Realistic reliability
10-05-2017, 07:12 AM
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Realistic reliability Hi guys n gals. I'm Nate and I'm new. I'm building my first LS and have some questions. Got a 3rd GEN 4.8 that I'm wanting to turbo and what I'd like to know is stock bottom end reliability @ around 600HP. I see all these articles about "stock junkyard " engines cranking out 1K+ ponies and obviously it can be done but just how long can they be expected to last ? I plan to have the block cleaned,honed, and decked. I'm gonna replace all the bearings and rings. I don't have a lot of money ( yes I know that making power is expensive ) and I know I'm not using the best LS to start but with my current financial ability I'm working with what I've got. I'm gonna use stock Heads with a cam/valvespring upgrade and will upgrade the stock rocker trunnions and possibly the pushrods if you guys think it's necessary. So what I want to know is if I can get this motor to put out around 600 ponies what kind of reliability can I truly expect ? A side note is that this thing will be on the street 99% of its life so seeing 6-7k rpm will be rare. Thanks in advance.
10-05-2017, 07:50 AM
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Run low timing, water/meth, a sub .600 lift cam with some single beehive springs, keep the RPM below ~6600 and it will last forever at 600 HP at the crank. No need to upgrade pushrods or rocker trunions with single beehives and low lift.
I typically don't replace rings or bearings. If you want to open up ring gaps, that's fine, but if the stock bearings are in good shape I usually reuse them because I know the clearances are going to be good and the odds of a spun bearing will be less.
I typically don't replace rings or bearings. If you want to open up ring gaps, that's fine, but if the stock bearings are in good shape I usually reuse them because I know the clearances are going to be good and the odds of a spun bearing will be less.
10-05-2017, 08:53 AM
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Run low timing, water/meth, a sub .600 lift cam with some single beehive springs, keep the RPM below ~6600 and it will last forever at 600 HP at the crank. No need to upgrade pushrods or rocker trunions with single beehives and low lift.
I typically don't replace rings or bearings. If you want to open up ring gaps, that's fine, but if the stock bearings are in good shape I usually reuse them because I know the clearances are going to be good and the odds of a spun bearing will be less.
I typically don't replace rings or bearings. If you want to open up ring gaps, that's fine, but if the stock bearings are in good shape I usually reuse them because I know the clearances are going to be good and the odds of a spun bearing will be less.
10-05-2017, 10:57 AM
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Most of us cheap *** turbo guys just run stock rings/bearings. I have a 240k mile engine in one of mine and its taking boost very well without opening it up. I was putting boost through it without ever so much as taking off the valve covers. I replaced cam and did valve springs and head gaskets in it a couple of weeks ago. I still haven't touched the bottom end.
Stock rockers are good to around .620 before you really need to consider an upgrade, whether it be trunions or aftermarket rockers. .480 is laughably funny, you're dealing with a machine shop that has no LS experience which might be a bad thing. There are stock cams with .550 lift.
Meth is most certainly an option. Blue windshield washer fluid is typically 30/70 meth/water and is CHEAP. I just top it off when I fill my gas tank.
Trunions and hardened pushrods will depend on valvetrain stress. A low lift cam with single beehive springs isn't going to put much force on the pushrods or rockers, so upgrading them isn't necessary.
Stock rockers are good to around .620 before you really need to consider an upgrade, whether it be trunions or aftermarket rockers. .480 is laughably funny, you're dealing with a machine shop that has no LS experience which might be a bad thing. There are stock cams with .550 lift.
Meth is most certainly an option. Blue windshield washer fluid is typically 30/70 meth/water and is CHEAP. I just top it off when I fill my gas tank.
Trunions and hardened pushrods will depend on valvetrain stress. A low lift cam with single beehive springs isn't going to put much force on the pushrods or rockers, so upgrading them isn't necessary.
10-05-2017, 11:28 AM
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So it wouldn't be a horrible idea to just look at the bearings since I have it torn down and if all looks good just reassemble and roll ? I would like to get ARP connrod bolts but don't the rods have to be modified ? The machine shop said it'll just depend on what they look like as whether or not they'll have to be modified. This machine shop does a lot of LS's but the LS guy wasn't in that day and the guy I spoke to was a "old school " as he put it. I had no idea you could run windshield washer fluid lol is the meth/water stuff require anything special fuel system wise? I don't believe it's mixed with the fuel right ? I'll have to see if my Sniper EFI can run meth/water. So I could safely go to a .600 lift cam with stock rockers and upgraded springs ? Thanks guys you have helped significantly already. All these questions have me at a stand still on the build ATM.
10-05-2017, 11:36 AM
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10-05-2017, 11:50 AM
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So it wouldn't be a horrible idea to just look at the bearings since I have it torn down and if all looks good just reassemble and roll ? I would like to get ARP connrod bolts but don't the rods have to be modified ? The machine shop said it'll just depend on what they look like as whether or not they'll have to be modified. This machine shop does a lot of LS's but the LS guy wasn't in that day and the guy I spoke to was a "old school " as he put it. I had no idea you could run windshield washer fluid lol is the meth/water stuff require anything special fuel system wise? I don't believe it's mixed with the fuel right ? I'll have to see if my Sniper EFI can run meth/water. So I could safely go to a .600 lift cam with stock rockers and upgraded springs ? Thanks guys you have helped significantly already. All these questions have me at a stand still on the build ATM.
ARP rod bolts are a waste of money if you keep the RPM down. Power has no effect on them. Honestly, taking the engine apart is more harm than good if you've never done this thing before. Most people end up taking it apart, and then wasting 4 months getting machine work and having it put back together. Just run it as it.
Water/meth doesn't mix with your fuel system at all. A separate pump and nozzle sprays it into your intake or intercooler piping. Your PCM has nothing to do with it either, its all separate in most cases. A hobbs switch will kick on the meth pump at a certain PSI.
10-05-2017, 12:28 PM
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AEM, Snow Performance, Devil's Own, Cooling Mist are the most common around here. Most companies piggyback off of their designs. Even Nitrous Express is now selling meth kits.
10-05-2017, 02:42 PM
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So what do guys think would take to get this engine to put out 600 ? The kit I'm looking at ones with a 6-7 psi spring and I'll be upgrading the cam and nothing else except maybe head studs. My sniper has a built in 2 bar MAP so I think 15 is the max boost it will read but what is considered too much on stock components ? If I don't hit the 600 mark it's not that big of a deal cuz it'll still be the fastest truck around here. I just pulled 500 at the wheels cuz it sounded good lol. If this is the wrong thread I apologize but what kind of cam specs should I look for to get good low end torque cuz this engine is going in a 4300lb 89 C1500 ? I've read so much my head is spinning at all the choices.
10-05-2017, 03:49 PM
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JFR Triple 12 cam, PAC1218 valve springs, some new OEM LS1 head gaskets. Something like an On3 7665 single turbo.
I don't have much input on the Holley Sniper stuff. I've done a ton of setups and never used them. I don't know many people here who have. Its just always been so much easier and cheaper to go with the stock computer or something from the Megasquirt family. Of course, they don't tune themselves.
I don't have much input on the Holley Sniper stuff. I've done a ton of setups and never used them. I don't know many people here who have. Its just always been so much easier and cheaper to go with the stock computer or something from the Megasquirt family. Of course, they don't tune themselves.
10-05-2017, 04:02 PM
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Ok I already plan on going with the On3 single kit with the bigger 76mm turbo and I'm going with the sniper because I've already got it on the SBC that currently resides in the truck. So so I have to get is a carved intake and the MSD ignition controller. The sniper has an 800 ctm throttle body and 4 100lb/hr injectors and supports 680 horses. Plus I don't have the engine harness or the PCM so I would imagine with this combo and having the stock cam 600 should be relatively feasible given the kit claims to be able to do it on a completely stock engine. I just want a cam that gives me low end torque to get me off the line within the hour lol being so heavy. I've been looking at Texas speeds cams and am gonna give them a call for a recommendation as well as COMP and maybe Cam motion. Are the BTR cams any good ? I've heard some folks say they are a joke like the Comp thumpr cams but everyone has an opinion. The SBC in my truck now with a ***** Thumpr, Sniper EFI, bored .60, and no tune and 28 degrees timing put down 243HP/467TQ with stock heads. It'd make a towing motor lol.