c5blkvette

I bought these LS6 heads off a 2003 Z06 with 2700miles. Did the porting with standard carbide tips, sanding rolls and crossbuffs. My main intention was to clean up the flow and minimise increasing the port volume. I had Bob Bruneau machine shop open up the valve seats (I then blended), cut the valve seats and back-cut the valves. I put in 2.02/1.575 Manley valves, 918 springs and 772 titanium retainers.

Cost:
$900 complete heads w/ valve covers & pushrods (includes $50 shipping)
$300 machine work
$920 for intake and exhaust valves, 918 springs, 772 titanium retainers, CC hardened pushrods & CC XR275HR cam
Reused 2700mile valve seals and locks

Total cost (excluding fluids, gaskets and misc.) = $2120

Josh

iTrader: (9)

Looks nice! Should be a worthy compliment to your setup.

Josh

samz28

sweet how much did you gain /track/dyno after your home port job? man i need some ls6 heads on the low-low

nice car too

c5blkvette

I havent had any dyno/track time since the work but hopefully I will be getting it tuned this weekend by Kevin (NOGO) at East Side Performance. I will post the results next week.

02Reaper

iTrader: (2)

Did you add the heads and the cam at the same time?

Heretic

I've heard its a good idea to leave the swirl ramp in place in the intake port, but why not cut out the protrusion for the rocker bolt?

c5blkvette

Yes, I added the heads cam and headers at the same time. I thought I should get it all out of the way all at once and then get it tuned... what pushed me was the sunny days starting to arrive here in CT

I left the swirl on the advise of Bob Bruneau and the reason I left the rocker bump was because I was lazy and didnt want the hassle of having to grind down the rocker bolts, threadsealant etc. I also dont think there are BIG gains from removing it... I really concentrated on the valve and bowl areas.

foff667

iTrader: (2)

looks pretty good, gets expensive quick doin it on your own though huh? HOpe it works out well for ya as you have bigger ***** than i got

c5blkvette

yeah... the $$$ add up fast . You just dont realise how much all the "extras" will cost when you start. I recommend anyone doing it themselves to have a couple extra thousand in the bank... $550 for the tune is what is going to break the camels back though!

For my headers, I made the cat section myself that connects the headers to the bassani x-pipe (~$200 + bashed knuckles). Heres a pic:

Heretic

Seems harmless.

I have a set of LS6 heads for my 99 FRC, I was thinking about doing a bowl blend and casting clean up on them before I bolt them on.

c5blkvette

"I have a set of LS6 heads for my 99 FRC, I was thinking about doing a bowl blend and casting clean up on them before I bolt them on."

Right next to the valve seat insert, there are major imperfections from the factory where they bore out the head to fit the inserts. Both the intake and exhaust were terrible on the large radius side. If you use some sanding rolls to just blend, I think you will achieve measurable results. This point just before the air has to flow past the valve is the most critical for flow. I really should have taken some before and after pics.

I was a bit hesitant at first to start grinding away at my $900 castings, but once you get started, it really is pretty easy. I believe anyone can pick out the imperfections that will restrict flow and then blend them.

foff667

iTrader: (2)

im assuming you didnt flowbench the heads?

Heretic

I've seen some really bad imperfections in that area, my LT4s were awful.
Blending the seat into the bowl, and then working the sides of the bowl smooth is where you make 80% of the improvement in flow.

Thanks for the info BTW.

ZL1camaro

c5blkvette

No flow numbers... but again, high flow numbers were not my goal. I was trying to minimise increasing the port volume to achive high port velocity. I guess the better indication will be the dyno numbers (torque curve) and ultimately track times. Will post the dyno results next week.

The LS6 heads are beautifully designed but there is definately a lot of room for improvement. GM cant spend hours blending and smoothing out every head they put on a car.

foff667

iTrader: (2)

im assuming this isnt your first port job on ls1/ls6 style heads? did u get the runners cc'd? With the talk about velocity and such id just assume youd try and see where your #'s stack up against aftermarket stuff out there.

c5blkvette

If you want LS6 heads on the low-low, wait till next year when they will be more plentiful... they should drop a bit in price with the release of the AFR heads also.

Thanks for the compliment. She is my baby

c5blkvette

I am from Australia where fuel is nearly $1AUD /litre so before 2yr ago I was a ricer ...Although my 1.6L supercharged Toyota did pull 12.2s 1/4mile before the wife crashed it. I ported a few 4cyl heads so basically these are the same (just 2 of them bolted together). I dont proclaim to be an expert porter by any means but I dont think it is the black majic that the industry trys (and they do try) to portray.

foff667

iTrader: (2)

im not saying its a "black art" or anything but ive seen some pretty botched hand port jobs by people that have done them before, thats the only reason I ask.