LS6 maintnance and updgrades - Euro car kid could use input from the hive on pushrod POWA

Once again back to ask the hive for input as I progress in my pushrod education.  Any direction from the team on heads, cams, intake, and other aspects if I'm missing something i should do while it's apart.

I start my trip down the rabbit hole because I have some unacceptable lifter noise and worn factory valve springs.  From what I read these are the two main failure points for these motors.  I also have a first gear synchro that needs replaced.  To do lifters the heads must come off.  Needless to say I have already had the motor and trans out once and would like this to be the last time.  I've been working the GMpartsdirect, Ebay 15% discounts, and Rockauto sites pretty hard and have only a couple big decision points left.  The game plan is to have everything on hand to do the work over a week. 

Overall target is a refreshed setup (top end and wear items) and ~100 wheel hp increase over stock.

Scope creep starts here.

General replace/upgrades to oem ish 

-Oil pump (OEM LS6 new)

-Timing chain and wear guides etc (OEM LS2 upgrade)

-Fresh LS6 dampener/balancer pulley

-T56 1st gear synchro and a few bits

-Water pump thermostat etc

-General oem fasteners, gaskets, seals etc

-I've already done a lot of maintenance bits like hoses, tensioners, oil pan gasket, plugs, wires, etc

POWA upgrades waiting to go on

-LS7 42lb injectors as the 28lb stockers won't cut it

-Stainless headers (maximizer OBX knock offs)

-Cometic 0.040 head gaskets to bump compression from 10.5 to 11:1

POWA upgrades I'm still researching

-Upgrade my Z06 243 heads to ported, polished, 3-5 angle valve job, fresh guts, and upgraded beehive springs

      -Easy button from Thompson Motorsports EBAY store for ~1250 delivered (everything but cam and pushrods)

               -These are well respected and use oem quality stuff but not exactly  how I would build them with the LS7lifters/trays, TI retainers, upgraded trunions, Dell West valves (nascar leftovers)

      -Pick up spare heads and build to suit with the above goodies mentioned gets me to more like 2K in the heads and I still need a cam

      - In either of the above head choices there are valve upgrades available to increase size and reduce weight but I'm just not sure 

-Cam upgrade to something like a 224/236 586/598 LSA114 

       - I think there are literally a million choices for ~400 with significant variations on lift, duration, and LSA

       -It's a manual and I have some tolerance for ill behavior but it still is a daily

-Pushrod length will be a mystery until measurement due to cam and thinner head gasket but otherwise it seems like hardened chromoly from anyone works fine

-Intake and throttle body is a bit odd as it has the LS2 90MM throttle body and intake already which should be a nice upgrade over the 78MM stock LS6 setup

     -Unless a Fast intake setup hits my Craigslist search really cheap I cannot justify ~800 for an intake and another ~250 for the bigger DBW throttle body for ~15hp

     -There is likely a middle of the road option to port out my stock LS2 by hand and add the bigger aftermarket DBW throttlebody for ~250 to get a ~10hp improvement

           -Aside from doing the Dorman LS2 upgrade the LS2 Trailblazer upgrade is too tall (like many of them)

 In theory the ~100hp adds up below

-Header 30hp

-Cam 30hp

-Headwork and compression 40hp

In theory I'll have about $2900 out of pocket and ~500 of that comes back from flipping my old heads, injectors, and a few spare bits.  In GRM style this is 2K in HP adders and 900 in maintenance

Get a cam with lift in the low .600's.  Thompson Motorsports built my 383, I didn't like their heads and used a set of RHD heads instead.  I'd stay away from "CN C ported" whatever heads from any company.  Your money is much better spent on a set of as cast heads from Trick Flow, RHD, etc.  Leave the intake alone, a 90mm intake will flow all you need it to.  A good set of long tube headers are totally worth the extra cash, I like Kooks.

Appreciate the input sir.  Aside from not being a fan of the Thompson heads were you happy with the 383 and their overall service? 

I'm doing a bunch of research on the cams, ramp rate, etc.  With regards to springs I liked the idea of the Beehives for smoother revs and lower weight but may need the spring rate of the duals.  The headers are stainless longtubes but not the Kooks variety unfortunately due to project cost controls.

Their service was impeccable.  Very happy with them in that regard and the 383 was a monster.  I initially had beehive spring but ditched them for a dual spring setup, that way if one spring breaks you don't have a catastrophic failure as the 2nd spring is still there.

Appreciate it.  I've heard two sides if the valve spring discussion and can't tell which is right.

Forgetting lift as a factor the arguments seem to go as follows.

Early beehives did have issues as GM underspec'd the rate for the LS6 cam and they broke.  

Beehives match valve action better by matching the movements at a lower weight.

Duals have the higher pressures and offer a theoretical failsafe.

I'm told the different coils in the duals have diff rates.  If one fails, you are cooked as the other is soon to follow.  

It seems like neither of the correctly matched beehives or duals fail these days but I could be wrong.

This messes with my cam choice as I had kicked around picking something sub 600 to allow the higher end 1211 behives to handle it.  If there is indeed reasonable to be found in the 580-610range then dual springs it is.

Give American Heritage Performance a call. 

310-326-2399

They sponsor me but I asked them to because they are the best at this kind of stuff.  Tell them jeremy the stuntman referred you if you decide to call them!

also, their recommendation to me was to run single valve springs as they don't have issues with them breaking. 

Appreciate it sir.  I’m having fun geeking out on the best setup here and looking for all input available.

i'd consider buying your old 243s, if you're willing to ship.

I had an LS6 a few years ago and FWIW I was planning AFR heads, englandgreen cam, and LG motorsports long-tube headers. I sold the car before I got there.

stylngle2003 said:

i'd consider buying your old 243s, if you're willing to ship.

I’ll drop you a line before I list it up.  I suspect I may miss the Z06 sodium filled valves if I don’t do something similar with the new setup.

Making progress on acquisitions with a reasonably short but expensive list remaining.  For budget reasons I’ll end up with 243’s that have been worked.  

Currently looking up valve material and size options.  Currently leaning towards a set that has oversized Del West TI valves...

Piston to valve clearance is apparently an issue that will help decide my cam choice.  I went with the cometic thin gaskets to gain the 0.5 point in compression.   

Picked up the low buck Dorman LS2 intake that is supposed to be nearly a Fast intake after porting.  Got started on the porting today.  Big issue is overall size as the intake on the ported heads is 1.15" vs 1" for the LS2 manifold.  There's a bunch of flash and nasty edges where they get welded.Doing a first pass on all of them and it seems to take ~40min each.  Got 4 done so far and will be back to it as soon as Mrs 84FSP gets home to watch the mini minion.

In theory there is ~7hp here over the stock Doorman LS2 mani.

Cloae to go time on the motor.  Hitting michigan mon to pickup an interior to improve the worn setup.

So the good news is the seats are super pimpy for a deal.  The intake mani is all ported and perfecto.

Got a suspiciously early ~2500 not 3000 mile signal to change the oil.  Pulled my magnetic oil plug to find silver fuzzy sparkles...

Trying to decide if I confirm with a sample to Blackstone or not.  

It may be time for an escalade or LS3  6.2 aluminum  takeout.  In theory another 0.5 ltr should be tasty... Gold plated Caddy here I come...

So this escalated to a completely diff setup over the last 14 months... 

Bob at On3 in Columbus get V all tuned up tonight.  The Mustang Dyno with Atmospheric read out 424tq and 434hp.  Using the low end of the 12-14% correction to a Dynojet number brings us to 475tq and 486hp which is exactly what I expected to see.  As expected it stalled out around 6K where the ported LS2 Dorman ran out of breath.  I’m a bit confused about needing to pull back from 26deg thing to 23deg timing after 5k rpms.  Wondering if the Corsa setup is choking her off?

Gotta figure out how to load videos.