Stroking a LS3 - Some serious expertise needed...

[TinyToasta]

As I am planning to putting on some decent hp gains whilst staying n/a, I did some of my homework on researching cams and header options. Good stuff out there, but....

...after that I started leaning into the option of stroking my LS3 to 427cid engine. No crate engines, just rotating assemblies and everything else needed to convert my engine.

Being a complete noob when it comes to stroking an engine I thought to put out another one of those "rare" stroker threads here.

Questions would be as following:
1.) What options are out there to change a LS3 to a 418 or preferrably to 427cid engine?
2.) What packages are out there (e.g. the TSP427LS3)?
3.) What kind of cams would be a suitable option for a stroked engine?
4.) What else is needed in terms of bolts, studs, gaskets, bearings, rods and all the other bits in pieces, to succesfully finish off the build?
5.) How many hours are we talking about having a pro shop performing the job?
6.) What kind of hp could be achieved, without taking all the options beyond dd-ability?
7.) What budget should be allocated to such a build?

especially on the budget point, I know it's not gonna be a "cheap" build, but still I'm trying to keep it at a reasonable level (similar to / below a SC build...)

Loads of questions, I'm afraid, but that's a complete novice reaching out to some of you guys having experience in such builds!

Thx a lot!

[CamaroCowboy]

moiy1983 talk to him he did it already.

[danhr]

My first question/advice would be:

"Why on god's green earth, would you want a 427ci ls3 motor?"

That means you would be running a 4.1" stroke crankshaft, which most have figured of too long of a stroke, and the piston skirt goes too far down out of the cylinder walls.

[Slowhawk]

The cheapest/best way is to have a reputable shop build you a 418/427ci shortblock. That way you can just sell your existing setup. The shop could even build you a complete motor. The biggest benefit of a stroker motor is the low/midrange power.

I would go 418ci over 427ci on a LS3 block unless you sleeve the block because the liners aren't long enough to support the extra stroke of the 427ci.It will work but not the best.

On another note - why not just put a blower on your car? That will keep it 100% streetable and make more power than a streetable NA stroker motor.

[moiy1983]

Originally Posted by TinyToasta

As I am planning to putting on some decent hp gains whilst staying n/a, I did some of my homework on researching cams and header options. Good stuff out there, but....

...after that I started leaning into the option of stroking my LS3 to 427cid engine. No crate engines, just rotating assemblies and everything else needed to convert my engine.

Being a complete noob when it comes to stroking an engine I thought to put out another one of those "rare" stroker threads here.

Questions would be as following:
1.) What options are out there to change a LS3 to a 418 or preferrably to 427cid engine?
2.) What packages are out there (e.g. the TSP427LS3)?
3.) What kind of cams would be a suitable option for a stroked engine?
4.) What else is needed in terms of bolts, studs, gaskets, bearings, rods and all the other bits in pieces, to succesfully finish off the build?
5.) How many hours are we talking about having a pro shop performing the job?
6.) What kind of hp could be achieved, without taking all the options beyond dd-ability?
7.) What budget should be allocated to such a build?

especially on the budget point, I know it's not gonna be a "cheap" build, but still I'm trying to keep it at a reasonable level (similar to / below a SC build...)

Loads of questions, I'm afraid, but that's a complete novice reaching out to some of you guys having experience in such builds!

Thx a lot!

talk to eric at HKE
http://www.hkracingengines.com/index.php

[litle88]

Originally Posted by danhr

My first question/advice would be:

"Why on god's green earth, would you want a 427ci ls3 motor?"

That means you would be running a 4.1" stroke crankshaft, which most have figured of too long of a stroke, and the piston skirt goes too far down out of the cylinder walls.

Why not?
There isint a draw back on that, the block just needs to be machined for it, thats all. AES makes a 427 Lq9 iron block, i have seen other shops make 427's from Ls2's, again machine work and good parts.

After those mods Gods green earth wont be so green no more cause we'll be sucking gas and blowing lots of Cabron monoxide.

Im going this route and hope to reach 550hp, we shall see!

Slowhawk---- the low profile elbow is going back to Summit and am saving for a FAST 102, all this time I didnt know that that elbow was so frowned upon.

[klatterblast]

i think to get to 416cid you just stroke it and for 427cid you stroke and bore to larger pistons , but what i have heard that boring for 427cid will decrease cylinder wall thickness and would lose durability.

[moiy1983]

I have a HKE 416 with 11:1 compression, forged internals custom ground crank with a decent duration and small lift, West Coast Customs Cylinder Heads stage 2 porting, stock intake, Spec 2+ clutch assembly,Cold Air industions CAI,1 7/8 Kooks headers,Catted Corsa exhaust. The drivabilty is very stock. No surging or bucking at any speeds and it made 510rwhp/486rwtq. let me tell u nobody would think I have that much power by seeing the car and are just blown away when i pull away so fast:-)

[klatterblast]

Originally Posted by moiy1983

I have a HKE 416 with 11:1 compression, forged internals custom ground crank with a decent duration and small lift, West Coast Customs Cylinder Heads stage 2 porting, stock intake, Spec 2+ clutch assembly,Cold Air industions CAI,1 7/8 Kooks headers,Catted Corsa exhaust. The drivabilty is very stock. No surging or bucking at any speeds and it made 510rwhp/486rwtq. let me tell u nobody would think I have that much power by seeing the car and are just blown away when i pull away so fast:-)

sounds like a good combo , should be able to handle a nice shot of nitrous.

[2010 SS RS]

Well you are doing it the right way. I had to learn on the fly. First thing is to find a builder you feel good about and trust. There are no shortcuts with a good build. 418 seems to be a good size for an ls3 as you can do it with a hone to a 4080. Stock should be around 4064. 4inch crank. H rods are a better option to an I beam. Racing bearings. and some very good pistons. Cost is around 2450 if you get the good stuff. Block will run around 500 but have your pistons before sending it to the machine shop. Make sure you tell them you are using steel rings as they grind it slightly different. ARP 2000 bolt on the rods. and head bolts are suggested. new gaskets and i would use ZR1 head gaskets.
Good time to install headers too. Also timing chain and tensioner. Cam is what you want it to be. But be realistic if you ever plan to SC your motor cause no reason to have the wrong cam if that is the way you are going. Bottom end will probably come in around 5K to 6K. misc no brainer do it now items 2K so you should be done around 7 to 8 K. And you will be throwing some bad SS torque numbers. Good luck and have fun.

[JUISSD]

Originally Posted by moiy1983

I have a HKE 416 with 11:1 compression, forged internals custom ground crank with a decent duration and small lift, West Coast Customs Cylinder Heads stage 2 porting, stock intake, Spec 2+ clutch assembly,Cold Air industions CAI,1 7/8 Kooks headers,Catted Corsa exhaust. The drivabilty is very stock. No surging or bucking at any speeds and it made 510rwhp/486rwtq. let me tell u nobody would think I have that much power by seeing the car and are just blown away when i pull away so fast:-)

An HKE 416 is what I want to eventually run. Mind if I ask how much it sent you back?

[danhr]

Originally Posted by litle88

Why not?
There isint a draw back on that, the block just needs to be machined for it, thats all. AES makes a 427 Lq9 iron block, i have seen other shops make 427's from Ls2's, again machine work and good parts.

After those mods Gods green earth wont be so green no more cause we'll be sucking gas and blowing lots of Cabron monoxide.

Im going this route and hope to reach 550hp, we shall see!

Slowhawk---- the low profile elbow is going back to Summit and am saving for a FAST 102, all this time I didnt know that that elbow was so frowned upon.

you machine for it?

I'm sorry, you machined the cylinder walls longer? how the eff do you do that?

unless, as mentioned before, unless you are talking about re-sleeving the motor (which costs thousands), a 427 isn't optimal.

Ask any reputable builder, they will say the same. They may offer a 427, but i bet the recomment a 418/416.

[TinyToasta]

Anyone tried the TSP 418cid (#25-TSP418Assy.)? Worth doing?

Question is on the piston choice, I assume the diamond 4,065'' would be the suitable option?!?

What else is needed to complete the part list?

[2010 SS RS]

Originally Posted by TinyToasta

Anyone tried the TSP 418cid (#25-TSP418Assy.)? Worth doing?

Question is on the piston choice, I assume the diamond 4,065'' would be the suitable option?!?

What else is needed to complete the part list?

You wont see a real 418 at 4065...more than likely end up at 416.... also I would go ahead and hone that baby out to fit the new pistons anyway rather than trying to fit into stock. Diamond, Wysco, or other high quality pistons are all good choices. As seen in my sig...I chose CP pistons. But I was going for a specific compression of 10.07to 1 and was able to find these in stock and ready to ship. Once I got them I was like saying to myself...Damn these are really nice pistons. Also came stock with the steel rings. Absolutely no blow by either. Here is my set up vs. stock.
new ones although larger wer 2.4 lbs each vs 3.00 for stock.