myZ

I have a 2002 z28 and want to upgrade it to ls6 specs...pcv, heads etc...Any who i want ls6 cnc ported heads on it...with undercut valves... with the ls1 cam... is there such a thing as over heading??? Or will the ls1 cam hold off till i decide which cam i want to get. Where shold this put me for horse power....lookin at the ls1 to ls6 cam it looks like only 15-20 hp difference???
Any help would be great!!!
Thanks
eric

onfire

iTrader: (17)

IMHO the ls6 heads from SD (the ASA heads that LPE ports) are the best stage 1 head for the money. Won't hurt a thing to add the heads without a cam, but I would get the cam also since it would keep you from doing some of the same labor twice. Those heads should add 20-30rwhp. Add a Thunder 220 cam for a stock idle and another 20rwhp....plus you really need Longtube headers to complete the deal. That would make a real nice sleeper. Good luck!

LS1derfull

MyZ, i agree with Onfire but understand stock LS1 cam will give up alot with these CNC heads. It appears the port volume is too large for mild applications but nobody i have seen has posted poor results with these heads, so things on paper dont always happen real world and LS1 style engines do have some mysteries left to them. Good luck. <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" />

99 Black Bird T/A

iTrader: (4)

Do we know for a fact the compression on the LPE LS6 heads isn't too high for a stock cam'd car?

Seems to me like there could be a potential problem or very little safety margin with stock cams and high compression heads. Which LPE LS6 heads are we talking about? The GMPP LPE LS6 heads are milled like .050 aren't they to raise compression even more?

Most people that do heads also do cam, so I don't know of many head only cars. There could be and I just don't know, so I'm asking, not saying otherwise.

Many stock cam'd LS1's will ping with stock compression. In part because the stock cam doesn't have a lot of overlap and the cylinder pressure is high at low rpm. Some stock cars will ping at high rpm too as a result.

The LS6 heads have more compression than stock heads do. Ported LS6 heads have more compression than stock LS6 heads do. Stock LS1 cams don't bleed off much cylinder pressure. The 01+ stock fbody cam closes the intake valve sooner to raise cylinder pressure.

Other comments?

If you going to do the LPE ported LS6 heads, I would do at least a 02 Z06 cam too!

LS1derfull

This is a good question, i agree that combo would be very troublesome.I believe LPE head has finished chamber of 60cc which would be over 11.0 to 1. This would require tuning to work(less timing) Large cam like 224 or 230 on a 112* would work best imo.Interesting that they relieve chambers with stock valve size, i wonder whats left in flow on LS1 heads by doing this?

LS1derfull

Bigger cam will help limit cylinder pressure some, but at hi rpm it will be higher than stock cylinder pressure. Tuning will be necessary or you will consantly be running on low octane table, losing timing and power. Oh and say goodbye to low octane fuel. Hi compression will boost low speed torque, where bigger cam and 250cc intake ports will make less 4000 and below.
Still worth doing in my opinion.

myZ

'delete"

myZ

"delete"