Here's my take on displacement. If you get a 6.0 you can make the same hp with less boost than a 5.3 or 4.8. That means a longer life for a street car with less stress on parts. Now drag racers who dial up the boost on a junkyard engine and replace it every couple years is a different story.

 

Depending on your goals and budget, sure. If we talking power levels beyond an SBE LS motor. Then the LS platform doesn't even make sense. If you want the most HP per $ spent. Might as well go BBC at that point. And aftermarket BBC once you hit the ceiling there.

But when dealing with SBE LS motors limited to around 1200 crank or under... The small bore stuff is stronger and cheaper. So its a no brainer if you want the best bang for your buck ET wise. Generally you don't want a bigger motor that makes more power and TQ below 5k. That just breaks parts. Esp. on a heavier car.

 

I hear that a lot, but its not really true for the exact reasons I explained above. A 6.0 making 1200hp at lower RPM and boost is harder on the SBE than a 4.8 making 1200hp at higher rpm with higher boost. Has to do with cylinder pressure peaks and heat. The motor making the power later in the rev range has the advantage of being easier on parts. An engine is also less likely to detonate at high Rpm than low rpm. So in general, the higher you buzz it, the more boost you can get away with. (to a point of course)

Boost is also more efficient at making power than cubic inches.

Using 2005 motors as an example.

6.0 is rated at 300/360.
Alum 5.3 is rated at 310/335.
4.8 is rated at 275-295 depending on trim.

So less than 1lb of boost more than makes up for the power difference between a 4.8 and a 6.0. (of those years anyway)

But all the bandwagon LS community thinks they need the 4" bore motors bored and stroked with forged guts to make power. So it drove the price of 4" bore motors through the roof. When they could all do the same damn thing on a $300 4.8 with stock internals. Because the OEM block/crank/rods and pistons all have a very similar failure point power wise. Meaning that sweet $15k+ forged 408 is gonna crap out right around the same peak power levels as an SBE small bore short block. Or even before due to the weaker big bore blocks and water passages.

 

Your first sentence was really the only thing that needed to be said and exactly my point. Everything else is irrelevant to the point I was making that sometimes more cubic inches make a heavy car more fun to drive on the street.

EVERY day you are on here telling anyone who doesn't build a sbe LS with a turbo on it they are doing it wrong, but not all of us have the same goals or are limited to $300 to build a motor like you are.

I'm probably close to your power levels that you ran mid 8's with but I'm using a daily driver with IRS that weighs over 4000 lbs. I also have more than $300 to spend so yes, I want more cubic inches.

I'm at the drag strip almost every week when it's open and have ridden in a lot of different combinations including 1000 rwhp turbo 5.3's. I can tell you playing around on the street they didn't feel the same as a 427 with a twin-screw blower on it even though peak numbers were pretty close with the 427 possibly making less peak hp. I've also rode in 4 cyl turbo cars and big blocks. The big block didn't make as much peak power but with that many cubic inches and high compression it was a riot.

At the track there are many factors as you know with weight being a big one as well as suspension, gears, converters, etc. etc. So yes, a 4.8 turbo can beat a big block at the track.

In the case of the 5.3 vs the 6.0 if the 5.3 is aluminum and the 6.0 is iron I'm going with the aluminum block in a streetcar just to keep the weight off the front since the displacement difference isn't enough to matter.

Plenty of people have made over 1200 crank hp with an LS reliably so no need to go big block and add all that weight up front unless you purely want the cubic inches to fit your goals.

Bottom line is goals/budgets and intended uses vary there isn't one combination that is best for everyone.

 

That's a bunch of nonsense. I've never said anyone was doing anything wrong. What I said was if you want the biggest bang for your buck... follow this path. Which is a fact, not an opinion.

Because you chose a heavy vehicle and a more expensive (and less effective) power adder doesn't mean the rest of us should follow in your foot steps. If you are looking to go as quickly as possible for the least amount of money spent, those are both horrible choices! Which is fine. But don't put that nonsense on others. Or try to claim its a better path. ET is the bottom line. What I've said about the best way to get the lowest ET for the $ is true.

Give some examples of 1200+ HP "reliable motors". Pull the mains on any 1200hp+ factory crank/block LS and show me that they weren't moving around and making metal. Its not gonna happen! Then pull the mains on a 1200hp stock crank/block BBC and compare. If you had actual experience with either, you wouldn't be trying to argue. It would be clear as day which platform was superior.

 

you are way out in left field. Im
going to quote the op’s first post and you tell me what all the horsepoo you are going on about has anything to do with his post.

“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”

 

For a street engine you want power(torque) under the curve. DIsplacement or a twin screw blower are the ways to get that. i have a friend with a 3.8 supercharged Fiero and that thing is an absolute torque monster. If you are launching at 3500 rpm and shifting at 7200 rpm at the dragstrip you don't need that under the curve power.

 

There are plenty of LS engines over 1200 crank hp Ryan Mitchell is beating up on 5.3 turbos at every event he goes to with his 427 LS 4 bolt head combo.

ET isn’t everything for everyone. Some people like me have a daily driver with AC, heat, stereo system etc so fun on the street is a big factor which requires more low rpm torque.

If ET is all the matters then look around at all the fastest cars in non nitromethane classes. More and more of them are Procharger or Blown and more people are moving away from turbos to those options.

Don’t even start on how they aren’t street cars you said yourself only ET matters and it’s not your fault if someone chooses to build a street car with all the comforts lol.

I’ve got a little something else im working on purchased as a rolling chassis much more appropriate for better ET but it’s on the back burner right now.

I’ve been around plenty of fast cars I practically live at the drag strip so yes I’ve seen fast cars of all different combos and ridden in several. I have multiple friends with resleeved 5.3’s 427 and 388’s making way over 1200 crank over 1200 wheel for that matter. Turbos, prochargers and even huge directly port nitrous LS combos all living.

Even had one friend at 2000 rwhp with a dart block LS that died due to heads cracking and hydro locked the motor with water at 8000 rpm. So the cause of death wasn’t the block flexing.

I can leave off idle with a foot brake and run 6.1 in the 1/8th at 4000 lbs not sure a 5.3 turbo can do that in a 4000 lbs car. Or maybe you leave every stop light sitting on the 2 step building boost lol. Still a lot left in my heavy car I’ve gained time every trip to the track and daily the sob lately in comfort.

 

He always moves the goal posts and when you make a good point he will move the goal posts again. He always brings up his light **** box running mid 8’s but I’m not sure it is even currently running while we daily drive our cars.

yes a 5.3 sbe turbo can make 1000 hp for a while and sometimes a long while. It’s not the answer for everyone especially those who want a fun reliable daily driver.

plenty of forged 4 bolt head LS combos making 1200 rwhp and plenty of 6 bolt LS combos making more than that.

 

That's also Holdner nonsense. I've never once gotten into a turbo LS and said... Dang I wish I had more low end power. Esp. on an unprep'd street! Traction is the biggest issue and every street setup I've run I've had to pull tons of power "under the curve" to get it even remotely close to sticking on asphalt. You can't even start adding real power into the tune until you are around 50-60mph. I was pulling tons of boost/timing on a cam only 4.8 with an s480 to get 30x12 slicks to plant on the street. So you are saying a 4" bore with a twin screw is more enjoyable as a street engine? That's instant power you can't even use. How is that better? What is the point of tons of TQ you can't even use?

 

No one said you haven't been. I said pull the mains on any of them over 1200hp with a factory block/crank and show me the mains aren't moving around. Forged rods and pistons don't help this.

A dart block isn't a stock block... Not sure how that's relevant at all. And yes... lol a 5.3 turbo can easily do a 6.1 in a 4000lbs car. That requires about 865 crank HP to do. There's only so much power you can put to the ground, esp on asphalt "stop light to stoplight". I don't need to build real launch boost on the street because it isn't useable. Get a draggy and we'll post up stop light to stop light numbers and compare.

I never once claimed people weren't' making big power on factory stuff. I said its not reliable and the parts are moving around a ton when they do it. Which isn't "reliable". And that rods and pistons don't change that movement in any way.

The guy wants to make super reasonable power that can easily be made with a mild cam only 4.8. And guys are suggesting completely unnecessary parts to get there. That is the point! To anyone starting out, that is be best route to go when looking at HP vs money spent, period. I list examples and facts from direct experience racing turbo cars over 25 years. I do this because the poor guy is getting horrible advice.

You trying to Claim that a 4000lb+ car is more reliable than a light weight vehicle is ridiculous. You are 10x harder on parts trying to race them at that weight and much LESS reliable. Trying to make some sort of all purpose super car that can do everything is always more expensive than having a dedicated "Race car" and a sensible daily of some sort. I went 5.50 @ 129 on 15lbs w a crappy 1.35 60' and I don't even run an intercooler. The cars done 1.28 60's. I drive to and from the track as well and hard parts like transmissions/rear ends/axles etc will last MUCH longer in a 2400lb car than a 4000lb car at like ET's. Its common sense.

 

How is it not relevant? You told the guy he needed rods and pistons. He doesn't. I listed the point when aftermarket rods and pistons are needed. Then stated why once you reach the point of actually needing rods and pistons its foolish to do so without also running an aftermarket block and crank as they flex and move at those power numbers. IE putting in rods and pistons does diddly for reliability. Smart money would simply buy another stock piston/rod and drop it in. Then gap them all properly and go back and review the tune up. Or if there's damage, grab a gen4 4.8 and press on.

 

Of course you took things I said out of context and in some cases changed words around into something I never even said.

We got off subject because you moved the goal posts. We addressed those off topic things you said and you moved the goal posts again.

You said a sbe can make 1000 rwhp which it can but you also said spending money on forged parts or good parts in general was dumb because a sbe will do everything you need and anything you want beyond that you should just go straight to a big block.

I never said a heavy car makes it more reliable that’s more of your bipolar crap you are all over the place.

You said only ET matters to you so if we have a heavy true daily driver we are dumb and chose the wrong car. Lol

If only ET matters check out what all the fastest radial cars and small tire classes are running now. Most are moving to Procharger or blowers and moving away from turbos.

You aren’t likely to run 6.1 at 4000 lbs with only 850 rwhp and a turbo 5.3 leaving while idling with a foot brake. It’s going to leave like a turtle with no boost and you know it. I’m sitting there idling and leave like that and still run 6.1 at 4000 lbs because I don’t need to build boost on a 2 step before leaving.

No one is going to pull the mains off their daily driver just to prove a point to a guy we don’t know on the internet and you know it’s a stupid thing to require to prove a point. lol.

When is the last time you ran your car did you drive it to work today because I drove mine. I’m at the 1000 rwhp mark tjrough an auto and irs with a stock block going on 6 years now with n inferior bro charger to boot with a stock crank and forged rods/pistons. I feel like I got my money worth out of it already. Sorry you can’t afford more than a $300 junk yard short block.

 

You are right that a heavier car is harder on parts not just the engine but all the driveline parts. All the more reason to consider a forged bottom end with more cubic inches if building a true daily driver at full weight.

Sbe 5.3’s have their place they just aren’t the best option for all goals like you stated.

 

Lol, you are an insecure child and think every one is personally attacking you and your setup on nearly every post you make! You repeatedly bring up "fun reliable daily drivers" insinuating that's what you own. You insinuate that to be "fun" and "Streetable" they have to be heavy with a big motor. Then brag about your ET like its impressive. So yea, I do assume you want to go fast and ET matters. You bring up your ET and vehicle weight in almost every post you make so clearly it matters yo you.

I called no one dumb. I simply stated facts. Something you seem to have trouble doing. When you try to argue points made (poorly I might add). I nicely try to point out how and why you are incorrect and even give examples. But you can't get over being butthurt thinking everyone is talking down to you long enough to learn something. You do you, buddy! Just don't comment like you have a clue. Until you've built and blown up a dozen+ motors. Then torn them down to see what was damaged and why... then you don't have much experience. Which is fine. But don't act like you do. Plenty of guys have gone quicker than 6.1 at your weight. I can be ready to go at the light just as quickly as you are if we were to line up at any track. Bragging about a foot brake launch capability is ridiculous. Trans brake is the way to go no matter what the power adder is. Even if you're na, its far superior in every way.

You'll eventually learn it is stupid to try to daily a race car. Just give it time. wisdom comes with experience.

I didn't ask anyone to pull the mains on their daily. talk about putting words in peoples mouths! If you race, you are around actual race engines/cars. So you'd of seen many examples of this already, as I have. It is clear as day when any SBE LS is torn down that's making big power. Hell mine would even shift a bit and I doubt I was making much more than 950. People that make big power with anything tear down motors and replace bearings all the damn time to inspect the parts. If you have no direct experience with that, why are you commenting at all? Ask others that have. Look it up online if ya don't believe me. But don't act like you know what your talking about when you clearly don't.

Not that it matters at all or is even relevant, but I drive the Model T to work several times a year for fun and for the car shows we have there. Also have a "street car" LS powered RX-7 that I drive all the time when the weathers nice that isn't my daily.

Trying to insult me by bringing up that I have much less invested in a combo that runs circles around yours isn't making you look intelligent. If I wanted to spend 4x the money to go slower, I could easily of gone your route. I actually did when I was young and dumb. Had a 4000lb G-body with a built 383 and a blower that I daily drove for a few years. I learned quickly that wasn't the best bang for my buck ET wise, fun wise, or reliability wise. You may not admit it, but you'd have a ton more fun if your weekend race car weighed 2200lbs with the same power plant.

Again, I never claimed anything was "the best option for all goals". I said for some one just getting in to turbo world, the biggest bang for his buck ET wise is a small bore SBE. Sinking a bunch into 4" bore motors, rotating assy's, and machine shops initially isn't wise. Mistakes will be made. Best to learn on the cheapest platform and replace if necessary.