 

Dumb question ahead....

If they have a GM part number, can you put them on without fooking your engine warranty?

 

I definitely would change the springs, but pushrod length and p2v clearance would be a concern.

 

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by McRat:
<strong>Gmpartsdirect has them listed at $906.50 each...</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Yeah and charge $360 in freight. when I sent a e-mail questioning their high freight amount, here's the repsonse they sent.

Gmpartsdirect.com sell parts for dealer cost plus a percentage for a
shipping and handling fee. This fee is not UPS only.
The shipping and handling pays for the shipping charges plus our other
expenses like web programming, employees, etc.

We make no sercret on how are rates are. In most cases prices to your
door are at wholesale.

Thank You, GMPartsDirect.com

 

I forwarded the link to Cary from SDPC and he said he will get answers to all the questions and reply.

 

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by BLKTA:
<strong> </font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by McRat:
<strong>Gmpartsdirect has them listed at $906.50 each...</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Yeah and charge $360 in freight. when I sent a e-mail questioning their high freight amount, here's the repsonse they sent.
</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">FWIW, that is the wholesale price on the parts that the dealer's get them at. I guess they have to make their money somewhere!

-Geoff

 

Thanks PSJ!

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by Pro Stock John:
<strong>I forwarded the link to Cary from SDPC and he said he will get answers to all the questions and reply.</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif"><img border="0" alt="[hail]" title="" src="graemlins/gr_hail.gif" /> <img border="0" alt="[hail]" title="" src="graemlins/gr_hail.gif" /> <img border="0" alt="[hail]" title="" src="graemlins/gr_hail.gif" /> <img border="0" alt="[hail]" title="" src="graemlins/gr_hail.gif" />
<img border="0" alt="[hail]" title="" src="graemlins/gr_hail.gif" /> <img border="0" alt="[hail]" title="" src="graemlins/gr_hail.gif" /> <img border="0" alt="[hail]" title="" src="graemlins/gr_hail.gif" /> <img border="0" alt="[hail]" title="" src="graemlins/gr_hail.gif" />

 

Good deal! looking forward to those responses.

 

Please thank Nicky Fowler of Scoggin Dickey for taking to the time to write this response...

2002 ZO6/LS6 Cylinder Heads - Bare and CNC Ported

First, several questions have been asked about the price difference and why there are two different part numbers for the 2001 and 2002 bare LS6 cylinder heads. One of the most important facts to know about GM part numbers is that
there are about four basic distinct styles of part numbers within the GM hierarchy(internal, industrial, service replacement, and racing), only two of these have any real concern to the typical consumer. One being service replacement part numbers, such as the 2001 and 2002 LS6 cylinder heads.

These parts have a very strict set of guidelines, as in zero tolerance from the engineering print and specification. Something as simple as tapping one threaded hole an additional 0.100" deeper will require a complete new set of prints, validation testing, and a new part number in the GM system. If a change is made in suppliers, even though the part is still being manufactured to the same engineering spec and nothing else has changed, a new part number can and more than likely will be generated. How a part is
packaged can cause part number changes! In a nutshell and without divulging any internal secrets, the 2001 head was a very limited production run. Small production runs equal increased cost. There was an anticipation by
engineering that a change might be required for the 2002 LS6 head to meet specific assembly line requirements, hence a new part number. The change had absolutely nothing to do with fit, form, or function of the LS6 cylinder head. It was also determined the '02 head would be used for the '03 models and that the new part number would also replace the 2001 service replacement part number when that stock was depleted. Therefore a lot more production and a lot less cost. For all practical purposes the bare cylinder heads are
identical.

The LS6 CNC cylinder heads fall under the GM Racing category. These part numbers can have radically different production changes in the finished product to enhance performance, without experiencing any part number changes. They are not intended to be service replacement parts for your car, in fact the sole purpose of parts that are produced by GM Racing is to win races. GM Racing has its own dedicated engineers for parts development and these parts are continuously being updated and improved to meet the demands
of racing. Therefore the block that you ordered two years ago may not be exactly the same the one you purchased today, even though it has the same
part number.

GM Racing changed the part number for the CNC LS6 heads this week, the new number is 88958622. If you purchased a set of 12480176 heads last year, then you received the 2001 LS6 assemblies with the 2001 GM CNC racing program. If you purchased a set of 12480176 heads this year (as long as it was not some dealer's old stock that had been sitting on the shelf for 9-months), you would have received a set 2002 LS6 assembled heads and the 2002 GM CNC porting. The part number change was made to avoid the internal problems of providing the correct parts for race teams with CNC ported heads, i.e.; do we need the '01 valves and valve springs or do we need the '02 springs and valves for repair and maintenance.

Besides the fact that the '01 and '02 heads have different valves and valve springs, the CNC porting was also changed for the '02 head. The sole intent of the CNC LS6 head from GM Racing is to support Corvettes competing in SCCA. I believe they are currently being used in the American LeMans series class known as Grand Am Cup. I have listed below the flow figures for the '02 CNC LS6 cylinder heads as tested on a SF1020 at 28" H2O on a 4.030" bore plate.

Lift Int Exh
.100 65 58
.200 138 113
.300 214 157
.400 261 191
.500 292 210
.525 295 212
.550 285 214
.600 282 218

One of the key things to remember about this particular head is that this CNC port was developed for a particular camshaft, hence the intake peaking in the 0.525" area. It was designed to provide maximum flow under the entire
lift curve! Air flow is a dynamic process occurring over a timed event. When comparing heads we look at the entire flow thru the cam profile. Also you should note these numbers are with the stock diameter valves. We have flowed
heads in back-to-back comparisons with larger intake valves that will not flow any more air than these and in some cases less. Port design, velocity past the valve, and flow quality are all very important features when evaluating cylinder head flow. Let's face it, GM has a bigger bank account to R&D head flow than all of us put together. They have done their homework on this head. Problem? These heads are very limited production and they are very hard to get. We are pushing them to increase their production. And yes
this CNC program is proprietary to GM Racing, so no you can not buy the same CNC port and valve job from anyone else.

We know for a fact from own testing that the light weight valves have a huge impact on performance. I think people tend to under rate the value of the '02 valves. This is kind of like getting titanium valves for the price of production stock valves, it is a real bargain.

The heads are milled 0.055", this brings the combustion chamber down to approximately 60.7cc's. This causes several concerns for installation, the least of which could be your compression ratio increase. One, you do need to
check the piston to valve clearance to verify that you have enough. We recommend a minimum of 0.080" on the intake and 0.100" on the exhaust. These are minimum numbers!

Next this means that it is absolutely necessary to check the pushrod length. I have read about some of your members wanting to upgrade their
lifters for high performance applications and/or having problems with lifters. We have found that a lot of lifter problems are the result of the
incorrect pushrod length, most of the time it is too long. The GM lifters are very good, especially with the '02 light weight valves and the correct pushrod length. The GM lifters are capable of supporting 7400rpm's on aggressive cam profiles. Obviously these heads will require a shorter pushrod if nothing else has changed except for the cylinder heads. Depending upon your camshaft and what base circle it has, you could need anywhere from a 7.200" to a 7.350" pushrod length(in most applications). We keep pushrods from 7.000" to 9.250" in 0.050" increments, FYI. Last, you must verify the
mounting of the intake to the heads. If you will notice, there are two brass inserts that are used as alignment dowels on the intake that are located at the passenger's side front corner (#2 intake port) and one at the driver's side rear (#7). With milled cylinder heads, these dowels can prevent the intake from fully seating against the intake gasket and causing a vacuum leak. These alignment dowels can easily be removed from the intake, at which point we will machine 0.050" off of the length then re-install the dowels
into the intake manifold. Make sure you check this!

Just FYI, we have had one customer report to us that by just changing the cylinder heads on his '02 ZO6 to the CNC version he picked-up 28 rwhp. He did this in a one-day session! Baselined the car, backed it off and changed the heads and pushrods, and back on!

Hope this answers most of the questions concerning the CNC ported heads. They are steal at $1970.00 per pair, but get in line. We have a waiting list now!

Nicky Fowler
SDPC

 

Thank You PSJ and Nick!