LR4 to 7000 rpm?
12-21-2004, 01:06 PM
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LR4 to 7000 rpm? I'm looking for input on assembling an aluminum 4.8 liter (LR4) and having it live at sustained 7000-7500 rpm with a hp peak at 6500-6800 rpm.
The engine needs to be 5.0 liters or less and CR between 10:1-11:1.
I'm thinking of an aluminum block 5.3 (LM4) with the 4.8 crank, rods and pistons and LS-1 intake and cam with LS-6 valve springs. The shorter stroke of the 4.8 should allow it to spin easier(?)
*Can the 4.8 pistons and rods take 7000 rpm?
*Are the LS-6 springs good for 7000 rpm or should I go aftermarket?
*Can the 4.8 crank take 7000 rpm?
*Will the LS-1 cam in a 4.8 liter make power at 6800 or should I go with something else?
*Will the smaller 862/706 valves let it spin to 7000 rpm?
Any input (other than "why?") is appeciated.
Randy
The engine needs to be 5.0 liters or less and CR between 10:1-11:1.
I'm thinking of an aluminum block 5.3 (LM4) with the 4.8 crank, rods and pistons and LS-1 intake and cam with LS-6 valve springs. The shorter stroke of the 4.8 should allow it to spin easier(?)
*Can the 4.8 pistons and rods take 7000 rpm?
*Are the LS-6 springs good for 7000 rpm or should I go aftermarket?
*Can the 4.8 crank take 7000 rpm?
*Will the LS-1 cam in a 4.8 liter make power at 6800 or should I go with something else?
*Will the smaller 862/706 valves let it spin to 7000 rpm?
Any input (other than "why?") is appeciated.
Randy
12-21-2004, 03:03 PM
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*Can the 4.8 pistons and rods take 7000 rpm? Yes. But for how long. ARP rod bolts are needed her
*Are the LS-6 springs good for 7000 rpm or should I go aftermarket? Yes but i would not do it.
*Can the 4.8 crank take 7000 rpm? Yes
*Will the LS-1 cam in a 4.8 liter make power at 6800 or should I go with something else? No. Stock *** cam is worthless past 6200 or at least it was in my car
*Will the smaller 862/706 valves let it spin to 7000 rpm? The lighter the better so i guess it will. I would put a nice set of ported heads on the motor.
*Are the LS-6 springs good for 7000 rpm or should I go aftermarket? Yes but i would not do it.
*Can the 4.8 crank take 7000 rpm? Yes
*Will the LS-1 cam in a 4.8 liter make power at 6800 or should I go with something else? No. Stock *** cam is worthless past 6200 or at least it was in my car
*Will the smaller 862/706 valves let it spin to 7000 rpm? The lighter the better so i guess it will. I would put a nice set of ported heads on the motor.
