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So, bone stock, #821's i'm coming up with 284 cfm @ .700 lift, 280 @ .600 this is using a 4" bore test plate. I have read people post much higher #'s. but this is on my antique bench, at 10" I have read claims of 320+ plus at this lift with this head? Don't get me wrong, 280 seems good to me at bone stock. And maybe there getting the bigger numbers with a 4.155 test plate.? So now on to some gasket matching, thin the guide boss down, some simple bowl blending and remove some funny bumps in the intake runners. Whats the norm on what i should be getting for improvement with such mods? Can I expect 25-30 cfm improvement?
Most test bores used for the test in ? 4.060 that of a stock ls3.....340 to 360 cfm is typical depending on how in depth from porting...Hogged out 400's with +.125 bore size. What's spoke on in terms of porting is the norm...
 

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ls1 s/s notch on 28s
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they seem to avg around 315cfm at .600 for rec port stockers and like he said you should be able to get some in the 350 area so prob like 320 on your bench..theres cnc ports that get like 380 with stock valve sizing..
 

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Discussion Starter #123
they seem to avg around 315cfm at .600 for rec port stockers and like he said you should be able to get some in the 350 area so prob like 320 on your bench..theres cnc ports that get like 380 with stock valve sizing..
Hell yeah! at 10" just maxxed her out on my bench at 100% so yes 325, at .600 lift., but probably 350 real world like your sayin Suicidal. Now to do the exhaust.. 750hp in the making I'm hoping!!
 

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Combo built in 2011 -
5.7L
12.8-1
LS2 heads milled .110", Unported, 2.000" valve 241 cfm @ 28"
Unported Super Vic, Wilson tapered, 750
Hyd. roller .545" lift, 260+ @ .050"
Morel 5206
625 HP @ 7300
10.20 @ 3300 lbs. foot-brake, 5800 flash 8" converter

Sent the heads off to Brett Land in 2013, he installed 2.020" valves, opened up the throats, and picked them up 33 cfm.
Had a 37 lb. billet 8 c/w 2.250" main crank made, billet guided pistons with .927"x1.800" pins, gas ported .7mm top rings. Lightweight internal TH400/brake with Ultimate 7" converter.

Was hoping to be more competitive against the 5.0 Mustangs in NMCA Mean Street, but NMCA cancelled the class before I got the new combo together.
 

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In the shop with my Vette
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with a factory ls3 block 418,trick flow square ports super victor solid roller i was a best of [email protected] at a race weight of 2990.
Just put motor back together with little more cubes and compression, same cam and 4.0 CID. First time out foot braking and short shifting it and on limiter on the big end I went 115.1 to the 1/8 and 9.51 @142 in 1/4. same race weight as before. Once i raise the limiter it will be back over 144 again.


You race with this guy?
 

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Banksters Paradise
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Combo built in 2011 -
5.7L
12.8-1
LS2 heads milled .110", Unported, 2.000" valve 241 cfm @ 28"
Unported Super Vic, Wilson tapered, 750
Hyd. roller .545" lift, 260+ @ .050"
Morel 5206
625 HP @ 7300
10.20 @ 3300 lbs. foot-brake, 5800 flash 8" converter
Nice. Simple effective and not a huge dollar build.

but...but...but... them single plane intakes don't got any torques, so how on earth could a little 5.7 with unported cathedral heads run 10.20's @ 3300 lbs ??????? Sorry i forgot for a second i'm on YB and not ls1tech:p:ROFLMAO:
 

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but...but...but... them single plane intakes don't got any torques, so how on earth could a little 5.7 with unported cathedral heads run 10.20's @ 3300 lbs ??????? Sorry i forgot for a second i'm on YB and not ls1tech:p:ROFLMAO:
I dunno, but with a OEM style intake, unmilled heads so almost 2 points less compression, a hyd roller cam 20+ degrees smaller duration we went 10.teens at 3250# :)
 

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ls1 s/s notch on 28s
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nope was a legit ls6..they went like 10.00 with it or 9.9x with just a intake..the 9.60s was cam an intake..rules for that class was stock short block an heads..heads could only get a valve job, had to be hyd roller ..that was the rules for all motor at world cup in 2015 when he won the class an went 9.60s
 

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I know the class, I was the first and only LS racing in it for while lol

I'd have to ask rob because I know he had a short stroke 347 and they weren't doing tear downs they were just P & G the motors if protested but didn't do that even
 

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ls1 s/s notch on 28s
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25,415 Posts
I know the class, I was the first and only LS racing in it for while lol

I'd have to ask rob because I know he had a short stroke 347 and they weren't doing tear downs they were just P & G the motors if protested but didn't do that even
this is from his ls6 run 9s thread,could he had a special engine im sure..that class i loved till they let the imports become nitro injected combos..be cool if the let carbs in an let the ls guys have any intake what so ever..
Update
I stand by this statement as we were able to run 9.6 and just under 142mph with the car last fall with the addition of an hydraulic cam and aftermarket valvetrain with 243 unported GM heads.
Yep. My motor is an untouched SI ls6 just like it comes from the factory including stock oil pan, valvetrain, etc.

The 10.02 in +200 DA we ran was on a 1.438 60' with a baby drag radial and a c5 rear diff.

Give GM the credit.

Like it says in the title of thread.
 

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Yeah Jason started effing that class up by trying to let it run whatever the all motor hondas were and letting them take out weight on top of that. It was originally meant for them and your more typical cam only LS stuff (when I ran it I threw together car in a day and qual number 2 or 3. Put it on bumper in elim of course)

All he had to do was keep them on normal fuels and add weight as things evolved, and allow intake manifold changes for LS stuff and it would cost people maybe $1000 to run class. Now you have to build a purpose built motor that's useless anywhere else on earth

I stopped running it and so did all my customers because the rules are always so idiotic for LS LS cars
 
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