My LS2.5 Rebuild

[Petro]

I'm on leave right now...But I'll be visiting my hometown next week...after that I have to go to a school ( WLC ) for 2 weeks...get back from that prep to go to NTC ( National Training Center ) out in California for a month.. Get back from that at the end of October then prep for deployment...And then Deploy for about 12 months in December...I'll be stop lossed from November til the end of deployment. Stop loss is where I was supposed to be getting out of the Army... But they say hey to bad you're staying in until we don't need you anymore or you can re-up. So I choose stop loss because that's $500 extra each much on top of tax free deployment money and they aren't giving out any re-up bonuses...I'll come back from deployment with a extra $40,000 cash easily...So the truck will be getting put together as soon as I return...Right now I'm enjoying gathering parts and trying my best to do things myself...If the engine blows up or something oh well....Lesson learned I guess...haha..

[LS2Sonoma]

why would it blow up?? im helping you!!!

[Petro]

Quote: Originally Posted by LS2Sonoma

why would it blow up?? im helping you!!!

I have been getting lots of help/input from other people on this also...and I appreciate every word of advice...I'm feeling pretty confident it'll do well...My bearing clearances are a lil tight at .0017 and the ring gaps are a lil more than recommended but hey she might just run better than most would expect...hopefully anyways...Oh and I'm sending you a PM...

Oh and I thought of doing a leak down test on it after I finish putting it together even though it won't be "broken" in...Then I'll do another after I finally do get to break it in and I will have some numbers to compare too...kinda like a idea of well they seated I guess...

[LS2Sonoma]

honestly, i think youre wasting time doing the leak down test. run the engine, if it seems to have mucho blowby after 500 miles (breaking it in properly) then start worrying. i doubt youll have any problems

one and seven tenths isnt too tight for this engine, youll be fine mang!

[Petro]

I'm was just going by the book as that is all I know...but had some more reading yesterday and found that the .0017 isn't that bad like you just said...and that my ring gap/bore taper are within reason....Hone could've been a bit better..We'll find out either way...I wonder if i could find a engine dyno to run it before I deploy??

[LS2Sonoma]

engine dyno = your truck

hurry up!!!!!! :P

[Petro]

This is a off topic from my rebuild but it's not really LSx either...I just wanted some opinions on the drag setup I'm shooting for...Even though the truck will predominantly be a DD but I will still be taking it to the strip..Hopefully quite a bit...Back home there is a 1/8th mile dragstrip about 2 miles from my house ( Huntsville Dragstrip ) ...Of course I'll have the LS2 , 4L60E , and 3.73s w/ Detriot Truetrac , and something like a 28" tall DR ....Any advice on torque convertors , line locks , or anything at all??? Thanks

[LS2Sonoma]

need more specs... compression ratio, cam specs, any bottom end mods?

sorry if i missed it, is your truck regular or ext cab?

[Petro]

Compression will be about 11.4:1 .....Cam will be 224/230 @ .050 .... .581/.588 Lift w/ 114LSA ....stock LS2 bottom end....and 2002 ext cab S10...There will be minor weight reductions...Just tubular upper/lower control arms , tubular trans crossmember , new fabbed carrier bearing crossmember , 2 piece double cardan driveshaft to 1 piece ....

[LS2Sonoma]

did you get arp rod bolts? that would be a good idea

as for a converter with such a little cam i wouldnt suggest much. stall speed should be 1800 - 2200. use the stock one

[Petro]

No but I could get some...I've read that the stock bolts aren't a common failure though....I may decide on a different cam as I don't have a problem with flycutting....

[Petro]

I'm sorry I was off on my CR...it should be 10.9:1 ....I thought I had done my math wrong...haha

[LS2Sonoma]

you dont even need to think about flycutting

[Petro]

Quote: Originally Posted by LS2Sonoma

you dont even need to think about flycutting

Why's that??

[LS2Sonoma]

you can run a pretty big cam and still have enough clearance

[Petro]

That's what I'm worried about is clearance...

[LS2Sonoma]

with a flat top piston, you need to worry about that when your cam starts getting into the 270 @ 50 duration

[Petro]

Yeah but with the LS3's 2.16 intake valve it becomes a issue with milling a .040 head gasket...The cam I mentioned earlier should have problems but if I decide on a larger cam then it'll become a issue and something like a 111LSA...correct???

[LS2Sonoma]

haha ok... well, id be very surprised if you have that issue

if youre worried about it, slap a head on and give it a test

[Petro]

I meant to say with the cam I have I shouldn't have problems....oops my bad...haha

[LS2Sonoma]

anyway.. how come you went with that cam?

[Petro]

Phil recommended it..I was going to go with the one SweetV8S10 went with...But his is a lil larger split...After more reading most are going with something around the 224/230 114LSA mentioned earlier...It seems to make good results..I haven't purchased the cam yet so nothing is set in stone....

[SweetS10V8]

How much have you milled the heads?

Hot Rod just tested a bunch of Comps most popular cams with a LQ9 with stock (unmilled)LS3 heads. Although the LSR cam they tested was bigger than I would like..... 227/235 .614/.621 113+5. It was as big as they could get without piston to valve issues. I milled mine .030" and the largest I could fit is 219/235 .607/.621 113+5 with the exact same engine as they have. Remember that stock head gaskets are .055" so even if you dont mill at all, your .015" closer already with .040" gaskets.



"First, what size engine? We decided on the 6.0L/364ci size (4.000-inch bore x 3.622-inch stroke), an iron-block truck motor widely available in wrecking yards (although our test engine was actually based off a GM LQ9 crate motor)."

"Second, which heads? The new rectangular-port heads were the obvious choice. They've taken production 6.2L-and-larger LS-based engines to a whole new level. L92 6.2L Caddy Escalade engines and the new Vette and Camaro all use some variation of these castings. The newest player is the LS3 Corvette package with lightweight intake valves."


http://www.hotrod.com/techarticles/engine/hrdp_0909_gm_ls_engine_cam_test/index.html
for some reason page 3 doesnt work

[LS2Sonoma]

with all the changes like milling and thinner gaskets it would be neccessary to check ptv clearance for sure. i am surprised that cam is pretty little.. but i guess thats what happens when you put big block sized valves in a small block lol

you could always just leave your rockers loose so it wont open the valve as much

[Petro]

I haven't milled the heads yet , purchased a cam , or head gaskets...So I'm still wide open on choices...How much of a noticeable difference would the CR of the above setup ( 10.2:1 roughly ) be over a CR of 11.0:1? Wouldn't low end be affected? And like everyone always says it's not necessarily the Dyno #s but rather the track times ....I'd like to have a nice strong all around runner...rather than being strong up primarily up high..

[SweetS10V8]

Going a full point down in compression, say 11:1 to 10:1, will decrease power by about 3-4% typically. So if you had the engine in the graph I posted you would go from 525hp to 505-510ish HP.

I wouldnt mill them at all and use the GM gasket(#12610046), so you can run almost whatever cam you want. A slightly bigger cam will make way more power than a .5 point of compression that you would gain from the compression, because the heads really flow well.

But head flow is what really matters, as long as your heads flow well youll make plenty of power. 10.2:1 will most likely run on 87 octane too, Im going to try it in mine next time I fill up just for fun.

[Petro]

Hmmm...I'm going to have to do some more reading....Thanks for the info Sweet....Also if I don't mill them then I have more options down the road....

[Petro]

Now I want to build a 408 too...haha....Still thinking about cam setup for this build though...

[LS2Sonoma]

you dont need a 408... ls make enough power for you.

as for a cam, just ask sweet... hes the guy i would ask

[Petro]

How do you think it would do with unmilled heads and the 224/230 114LSA cam , and stock head gaskets ( may go with the .040 gaskets ) ????

[LS2Sonoma]

use stock gaskets. that cam is ok for your setup i think. considering the heads your using, you cant go too wrong with a mild cam like that
sweet will have more details on a cam that i can give ya

[Petro]

Hey Sweet what CC were your heads after porting and milling ???

[Petro]

I'm back from NTC and will be ordering some more parts here soon!!!

[Petro]

Which of the two cams would be a "better" choice??

223/231 .610/.617 115+4

227/239 .614/.624 115+3

[Petro]

I'm going to take the plunge and try out the 227/239 Cam...Now for checking the PTV clearance I planned on doing the clay method...But how do I know what solid rollers to buy to check it?? And how many cylinders should I check it on? Any help is invited....

[LS2Sonoma]

solid roller???

[Petro]

No it's a Hydraulic Roller Cam and but I read that if the cam you choose uses hydraulic lifters you need to use solid lifters to check...Since hydrualic lifters bleed down and provide a false measurement...

[LS2Sonoma]

yea, they bleed down with the monster spring on there! use a test spring and you dont need to buy anything

it doesnt make any sense that you would test ptv with a different lifter

what have you been reading!?

[Petro]

Here a reference I was suggested....Read #4 it's about the lifters..

http://www.racingheadservice.com/Inf...eClearance.asp

[LS2Sonoma]

ive never heard of anybody doing that before

the only time weve ever used clay is to check a piston's dome clearance to the combustion chamber

we basically just use test springs and turn the engine over slowly while pressing the valve down softly till it contacts the piston. you will see how much room the valve can move, and if its close you can always stick a dial indicator on top of the retainer and measure

[art]

you can turn your hydraulic lifter into a "solid" Make sure to use a junk one since you can't reuse it. I'll look in the book that has the info on how to do it.

[Petro]

I love this tool:

[LS2Sonoma]

dont scratch the head surface!

[Petro]

^^ Of course not...They are still smooth and shiny as could possibly be...

[Petro]

I'm trying to justify myself if I buy Yella Terras LS3 1.7 Shaft Mount Rockers or should I just purchase a set of stockers???

[Petro]

I took the plunge and got a cam and springs....My question is are the PRC Double Springs a good choice for the cam I choose....Link to springs:

http://www.texas-speed.com/shop/item...d=173&catid=48


The cam I choose is very similar to the new Comp LSr 277HR cam...It's the Vegeance Racing LS3 Stage II cam with 227/239 .614/.624 115+3 ....Good choice for spring kit or no????

[Petro]

Does anyone know the torque specs for ARP rod bolts and head bolts???

[LS2Sonoma]

45 lbs on the rods. head bolts are 70 lbs. since our blocks are aluminum, you dont wanna do much more than that. the 8mm bolts are 18 lbs

ps. if you do strip threads, my shop specializes in thread repairs

[Petro]

Even though these say "LS1" rod bolts will they work with my LS2 rods?? I know there are two different style bolts GEN III and GEN IV.

http://speed-eng.com/store/arp-perfo...od-p-8040.html

[Kampz69]

well those are for the "cracked" rods...are yours the cracked ones? i dont know if the gen IV were cracked, but the gen 3 are right?