Whiskeyboy84

iTrader: (8)

Like the title says I am wondering what kind of durability and mileage you guys are getting between rebuilds on these LSX’s with 4.125 stroke? I am currently in the process of planning a build for my 73 El Camino it had a cam’ed gen iv 6.0 in it but I wiped out the thrust bearing and spun two rods because I had too much pressure in my torque converter I have since remedied that problem and I am thinking of buying a GM crate engine like the LSX 454 or the LSX 376 B15 or B8 and doing an LSA blower I want this thing to last like 100k miles kind of last. Not really after big wheel HP because let’s face it it’s an El Camino so getting it to hook will always be a problem.

showdog75

iTrader: (8)

If you're not after big wheel horsepower then why even consider a lsx454? Save yourself lots of money and put a ls3 in it.

rkupon1

iTrader: (3)

Lsx 376 B series is nice, bcuz you can throw it in, and get it running/sorted. Enjoy it. Add boost later and relive those smiles per gallon all over again. Go for the B15 tho, boost is like crack-cocaine. Highly expensive, addictive, leaving you always wanting more!!!

Che70velle

iTrader: (6)

I’ve been following the LS3 SBE wars. It’s amazing how much abuse the Oem aluminum short blocks can handle.

rkupon1

iTrader: (3)

Its all in the tune!


p.s. its also all in the motor build, dont ask me how I know.

old motorhead

iTrader: (10)

N/A, the bigger the better...as long as it is reliable. One of the guys on camaro5 scattered a brand new LSX 454 on the dyno with mild boost. GM politely declined warranty becuz the engine was not designed for boost...even low boost. Buyer beware.

91 Z28

iTrader: (3)

Just build your own engine if your going to spend money, or call Texas speed and get one built for what you want

BCNUL8R

iTrader: (2)

Normally I wouldn't spend the money for a crate engine, but since you said 100,000 miles it might be the way to go. Built motors with forged internals are usually not 100,000 mile motors. Since you are adding boost though the compression on the 454 would make ethanol the ideal fuel. Also depending upon power levels that crate may not have the ring gap for high boost.

Kind of a tough decision I'd generally want an engine built specific to what I'm doing that is why I'd steer away from the crate engines, but 100,000 miles is a lot to ask of a forged motor.

showdog75

iTrader: (8)

I don't quite follow your thinking about forged engines not having longevity. I think that the opposite is true. It's the tolerance's that vary from a long lasting engine verses a pure drag race engine.

BCNUL8R

iTrader: (2)

I'm not going to get to much into it people can disagree that's ok. Ask yourself how many sbe ls motors are out there with over 200,000 miles on them being run hard and how many forged internal motors last that long? Then you mention tolerances...well tighter tolerance can be had with cast pistons because thermal expansion is less than with forged. Forged motors are great if you actually need the strength to handle the power you are wanting to make, but don't expect 100,000 miles out of them.

bortous

I wouldn't expect 100,000 if the motor is being driven hard.
Surely you could get at least that mileage for general street driving with the occasional foot to the floor thrills?

BCNUL8R

iTrader: (2)

How many people do you know that have forged motors with 100,000 miles on them without being freshened up at some point? There are a bunch of sbe's over 100,000 miles though that were cammed and beaten on then boosted and never had the sbe touched. I'm the odd ball on this one I guess. I even have a forged bottom end, but like I said the forged is obviously the choice if it's needed to handle your power levels. I just don't expect 100,000 miles out of it like I would a factory built engine with hypereutectic pistons as long as it was within it's power limits.

G Atsma

Forged bottom ends get put into engines that get rode hard repeatedly, and living to 100k miles is usually NOT part of the plan.
So you want to build a high $$$ forged engine and soft-pedal it most or all its life? Right. Get an LS3 and never know the difference.

Whiskeyboy84

iTrader: (8)

I was actually thinking 🤔 about the LS3 525hp engine that GM sells but I thought that for a few grand more I could buy and bolt together an engine that would make a bit more and last just as long. To clear things up a bit I don’t want to boost the LSX 454 if I went that route only thinking about doing an lsa supercharger on the lsx 376 b15 or b8 that being said I would be open to going with an LSA Also I just want around 650 crank horsepower I mean even with the LS3 with a 100 shot would be awesome but again I want it to last. Honestly if I could get 60-70k miles out of the lsx454 I would be happy. I think I may be setting my longevity goals too high

G Atsma

Thing is, a forged bottom end does not add longevity to an engine. It just keeps it from blowing up as easily.
The difference is, to take full advantage of the forged bottom end means driving it in away not very conducive to overall longevity.
The ticket to 70k-100k engine life is to drive it in away that would never endanger a stock bottom end.

99 Black Bird T/A

iTrader: (4)

I think its a wild card - depending on use, engine builder & maintenance.

FWIW - If I recall correctly, famed engine builder Dave Diluca built a forged 427 (or maybe a little bigger) from a sleeved LS6 block for a member that goes by LS6427. Back in the day, that fragile sleeved big cube LS6 went 173,xxx miles. It meticulous maintained & drove hard regularly but the engine wasn't pulled or overhauled.

The forged crank and forged rods aren't likely to hurt durability or mile wise IMO if the engine is properly built.. If mileage is key its probably better to go 4032 for the pistons instead of 2618 etc.

With that said with 2618 pistons, I was told by a reputable engine builder - consider planning to re-ring and maybe new pistons after 50,000 to 60,000 miles with the typical 4 inch LS stroker. Oil consumption being an indication etc.

rkupon1

iTrader: (3)

^^^That is far from the norm tho. 200k+ mileage factory swaps are! I think thats what he was getting at. Can you have your cake and eat it too? I say yes, with a SBE LSX build with a well thought out n planned top end. Rarely happens like that. We always want more

old motorhead

iTrader: (10)

If you're going to stick with an LSA blower, there's really not much reason to go with any kind of a stroker. You don't have enough blower for big cubes. You'll just increase low end grunt, but you'll have that in spades anyway with a 376 with an LSA on top. Spinning it fast enough to fill big cylinders is just going to turn it into a heat pump.

spanks13

iTrader: (5)

Or just get the LSA crate motor from GM

Kjduvall

[QUOTE=Whiskeyboy84;20295499]I was actually thinking 🤔 about the LS3 525hp engine that GM sells . If you were considering this crate, that was a bad idea for what you were doing any way. The only difference between the ls3 430 and ls3 525 is the asa cam. By today's standard that's not really a good set up any way. Much better cam technology is available now...just for example, after the manufacturer rebate. The ls3/430 is 7,296.00 and the ls3/525 is 8,943.00 , so you could buy the ls3/430 and get a tsp dual spring cam kit LS3/LSA blower cam package stage3 (231/239 115lsa) with dual springs 690 bucks..And still be a thousand bucks less, but ready for a small blower.