dogsballs

In the process of upgrading a stout factory bottom end 6.0 using factory ls3/l99 heads but moving to decent solid roller, new ls3 super vic. Got a spare set of heads, just throwing some wild ideas around. Fwiw, current 6.0 run 10.0@135.5 in 2600lb car.

So anyone angle milled/decked an ls3 or other ls heads from 15deg to something like 12deg on ls7 heads?

S10xGN

iTrader: (11)

Won't accomplish anything other than reducing the chamber size. That "oft-mentioned valve angle" concerns the angle between the valve stems and the ports and is determined during casting.

Jimbo1367

lol. tf

dogsballs

Current chamber is 58cc with 100thou removed. Got zero issues doing weird stuff like that. Angle mill while help free reduce ptv issues

LLLosingit

iTrader: (4)

As I understand it the valve angle is determined by the axis of the valve stem to the bore.
There are benefits to angle milling but they come at a cost especially on street engine. When you angle mill heads you are also changing the angle of everything associated to them so for every degree you tilt the head you are causing alignment issues with the intake mating surface and intake bolts, The head bolts/studs now out of alignment and your headers may have clearance issues. There are many articles on the benefits but I think you'll find that they aren't that great unless you're trying to get every last HP out of a combination. Angle milling may gain 20-30 hp and that would be a worthwhile advantage on a 700hp circle track motor but probably not worth it on a daily driver.

dogsballs

Cool, good info to know. Alignment of bolt holes and manifold not a huge stress. Geometry of valve train as not too stressed with big wall pushrods and solid, as long as they dont rub (which we can clearance for)

Race only engine pushing 615+hp, running vac pump and yes definately trying to chase every hp

blackonblacksls

iTrader: (1)

I have ran angle milled heads on vettes and camaros with no issues with stock or fast intake manifolds.

my machine shop matches up all the faces to the same angle as they do the heads.

LLLosingit

iTrader: (4)

I'm not saying it can't be done, It's done all the time but the money spent on the extra machine work could be spent on something else that would be a better bang for the buck but if he's chasing every last HP he can see gains with angle milling.

dogsballs

aim of this exercise is to see how far a stock bottom end 6.0 and factory head castings can go.

about experimenting and trying weird stuff. not just calling up TSP or whoever and ordering a 400+ cuber with all the goodies.

KCS

iTrader: (20)

It's been done to heads for years, I don't see why it wouldn't work out on an LS head as well. The valve cover rail is square and parallel to the deck, so it's a little easier to spot face all the bolt holes, etc. and with the manifold, you may be able to just slot and sport face the intake bolt holes.

If say to for it and post some pics/results.

S10xGN

iTrader: (11)

Angle milling will increase compression and can help unshroud the valves on some engines, but will not alter the relationship between port angles and valve stem angles...

KCS

iTrader: (20)

It should still be worth something, though.

Tony Mamo @ AFR

iTrader: (13)

DB's.....What the hell are you up to

Your idea isn't practical for lots of reasons....the largest one being you would mill into the water jacket on the plug side of the chamber. Just a 1 degree rollover is close to a .150 angle mill.....a 3' move (15' to 12') would literally wipe the deck out which your lucky if its .400.

Nothing would fit intake manifold related....you would push the engine off the side of a cliff before it was all said and done.

Take the plunge on some LS7 heads.....I have a set I have been porting for stock right now. 407 CFM and 270 exhaust.....good luck getting within 30 of that on an LS3 casting.....not going to happen.

Don't waste your time thinking of pursuing this any further....its just not going to happen

Hope you don't mind me sobering you up!

-Tony

dogsballs

lol tony, even the more reason to try it. everything with the engine to date was to prove stuff.

i'm not going to a ls7 head and to some extent i don't care about big cfm ratings. this combo will be about cleaning up the flow thru the big ports, careful matching of everything to get a good ve.

i'd agree on the deck thickness at 400thou, if its not practical to go to 12 deg's, i'd be happy to try a degree or so.

manifold lining up is interesting, i've had both a plastic manifold and vic jnr line up fine on a current set of heads decked 100thou (when people swear it won't line up). i'm under no illusion angle milling will change things.

thanks kcs, will keep updated on how we go

blackonblacksls

iTrader: (1)

Angle milling cost me 200 bucks.

Compared to 80 for flat milling at the same shop.

What would you spend 120 on to beggee improve performance??

MuhThugga

Spend the extra on a valve job.

speedtigger

iTrader: (16)

DB, have a look at these guys combos:
3Pedals
StunningMan
IllusionalTA
IheartLS1
ThirdGenBum 2
DmMizell
06X6spdGTO

Each one of them has a single plane combo that is making about 65-85 more horsepower out of a 6 liter. I don't think any of them are doing anything unusual to do it. They are just doing the usual really well.

dogsballs

totally agree speedtigger, when the engine was originally put together i had a super tight budget, things weren't optimum but worked well. to be honest i think my car makes similar hp to dave mizells when it ran 9.87, but his notch was set-up killer and 60fts way better than mine. actually it was based on that 6.0 engine

speedtigger

iTrader: (16)

Dave was 150 pounds heavier and went 3mph faster. By my math, he was making about 65 more HP. I think Dave would have ET'd much better with more converter.

dogsballs

my weight is a guess, never properly weighed it, but fox body smaller car. his was definately faster with 137.7ish and 1.35 60ft, compared to my 135.5 and 1.42. anyhoo, upgrades on the go.