If you are going to do a "build it once" motor, then get the shortblock right and the topend can evolve. The longer I do this, the more I like the 3.90 cranks. I reallllly don't like having the piston pin poking into oil ring groove. No OEM does this, and I'm firm believer that is why you don't see strokers with 100k+ on them.

 

I spoke with several repuatable places about building my engine but like you I wanted to take it on myself so the first engine I ever built was an LSX427. I built my engine in 2014 and it now has over 20,000 miles on it and is still going strong. It took me seven years of saving and buying parts before finally building my car and I did a complete overhaul, engine, transmission, rearend, exhaust and suspension. One would think you're taking a huge risk building such an expensive engine yourself and sure I could've paid someone who was experienced that could've possibly built the engine to make more power but where's the fun in that.

When I finally had everything to make the swap I assembled the engine and once built my determination to get the car done was pushed into high gear. It was a journey I'll never forget but it did not come without some pitfalls. My advice to you if you're going to take it on yourself is to do some research first and there's some books I recommend you check out. "How to Build and Modify GM LS-Series engines by Joseph Potak and How to Build High Perfomance Chevy LS1/LS6 V-8's by Will Handzel". Both of these books have a wealth of information on engine building with the latter touching base on how to remove an LS engine from an Fbody car.

You're going to be spending money on tools so buy good tools as it makes all the difference. You'll be spending money you didn't account for it's just one of those things but I will say that it's very rewarding doing the work yourself and the feeling you get when you hear your car breathe life again..Priceless!

One last thing..If you do not know how to do the work yourself be very careful with who you trust with your parts. It's a dog eat dog world out there and there's people out there looking to take advantage so only deal with reputable people and places.

Good luck with your build, I wish you all the best..

 

Appreciate the advice! I’ll undoubtedly stick with a 3.9-4” stroke based on a block that can manage that easily. I agree that pushing the limits on that is unwise for longevity.


I love that, thank you! Really appreciate the encouragement and reference material. I’ve done a ton of top end jobs over the years, but always avoided the short block. Something a bit intimidating about bolting things together that spin and get flung as fast as that stuff does lol! I do love the idea of that I’ll know exactly what I have, and that no corners were cut. To your point, there’s a lot to be said for that.

 

https://ls1tech.com/forums/dynamomet...-601-rwhp.html

Food for thought....
and I have a virgin LS2 block I can sell you...

 

I came across that post, but didn’t read the entire thread until now. My only concern going with a 408-416 is that getting there takes the best of everything, and then you’re done. With a 427+ you can get there (or close) with off the shelf parts like a BTR stage 3 LS7 cam, TEA/TFS 260’s, and an MSD, and then if you get those parts Mamofied down the road you could see another 50-100. Knowing how I like to tinker, that’s probably a better path for me. That’s also assuming I don’t just take my time and save up for all the best parts along the way. Depends on how patient I can be, and how quickly I want to get the bullet in the car once the short block is done.

Thanks for the offer, I’ll certainly let you know if I decide to go that route.

 

I agree with your outlook, I'm the same way, always more. Potential is everything. I would just buy a sleeved block or, if you go iron, I have a new LSX block I'm selling too The block is the key, it's all about the bigger bore. If you want to do a half step, you could big valve your TFS heads and port the **** out of the Fast intake and put it on whatever short block you dream up. Not ideal, but you already own it and minimal upgrade cost considering the power it can make. Topend can always evolve, as long as the bore is not the limiting factor.

 

I will say up front I have never owned, or built, a FI motor. I've always had built NA motors in snowmobiles, motorcycles, and cars. That said, if the OP wants approx. 600whp, the most economical way would be to buy a used LS3 and throw a blower on it. You'll get near stock reliability, and make big power. Careful shopping could net a good used LS3 for $5,000, or less, and a used A&A blower kit for maybe another $5,000-$6,000. Of ccourse, you'd have to change the pistons to lower compression. Or run thicker head gaskets, though I'm not a fan of thicker head gaskets, especially with a FI motor. By replacing the pistons you'll have a first hand look at the engine internals to ensure the guy that sold you the motor was honest. Set boost@10lbs to start out, have it tuned for another $750, and for approx $12,000-$13,000 you could be making well OVER 600whp. Buying another good running engine would also allow you to keep your original engine. This is just another option. If you're dead set on NA, disregard......

 

I definitely want to stay NA, and it’s not necessarily about taking the economical approach for the build, just trying to limit the loss should something I do myself fails for some reason. I am confident in my abilities in general, but have not built a short block myself before. There’s no way around these parts costing $$$, though, so I just need to make my peace with it.

 

In the process myself of putting together a 427 Darton sleeved 5.3, with forged Compstar/ Mahle rotating assembly. Those 2 items alone hit $8K. Adding exhaust and intake and high stall and lifter and cam, etc. Final cost comes in close to $15K. I am using high end parts and if I hit 600 RWHP I will be very happy. Ordered the Cam Motion stroker cam they recomended, More top end power and safer cylinder pressure than what I had in mind. Car recently hit 80K miles. So storing some funds for driveline emergency. My AI buddy Grok puts me 550-620 RWHP. I decided to build an NA that won't leave me wanting with too much compression for a blower to make me stop.

 

Nice. Make a build thread on here and let us know how it turns out! I hate to say it, though, upping the compression in hopes of avoiding the desire to go forced induction later will not work. All that's going to do is cost you more money later when you wish your set up was a point less in compression so you could add power without replacing the heads. For only a 4% max gain, I'd keep the heads at something that would allow growth in the future, not discourage it. That's up to you to self reflect on, though. I love boost, but know I'll never take my WS6 that route. That'll be a build for another car at another time. Even knowing that, though, there's always a better build you could do. And trust me, someday you'll want more. The only people that don't are the ones that don't start modding, and they aren't on LS1Tech lol!

 

Stock LS3 add a cam and springs ... 600+

 

ER built a SBE LS3 on YB that made 732hp if I remember right. SBE, hyd roller, low ran intake, stock rocker, he ported the heads/intake, ran out of valve spring and was still pulling at 7800rpm. Don't know the compression, but guessing in the 12-12.5:1 range.

 

Yes, can be done. Look at SpeedMullet (AKA: Matt) 8's NA ........440" I think it is ? ....775-850 hp ?

 

I agree with what Tony said, 600whp isn't unattainable but you have to be realistic on budget and expectations. I spent every bit of $17-18k on my engine and it will not crack 600WHP . I don't think it'll be too far off from that number but it still won't break it. That last 20-30hp is where you really need to start looking at the build. Sure more camshaft could get me closer, changing the intake to support the new cam. Maybe even swap to LLSR but that's where you start giving up drivability and such. Right now it drives down the road so smooth you would never know its 402 cubes and makes the power it does. Step on the loud pedal and all hell breaks loose, keeping the rear planted while tuning has not been easy.

If I had to do it all over I would have sleeved the block to begin with and gone with 427ci+

 

I'm in a similar boat...little LY6 clone is showing some wear. Debating on just buying a long block or having mine rebuilt to 408". Even thought about a LS3 and adding a cam, but then back to the same $$$$ or more.

Looking, looking, looking.

Would love to do it myself, but for the few $$$ for them to assemble and give a warranty...hard to say no.

 

If you already have a Ly6 block and a good crank, just punch it to 4.065 bore, maybe throw a set of cheap Compstars h beams in it and have a solid 6 2 that opens up the options on head choice a lot. You can even go 4.080, if you want to take it to the max. I wouldn't stroke it unless the crank is shot.

 

just don't hear a lot about 370" anymore and most pistons I see are for the bigger rods, so doing pistons AND rods,,, why not the crank too ? Just a thought.

Just looks like 408" was go to.

 

The reason not to do a 408 on an iron block is they just wear out prematurely from the short cyl sleeve and pin sticking into the oil ring groove. If your machinist knows what he is doing, there are ways to make it better and last longer, but there is a reason you don't see high mileage strokers. The stock stroke works, the bigger bore opens up cyl options, the power is in the topend.

 

You make some good points. As far as the warranty goes, most everyone finds a way to weasel out of them. I've had them tell me that "If it's something we did, we'll take care of it." Which quickly morphs into "Those are racing parts in your engine, and we don't warrant racing parts." Just sayin'. In my 50+ years of doing this on cars, bikes, whatever, I have NEVER gotten any free parts OR labor. I know you can pay extra at Lingenfelter for a warranty, but good grief, Lingenfelter already charges probably more than anyone else does. I've never had a problem with their stuff, and they do make really good equipment. But you're kinda paying higher than premium prices BEFORE getting the warranty, if you go that way...

 

Already have LS3 heads and shaved .050...so need a -10 or -12 cc piston for a 6.098 rod with a .943 pin.

Sorry, not trying to steal a thread.