Hey everyone, new to the forum here (not my first post but one of my first). I recently just pick up an LS6 engine that came out of an 04 Z06. Not to sure on the mileage of it though. Anyways, it is in very great condition for being a 10 year old motor. The block is extremely clean and cylinders are very clean as well. I have everything to put it back together but since it's all taken apart I might as well do whatever I can to the internals that might need to be done.

This is my first engine build and I've done my fair share of research but you can never stop learning. I'd like some advice from you guys.

My LS6 has the 243 heads (not sure if those come from factory or not but they are the 243s) while everything else is original as well.

My goal for this build will be 400-450rwhp and I would like to add a 150-200shot of N2O later on down the line. For now, 400-450rwhp will hold me over lol.

My question for you guys is, my pistons and crankshaft have the usual gunk on them (obviously from being 10 years old) and was wondering if I should have a shop clean them or if they'd be good to go to just reinstall as is? It's nothing that I couldn't scrape or get off with a little bit of elbow grease so I'd rather not have a machine shop clean them unless it'll benefit from more power or hold up longer. But like I said, it's something I could easily clean off myself as it isn't much build up at all.

Onto the cam decision... Now like I said, I want 400-450rwhp and I've read that it's extremely easy to obtain with stock 243 heads, full bolt-ons, and a cam swap. Now should I get a custom grind cam, or should I get a nitrous cam since I will be putting nitrous on my LS6 later on or should I just buy a good cam that'll put me at my rwhp goal and just spray on top of that when I decide to start spraying?

That's about the only questions I have for now, I'm sure ill think of some more sooner or later. For now I'm just getting a plan together for my build and goal I want to reach so I'm not modding aimlessly for no reason. I feel like the questions I've asked need to be answered before I can even start building since its all taken apart.

Another thing I should add is that I will be porting the intake manifold and the stock throttle body as well if that helps with some additional information. Anyways, thanks everyone ahead of time and I'm looking forward to hearing y'all's feedback. I am excited for this build and ready to make an LS6 monster. Thanks!
Nate.

 

243s are stock on the LS6. They have the sodium valves (exhaust) where as the LS2 243s don't. The LS6 in mine had been very reliable... However I did break a valve spring a few thousand miles ago. I know your talking custom cam, and therefore new springs, but just a heads up I guess. My car had like 85k miles on it at the time. From research I have done it is a known issue in some LS6 motors. My spring didn't drop a valve or anything. I shut it down as soon as I heard the car misfire. So I replaced them with LS9 springs from lingenfelter for like $70. As far as the lower end, I'd leave it alone unless you are going to take it completely apart to replace the main bearings. If it ran fine in the previous car, it will probably be ok in the new one.

I'd do a cam from tick. I like the SNS stage2 milder cam as it fits my requirements for a quick daily driver. I don't plan on spraying anytime soon but I believe that cam is good for like a 100-150 shot according to their website. They will spec you a custom cam if you'd like.

http://www.tickperformance.com/tick-...1-ls6-engines/

 

I'd would be more likely to go with the Tick, Street Heat Stage 2 (with spray in mind) which is larger, but has less overlap. Overlap with it is 8.5* compared to the "SNS" torqueMAX Stage 2 which has 10 to 11* depending on which version you're looking at.
http://www.tickperformance.com/tick-...1-ls6-engines/

The Brian Tooley Racing(BTR) Stage II (227/234 113lsa+3) is also worth a look.

 

Thank you guys for y'all's inputs! The LS6 is completely torn down right now. Down to the bare block. I'm having the block, crank, heads, rods, and pistons checked/cleaned up very soon. I'm gonna have a machine shop do this since I don't really have any information about the engine other than it was an 04 Z06 engine and it has some milage on it.

Also from what I can tell, there are two brand new pistons and on one of the connecting rods bearings it is slightly grooved. Also where that same exact connecting rod sits on the crankshaft, it is grooved there as well instead of nice and smooth so my educated guess would be that the previous owner must have blew that piston/rod or there was some detonating going on for sure. Other than those two imperfections, everything looks and seems perfect to my eye. That's why I'm going to have a shop check everything over and clean everything up as well.

Now I've got another question. Is the LS6 stock bottom end good good for 600-650rwhp? I stated before that I want 400-450rwhp all motor but I will spray later down the line a 150-200shot. So will the bottom end hold up to a total of 600-650rwhp with spray?

And back to the cam; these cams that you guys suggested, do they have good mid-range to high-end power? I could careless about low end power cause I really don't want to sit and spin the tires like crazy lol. Also do they have a badass lope to them? Lol I'm not good with cam specs at all (I need to do more research on them, I know).
Thanks guys!
Nate.

 

99blue's cam will definitely be more aggressive and have more of what you are looking for. Martin, PatG, Brian Tooley, and a few others are all good guys to talk to. I have shot emails to Martin and he has responded quickly even though I'm sure he is quite busy. Have one of them spec you a cam, most will be able to point to an off the shelf cam that can meet your needs. If you peruse Tick's website, there are quite a few cams that might catch your eye.

 

Thank you for your input buddy. Now will the stock bottom end handle a more aggressive cam with nitrous in the future? I plan on keeping the stock 243 heads (don't know if they should be ported for my rwhp goal??), plan on swapping the cam out, and full bolt ons along with a 150-200 shot in the future.. Will all that hold up on a stock bottom end or should I have my parts forged?

 

IMO, if you can afford to go forged then do it, especially if your looking at 550 up to 650 rwhp on the spray.
Otherwise I'd at least have a set of ARP rod bolts installed.

 

add the ARP rod bolts ,but you should have the the connecting rods resized .you won't make 450 rwhp with unported heads ,and a ls6 intake .soak the parts in a clean bucket of degreaser .make sure to blow out all of the head bolt holes .go to Texas Speed for stuff like ,gaskets ,timing chain ,bolts .

 

I recall reading that the stock 243 heads are easy to make 450rwhp? I've been doing tons and tons of reading lately so maybe I'm mixing up information but I'm pretty sure I've read multiple different statements about stock 243 heads being fine for 450rwhp. And I also thought the LS6 intakes were one of the best intakes to install besides the FAST brand. Especially if the LS6 intake is ported, I've read its really good.. But anyways, maybe I should have my heads ported anyways since ill be spraying for more power later down then line..

 

I'm currently doing my own research for my build so take this with a grain of salt... Especially because my goals are different than yours with nitrous vs boost. The bone stock 243s are good to like 400who with a big cam depending on drivetrain. But porting them and matching the LS6 intake will definitely improve the flow a lot. I was originally intending to just do heads and cam on my car. But the Mrs. gave me a green light for a big power build... Before that I was going to send the heads to Advanced Induction for their 232cc port job, LS6 intake clean up, and TB port. The main issue I see with the LS6 is that the block is weaker because of the windows cast into the block. I have been doing a lot of reading because I want to punch mine out and have some Darton sleeves put in there. There were guys going up to 427ci with darton wets when the LS6 came out in the early 2000s because the LS1 was hard to find. While you have it all apart, I'd definitely do a set of forged rods and pistons. I don't think you'd have a problem with the LS crank at 600+/- HP I have read of guys going to 800+ on a stock crank. But if you have the money I'd get a Callies compstar for reliability's sake.

I'm kind of the school of thought where you build a motor and heads for excellent N/A flow and then put a cam to match your power adder.

At this point my plans are darton sleeves with 400+ ci with forged dished pistons and rods with a Callies compstar, port the 243s for a blower and get a matching cam, intake Mani and throttle body, and put a procharger on it. My goal would be a really fast road course car. We have real high power tracks out here so I'm shooting for 700-800hp.

If that doesn't pan out, or if the cost/benefit is lacking, I'm set on a LS3 to do similar stuff to. Port the heads, manifold and tb, and spec a good blower cam.

Links to the AI info I was reading about.
http://www.advancedinduction.com/LSX...adsCamKits.php

 

Thank you for the loads of information ryridesmotox. Looks like I need to change my plans up a little bit then. I'm a college student so I was trying to stay on a budget (not that you can necessarily budget for building a powerful engine but I wasn't going to go all out with it... Yet). So after reading you guy's inputs, looks like I'm going to change my plans up a little bit..

Now I'm thinking I should port my 243 heads, port my LS6 intake & throttle body, and pick up some forged rods and pistons. I know 600rwhp is a lot on stock pistons & rods but it won't be a constant 600rwhp since ill be spraying nitrous. Plus it's going to be a weekend warrior type of car. I won't be daily driving it nor will I be spraying the N2O every single time I get behind the wheel of it so I figured maybe the stock rods and pistons would be alright but maybe not?..

 

Is there stages to porting heads? Or porting in general? Because I'd hate to pay for an extreme port job that could handle 1000+rwhp when I only need a port job to handle 600-650rwhp..

 

I bought a new crate LS6 for my '98 Z28 back in '04. The internals haven't been touched, and with all the bolt-ons (but with shorty headers), I put down 385 RWHP (376 with stock pulley, then swapped to underdrive pulley and got it up to 385). At the time, I didn't want to void the warranty, but hindsight being 20/20, I wish I had put at least a mild cam in there (something along the 224/224) to put me over the 400 RWHP mark. IMO, if you do a mild cam and longtube headers, you'll easily be in then 420-430 RWHP mark. If I were in your situation, and wanted a car that was perfect as a daily driver, here's what I would do:

-Add a mild cam
-Send the LS6 heads off to be ported
-Go with a FAST 92 intake over the LS6
-Go with LT headers

I wish I had sent my heads off to Lingenfelter for porting...they might be a little higher in price than some other shops, but they did the porting pattern for GMPP's ported LS6 heads if I remember correctly.

You can see all the bolt-on mods I'm talking about, as well as a full write-up on my swap at the link in my sig.

 

I have changed my plans. I am going to get my heads ported now, you guys have swayed me in a different direction lol. I was planning on doing full bolt-one already with a good/badass cam for mid-range to top-end power. Possibly a nitrous cam for spray in the future, not to sure yet?? But here's another question for you guys. Will any performance/machine shop know how to port my heads according to my rwhp goals? Or is it a one stop port does it all type of thing? Cause I don't want to pay $1000 for a port job that'll handle say 2000+ hp (sarcasm but you get what I mean) when I can pay $500 for a port job that handles my easy goal of 600-650rwhp.. So if I were to explain to a machine/performance shop my rwhp goal for my build, will they know exactly how to port them for me? I don't know jack **** about porting other then that it's good to let more air flow lol.

 

Your rwhp goals is only a small piece of the puzzle, they really need to know a lot more to give you your best option/s. Imo, any good head porting shop would want and need a lot more info to make you a happy customer.

I'd consider either TEA or AI, with the TEA being my preference with it's noticeably better exhaust flow than the AI ported LS6 heads.

 

Oh okay I see. I was actually just looking at AI's website and was reading about their port work on the 243 heads. A lot of people seem to be impressed by them so far. They also off a few bucks off a cam if you get head work done by them when purchasing a cam so that's a pretty solid deal.

I've seen people talking about TEA on this forum so I will have to check them out as well.

What other information would a machine shop need to know when porting to satisfy the customers goals, wants, and needs for their engine build?

 

You can get that LS6 to do low 400s without touching the heads or cam but it will be costly.

Get an more clear idea of what you want...

 

Brian Tooley gets 450-460rwhp from an LS6 w/ his stage 4 cam and headers. Also a great bang for your buck mod is have a really good valve job done by a company like TEA or AI. You will pick up considerable flow even without CNC porting.

Use a .040-.045 head gasket to improve quench, mill the heads to 61cc's.

The above mentioned combo would be killer for not that much money.

 

Okay guys, another question. I'm reading up about this stuff but as I read, I need to ask questions as more confusing information fills this empty skull lol. Now when changing te compression ratio, I know the heads and the pistons play a huge factor in that. Does porting of the heads change CR as well or does only milling/shaving of the heads change CR? I also know changing your piston will change your CR as well. So my LS6 is at 10.5:1 CR; how would I get it to 11.0:1 CR?
How much milling/shaving of the heads would have to be done? Can port work get me there? What type of piston changes would get me there?
Reason asking is because if I'm going to go ahead and build my Ls6 for nitrous now, then I want to change the pistons and rods out for forged parts and whatever piston I choose, I want to know what CR it'll bring with it.. Also if I have to mill/shave the heads to match then I'd like to be able to know what CR I'm at when all said and done..

If I end up doing the all out nitrous build then I'm looking at getting Mahle 3.898 forged pistons w/ Eagle H-Beam 6.125 rods. The heads will get ported (leaning towards AI at the moment unless I find a machine shop near me) but I'd like to know what CR I would have if I went this route since I'm changing the pistons and heads up. The Mahle pistons I'm looking at are -4cc I believe if that helps with further information.

 

Alright guys, I've been looking at cams and I really like the Tick SNS TorqueMax Stage II (as some of you suggested) and I also like Tick's Polluter cam. From what I've been reading, the SNS TorqueMax Stage II is an all around good cam making tons of torque and awesome mid-range/high-end power which is what I am looking for/want. I am more into high-end power as my car will be street/highway puller so the Polluter cam was brought to my attention. It makes an *** load of power on the high-end from what I've been reading about it. Now with that being said, would the Polluter feel like a dog on the low end? I don't mind not having a ton of low end torque but I also don't want to have to put my foot 3/4 into the throttle just to get above 2500rpms because of no low end.. So I guess what I'm trying to ask is, is the Polluter cam going to disappoint me with its low end power since its really built for top end power? If yes for disappointment, then ill option out for the SNS TorqueMax stage II as I really like that cam too but if the Polluter can make some decent low end power then I'd much rather have the Polluter since its a monster up top which is more of what I'm looking for in the long run.