Stock heads for 600hp
04-07-2019, 09:44 PM
#21
You name it a factory ported Ls3 has done it. Most cry about Tq....... too lame to consider a re gear for what you've got with heads and cam. Or use a shorter duration cam. Rule of thumb still applies, with getting air in under the curtain. That's y most of these intakes suck. The ls3 has some area in size for port area. So how do you fill a larger void? Lift. Generally speaking most to all >intakes< Hinder flow with a head that >needs< lift* so more air is tooken in to fill the larger runner.
Sidenote:
If you really want to know, it's Honestly a waste to buy a aftermarket ls3 head @ a high cost. They shrunk the port. So what? Use a smaller cam to help. Heck U can get 11"degree ls3 heads for 800 bucks bare.
Factory Ls3 heads have covered anything a money man has done cheaper. U can't beat that.
890+ hp Lq4 4.100 bore x 4.0 stroke, comp 14:8+
790 - 800 hp 376ci Ls3 12:5 comp
800+hp 416 ls3- 13.2 comp. 8.8 sec !/4mile 1.3x 60ft. 2780lbs
550 rwhp stock Ls3 with FED heads & llsr
i have a 4l80e. Wait till you need a 8 inch stall & i have the stg1 heads and a 260/272 cam with .730 lift. If i wanted less rpm i'd shorten the duration, But Keep the Lift. Springs and cost....as the head can use it.
Sidenote:
If you really want to know, it's Honestly a waste to buy a aftermarket ls3 head @ a high cost. They shrunk the port. So what? Use a smaller cam to help. Heck U can get 11"degree ls3 heads for 800 bucks bare.
Factory Ls3 heads have covered anything a money man has done cheaper. U can't beat that.
890+ hp Lq4 4.100 bore x 4.0 stroke, comp 14:8+
790 - 800 hp 376ci Ls3 12:5 comp
800+hp 416 ls3- 13.2 comp. 8.8 sec !/4mile 1.3x 60ft. 2780lbs
550 rwhp stock Ls3 with FED heads & llsr
i have a 4l80e. Wait till you need a 8 inch stall & i have the stg1 heads and a 260/272 cam with .730 lift. If i wanted less rpm i'd shorten the duration, But Keep the Lift. Springs and cost....as the head can use it.
04-07-2019, 10:45 PM
#22
I went with the stg 1 cause Chris did a 414ci that made 750+ hp. I baselined, my combo from his. Same basic spec's honestly. Chris cam was like 257/268 same basic cam. 11.7 comp. i'm around 11.8 and 408ci. Stg2 would lose Tq but have a higher peak due too being a larger CSA or runner. Either way stg 1 or 2, would like lifts above .700 as to fill the larger area. There's a major difference in port size vs a Ls7 both being as cast. Compensate with higher lifts is the thought. not saying you have to get a higher lift but knowing y, is even better
Hear's another thing>>> all Ls3 carb style intakes & Holley hi ram, tell you the intake port face size. Does a smaller runner size head still measure what the typical race style intake that they sell measure (that's made for factory Ls3 heads)? Port the head or epoxy the intake to match.... something to ponder for listed race intakes with port size @ the face
Hear's another thing>>> all Ls3 carb style intakes & Holley hi ram, tell you the intake port face size. Does a smaller runner size head still measure what the typical race style intake that they sell measure (that's made for factory Ls3 heads)? Port the head or epoxy the intake to match.... something to ponder for listed race intakes with port size @ the face
Last edited by Smokey B; 04-07-2019 at 10:57 PM.
04-07-2019, 11:26 PM
#23
If you are talking about the ITB stack intake by speedmaster…..I was going to go with that setup until I talked to several people that had run it, Not a single one ended up keeping it. They all said it was hard to tune and in the end wouldn't run for very long without the need to keep adjusting something on it. Most said it would run great for a few days and then suddenly not want to idle (vacuum leaks) or one they couldn't keep them synced for very long. I may still end up getting the setup for my street legal sprint car project but it won't be driven very often.
04-07-2019, 11:38 PM
#24
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Im trying to go with a classic style look to go with the year of the truck, chevy engine red, silver valve cover script, im going to end up using the ls coil pack relocators so i can use classic valve covers. That was why i was wanting to use the speed stacks, or i might go with a holley carb style throttle body and intake.
04-08-2019, 04:26 PM
#26
Life is good...as the dumbest question, is the 1 never asked. thought i had looked at all that was available from web browsing & lookin
Finally found a 1.3 od spring with 850 lift. The man said he would like over 800 lift 4 ls7 heads (darin to me)..couldn't find the matching springs for a while. So Pac .800 lift springs was the focus (what other & myself thought). Talked to Dave @ psi, who referred me to Joe Hornick who owns and runs JH Enterprise. Great guy. I finally was able to solve the last part of the riddle for a, bigger lobe or rocker arm. Rocker arm ftw.
Finally found a 1.3 od spring with 850 lift. The man said he would like over 800 lift 4 ls7 heads (darin to me)..couldn't find the matching springs for a while. So Pac .800 lift springs was the focus (what other & myself thought). Talked to Dave @ psi, who referred me to Joe Hornick who owns and runs JH Enterprise. Great guy. I finally was able to solve the last part of the riddle for a, bigger lobe or rocker arm. Rocker arm ftw.
Last edited by Smokey B; 04-08-2019 at 04:32 PM.