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LS3 Carbed build

General engine tech -- Drag Racing to Circle Track

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slo-svt
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Re: LS3 Carbed build

Post by slo-svt »

So what's next for project overflowz? I'm sure you feel the same but I think it would be nice to have a day of testing with the vacuum pump working the whole time and revisit cam position with the timing curve you develop from the last session. I would be also be interested to see another set of headers put on it as well. Hopefully I can get over there soon to get this new connector put on the torque sensor and maybe tidy up some other stuff while I'm at it.
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Re: LS3 Carbed build

Post by CGT »

slo-svt wrote: Tue Oct 22, 2019 10:04 pm So what's next for project overflowz? I'm sure you feel the same but I think it would be nice to have a day of testing with the vacuum pump working the whole time and revisit cam position with the timing curve you develop from the last session. I would be also be interested to see another set of headers put on it as well. Hopefully I can get over there soon to get this new connector put on the torque sensor and maybe tidy up some other stuff while I'm at it.
I agree...may as well try another cam if it goes back on there.....been looking at cam lobes and headers off and on all day. Lol.

Maybe shortening up the secondaries on the current headers might be worth a try. That deal may be worth a call to Mr Elston. Looks like 108icl was better than 104.5 from 5500 or so....but got missed with all the other stuff going on...
steve cowan
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Re: LS3 Carbed build

Post by steve cowan »

Chad,
thanks for the spreadsheet i just printed it off for closer look
was there much of a power increase after 30 deg total timing
looks like the fuel consumption # are close through the timing sweeps,at a guess this is what you like to see??
do the BSFC change if there is to much total ignition timing,great build Chad and well done to all involved
steve c
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Re: LS3 Carbed build

Post by slo-svt »

steve cowan wrote: Wed Oct 23, 2019 2:01 am Chad,
thanks for the spreadsheet i just printed it off for closer look
was there much of a power increase after 30 deg total timing
looks like the fuel consumption # are close through the timing sweeps,at a guess this is what you like to see??
do the BSFC change if there is to much total ignition timing,great build Chad and well done to all involved
There were decent gains throughout the curve from 5500-7500 with timing numbers greater than 30. 10-15 From 7-7500 with 36 degrees.
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Re: LS3 Carbed build

Post by CGT »

steve cowan wrote: Wed Oct 23, 2019 2:01 am do the BSFC change if there is to much total ignition timing
With BSFC being basically fuel unit/horsepower...yeah. If the timing change hurt power on the same amount of fuel the bsfc number would increase(bad) or if the timing change improved power on the same amount of fuel the bsfc number would decrease(good).
steve cowan wrote: Wed Oct 23, 2019 2:01 am was there much of a power increase after 30 deg total timing
Screenshot (39).png


Steve in that screenshot you see 4 columns, listing pulls 30° 32° 34° 36°. The columns on the right with the green highlighted areas show where each timing setting was up on power in relation to rpm.. Following the pattern of the segments of those green columns will be my timing curve next time on the dyno.
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Re: LS3 Carbed build

Post by randy331 »

Be easy to get that thing to peak higher than where hyd lifters will be happy. LOL :D

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Re: LS3 Carbed build

Post by CGT »

randy331 wrote: Wed Oct 23, 2019 9:23 am Be easy to get that thing to peak higher than where hyd lifters will be happy. LOL :D

Randy
The crank and connecting rods may not be happy there either.
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Re: LS3 Carbed build

Post by CGT »

randy331 wrote: Wed Oct 23, 2019 9:23 am hyd lifters will be happy. LOL
Seems to be a pattern on this thread with you and anti-hydraulic lifter rhetoric :lol:
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Re: LS3 Carbed build

Post by steve cowan »

Chad,Josh,
thanks for the information really appreciated :D
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Re: LS3 Carbed build

Post by randy331 »

CGT wrote: Wed Oct 23, 2019 9:43 am
randy331 wrote: Wed Oct 23, 2019 9:23 am hyd lifters will be happy. LOL
Seems to be a pattern on this thread with you and anti-hydraulic lifter rhetoric :lol:
LOL. well look where it's making peak HP and not falling to 7800. For drag racing you'd need a stall speed close to 7000 rpm and need to shift it over 8000 rpm, 8200-8400 most likely, and ran out to 8700 ish at the finish line to use the best average power and get the best et. What's the odds the hyd lifters will be ok up there ?

Or,.... put the heads/intake/cam etc on 400 plus cubes and lower the rpm. LOL


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Re: LS3 Carbed build

Post by slo-svt »

randy331 wrote: Wed Oct 23, 2019 9:46 pm

Or,.... put the heads/intake/cam etc on 400 plus cubes and lower the rpm. LOL


Randy

There is a 15 degree 403 at joes that needs assembled and a 12 degree 429 at my house that we could try this on if chad had any interest of doing so.
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Re: LS3 Carbed build

Post by paulzig »

randy331 wrote: Wed Oct 23, 2019 9:46 pm
Or,.... put the heads/intake/cam etc on 400 plus cubes and lower the rpm. LOL
What about less camshaft?

Lower comp, small cam which peaks around 6000-6200 carry to 7000 RPM might make a good daily driver
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Re: LS3 Carbed build

Post by randy331 »

paulzig wrote: Thu Oct 24, 2019 12:12 am
randy331 wrote: Wed Oct 23, 2019 9:46 pm
Or,.... put the heads/intake/cam etc on 400 plus cubes and lower the rpm. LOL
What about less camshaft?

Lower comp, small cam which peaks around 6000-6200 carry to 7000 RPM might make a good daily driver
it would take an extremely small cam to get Chad's 378 to peak at 6000-6200 rpm. I did a 408 ls with ported cathedral port heads, 2.02"/1.56" valves, 243/258/110 cam with .625" lift. sv intake, 4150 carb. It made peak HP at 6000-6200 rpm. The induction trac is the number one thing that determines where an engine makes peak at.

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Re: LS3 Carbed build

Post by CGT »

All I need is another hydraulic cam with 10°'s or so more high-lift area, no more max lift, requires no more spring pressure, that will be stable to 8000rpm or so. :oops:
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Re: LS3 Carbed build

Post by zums »

Nice numbers for a hydraulic cam, im not tuned in on ls stuff, what type of average intake runner and head csa dose it have
Tom
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