LS3 Carbed build

General engine tech -- Drag Racing to Circle Track

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In-Tech
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Re: LS3 Carbed build

Post by In-Tech »

Hiya, just to chime in with my opinion. Iron block aluminum head I usually shoot for .015" - .020" preload on my high rpm hyd roller LS stuff and .010" more for alum/alum. So far it's worked well to 8000 rpm.
To each his own, just passing on some experience. Having non adjustable obviously needs the stem heights to be as close as possible and I don't get crazy ordering lot's of pushrods either, most turn out fine with 7.350" pushrods.
Nice build, btw.
Heat is energy, energy is horsepower...but you gotta control the heat.
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Re: LS3 Carbed build

Post by 202ci EH »

Thanks for those 2c In tech
That's like 1/4 -1/2 turn of preload, is my math right? ( will be setting it with a dial indicator of course)

CGT,

they are 2.05/1.6 . 2.5" mcsa intake / asthmatic 1.3 sqin ex :lol:
I wll update it all when I get further along, busy collecting parts and doing rust repairs/fab at the moment.
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Re: LS3 Carbed build

Post by CGT »

In-Tech wrote: Tue Dec 11, 2018 4:33 pm most turn out fine with 7.350" pushrods.
That is very unlikely with this build to be the correct length. Thanks for the input on the preload.
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Re: LS3 Carbed build

Post by steve316 »

how is the build progressing
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Re: LS3 Carbed build

Post by CGT »

steve316 wrote: Sun Feb 10, 2019 11:45 pm how is the build progressing
It's been at a standstill. I've been tinkering with the budget vortec build(I have a thread somewhere on ST on it)....wrapping it up and getting it dyno ready. The LS3 heads and the CID manifold are out your way(Rosendale). But should be returning shortly.

Not a ton left to do on it honestly, at least not for it's first voyage. 8) . Valve job, some measuring to see how much I can cut the heads and that's about it. Of course stuff always takes longer than it should and unforeseen stuff always arises... you know that. #-o How is the SB2? I have a cam for a Windsor I need to order from you btw.
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Re: LS3 Carbed build

Post by steve316 »

Rocker arm ratio & carb change on SB2. Been out of town; just let me know on cam.
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Re: LS3 Carbed build

Post by CGT »

Back on to this project. Any new predictions?
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Re: LS3 Carbed build

Post by FC-Pilot »

CGT wrote: Mon Apr 08, 2019 3:13 pm Any new predictions?
It will run when it is good and ready. LOL I gave up on predictions long ago on my own stuff. Any time I had hopes of hitting a certain number it never seamed to fail there was gremlins to work through. Once I gave up and let the dyno tell me what an engine makes (instead of me yelling at the dyno telling it what it should be showing for numbers) I always ended up happier and in a better mindset to harvest the last bit of power. Then again I am light years behind most guys on this forum.

Paul
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Re: LS3 Carbed build

Post by Rowdy Yates »

Side note met a great guy in Joe Hornick for springs. Dave @ PSI recommended i call him as he's a psi dealer. :D Hadn't been able to find the spring rate for a 1.3 od spring.
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Re: LS3 Carbed build

Post by 202ci EH »

CGT wrote: Mon Apr 08, 2019 3:13 pm Back on to this project. Any new predictions?
not enough details :-k

If it's got 4"sqin at the ssr window, 30 or 32/45/60/75 seats and 100+cc Ex port....then disappointing; but I bet it will not :D
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Re: LS3 Carbed build

Post by CGT »

202ci EH wrote: Tue Apr 09, 2019 7:14 am
CGT wrote: Mon Apr 08, 2019 3:13 pm Back on to this project. Any new predictions?
not enough details :-k

If it's got 4"sqin at the ssr window, 30 or 32/45/60/75 seats and 100+cc Ex port....then disappointing; but I bet it will not :D
It has 4 inches at the plenum, 2.97 at the flange(working on the in between) and 2.71 ish at the throat which may change a bit after the valve job. 202, how's your LS coming along?
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Re: LS3 Carbed build

Post by 202ci EH »

Sounds good to me, did you cut the intake valve down some?
I was more just taking the piss out of most of the cnc stuff on the market \:D/

Short block is together, still working on the heads. Had some comp HUC lobes cut on a cam, 247/255, .630 lift 109lsa.

Heads haven't been VJ'd yet, still 2.05 valve.
2.68 MSCA 3" at the flange, moves 340 flowz, still chipping away. Super vic is wearing me out, inside runners had reverse taper ](*,)
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Re: LS3 Carbed build

Post by Olds455 »

202ci EH wrote: Tue Apr 09, 2019 4:07 pm Sounds good to me, did you cut the intake valve down some?
I was more just taking the piss out of most of the cnc stuff on the market \:D/

Short block is together, still working on the heads. Had some comp HUC lobes cut on a cam, 247/255, .630 lift 109lsa.

Heads haven't been VJ'd yet, still 2.05 valve.
2.68 MSCA 3" at the flange, moves 340 flowz, still chipping away. Super vic is wearing me out, inside runners had reverse taper ](*,)
What is 340 flowz? I don't think I've heard that before?
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Re: LS3 Carbed build

Post by CGT »

202ci EH wrote: Tue Apr 09, 2019 4:07 pm Sounds good to me, did you cut the intake valve down some?
Yes they are 2.125 now. Sounds like your making progress. The HUC lobes are very nice and stable. And just ignore makinolds455paintchipz, he has an obvious learning disability or has smoked his breakfast. .
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Re: LS3 Carbed build

Post by CGT »

202ci EH wrote: Tue Apr 09, 2019 4:07 pm Heads haven't been VJ'd yet, still 2.05 valve.
2.68 MSCA 3" at the flange, moves
So your at about 91.5 percent of your 2.05 valve now?
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