I’m looking to get a motor for a turbo don’t know what to go for and what to put in some people are saying 5.3 and gap the rings but I want it to last for more then a year. I want around 650/700whp what should I get and what should I do

 

Yep, good choices.
You are on the right track with the 5.3 or 6.0

. Others have gone down this path before you.
Look around the Forced Induction sub forum, scroll back through 40 or 50 PAGES and YOU WILL LEARN MUCH.

 

ok thank you so much! I posted this on facebook and saying ls1 bone stock with cam and boost will be ok at 800

 

IF you have enough FUEL delivery, AND you keep your timing table in check ( around torque peak, spark advance will be surprisingly LOW ) the motor will take FAR more power than your stock transmission.

 

For how long though? With stock pistons you have zero room for error at that power level. Lean out accidently once or twice, done. Add 1 or 2 degrees too much timing, done. I went down this road, it'll be fine at first until you decide you want more power and realize making more power is so easy with a turbo... but a stock motor isn't going to live a long life unless your tune is spot on and safe and you don't run it alot. What am I getting at? You can put a set of good rods and forged pistons in the motor with arp main studs and arp head bolts and the motor will live a long time, and hold way more boost safely. Check out my build thread in my signature. That motor is still in the car, has not been out and has seen 15psi hundreds of times and over 20psi countless times on 93 pump. I drive the car quite a bit. I broke the stock ls1 on 10-12psi of boost because I added 1 more degree of timing at the drag strip, testing and tuning.

 

I don’t agree with the above 100%. Gen4 (2005+) motors will easily take 650-700whp. Especially when just starting out, buy the absolute cheapest *healthy* LS you can find. 99% of the time this is a 4.8. (usually $300-500 in my area) Which will EASILY make your target HP. Larger bore motors typically cost 3-4x what a 4.8 does and break just as easily at the same peak power levels. They just take less boost to make the same power. Which is cool and all, but not worth 4x the money.

Similar deal with forged rods/pistons. The block and crank are matched pretty damn well with OEM pistons and rods in terms of peak power handling. Putting aftermarket rods and pistons in a motor with a weak crank and block aren’t doing much. The crank/mains/block/deck etc all still move around at X amount of power. Forged pistons or not. (usually around 1200 crank) So what are you really gaining?

*IF* you keep the timing super soft down low and run good fuel. Its not likely you will rattle/harm an SBE motor at 700whp.

In my experience typical local machine shops can do more harm than good. The machining quality usually isn’t as good as OEM and the down times are horrible. A healthy stock motor with 150k is broken in nicely. If its not making metal now. Its not gonna do it until YOU cause it to. Same cannot be said for most machine shops. Esp. “affordable ones”. I’m not saying you can’t spend good money at good shops. But then you are into the motor for 4-10x what you should be. And for what? An engine that still has a weak crank and block that still flexes and moves at the same power levels an oem long block would?

In my experience you are much better off when first starting out to buy a couple cheap 4.8/5.3's. If one breaks, cycle in another and press on. Learn form your mistakes. Stock 4.8’s are stout underrated motors. They will squeak out 1000ish crank hp semi reliably if tuned properly. Went mid 8’s with one for several years around 160mph. Should be able to pick up 2 small bore long blocks semi complete for less than a set of pistons and rods would cost.

 

I don't expect everyone to agree with my post. They supposedly have people claiming to run 50psi on a stock motor (I can post a link to prove I'm not exaggerating). 1000hp stock motors are the norm (on the internet) but from what I've seen in real life, people be bullshitting and/or they full of ****. Making a few passes here and there running it on the ragged edge and they act like it'll run that way day in, day out... for years. That aint happening. Mine was a gen 4 floating pin ls1 from a gto. Ran fine for a while on 10-12 psi on 93 with 11 degrees timing. added just one degree and busted the piston. I'm no professional and admittedly this is the second boosted vehicle I had tuned at the time, first turbo vehicle, but that still does not discount the reality that the tuning window for stock **** is very narrow and it better to err on the safe side.

If I recommend something to someone, I'd rather err. on the safer side. Or at least let them know what chances they might be taking. Not everyone gets so lucky to run 8's every weekend for years and have a stock motor last. If this were reality, there would be not much point in building a motor. The reality is, people do that, blow it up after a small amount of passes, go buy another one cheap and repeat. Me, and probably some other people, aren't wanting to be constantly swapping engines. I'd rather do it once and it last 5 years or more. Just like what I have now.

I do agree without your statement on machine shops. Most of them SUCK these days and if I had to get a block bored or line honed, I'd rather just get another block because the job I'll likely get will be garbage. The 5.3 I have in my car is stock bore because of that very reason. I DID NOT line hone the block when I installed main studs (so much for that bullshit myth of having to line hone a block because main studs) because they would probably screw my block up.

-"*IF* you keep the timing super soft down low and run good fuel. Its not likely you will rattle/harm an SBE motor at 700whp." (agreed)
-"Similar deal with forged rods/pistons. The block and crank are matched pretty damn well with OEM pistons and rods in terms of peak power handling. Putting aftermarket rods and pistons in a motor with a weak crank and block aren’t doing much. The crank/mains/block/deck etc all still move around at X amount of power. Forged pistons or not. (usually around 1200 crank) So what are you really gaining?" the stock crank will easily hold 1000hp. putting aftermarket pistons and rods gives you a safety margin. If you rattle a forged piston, it will tolerate it more than a cast piston will. It will mean the difference between breaking and not breaking. The stock blocks are not weak either. the weak point is the piston and rods. But you already know this....

 

I agree with both of the guys above... well kind of a combo of both ... LOL

IF you have a good machine shop/engine builder then I'd go with a forged rods/pistons stock crank short block. If you don't have a machine shop and/or engine builder, you trust then I'd definitely do a sbe and take my chances rather than spend $$$ with a machinist/builder that isn't reliable.

In either case forged rods/pistons build or sbe build you need a good tuner. Neither engine will live long with poor fueling or a poor tune.

Plan out a good fuel system that will support more power than you want. Fuel delivery issues at that power level will hurt either engine pretty quick.

 

Yea a shitty tuner will wreck a motor quick. A shitty machine shop will result in the same. Definitely have to do a competent fuel system. If you have fuel fluctuation problems, you will have motor problems. However, I feel like because I have good rods and pistons and I was having fuel problems (intermittent leaning out) I think the engine would have failed with stock pistons.

 

HP claims are one thing. Weight vs trap speed are another. Pretty hard for a time slip to lie.

Not discrediting your single experience with one broken piston. But take it from someone who has experience with dozens of broken pistons... a forged unit isn’t the answer to a bad tune up. And while it may be easy to blame a factory piston on your failure. There is always much more to it than than 1* of timing. The amount of detonation required to munch a factory piston will generally take out a forged unit as well. (or at least damage it) And signs should be clear well before you get to that point. The idea is to know what to look for before you get there. If a factory piston let go at 12*. The plugs would have read hot enough at at 11* that you should have backed it down to 10* or less. Which I admit sounds odd. So likely other things were at play. Other tables altering the timing, fueling or spark issue on that hole etc.

You aren’t telling me anything. “weak” is relative. 1200 hp is weak to some. As I said factory crank and block start moving quite a bit right around 1200 crank. (Kurt Urban who has tested 1000’s of LS motors came up with this number, not me) Thats just a fact. So if ya make 1000ish at the wheels through an auto the main caps and deck are moving around and you are stressing an OEM block/crank. That doesn’t mean guys don’t push it anyway and see how long they can get away with it. So what real safety margin are you gaining by putting in a piston at 1000 crank? When the factory parts handle those loads. Why suggest aftermarket parts for a 700hp build?

If you rattle a motor you likely aren’t tuning it properly. Mistakes happen and unavoidable failures happen all the time though. Fuel pumps, injectors, coils, ECU’s, etc all fail. If they fail and you rattle a motor at 1000+ (forged piston or not) its very likely doing serious damage that would require a tear down at the least. Personally I’d rather damage a $500 long block and replace it with another in an afternoon. Than play with forged parts and machine shops. Now if you are over 1200 crank (like many are). You are pushing your luck any way you look at it. If you want safety and reliability you absolutely need an aftermarket block and good rotating assembly. Replacing one and not the other leaves a weak link and makes no sense.

What kinda irks me is aftermarket companies telling us we “need” things without data showing us why. How much stronger are the aftermarket rods/pistons you bought compared to stock? What tests were done? Where is tha data? Are you sure your lighter forged rod is stronger than a heavier gen4 unit? How much stronger? 5%? 15%? 20%? This data should be out there. IMO Its not for a reason. They don’t want you to know the rods you bought are only 2% stronger than stock. Or that you can push a factory setup to 1000hp without issue.

The data I see is guys buzzing these things to 8300rpm at 40-50lbs making 2000+crank hp and surviving on 4 second 1/8th mile rips for entire seasons. Yes, the motors are being damaged that entire time. But so what! Wouldn't most be money ahead running stock motors and replacing them as necessary instead of blowing $20k+ on a “reliable” 1000whp motor? So what is the truth and when do we really “need” better parts is the question.

 

Do ye old 2-column analysis. Down one column, list the advantages of the 5.3; down the other next to it, list the advantages of the 6.0. Then start 2 new columns, listing the disadvantages of each, next to each other. See which one's pluses outweigh its minuses in your application, whatever that is, and your budget, whatever that is, which you don't tell us. DD? Towing? Strip only? etc. Or even, WHY you want that particular power level in the first place; would you settle for 5% less if that saved $1000? If it cost $1000 more to get 50 more HP would you do it? etc.

Pretty simple mental exercise really. I wish I had a brain, so that I could understand it. I know I'll never be able to do it though, too complicated for somebody like me. [scarecrow] If I only had a brain [/scarecrow] Unfortunately I don't so I can't. Seems like somebody as smarrrrrrrt as you though, able to post on the Interwebz and all, should be all over that like white on rice.

Let us know what your comparison columns show.

 

thank you guys so much. I’m definitely on your guys side with not wanting to swap out a motor consistently so I should save up for rods and pistons on a 5.3 so it’s safe

 

im not sure what you are doing or trying to prove, but the things you are trying together in this conversation really doesn’t fit in. Dude ain’t worried about making 1200hp. He stated what he wanted earlier in the thread. I’m replying my opinion based on my experience. I’m answering his question honestly based on him having similar goals and interests as I. He’s not wanting to go 8. Or make 4 passes in the 5’s and yank the motor and put another. And I’m not going to even waste my time arguing that forged pistons and H beam rods are definitely stronger than stock ****. I’m surprised you’d even mention that. And yes, a forged piston will take far more accidental abuse than a cast piston, to say otherwise is just silly. Ultimately the Op is going to do what he wants and what he can afford. If he’s anything like me and tries a stock motor first and breaks it, I think he will then cut his losses like I did and build a motor that will last and take more abuse.
the only think I can say about my **** breaking is it was on 11 degrees of timing and daily driven for over a year. I ran numerous logs on it. Ran logs while I was at the track. It picked up knock on that pass. It never picked up knock on any other pass at 11 degrees. It was right on the edge. I added one or 1.5 degrees to it and made a pass and then it started knocking when I drove back to the pit area. When I pulled the motor apart it had busted the top ring land. Checking ring gap it had .025-.026 on all of them. I dunno. I know it’s my fault. But if I do that with this motor, it stays living. That’s all the proof I need.

 

There's no replacement for displacement. If you can find a 6.0 get that.

 

meh… it’s less important with boost. I like a larger bore and aluminum block so I went with an ls3 block and displacement does help some for out of boost response.

With over 20 psi on a 377 I find myself taking out timing down low to reduce power to help me hook up at the track on 28 x 10.5 slicks so blowing the tires off on the street with drag radials is easier than it needs to be even with timing pulled.

 

Didn’t try to do anything. I explained why the part wasn’t needed and the best bang for his buck route to reach his goal. I made a point with actual data and years of real world experience with many SBE motors. Its all a learning experience and no one should ever feel “dumb” for making a mistake with a motor. That's the only way to learn. I’d simply suggest figuring out the root of the problem and correcting it before spending money on aftermarket parts *if* they aren’t needed. You’ll spend plenty of money on this hobby, Might as well put it where it will do the most good.

1200 *crank* HP (1000ish whp) was mentioned because that is the point where people should be looking seriously at aftermarket parts. This is proven with actual data and thousands of hours of testing on many many engines by some of the top names in the LS performance world. Its not my opinion. Since the OP’s goals aren’t anywhere near that point it proves rods and pistons are not needed to reach his goal. That is a lot of money/time wasted for something not needed.

You broke 1 piston and jumped the gun on aftermarket pistons and rods when they weren’t needed. Now you want to feel good about your decision. So you are suggesting others do the same when you don’t even know why your piston failed. Rods and pistons at that power level are simply a false sense of security and a waste of money better spend elsewhere.

Have pics of how the top ring land let go? Forged pistons expand less and need less gap than the oem pistons. You may have simply butted a ring if it pulled the top of the ring land off. Pretty much Impossible to say what happened, with the info provided, so I won’t try.

All I can say is there are ALWAYS indications well before detonation occurs on the plugs. Especially with pump gas. If an additional 1.5* took out a piston, then the plug would have read excessively hot at 11* and an experienced tuner would have backed timing down, not up. If the plug read great, then you had another issue. Either way, forged pistons aren’t necessary.

 

I agree bigger is better to a certain extent if you are all out heads up racing with aftermarket blocks that can actually handle big power. But def. not for the OP’s goals or SBE LS motors.

The literal replacement for displacement is boost. Esp. if you have a set power goal easily met by a smaller much cheaper motor. Makes zero sense to spend 3-4x the money to make the same amount of HP. The alum 5.3 is the best factory motor if you want to split hairs.100lbs off the nose and has the strongest block and best heads.

I’ve ran all 3 motors in the same chassis on the same turbo kit. 4.8, 5.3, and a “built 6.0”. Was very easy to run the same mid 8 second pass on all of them.(all my cage is good for) Which is why I sold the “built 6.0” and finished out the year running the same ET’s with a $350 4.8 form a rolled U-haul! lol

Once the trans brake is released they all ran the same times and felt the exact same. The only difference was the smaller motors needed a little more rpm and boost to run the same times.

Bigger motors make more TQ and make power earlier in the RPM range. Which when dealing with SBE stuff tends to break things more. The 4.8 is the opposite. Makes less power and TQ at low rpm. So you can pour on the power in the upper RPM. Making it less likely to bend rods and bust ring lands.

A 4.8 with a cheap lazy cam (ls9) and loose converter is the best setup for someone just getting into turbo LS racing IMO. Best ET for your $ and harder to hurt it.

 

Agree here 100%
Lots of 1500-2000 hp 4 cylinder Hondas out there. With bewst, anything is possible.

 

I don’t agree 100 percent. Displacement is less important with boost but still has some relevance.

In this case I’d take an aluminum 5.3 over an iron 6.0 because the displacement isn’t enough to matter and I’d rather not have the weight on the nose.

In a full weight true street car I’d take a 427 LS with 1200 rwhp over a 1500 hp Honda 4 cylinder though. That 427 is going to be a lot more fun on the street than that 4 cylinder especially in a heavy street car.

 

a ly2 4.8 would be perfect for this, and use the rest of money saved for a great fuel system.