CJS

Wooeee! Just got back from my local Chevy dealer to start the oil consumption test ( about 1375 miles per Qt./ by my records). The very knowledgable service adisor said they would be happy to install ported Z06 heads and aftermarket cam at the same time! No extra charge except for the timing cover labor. He even suggested I may want to do a performance timing chain etc. at the same time! Now I will just have to decide what heads and cam to get so I retain all the stock drivabiltity (this is a daily driver in traffic etc., all help is appreciated! (2001 MN6 coupe, 18,000 miles)


[Modified by CJS, 5:46 PM 7/12/2002]

MattG

It all depends on what performance gains you are looking for, and how much you want to spend. Agostino Racing offers three different levels of heads/cam packages... Their most affordable is their Street Eliminator Heads/Cam package for $1650... It includes ported LS1/LS6 heads (depending on your core), a custom grind or your choice of camshaft and moly pushrods..

Email me if you want any more info on the packages they have available, or if you have any questions.

need-for-speed

Now THAT'S customer service.........what a cool dealer!

Patman36

Seriously... that is rad :D

Patrick :cheers:

0Sales@MVPAutoParts.com

Where are you from? Maybe I should start driving to that dealer for service from now on. :crazy: :crazy: :crazy:

Corvette Poor

Hey Matt, would you email me the information on those head and cam packages. Thanks !


[Modified by Corvette Poor, 6:42 PM 7/12/2002]

McRat

GM Performance parts sells ported Z06 heads with the sodium valves and Z06 springs that have been milled 0.055". GMPartsdirect sells them for $900 no exchange each.

Then get a Hot Cam.

Be all GM and make some good streetable power.

Mako

The GM heads will not be anywhere close to as good as the tuner heads.

The GM HOT Cam is rather lumpy I believe and has a LSA of 112 or 110.

Try LS6 polished, ported and milled heads from a top tuner.

I suggest the MMS 224/224 564 114 cam. It will give you a great bump in torque and horsepower through the usable powerband, but retain great idle quality and drivability. The cam and heads packages you are seeing at 440rwhp and 420rwtrq DO NOT have anywhere near stock idle and drivability and those cars also have many other mods to make the car breath better--that is also peak power. I suggest you shoot for about 405rwhp and 395rwtrq with cam, heads, headers, pulley, intake and exhaust, high-flow cats and custom on-the-dyno pcm tuning.

Congrats on the Dealer cooperation and keep us posted!

CJS

Thanks all for the advice so far( keep it coming if you have thoughts on this). I am going to do this, but it is contingent on me being approved for the re-ring! I am sure I will qualify! (I will drive it very hard during the oil consumption test).
I can spend about $5000 on the heads/cam and other speed parts. I really don't care about a high rwhp number, I want it to have stock like driving, starting, longevity characteristics, but with more power. I will keep the forum posted on how it turns out. The consumption test starts next thursday.

pip

His zip code indicates he's from New Milford, CT. Fairly long drive from TX!

McRat

I've got 2 (3?) friends with MMS cam packages that had the valve springs bust and trashed the engines. A couple more friends have had poor luck as well: Over 1 year to get 427ci engine that was pre-paid (15K), and over one year to get an LT1 car done. Lots of folk have NO PROBLEM with MMS stuff, but please inquire as to warranty issues in writing beforehand.

Some dealers will warranty GM parts that they put in. Ask. There are faster parts available than GM parts, but they tend to be high quality and very streetable. I believe LPE does the Z06 CNC porting for GM. (I do know that an early batch of Hot Cam's were bad. GM replaced all of them at their cost, including labor.)

Then if someone asks what is done to your car, you can tell them it's just got a rebuild using GM OEM parts, and grin...

Just an opinion. I have not used the GM heads or a Hot Cam. I have a few friends with the Hot Cam, and it does have a lumpy idle, but not like a prostock car, very streetable. I have used other GM cams and race parts and have never been disappointed.


You can make lots more power with high end/big dollar EXCHANGED tuner heads. You will also pay more.

Mako

McRat: It is all you. Try some more research. MMS built my 427 and I can assure you that it is the best motor I have ever driven in any car--amazing power and drivability. True, it took a long time to get dialed in--including a cam swap and two timing chains.

Valve springs go bad and break sometimes--if you are not a big boy, then stay stock. There is no free lunch where you get great power, never have any maintenance beyond OEM, spend very little $$ and have stock driving characteristics. I now run dual valve springs. STAY STOCK IF YOU WANT STOCK MAINTENANCE--PERIOD. Your GM warranty is voided by using the GM Hot Cam--check it out.

That said, if the poster is in CT, Vette Doctors would seem to be an excellent choice for cam and heads to be installed by the dealer. I only mentioned the MMS 224 cam because I have it in my car and I have driven a MMS 385 with the same cam and though it was great. I had the 229 cam too and did not like it. I also had a DRM 218 cam with a LSA of 118 and did not like it-- too weak. I also spoke with people that had the GM Hot Cam, and they all said it was lumpy and not great as a daily driver.

Good luck in your decision or the Topic starter's decision. Just thought I would offer my personal experience to assist in the decision.

2000^C5

:cheers: :cool:

McRat

Mako, I wasn't slamming MMS just stating facts. Ask Leo or Robert or Zed at ls1.com. Have you EVER heard of someone breaking GM Z06 or Hot Cam springs? Springs should lose tension but never turn into shrapnel. I personally have never broken a GM spring.

Like I said, MANY people are real happy with MMS, and one of my friends runs into the 10's on a NA 346ci LS1 engine in his daily driver. Just be aware of their warranty policy for factory defective parts.

======================================== ===========
Here's some info on the GM heads:

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

Nate@CorvetteGarage

One word... Katech.

Smoke-N-Shot

That's the kind of dealer we all need! :eek: :yesnod:

Mako

McRat: The information you posted is really not relevant to aftermarket heads and cam cars. Those applications need a stronger valvetrain. Have you modifed your Corvette?

My car took a very long time to get dialed in (much, much, much longer that the original plan), so I did in fact have problems. Some just could not be avoided; some come with the territory in going for big power and non-oem parts; and some ideally could have been avoided.

I suggest going with a heads and cam package from a tuner that has done at least 10-20 identical packages on the same car. Having a Dealer install the heads and cam does have its downsides: the warranty will be voided as to those items; the dealer has never installed this combination; the tuner will not warrant another's install; the Dealer cannot do PCM tuning; etc.

Good luck!