SleeperGXP

O well I spoke to soon I'm 11B lol

DavidGXP

iTrader: (14)

Infantry leads the way

BlackImpSS

iTrader: (1)

Hey David I know you had really good results with the TFS heads, but how well do you think of these heads http://texas-speed.com/p-1172-prc-st...ted-heads.aspx with a 58 cc combustion chamber would work on our car.

91parkave

iTrader: (4)

Im reclassing right now feom 13B artillery to 15W UAV pilot

DavidGXP

iTrader: (14)

Do not use any head with a bigger intake valve. Our bores are to small for anything bigger then a 2.00" In fact, even the 2.00" intake valves cause's some shrouding issues at higher valve lifts. The TFS heads changed the valve centerline to 13.5* vs the factory 15* to reduce valve shrouding.

BlackImpSS

iTrader: (1)

So if I could get those heads with a 2.00" valve do you think they would perform pretty well in our application?

DavidGXP

iTrader: (14)

I would try to find some 706/862 off of an early 4.8/5.3 truck
The heads have a combustion chamber Vol. of 61-62 cc's and the intake ports are 200cc. The Intake valve is 1.89" With a 60cc chamber the new compression ratio will be 10.5:1

Once you find some heads, I would send them off to advanced Inductions for some CNC porting, and milling (.014" = new combustion chamber of 59-60cc). 1200 Max. They would make a torque monster. Leave the small valves alone!!

Stab in a 2000 Corvette LS1 cam with some 1.8 roller rockers. Scrap the DOD
P/N 12560968
198/209@ .050 .500/.500 lift and 115.5 L/S
You would be at .530/.530 lift with 1.8 rockers so have AI concentrate on low to mid flow numbers before machining.

This combo, with your LS1 intake, should cost less then 2000 and will make tons of torque with a shift points around 6000rpm. 2.93 gears in a heavy car needs lots of bottom end power!

http://www.advancedinduction.com/LSX...rHeads.php#243


gene@gmpartshouse.com for the camshaft

BlackImpSS

iTrader: (1)

The heads above are actually 862/706 cores that are ported. I emailed Texas speed to see if they could leave 2.00 valves in them instead of 2.02". For the cam I would most likely get one spec'd, and if I go H/C I would do the ls6 intake. I am just trying to piece together a shopping list because as of December I will be a full time engineer(no more being an intern, school will finally be done after this semester) and I should have some extra cash. Also a TEP trans would be in the near future with any of the above mods, so I would be upgrading gears as well. Thanks again for the info on the valves.

DavidGXP

iTrader: (14)

I spoke with Texas for about 20 mins about their heads, and they kept trying to sell me the PRC 2.5's. If I had a LS1, then it's a no brainer. The tech told me that they have used 2.02 valves in the 5.3's. Not my cup of tea.

Sittingmongoose used the PRC 2.5 heads and made 330hp
https://ls1tech.com/forums/ls4-perfo...o-results.html

BlackImpSS

iTrader: (1)

Yeah using used valves in 1300 heads does not work well with me. Didn't sitting mongoose run ported 243's though? I am pretty sure the 243 heads just aren't a good combination on our cars. Thats why i was looking at the 5.3 heads as they have simliar flow numbers, but offer a smaller runner. plus the should give a nice bump in compression. Guess I have awhile to think this over. I would not be happy with 330 whp after H/C/I.

BlackImpSS

iTrader: (1)

Well comparing the flow numbers of the PRC's and AI's 5.3 heads. The AI's are a much better head, however the AI's run about 1900 for there heads with dual springs. That is basically what the TFS heads cost. Do you think the springs in the tfs head are of pretty good quality. I think they were rated at .625 max lift.

DavidGXP

iTrader: (14)

.650" max, and I am using .601" lift, shifting at 6500 rpm. Very good springs!




I picked up 30-35whp with the head swap, and a lot more torque. I used to shift at 6800 and now I only make power up to 6500. I have not gotten a new tune yet. I have also spoken with a few of the TFS techs, and they are some of the nicest people I have ever delt with. They told me to call back once I get tuned.

I sold my 243's to offset the cost of the TFS 205cc Gen X heads. The heads use Iron guides, so you can re-use the stock rocker arms. 7.500 pushrods are required due to the 13.5* valve angles. I am using 7.425's with my cam and LS7 lifters. Dead quite! Zzzz....

BlackImpSS

iTrader: (1)

Yeah i was looking at the 5.3 heads for the torque and not needing to spin over 6500 rpm, and it seemed everyone using ported 243s werent having very good luck. Yeah I figured I could sell the 243's for 500-600 to recoupe(put elsewhere lol). Are you waiting to do the 90 mm inlet/TB before you retune, and if so you should do it during some nice cool weather because I want to see your car put down 400 whp n/a. It should have it in otherwise someone's going to need to find out how to get a fast on these cars to break that 400 whp barrier.

Oh and do you have the flow numbers of the TFS heads I can't seem to find them on any website.

DavidGXP

iTrader: (14)

In/Ex CFM over stock LS6 heads In/Ex.
.100 66/52 +4/+5
.200 135/109 +9/+1
.300 203/165 +19/+2
.400 257/209 +33/+46
.500 287/222 +36/+46
.600 299/237 +42/+54