how much hp are ls7 rods worth
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Joined: Feb 2022
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From: Southern TN
LS7 Crank w Titanium Rods to Stroke an LS3 Two identical engines, other than rotating mass, will make the same power but you'll get quicker acceleration from the engine with less inertia.
Power = Torque * Velocity
Torque transmits through objects regardless of the weight. The weight of the rotating assembly doesn't change how hard the piston pushes on the crank (and resulting torque). If you can get both engines at the same speed, and they make the same torque, then they'll make the same power too. Acceleration is dependent on mass though. Heavier things get up to speed slower but will eventually get there.
Sometimes people get confused because they treat mass like friction. It's not. Friction consumes things like torque and power so that you get a loss at the output of the engine. Mass doesn't consume things. It's just there, always present, not giving or taking, just there. And the engine has to haul it around every time it wants to change speed. More mass makes it harder to speed up, and harder to slow down, but it doesn't change the engine's ability to produce torque at a given rpm.
Power = Torque * Velocity
Torque transmits through objects regardless of the weight. The weight of the rotating assembly doesn't change how hard the piston pushes on the crank (and resulting torque). If you can get both engines at the same speed, and they make the same torque, then they'll make the same power too. Acceleration is dependent on mass though. Heavier things get up to speed slower but will eventually get there.
Sometimes people get confused because they treat mass like friction. It's not. Friction consumes things like torque and power so that you get a loss at the output of the engine. Mass doesn't consume things. It's just there, always present, not giving or taking, just there. And the engine has to haul it around every time it wants to change speed. More mass makes it harder to speed up, and harder to slow down, but it doesn't change the engine's ability to produce torque at a given rpm.
Looking for any Flaws in my Own Thought process
Looks like I can get a Deal on an LS7 Crank (almost New Condition) w New Pankl LS7 Titanium Rods would utilize Full Width King Bearings over Narrow ~ aftermarket Fillet radius) Plan 4.00 Stroke LS3 w Mahle -4cc Pistons with Wrist Pins Location to Match the 6.064 L Rods in a NA Torque application Swap into 96 Land Cruiser 6850lbs Brick
Extra 40 Cubes w Lighter Bob Weight/Rod/Piston Combo couldn't help Throttle Response on LOW End~ to Mid Range Torque mated w TAP shift 6L80 ( Understand Most gobbled Up by All Wheel drive Transfer Case & Toyota Floating Axles.
823 Heads Optimized Exhuast w 1 3/4 Custom Tri Flow Headers, Edlebrock Crossram w Truck Norris Cam for the "Dragon Slayer" Swap is Over Kill, But Moving a Triple Locked Brick w 35's pulling a Grizzly ATV.
. If your 5 Year Cancer Survivor Bucket List build include a Few Parts that will Never Reach their Full Potential - So Be it Note: Calico Coatings have a New GT3 Moly, Graphite, PTFE Coating for Ti Rods, but best suited with Precision Lap on Thrust Flat on Big End of .0075~.0100 (.004-.005 per Side, provide clearance for the GT3 Coating but also opens up the LS7 Rod to Rod Journal Spec couple thousands. Pin Diameters must be Honed from .925 to .927 OEM Clearance with V Oil Grooves.
. Know lot of Folk Scared of Titanium "Gall", Just think in Lower HP NA application will never See the High RPMs, Heat and tortue of Screaming Power adders ?
Im guessing for 505hp, they fit the bill and were plenty good. How many of ya happy with just 505fwhp? The ls7 as im told isnt a strong motor outside what it was designed for. Lots of material and weight hogged out to make the z06 light. Also using dry sump must have some kind of effect on this motor besides the gforces the vette can pull on the track. My guess is, the ls7 is a house of cards. Start to take certain things away and it all comes crashing down in strength n reliability. Swap a stockish ls7 in your hotrod and enjoy. Yet, theres Johns monte, so....
That's how I realized the oil was low, and I verified it on the dipstick. On a wet sump engine, lower oil levels leave more room in the sump for entrapped air to move around, improving bay-bay breathing. On a dry sump, there should be little to no oil at all, so theoretically, there should be improved bay to bay breathing, which adds power due to less pumping losses. In early development of the LS1, one of the front or rear covers blew right off the engine at higher rpm!!! This was later determined to be caused by insufficient bay to bay breathing, FWIW...... 
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The dry sump will be a power advantage at high rpm. Why? Because one problem "Y" blocks (LS engines, Ford 312, etc) have is bay to bay breathing. My older LS1 had the best trap speeds in the 1/4 mile when it was down 1-1/2-2 quarts (I wasn't aware of the lower oil level at that time!). When I left the strip that day, my low oil level light came on, which will REALLY tighten your rectal orifice!!!That's how I realized the oil was low, and I verified it on the dipstick. On a wet sump engine, lower oil levels leave more room in the sump for entrapped air to move around, improving bay-bay breathing. On a dry sump, there should be little to no oil at all, so theoretically, there should be improved bay to bay breathing, which adds power due to less pumping losses. In early development of the LS1, one of the front or rear covers blew right off the engine at higher rpm!!! This was later determined to be caused by insufficient bay to bay breathing, FWIW......
That's how I realized the oil was low, and I verified it on the dipstick. On a wet sump engine, lower oil levels leave more room in the sump for entrapped air to move around, improving bay-bay breathing. On a dry sump, there should be little to no oil at all, so theoretically, there should be improved bay to bay breathing, which adds power due to less pumping losses. In early development of the LS1, one of the front or rear covers blew right off the engine at higher rpm!!! This was later determined to be caused by insufficient bay to bay breathing, FWIW...... TECH Fanatic
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No, I don't have it backwards. Maybe that's true with an aftermarket dry sump system but the factory GM dry sump in the manual Grandsport, Z06 and ZR1 is more of a hybrid setup. It's absolutely worth, marginal, HP gains to convert to a wet sump.
I’ll grant that the LS7 dry sump system leaves a lot to be desired and I’d be 0% surprised if there’s a gain to be had converting to wet sump w/ scraper, but in general, a true dry sump (which the LS7 hardly is) will consistently outperform a wet sump.
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Verdad Gallardo LS engines have a small crankcase volume and need all the help they can get with oil return to pan and bay to bay breathing. Each newer series of LS engine (LS1, 2, 3, 7) got larger bay windows with the LS7 being the largest. I'm not sure if the truck Vortec engines got any bay windows at all?
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Yeah, pretty much. It also helps reduce air in oil too.
LS engines have a small crankcase volume and need all the help they can get with oil return to pan and bay to bay breathing. Each newer series of LS engine (LS1, 2, 3, 7) got larger bay windows with the LS7 being the largest. I'm not sure if the truck Vortec engines got any bay windows at all?
LS engines have a small crankcase volume and need all the help they can get with oil return to pan and bay to bay breathing. Each newer series of LS engine (LS1, 2, 3, 7) got larger bay windows with the LS7 being the largest. I'm not sure if the truck Vortec engines got any bay windows at all?
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No one said anything about a crank scraper lol, that’s moving the goalpost from the initial statement.
I’ll grant that the LS7 dry sump system leaves a lot to be desired and I’d be 0% surprised if there’s a gain to be had converting to wet sump w/ scraper, but in general, a true dry sump (which the LS7 hardly is) will consistently outperform a wet sump.
I’ll grant that the LS7 dry sump system leaves a lot to be desired and I’d be 0% surprised if there’s a gain to be had converting to wet sump w/ scraper, but in general, a true dry sump (which the LS7 hardly is) will consistently outperform a wet sump.
A buddy of mine did not show any significant gains going from the GM dry sump system to the aftermarket system sold by G Speed (I dont recall what brand they use in their kit). I've heard the claims of up to 30whp. Too many factors play into how much gains or losses you'd see.
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If your engine has to last the length of a race,, and there is money on the line, and your way north of 8500 RPM ,, TI pays off, along with the other 30 or 40 K worth of parts and machine work...
If its hauling you places every day, not worth it. IMHO. Ultralight rotating assemblies have there place.. But honestly,, to me,, Those places are few..
If its hauling you places every day, not worth it. IMHO. Ultralight rotating assemblies have there place.. But honestly,, to me,, Those places are few..
Yup, I agree! IDK where you got that info, but I'd like to see the info. Every serious racing engine developed in the last 50 or 60 years have had dry sump oiling, because they move the oil away from radiant heat, keep oil supplied to the engine under high g-forces, and allow for better internal breathing due to little to no oil level. I've never seen any serious racing engine use a wet sump......
Last edited by grinder11; Apr 3, 2022 at 06:24 PM.
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just wondering how much more a properly broken in factory ls7 motor would make on the dyno vs a properly broken in ls7 block but built with your typical callies/k1 forged crank, forged steel rods, and forged pistons......same compression/same stock ls7 heads on both. obviously nobody would build this motor im more or less just curious how much more power the lighter ls7 rotating assembly is worth