So I have an z06 with stock 243 heads. I have a TSP233/239 cam, vararam and headers. Would I see any beneficial gains if I go with a set of ported 243 heads? Here is the add from ls1, worth it?

Ported 243 heads. Port work done by Bill at Standard Machine in Glendale Az. Just got them back from WCCH from a valve job and freshen up with new valve seals. Glass beaded and decked .015", 62cc combustion chambers. 2.02/1.57 stainless valves. No springs or retainers. Just add your favorite valve spring package and you are ready to rock. I was going to have Richard at WCCH run his CNC program on them but after the valve job he said they turned out good and he would just run them as is.

Flow bench tested on a 4.030 bore

.100 67.6 55
.150 103.8 86.8
.200 143.5 110.6
.250 161.7 132.6
.300 189.6 161.8
.350 217.7 191
.400 243.2 203.6
.450 263.3 210.5
.500 284.2 215.5
.550 298.2 220.4
.600 302.6 222
.650 285.9 223.6

Asking $700 plus shipping for a 45lb package.


THANKS!

 

hmmm insterested in your findings. I have the same setup as you. Just got it dynoed less than 2 weeks ago. I saw a youtube video online with our setup except he did port his heads and his numbers 443/40X if im not mistaken.

 

Sure you will get an increase in power with those heads, and Richard at WCCH is one of the best cylinder head guys out there. Is it worth the money for a 20-30 hp increase? Only you can answer that.

 

You might also pick up a few ponies because of cc size may be less than your stock heads - thereby raising the compression slightly...

 

The 62 CC chambers will raise your compression some--with 93 oct fuel should be OK--but if you have 91 crap Calif fuel--could be iffy and the sensors may take out some timing
Your profile says you have Patriot Stage II 243 heads----If so they flow almost identical to the #'s on this set--I think it's pretty much a wash-IMHO they are too similar to make the effort--

 

Whoops. actually, i dont have those heads. I have just the stock 243 heads. I had those heads and was going to put them on, then I sold them.

 

OK got-cha----even still--If you go to the CHEVY LS1 performance book ( our bible)-- the # are still close--A very simple basic self clean up of the seams and rough spots could accomplish the same thing if you do it yourself----But for FREE--you make the call--Most head porters and flow people say to read the flow #'s at .400 or .450 to get the real performance expectaions---The #'s at .600 may be good but the cam is only there briefly or not at all !!! //

Your INT. flow chart: // STOCK 243 HEADS Int. flow

.100 67.6
.150 103.8
.200 143.5 ------- 156
.250 161.7
.300 189.6 -------- 204
.350 217.7 -------- 225
.400 243.2 -------- 243
.450 263.3 -------- 257
.500 284.2 -------- 268
.550 298.2 -------- 275
.600 302.6 -------- 278
.650 285.9

You can see that the STOCK 243 actually flows better up to .350
At .400 they are equal **** LIFT #'s that are most important here ***
At .450 0nly 6 CFM better
From .500 on there is some better obvious flow

MORE bottom end TQ is acheived with better flow in the lower lift areas
MORE Hi rpm HP is achieved with better flow in the higher lift areas

Typically for a 1/4 race you want the best of both worlds - My opinion is that the botom end TQ is what gets you the best ET's
Hi rpm HP gets you better 1/4 trap speeds
S0-if you have the time and $$ --swap them--If not--then just clean up the ones you have or have a friend or shop do a mild port and clean up on them--and they will outflow and outperform the ones you're looking at--and you can spend your money on something else-------

 

Wow, very good info! I think I will just keep the ones I have. In the winter, i think Ill take them off and give them a good cleanup. I noticed when I swapped out the lifters they had some carbon on them. I tried getting it off the best I could, but there could still be some to get off. THANKS!

 

Your PTV clearance with the new heads needs to be checked.. that's a pretty big cam you have there.

 

To be more representative, these should be flowed using a 3.90" Bore Plate as the higher lift numbers will come down a bit due to the increased valve shrouding next to the bore. I ported a set of 243's, cut a nice 3 angle valve job, back cut the valves, and flowed them on my Superflow bench with a 3.9" bore adapter and got:

73 cfm @ .100" lift
142 cfm @ .200" lift
206 cfm @ .300" lift
248 cfm @ .400" lift
287 cfm @ .500" lift
298 cfm @ .600" lift

These flow numbers are enough to make over 550 hp na with the right cam, compression, LS6 intake, and good quality long tube headers. These numbers were with about 8cc's of intake port volume removed, which is important to maintain air velocity and improve torque. Some of these ported heads have up to 30 to 40 cc's of port volume removed and do not flow much more, resulting in a lazy port and reduced torque.

I would recommend that the heads be flowed with the LS6 Intake bolted in place. With the above heads, the peak flow was reduced to around 260 cfm from 298 cfm at .600" lift. This is important as the head and Manifold work together, giving a more realistic indication of the potential horsepower to be gained. The head may flow 320 cfm, but with a stock intake bolted up, you can loose 50-60 cfm of peak flow. Moral of the story is keep the low and mid lift flow high, peak around 290-300 cfm, and remove as little as possible from the Intake port to keep the velocity and torque high.


Paul

 

Look more at cams that maximize air flow from .200 to .550 cam lift.

the 243 heads and LS6 intake were designed to work in this range.

.600 cam lift is almost meaningless and why having cam with lift above .588 is not going to help but may hurt performacne.

 

I dont agree with the compression being an issue on 91 oct, my brother has an LS1 in his truck with 59cc cnc'd GMPP 243's and a Comp XE-R 232-236 cam and NO knock at 28* timing. As long as your cam has enough overlap, which it does, you'll be fine.

 

" IFFY"-- what I meant fits what you're saying ---on some applications -no problem--on others maybe--- many variables that may cause detonation--like lean fuel--CC carbon build up---sharp edges---bad gas --Adding more compression has been known to cause a "ping"depending on if there are any unknown variables

 

True, true.