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#1
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500 plus CID LS engines
Any LS fans have experience on the permance of big displacement LS engines?
Pros/Cons? |
#2
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No experience, but curious as well. I wonder if the intake tract that is so phenomenal for up to 400", would get small at 500"? I personally know a guy making 620hp @ 402" N/A with cathedral ports( ported). I'd guess that the later square ports would be up to the task at 500". Hope you get some responses with real world experience.
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'65 Tempest 467 3650# 11.30@120.31 |
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#3
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500+ cu is going to be hard. I think the tall deck blocks are in the 480ish range.
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1968 Pontiac GTO - Verdoro over Ivy Gold - 400/4-speed/3.08 1987 Pontiac Grand Prix - Sage/Sage/Sage - GM 305/Th200-4r 2004 Pontiac GTO - IBM over Black - LSx 440/6-speed/4.10 SRA - Single Digit Stick Shift |
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#4
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In my example it was flywheel hp. ET/MPH pretty well backs it up, 10.2xx@130. Glass hood, full interior 2000 fbody.
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'65 Tempest 467 3650# 11.30@120.31 |
The Following User Says Thank You to Scott65 For This Useful Post: | ||
#5
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Zero experience with large ci ls engine..very little with any ls to be honest..lol
Are u looking to build a big inch engine Paul or is ya fishing.. Don't really see a need to go big from what I've seen and experienced with the ls ( limited experience). Got a co worker making 720 (crank hp) on pump gas with 427ci.. |
#6
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I have been looking into the feasibility of the LSX454 for some time now. Not many people use them but I can't find a reason why. It seems most people use smaller displacement with power adders, mostly turbo. Granted these people are realizing ridiculous HP with turbos on smaller displacement and stock bottom ends. I'm looking to use large displacement in order to avoid power adders. Info is seems to be limited.
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1978 Black & Gold T/A [complete 70 Ram Air III (carb to pan) PQ and 12 bolt], fully loaded, deluxe, WS6, T-Top car - 1972 Formula 455HO Ram Air numbers matching Julep Green - 1971 T/A 455, 320 CFM Eheads, RP cam, Doug's headers, Fuel injection, TKX 5 Spd. 12 Bolt 3.73, 4 wheel disc. All A/C cars |
#7
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#8
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If you're asking me, I'm looking for legit 600 HP with no power adders and not totally strung out.
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1978 Black & Gold T/A [complete 70 Ram Air III (carb to pan) PQ and 12 bolt], fully loaded, deluxe, WS6, T-Top car - 1972 Formula 455HO Ram Air numbers matching Julep Green - 1971 T/A 455, 320 CFM Eheads, RP cam, Doug's headers, Fuel injection, TKX 5 Spd. 12 Bolt 3.73, 4 wheel disc. All A/C cars |
#9
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You don't need big ci for that hp level.. I'm sure Paul could chime in here.. he has a lot of experience with the Ls engines and would be a good one to talk with to get you where u want to be..
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#10
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Ok I'll bite.
What LS engine is going to give me 600 legit HP with no power adder and not be totally radical? Like a .700 lift cam... Maybe a 427? At that point for the expense might as well go 454. 427's are not known for their reliability.
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1978 Black & Gold T/A [complete 70 Ram Air III (carb to pan) PQ and 12 bolt], fully loaded, deluxe, WS6, T-Top car - 1972 Formula 455HO Ram Air numbers matching Julep Green - 1971 T/A 455, 320 CFM Eheads, RP cam, Doug's headers, Fuel injection, TKX 5 Spd. 12 Bolt 3.73, 4 wheel disc. All A/C cars |
#11
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Google is your friend.. my co workers 700+hp pump gas ls is under .700 lift.. are u under the impression higher lift on an engine means lots of maintenance?
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#12
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In my example of the 402 @ 620 hp, they don't own a trailer. That car gets driven everywhere. Including back and forth to the track. I think it's in the low to mid .600 lift range.
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'65 Tempest 467 3650# 11.30@120.31 |
#13
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This...that's a fairly mild engine. Ls engines shine on the street.. they do well on the track too but tame 600hp street engines is where they shine
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#14
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What engine?
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1978 Black & Gold T/A [complete 70 Ram Air III (carb to pan) PQ and 12 bolt], fully loaded, deluxe, WS6, T-Top car - 1972 Formula 455HO Ram Air numbers matching Julep Green - 1971 T/A 455, 320 CFM Eheads, RP cam, Doug's headers, Fuel injection, TKX 5 Spd. 12 Bolt 3.73, 4 wheel disc. All A/C cars |
#15
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416ci... ls3
Not sure of his complete build, but if u want a turn key ls, call texas speed.. 427 with 630+hp for 19.5k... Last edited by Scott Roberts; 04-18-2022 at 11:29 AM. |
#16
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Just asking in regards to a recent conversation I had with a buddy. He was yapping about how bad azz LS engines are and they will out power bigger Pontiac engines. I was just wondering if any folks had first hand experience with the bigger engines? Perfer real world information over Google. I've found Google to lead one to believe the Pontiac 557 block with destruct at three hundred horsepower and be safe to a thousand.... Chit there is even info on Google that says Chicago doesn't have a crime problem. |
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#17
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I bet that guy never pointed to anything over 416ci. Bet he never saw the need too... I knew u were fishing. Lol As far as real world, how about 376ci with a blower making 687hp at the wheels and getting 21 mpg on the highway. Pontiac much? Figured u were fishing. Lol Last edited by Scott Roberts; 04-18-2022 at 11:43 AM. Reason: Ol |
#18
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Hi Frankie, generally for NA street build displacement is your friend. However at some point, the options that give you displacement starts to take away horsepower itself. Example a 4.5 inch stroke in a factory block Pontiac. The length of the intake tract will find a sweet spot for CID and RPM range also. |
#19
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625hp, $10,299 for longblock
https://paceperformance.com/i-8396421 525hp, $9,533 straight from the factory with coils, etc. https://paceperformance.com/i-7739382 Don't need big cubes here. Note the surface of the pistons: lotta Cray time there! |
#20
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For 13K you buy an 620HP LSX454 long block from GM. Just saying...
__________________
1978 Black & Gold T/A [complete 70 Ram Air III (carb to pan) PQ and 12 bolt], fully loaded, deluxe, WS6, T-Top car - 1972 Formula 455HO Ram Air numbers matching Julep Green - 1971 T/A 455, 320 CFM Eheads, RP cam, Doug's headers, Fuel injection, TKX 5 Spd. 12 Bolt 3.73, 4 wheel disc. All A/C cars |
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