4.3L V8 (L99) LT Based Max Cam Lift Stock Head
12-24-2017, 02:37 PM
#1
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4.3L V8 (L99) LT Based Max Cam Lift Stock Head So again, not looking for Negative Comments or why am I Camming the Motor that's in my Car. Just want to know if anyone has an idea of the Maximum Lift Camshaft I can Run without Piston to Valve. Will be getting LS7 Hydraulic Lifters and Hardened Push Rods. Also Springs. Yes, Injectors and a Tune too.
12-24-2017, 03:09 PM
#2
While you can use a .600° lift and not have piston to valve interference you also have to consider the actual duration of the camshaft. With that said i would not go crazy on a camshaft... Cams like the LPE 211/219 and 1.6 rockers would give a good amount of power. I would stay in the 540-570 lift area with not exceeding 228° on the duratiin side.
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Jeremy Allen (01-20-2020)
12-24-2017, 03:14 PM
#3
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So then if I go with the Big Daddy Rattler and Stock Ratio Rockers, I should be golden... Cool, cool...
https://howardscams.com/i-24076637-h...-camshaft.html
https://howardscams.com/i-24076637-h...-camshaft.html
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Jeremy Allen (01-20-2020)
12-25-2017, 01:00 AM
#5
Personally, I've used as much as .660" lift with ported OEM heads and rotating assembly with no issues.....and could've gone with more if the rest of the valve train could support if.
Seriously, though.....you won't have to worry about P/V clearance until you're using a cam that clearly has too much duration for that little V-8.
KW
12-25-2017, 01:42 AM
#7
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Thread Starter
Have a 1995 Caprice with an L99 in it. Strokin' it my man. Just if I need it, she got the Power I need to get down. Act Stupid every now and then. Just need the Power for when she is being called.
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12-25-2017, 11:37 PM
#8
Small displacement with what I calculate at about 9.5 to 9.7:1 compression ratio.
That cam is gonna make for a very weak off-the-line performer. And that's even if you put (3.73...4.10) gears in it. Also.....this cam will require a higher stall torque converter in your Caprice.
NOTE: L99/LT1/LT4 engines run on higher compression than the Gen-1 SBC due to the reverse cooling of these engines.
So when Howard cams says "needs 9.5:1 compression ratio", they are referring to a Gen-1. For a Gen-2 you need at LEAST one full point of compression (10.5+:1) more than you'd run in a Gen1.
KW
That cam is gonna make for a very weak off-the-line performer. And that's even if you put (3.73...4.10) gears in it. Also.....this cam will require a higher stall torque converter in your Caprice.
NOTE: L99/LT1/LT4 engines run on higher compression than the Gen-1 SBC due to the reverse cooling of these engines.
So when Howard cams says "needs 9.5:1 compression ratio", they are referring to a Gen-1. For a Gen-2 you need at LEAST one full point of compression (10.5+:1) more than you'd run in a Gen1.
KW
12-26-2017, 12:05 AM
#9
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Again, not to sound like a ***** or a know it all lol. Higher Stall is a given. I am heavily Mechanically inclined. Just getting over to the dark side with 4 more Cylinders lol. Ummmm, Compression? That can be took care of. Also, Injectors and Pump will be Upgraded along with a Tune my man. If it don't make at the least 350HP on Motor, I Failed. Fail is not an option for me Sir. I do appreciate the help though. Oh, do plan on going with a 4.10 Gear BTW too. Trans is out now. Had to send to my guy. 4L60E and it just got Clutches, Steals, Beast Sun Shell, Boost Valve, Stage 3 Vette Servo. Hopefully will last just a bit longer. All hard parts are good. Clutches was Garbage in my 3-4.
12-26-2017, 12:08 AM
#10
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All Internals in the Block will be Forged. Crank included. Everything will be Balanced and will be Balanced with the Stock Harmonic. It will all be Blueprinted. Hardware will be ARP. Gravy Train on Biscuit Wheels lol. ��
12-26-2017, 09:27 AM
#11
What size stroker are you building? If you are stroking it and getting good heads, it will "work". If you plan to install it now before the stroker, that would be a terrible cam for that motor stock cubes and ESPECIALLY stock heads. Shelf cams are fine for a daily or a mild sub 220 duration street car, but if you are looking into strokers and cams that size you are at the point where you should just tell a cam guy exactly what you want and go custom for like $100 more.
Do not run that cam on a stock headed 4.3. Hell, its still a bad choice for a 5.7 LT1 with stock heads and cubes. It is obviously spec'd for a gen1, with its massive duration and poor lift. Our motors - yes even the smaller LT - prefer higher lift with modest duration. We are blessed with higher compression and much better heads then stock SBC motors had. That cam will have zero low end and be a sack of **** for half of its RPM range...I would stick to something late early-mid 230s duration if you want an aggressive cam in that motor. You have a smaller motor and more weight to move than we do, so you should be looking at less duration, less of a split, and a cam lobe optimized for getting a big heavy car moving. Not a lazy low lift/high duration cam that is just made to sound aggressive.
I'd love to see your build finished since I think Caprice's make awesome sleepers - but I'd also love to see it not run high 13s due to a poor cam choice after spending thousands on a stroker, gears, stall, fuel, etc.
Do not run that cam on a stock headed 4.3. Hell, its still a bad choice for a 5.7 LT1 with stock heads and cubes. It is obviously spec'd for a gen1, with its massive duration and poor lift. Our motors - yes even the smaller LT - prefer higher lift with modest duration. We are blessed with higher compression and much better heads then stock SBC motors had. That cam will have zero low end and be a sack of **** for half of its RPM range...I would stick to something late early-mid 230s duration if you want an aggressive cam in that motor. You have a smaller motor and more weight to move than we do, so you should be looking at less duration, less of a split, and a cam lobe optimized for getting a big heavy car moving. Not a lazy low lift/high duration cam that is just made to sound aggressive.
I'd love to see your build finished since I think Caprice's make awesome sleepers - but I'd also love to see it not run high 13s due to a poor cam choice after spending thousands on a stroker, gears, stall, fuel, etc.
12-27-2017, 09:34 AM
#15
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With the little CID you will have using that cam profile, be prepared to stall and gear it to the moon. And when you get into a race with a stock Civic or maybe even a Geo Prizm for that matter, while you're revving past 7000rpm and still losing, perhaps then you'll come to the realization you did it wrong.
12-27-2017, 09:52 AM
#18
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I tell you what... What would you do for (Max Lift) and (Max Duration) at the very most if it was you? Specs and all Richard... More of an LT guy then me... I'm a Honda guy... All New to me...
12-27-2017, 09:53 AM
#19
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https://ls1tech.com/forums/lt1-lt4-m...l#post19799083
BTW, had 211/219 cam with LPE heads on my 350 and made 370rwhp and 355rwtq with supporting mods (LT headers/ORY, etc...) Shift points were at 6200rpm. Ran a best of 12.1 @ 115.5 with 3700lb race weight. Used 3.73 gears with manual/M6. Car was fun as hell to drive on the street.
BTW, had 211/219 cam with LPE heads on my 350 and made 370rwhp and 355rwtq with supporting mods (LT headers/ORY, etc...) Shift points were at 6200rpm. Ran a best of 12.1 @ 115.5 with 3700lb race weight. Used 3.73 gears with manual/M6. Car was fun as hell to drive on the street.