DenzSS

We're going to do our best to get you there.

DenzSS

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by MikesZ06:
<strong>Denz, here is a reply from one of the guys, TAMU, on our forum. Don't know if it's pertinent or not.

"Maybe the installer installed the cam sprocket 4* the wrong way? As in, they retarded it instead of advancing it? (I'm assuming 4* advance was recommended).

Does Katech grind advance into the cam, so that it should really be installed straight up (most vendors do this, as most folks don't go with a Cloyes timing set)?

I'm thinking it's gotta be in your timing/cam install. And yes, the front end of the motor would have to all come apart to check the install of the cam.."</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">The cam was installed straight up according to Katech's instructions. That was my first thought as well. Damn good thought though.

Katech knew the heads were for a blower car, but after looking at the heads I don't think they did much if any combustion chamber work.

The plugs and wires are in great shape. We've seen a lot of iffy plug/wire dynos and I don't believe this is one. Plus, they're new.

I think the P0300 is just from the cam. It is a high lift 224/228 114 cam and has a pretty decent lope to it. Personally, I wouldn't be suprised to see a P0300 from this cam, but please slap me around if I'm thinking incorrectly here.

As a whole, the car feels great. Hell, if I didn't know different, I'd think it was perfect. Damn frustrating.

We're taking it back to the stock LS6 program and doing 4-5 dynos while ATAPing. I'll post the ATAP results as soon as I get them.

Any other thoughts?

Mike--The exhaust is back on the car now. No more open headers <img border="0" title="" alt="[Sad]" src="gr_sad.gif" />

Denz

VINCE

iTrader: (1)

How thick are the gaskets...? They can drop your compression as well..

MikesZ06

Denz, Chris at Katech told me they opened the combustion chamber to 68.5 cc. I think that normal on the stage 2 heads is 62 or 63cc ( I could be wrong on the norm)

VINCE

iTrader: (1)

If that is the case.. That coupled with a thick head gasket will have you deep in the 9's compression wise... This will allow you to boost upwards of 10#'s w/out an issue with proper tuning.

DenzSS

I'll have to check on the gasket thickness.

If he opened them up that much, we are talking about a decent drop in compression. Hell, it might not be far off.

10# is the plan if I remember correctly. I'll update MC.

MikesZ06

Denz, just did some checking and 63cc's is the norm. Also, didn't Mark tell me you guys decided, after conferenceing with Katech, to go with some type of special 'steel lined' head gasket or something like that. Could that be thicker than the normal gasket?

DenzSS

Yip. They are a thicker than stock Cometic gasket. Very nice gasket. We used it to drop the compression a little more.

Once you get a shortblock, we can really up the boost <img border="0" alt="[devil]" title="" src="graemlins/gr_devil.gif" />

DenzSS

The gasket is .013 thicker than stock.

Anyone have a book handy? I don't have the calculation handy for CR.

DenzSS

Found it. <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />

Ok. Going by the following:

Bore: 3.90"
Stroke: 3.662"
Stock Deck Height: -.006"
Stock Head Gasket: .054 + .013 extra = 0.67"
Combustion Chamber = 68.5 cc
Valve Relief: 2 cc

Combustion Ratio= 9.70:1

MikesZ06

Denz, since stock CR on the Z06 is 10.5 and we're now at 9.7, could that be the problem?

DenzSS

Working on that now, Mike. Trying to find out the average drop in HP per .10 decrease in compression ratio for a LS1/LS6.

I have a sinking suspicion that we may be ok. We'll see though.

If my calculations are correct, we're a bit lower on the compression that we originally calculated.

MikesZ06

Denz, one last thing (and again I don't know if it makes any difference at all), the new ati damper you guys put on is, I believe a 10% underdrive pulley. Don't know if this effects your edit numbers or not.
<img border="0" alt="[cheers]" title="" src="graemlins/gr_cheers.gif" />

TAMUz06

Damn - I completely overlooked that this was for a blower car and the compression. That could very well be the issue.

I'm certain that if Chris B sees this post he can set us straight. <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />

DenzSS

The 10% underdrive should actually cause a slight increase in HP.

I got an answer on the HP/compression increase/decrease question. On a LS1/LS6 roughly 4%/point of compression.

12.5 - 9.7 = .8

4% * .80 = 3.2%

400 * 96.8% = 387.2HP

I'm basing the 400rwhp number on previous Katech heads/cam results posted on LS1tech.

We might be well within the acceptable range.

I'll post info as it comes.

MikesZ06

Denz, were they able to do anything today on my Z ?

DenzSS

Yip, got the exhaust back on and did a bunch of data logging on the dyno. Went back to the stock computer tuning and going through it again.

I'll get the ATAP logs from Chris tomorow and post the data.

MikesZ06

Thanks for the update, Denz <img border="0" alt="[cheers]" title="" src="graemlins/gr_cheers.gif" />

DenzSS

Might have a line on the jagged curve. Just didn't think about it. The plugs are one step colder than the TR6's. Great for a SC, not so hot for naturally aspirated. Will know more soon.

MikesZ06

That's right, Denz. You guys used those new cold plugs rather than the NKG's I bought. I forgot about that too <img border="0" title="" alt="[Roll Eyes]" src="images/icons/rolleyes.gif" />
Hope that's it <img border="0" alt="[cheers]" title="" src="graemlins/gr_cheers.gif" />