high torque at lower RPM LT1
#21
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Stock intake manifold... 210/212 .550/.490 on a 108.5 LSA, 105 ICL. You can use stock stock rockers on the exhaust, 1.6s on the intake. There's a drop in spring that runs ~90 bucks that will run that setup all day long. At 2500-3000 rpm you'd be around 340rwtq on a chassis dyno through a 6 speed. These are Comp lobes on this one... do a cast core and you'll be right at ~500 bucks for cam, 8 rockers, and springs.
#22
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A dynograph would be fantastic. I'm curious to see what the torque curve looks like as well as why it is believed a mini ram style intake can produce more torque at lower rpm than a TPI?
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I realize that which is why I suggested tried and true cams that complement both a TPI and mini ram style intake. Now, it would be cool if you could supply a dyno graph for what you suggested to see what the torque curve looks like. Can you do that?
Last edited by SS RRR; 07-07-2011 at 07:19 AM.
#26
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OP instead of overcomplicating this just use the LT1 in its stock form..........they make a very good amount of low end torque just the way they sit with a stock cam in them.........i think it will be more than enough for what you are doing........also the truck motors make great torque as well......ive got a 98 K1500 with the 5.7 vortec in it.......its all done at 4800rpm but at 3000 its got gobbsss of torque....pulls my rig perfectly
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OP instead of overcomplicating this just use the LT1 in its stock form..........they make a very good amount of low end torque just the way they sit with a stock cam in them.........i think it will be more than enough for what you are doing........also the truck motors make great torque as well......ive got a 98 K1500 with the 5.7 vortec in it.......its all done at 4800rpm but at 3000 its got gobbsss of torque....pulls my rig perfectly
#29
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We even have an airboat with a GM performance parts 572ci BBC down here in Louisiana but a light all aluminum 454 smallblock would be the King b/c of it's lightweight combined with big power and you must run a gear reduction or u will be screwed. Later Clint
#30
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Nope I've never built a 3000 rpm LT1, and neither has LPE, GM or anyone else. If you understood the cam specs I posted, and how I came to them, you would understand how the VEs translate into low rpm torque. It's a relatively quick intake lobe, and a nice slow exhaust lobe btw.
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Nope I've never built a 3000 rpm LT1, and neither has LPE, GM or anyone else. If you understood the cam specs I posted, and how I came to them, you would understand how the VEs translate into low rpm torque. It's a relatively quick intake lobe, and a nice slow exhaust lobe btw.
#32
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If you think some of the best cam designers in this industry rely on 100% personal experience with an engine combination you'd be 100% wrong. They draw on a varying mix of software, experience and math. I know the engine will make that torque based on 3 similar cam-only LT1. Ironically one was a 211/219, one was a 214/224, and one is a stock cam with 1.7 rockers.
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If you think some of the best cam designers in this industry rely on 100% personal experience with an engine combination you'd be 100% wrong. They draw on a varying mix of software, experience and math. I know the engine will make that torque based on 3 similar cam-only LT1. Ironically one was a 211/219, one was a 214/224, and one is a stock cam with 1.7 rockers.
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They also rely on results which you have none of. You have given him theory and that's it. IMO that isn't enough to spend money and time on.
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Do I have an unlimited budget for such testing? No. Do I have experience with 7 different cams from 4 different manufacturers in 3 different CID applications with 3 different cylinder heads, including DESIGNING AND SELLING MY OWN PARTS? Yes. How's it going throwing rocks from your glass house built on a 12 second SR 395.3 foundation?
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Wow. I did not realize you had such credentials. I would think with all that versatile experience you could show something that proves your theory?
Again, never said you were wrong, but I would love to see something other than words. Sometimes when area under the curve is being discussed I like pretty graphs and lines.
Again, never said you were wrong, but I would love to see something other than words. Sometimes when area under the curve is being discussed I like pretty graphs and lines.
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Yes on an airboat, the reduction box is actually a torque multiplier. Say your engine turns 5K, its going to take 2 rotations of the motor for one of the prop giving you a prop speed of 2500rpms.
Thanks for the advice, Im still looking in the deciding factor for motor, Im afraid the LT1 still might be too heavy for the hull to effectivy carry weight and not sit too low in the water. Anyone have a weight estimate on just bare motor, intake to pan with no accessories?
Thanks for the advice, Im still looking in the deciding factor for motor, Im afraid the LT1 still might be too heavy for the hull to effectivy carry weight and not sit too low in the water. Anyone have a weight estimate on just bare motor, intake to pan with no accessories?