Can an LS rev up to 8k rpm???
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Can an LS rev up to 8k rpm???
can a fully built b18a(built bottom end, crower 403's, valve springs, retainers, etc.) rev up to 8k rpm? how high can it go with that set up?
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Re: Can an LS rev up to 8k rpm??? (90teg)
remmeber the ecu? the stock ecu wont let you go that high, gotta either get a modded one . or maybe one from an si, gsr, or type R , not sure if willl workwith the wiring though.
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Re: Can an LS rev up to 8k rpm??? (90teg)
With a stronger valvetrain you can rev higher, but the rod ratio is the final say in how high you can safely rev.
The rod ratio is the length of the connecting rod, divided by the stroke of the crankshaft.
A longer rod ratio is easier on the cylinder walls, and is better for high reving. A shorter rod ratio gives more low end torque.
The rod ratio is the length of the connecting rod, divided by the stroke of the crankshaft.
A longer rod ratio is easier on the cylinder walls, and is better for high reving. A shorter rod ratio gives more low end torque.
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From: Suck it Trebek
Re: Can an LS rev up to 8k rpm??? (90teg)
the max your gonna want to go with the 403's is 8k. power falls off after 7500 k. the max you can really safely rev a ls head is ~ 8500 because of the rocker arm design. the botom end balanced built correctly will take 8500
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Re: Can an LS rev up to 8k rpm??? (JCushing)
News flash!
The stock LS bottom end can handle 8000 RPMs easily, as long as you get a Vtec oil pump. I know, I have taken my STOCK (stock rods, rod bolts, pistons, crank, sleves) b18b bottom end to 8000 RPMs a countless number of times with NO problems. I talked to many companies such as PYR, and EXOSPEED who said the stock b18b is good to about 8500 with the addition of a Vtec oil pump.
There is no reason why the a b18a/b block would not handle 9000+ RPMs with the additon of a block girdle, forged rods and pistons, and a balenced rocepricating mass. The b18a/b r/s ration is not that much differenct than the b18c's r/s.
The stock LS bottom end can handle 8000 RPMs easily, as long as you get a Vtec oil pump. I know, I have taken my STOCK (stock rods, rod bolts, pistons, crank, sleves) b18b bottom end to 8000 RPMs a countless number of times with NO problems. I talked to many companies such as PYR, and EXOSPEED who said the stock b18b is good to about 8500 with the addition of a Vtec oil pump.
There is no reason why the a b18a/b block would not handle 9000+ RPMs with the additon of a block girdle, forged rods and pistons, and a balenced rocepricating mass. The b18a/b r/s ration is not that much differenct than the b18c's r/s.
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Re: Can an LS rev up to 8k rpm??? (InfamousRS)
1.54:1 compaired to 1.58:1, not huge but it is a difference.
Sure you can do modifications to less the ware and tear caused by high reving with a low rod ratio, but its still butting more stress on your engine. Just because you can rev to 8,500 with out an immediate damage doesn't mean its going to be fine 50k miles from now.
Sure you can do modifications to less the ware and tear caused by high reving with a low rod ratio, but its still butting more stress on your engine. Just because you can rev to 8,500 with out an immediate damage doesn't mean its going to be fine 50k miles from now.
Rod ratio dictates the rod angle at which the piston travels up and down the cylinder. Lower rod ratios produce a larger angle between the rod and the crankshaft. The rod angle must not encourage excessive friction at the cylinder wall and piston skirt:
A greater angle (or a lower rod ratio) will occur by installing a shorter rod or by increasing the stroke.
A reduced angle (or a higher rod ratio like in a B16A) will occur with a longer rod or a shorter stroke.
Bottomline: a low rod ratio produces a steeper rod to crankshaft angle and more piston sideloading against the cylinder wall, as it travels up and down the cylinder. The consequence of a low rod ratio and resultant larger rod angle is more wear and vibration: you are forced to use a lower redline.
Secondly, when the rod ratio value becomes smaller, it has other effects: mechanically, on breathing ability, and on how you set your spark timing.
A. Mechanical Effects of a Low Rod Ratio:
Motors with low rod ratios (like our 2nd & 3rd gen. integras ) typically exhibit the following characteristics (compared to high rod ratio motors):
- shorter pistons, measured from the pin center to the bottom of the skirt.
- higher level of vibration
- greater wear on piston skirts and cylinder walls
- slightly higher operating temperature & oil temperature due to friction
- physically shorter engine (more oil pan, header, and air cleaner clearance), allowing for a lower hood line.
- lower block weight.
A greater angle (or a lower rod ratio) will occur by installing a shorter rod or by increasing the stroke.
A reduced angle (or a higher rod ratio like in a B16A) will occur with a longer rod or a shorter stroke.
Bottomline: a low rod ratio produces a steeper rod to crankshaft angle and more piston sideloading against the cylinder wall, as it travels up and down the cylinder. The consequence of a low rod ratio and resultant larger rod angle is more wear and vibration: you are forced to use a lower redline.
Secondly, when the rod ratio value becomes smaller, it has other effects: mechanically, on breathing ability, and on how you set your spark timing.
A. Mechanical Effects of a Low Rod Ratio:
Motors with low rod ratios (like our 2nd & 3rd gen. integras ) typically exhibit the following characteristics (compared to high rod ratio motors):
- shorter pistons, measured from the pin center to the bottom of the skirt.
- higher level of vibration
- greater wear on piston skirts and cylinder walls
- slightly higher operating temperature & oil temperature due to friction
- physically shorter engine (more oil pan, header, and air cleaner clearance), allowing for a lower hood line.
- lower block weight.
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From: Sothern Cali
Re: Can an LS rev up to 8k rpm??? (90teg)
^^^^ yes you should be able to . and about the ecu problem, i would go straight to hondata instead of a GSR ecu or what not, it may cost more but u will benefit from it alot with ur setup
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Re: Can an LS rev up to 8k rpm??? (JCushing)
why not? basically what would hold me back from reving up to 8k rpm (w/the head and the block is fully built is the r/s ratio. so why won't some gsr rods do the job? by the way, i'm asking cause i'm putting a turbo on my ls and want to rev higher than 6500rpms.
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From: Sothern Cali
Re: Can an LS rev up to 8k rpm??? (90teg)
oh! sorry i was thinking of oistons. i dont think u would be able to put in b18c1 rods(think do not quote) and if ur going turbo y dont u get b18c1/b16a head? that will help you a liltle bit
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From: Suck it Trebek
Re: Can an LS rev up to 8k rpm??? (90teg)
i think the rods are a different size. you can use stock rods to go to 8k you dont need gsr ones. just use arp rod bolts and have the bottom end balanced at a machine shop. also might wanna look into gettin a block girdle
[Modified by JCushing, 9:27 PM 7/18/2002]
[Modified by JCushing, 9:27 PM 7/18/2002]
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Re: Can an LS rev up to 8k rpm??? (itr206)
remmeber the ecu? the stock ecu wont let you go that high, gotta either get a modded one . or maybe one from an si, gsr, or type R , not sure if willl workwith the wiring though.
LOL
dont try this at home kids.
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Re: Can an LS rev up to 8k rpm??? (ITR#132)
Some of us arn't to bright, are we now?
Are you refering to using GSR rods in a LS/Vtec setup? IT WILL NOT WORK, unless you like hitting the bottom of your head and valves with your pistons...... The b18c rods are 0.039" longer than the b18a/b rods.
[Modified by InfamousRS, 12:45 AM 7/19/2002]
Are you refering to using GSR rods in a LS/Vtec setup? IT WILL NOT WORK, unless you like hitting the bottom of your head and valves with your pistons...... The b18c rods are 0.039" longer than the b18a/b rods.
[Modified by InfamousRS, 12:45 AM 7/19/2002]
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Re: Can an LS rev up to 8k rpm??? (InfamousRS)
[QUOTE]Some of us arn't to bright, are we now?
Are you refering to using GSR rods in a LS/Vtec setup? IT WILL NOT WORK, unless you like hitting the bottom of your head and valves with your pistons...... The b18c rods are 0.039" longer than the b18a/b rods.
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no, i was talking about for a turbo ls setup.
Are you refering to using GSR rods in a LS/Vtec setup? IT WILL NOT WORK, unless you like hitting the bottom of your head and valves with your pistons...... The b18c rods are 0.039" longer than the b18a/b rods.
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no, i was talking about for a turbo ls setup.
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From: assville, MI, USA
Re: Can an LS rev up to 8k rpm??? (ITR#132)
I dont see why not, the LS/VTEC guys do it.
The point is yeah you can rev high on a B18 and its not going to break down.. but the higher you rev on that rod ratio the more sideloading and stress you are putting on the engine. LS/VTEC engines are known to last less than 50k miles between rebuilds because of this.
