Wanting to put a 4.0 inch stroke on the car. Can this be done on stock LS3 motor or do I have to buy a complete new shortblock?

How would the 4 in stroke work on stock block with out pistons hitting heads?

 

No one else has advice?

 

Yes an LS3 can be stroked to 416

Any reason you want to do a stroker motor instead of Forced Induction?

 

The piston pin location on the piston is moved higher which lowers the piston in the bore. 4" stroke in a stock LS2/3 block works fine if you use a quality shop to do the work.

 

Good question, IMO I believe the stroker is capable of more torque, besides, I dont think you can put a supercharger on a base LS3 and get away with it, at least I wont. Its good to have all forged internal parts. I think LG did a dyno with stock bore 4.065 and a 4in stroke with there new GX6 cam and made somewhere around 530 rwtq.

 

No way. I made 630rwhp/575rwtq on the stock block with just a little Strim blower and meth. No other mods, stock headers, cam, etc. Put a small blower cam in the car, and probably would have seen 600-625rwtq with stock exhaust. Stock LS2-LS3 cars are making 700-800rwhp and close to 700rwtq with bolt ons, cam, meth and a blower. An NA 416 won't come close to an LS3 FI car in acceleration if the FI car has supporting mods. The only time I lost to an NA vette, was to a stalled auto at the track. On the street, it was nasty, even against LS7 Z06's at that my power level. At 100mph, I'd pull like they were almost standing still. The only reason I'd spend the money on an NA 416 if I were doing lots of road courses, or just hated FI setups. You can get more power and a lot better road manners out of a good FI setup.

 

Heh.. Not quite true..

While forging definitely helps higher psi apps, even without it you're going to get a LOT of torque with a LOT more reliability with TVS. I went a different path with a Vortech V-2 T (Andy rocks) and am getting 642rwhp and 546ftlb, and I've been driving it since 10/7/2008 without forged internals.

That's not saying a N/A option wouldn't kick ***, but stroking the crap out of your LS3 will prove more wear-intensive than an FI option on your non-forged motor.

 

Yup....I think my LS3 with TVS is over 550 rwtq from 2500 rpm on up.

 

Boost is always better!

 

I read these guys talking about force induction on a stock LS3 block and it scares me. This a LS3 engine with 8000 miles on it and the below listed mods. Right now I am having a 416 built and I will take that force induction challange. Who cares about pulling at 100mph 98% of racing is from light to light or 1/8 mile. I skin cares at the track all the time that have more power. OP just remember spinning is not winning, build a solid 1.4-1.5 60' car and you will kill people all day.

factory LS3 engines have weak rods if you ask me.

 

So you are saying we shouldn't use stock internals right?

 

There are many guys out there running big power on stock internals but I would not do it. Always build on a good foundation and you will not get a nasty surprise like I did. Buying a solid rotating assembly cost much less then buying a new long block. My engine had 8000 miles on it and other then the covers and accessories it is junk, .77 per pound is what I will get for it. My factory engine had a mild cam and made 453rwhp, the tune was perfect.

 

this stroker is forged internal, just the block is LS3

 

Couldn't agree with you more (having my own engine fail after around 8000 supercharged miles).
"Not building a car from the ground up to handle the power you want to make is like Reverse Jenga; the more you pile on, the higher the chance its going to topple over." - Me

 

Stock engines are a ticking time bomb with boost. Tell that to the guys at HOTROD magazine that took a stock junkyard 4.8L LS truck motor, increased the end gap on the top piston rings (no other changes to the rotating assembly), added a blower cam, worked heads, 25+psi from two turbos, and wound up with 1200 engine HP. And the engine is still alive.

Said that to say this....what masquerades as a capable "tuner" these days is a joke. Anyone with a computer and a sponship on some website is a tuning genius. You hear when they get lucky and have a good result. You rarely hear when bad **** happens. It's really impressive when the guy stuck with a blown motor because of a crap tune has the same shop build him a forged motor.....

There's no reason an LS3 won't live a long life with mild boost if tuned and and set up properly. Sure, there's a better chance of failure if the engine is making more power. Mild boost, if tuned properly, isn't a death sentence though. My LS3 is fine after 15K+ miles at 650+rwhp. That's 8.5psi with blower cam and bolt ons. It never goes north of 6000 rpm. High rpm with a stock short block is a killer IMO. N/a needs the rpm to make the power...even with more cubes. With a p/d blower, there's no need for big rpm.

 

who had the blown motor and built again by the same shop, what shop?
my LS truck motor blew a rod, 6.0 stock never tuned or ran over 4000 rpm 256000 miles

 

Let's just say I've seen it more than once and I'm going to leave it at that. If you look around a little, that scenario isn't too hard to find.

I've had quite a few GM motors well over 200K miles. The engines wore out the rest of the vehicle. 256K isn't too bad, is it? I knew an old guy with a 454 MKIV that claims he NEVER changed his oil in over 125K miles....just added it when low. I'm not in the "change it a 3K club", but 125K on the original oil is just a little much

 

Sounds like a bad tuner... Maybe I'm wrong, but I know plenty of 30k+ supercharged mile cars with LS2's and LS3's.

 

Perhaps.. I would be amazed if that were true, but I'm not going to challenge you. I do not know many stroked vette guys, but I know a LOT of stroked Mustang guys.. Most of them have issues.

I also know a LOT of blown Vette guys with stock internals, and I don't know a single one that's ever had an issue that has caused a bad motor...

Oil drips, blowers getting noisy whistle after 10k+, belt popped off, brake line blew off at high boost and had to clamp it down.....

Those issues I've heard... Not a SINGLE issue that screwed up a motor from a SC. Bad tuner or somebody did something really stupid are my only explanations as to why you would have problems. Generically speaking, N/A power == more maintenance and more wear. Ask your tuner, I'd be amazed if he disagreed.

 

He's bitter because I think his boost a pump failed, but says his motor failed. He even started a thread in the FI section about how many miles people have on their cars FI last night after getting smashed in another thread.

As far as not seeing a stroker motor fail NA, well, I've seen plenty. First one I ever saw fail was an MTI built 427, with 1200 miles on it in 2001. Actually, was my best friends.

If you live in Houston, there are hundreds and hundreds of vettes running around with blowers with lots of miles on the stock block, and no problem.