AnotherWs6

iTrader: (17)

A fellow tech member is putting an engine together for me currently. LS1 block, crank, rods with aftermarket hyper-T flat top pistons. Z06/LS6 243 heads all stock. LS6 cam. This will be going in my 4wd Silverado in my signature. We're building it because the parts are on hand so just going for it. Should I mill the heads? The gaskets are 051 thick. I run premium of course, minimum of 91 octane, many times 93 in my area.

I'm curious as to what my compression will be as is, and how much I can mill without worrying about detonation and PTV clearance. He's headed to a machine shop tomorrow so I'd like to be able to tell him yes or no and how much by tonight. If I can mill these things and get a nice, safe bump I'd like to do it now and touch this engine once. I am NOT looking for any max effort, max cutting number. Just a good, reasonable amount. Milling is relatively cheap so I don't want to leave power and drive-ability on the table because the cost isn't an issue. I'm not looking to change any other parts of the build because it's all there and nearing completion. Anyone have input? Would be greatly appreciated. Thanks.

AnotherWs6

iTrader: (17)

I'm googling my *** of and not coming up with much. Seems like this should be an easy question for - some - people to answer. And a common question to have been asked. Most threads talk about milling 243's on 6.0 or 5.3 or 4.8 motors. Odd.

Darth_V8r

iTrader: (4)

I would mill some. 11.3:1 would be a good aim. Run tr6 plugs if you do, not the stock. TR55

AnotherWs6

iTrader: (17)

I think I'm going to play it safe and just go .020 over. At that level a stock plug for an LS6 should be fine no?

Darth_V8r

iTrader: (4)

I'd still run the tr6. Mainly because you mentioned 91 octane

stockA4

If you are going to all this trouble you should really consider a different camshaft. You'll be leaving a lot of low end tourqe on the table with the LS6 cam. Remember that cam was designed for a light weight manual transmission car, not a big heavy truck. There are plenty of mild options out there that will still drive and idle nice, but will move out a lot better than the LS6.

98znasty

I would just clean up mill them and get a better cam, you won't notice anything from the mill but the cam will make a huge difference

Jtm2085

iTrader: (1)

I agree with this. Ls6 cam is not a good option

01ssreda4

iTrader: (96)

25 is what I typically get them cut in this application.

AnotherWs6

iTrader: (17)

Gonna cut them 20. As far as the cam goes, I'm doing this on the cheap and the parts are on hand. If I want a cam later fine, but I'm sticking with it for now. It matches the springs already in the heads. Keeping it simple. Also, my truck has 4.88's and a 3,200 rpm converter so I think it will be OK. If not well then I learned a lesson first hand. In the mean time I'm still knocking 100 lbs off the truck while adding easily over 100 horsepower. I'll just see how I like it.

RixTrix

Keep in mind - Excessive cutting on the heads or altering the base circle of the cam will require different pushrods.

AnotherWs6

iTrader: (17)

^^^^ This. Yes, I appreciate that. That's why I'm staying with a conservative 20. Keeping it simple.

PowellSixO

iTrader: (1)

You're going to hate that cam in a truck. Just saying. Keep your eye out for a 220/220 range cam on a narrow lsa, and lifts below .600". Get pushrods, and springs, and be happy. Or waste your time to save a buck, and regret it. It's your call.

AnotherWs6

iTrader: (17)

Oh it's only 1 buck for a cam, pushrods and springs? Well S, why didn't you say so earlier? I highly doubt I will hate the cam. What I do hate is the **** 5.3 that doesn't make any power until 2,800 rpm. Hence the 3,200 stall. With my stall I assure you that I am not going to "hate" anything. Have you ever driven a vehicle with a high stall converter? Doesn't matter, you're clearly an internet expert. I'd tell you to blow me but I'm not into that sort of thing. Learn how to talk to people tough guy. Nice lights BTW. You're cool because of them.

stockA4

This is correct. milling the heads too much will also make the combo more prone to detonation and is just not worth it for something like this project Imo.
It's just simply a whole lot easier to put a proper cam in the engine now while it's being built, get all the clearances right once and then get it tuned once.

AnotherWs6

iTrader: (17)

Thanks, that's why I'm keeping the milling conservative, that seems to be the consensus. Again, with my stall anytime I give even moderate/light throttle I'm at 3 grand right away. Pretty sure an LS6 with bumped compression, headers and true duals is going to be just fine above 3 grand. Thanks though.

PowellSixO

iTrader: (1)

Calm down Cinderella, don't get your panties in a twist. You're obviously the Internet expert here, so do whatever you want. But you will regret it. And I bet 20 bucks you'll be back here later trying to figure out why your truck sounds like a sewing machine,or why you have a bent valve or pushrod. You do realize how much it's going to cost you just in gaskets, head bolts, and pushrods to swap heads don't you? I'm just trying to save you some headache. You're 500 away from a cam and Springs. Save for another few months and do it right. Look at my signature. I'm not telling you to do anything I wouldn't do. I'm seriously just trying to help you out.

Darth_V8r

iTrader: (4)

I totally missed that this is going in a truck. I can speak from direct personal experience. I have the LS6 cam in a suburban, and I hate it. The power comes in too late. I fell prey to the hot rod magazines, which I've learned to ignore. If I could do it over, it'd be a 214/224-112+4. Run that with .550 lift, and you can use the stock LS6 springs, lifters, and probably even the pushrods.

Edit - I'm not talking about the S10 in my sig. That thing is light enough that the LS2/LS6 cam is fine

PowellSixO

iTrader: (1)

Could of fooled me. There's a lot of truth in all sarcasm. And you are from New York.


And those are just stock lights. I guess I am pretty cool because of my kick *** stock lights. But if you look closely you'll see why the lights are on dick hole.

AnotherWs6

iTrader: (17)

I'm not the internet expert, hence me asking questions about milling. Why would I bend a valve or pushrod on a basically stock motor?

This isn't for the motor in my truck. It's a separate, build. Top to bottom. Cam is already in the motor. I set a budget for this thing and I'm sticking to it. Can't be worse than my 312K mile stock 5.3. Bigger, lighter, up 100hp and change. I'm gonna be just fine. My current motor runs strong, I'm changing it because I have access to CHEAP PARTS. Not shitty parts, cheap parts. Otherwise I wouldn't even be talking about a new motor until my current one blew.

I'll report back my dismal results when it's all done.