WizeAss

iTrader: (5)

is there a difference in the two?

LS6 Head vs. LS3/L92 Head


by the way... here are the specs on the LS3 motor for the 2008 Corvette. c/o CorvetteForum.com. I bet the bore helped kill some of the valve shrouding. Makes me wonder if those that are doing 2.165 stock valves on a 4.030 or smaller bore are making a mistake. Cant wait to see what my 4.030 bore does with a 2.125 intake valve!

Here’s a look at the new and enhanced features for ’08 Corvette models:

Engine – A new, 6.2L LS3 small-block V-8 is the standard engine in Coupe and Convertible models. It is rated at 430 horsepower (321 kW)* and 424 lb.-ft. of torque (586 Nm)* with the standard exhaust system; with the new, optional two-mode exhaust system, power ratings increase to 436 horses / 325 kW and 428 lb.-ft. / 592 Nm. As a result, the standard Corvette is true supercar, capable of 190 mph. The LS3 with the six-speed paddle-shift automatic is the fastest automatic-equipped Corvette ever, with 0-60 mph capability of 4.3 seconds.

This new iteration of the storied small-block family features a revised, larger-bore cylinder block – 4.06-inch / 103.25 mm vs. the previous 6.0L’s 4.00-inch / 101.62 mm bores – high-flow, LS7/L92-style cylinder heads; larger-diameter pistons; revised camshaft and camshaft timing; revised valvetrain with offset intake rocker arms; high-flow intake manifold; high-flow fuel injectors from the Z06’s LS7 engine; and a new engine beauty cover.

The LS3 features an aluminum cylinder block with cast iron cylinder liners. In addition to its larger bores, which help create a 376-cubic-inch displacement, the block casting also features revisions and machining in the bulkheads that enhance its strength and improved bay to bay breathing. But while the bore of the 6.2L engine is increased when compared with the previous 6.0L engine from 4.000 to 4.060, the engine’s stroke remains at 3.62 inches (92 mm). The pistons for the larger 6.2L engine also are new and are designed for its high-rpm performance capability.

Breathing for the new 6.2L engine is accomplished via new, high-flow cylinder heads. They’re based on the large port/large valve design found on the LS7 engine and other GM L92 engines, with larger-capacity, straighter intake ports. The design optimizes intake flow to the combustion chamber and the exhaust ports are also designed for better flow.

Complementing the larger-port design of the heads are commensurately sized valves. The intake valve size alone increases from 2.00 inches (50.8 mm) to 2.16 inches (55 mm) – an increase of nearly 9 percent. The intake valves feature lightweight hollow stems, which enable the engine’s 6,600-rpm capability. The exhaust valves also are large, measuring 1.60 inches (40.4 mm) in diameter.

To accommodate the engine’s large valves and enable more direct intake port flow, the intake-side rocker arms are offset 6 mm between the valve tip and the push rod. Actuating the valves is a new camshaft, with intake-side lobes providing more than a 5-percent percent in increase in lift, from 0.521-inch to 0.551-inch (13.25 mm to 14 mm). Exhaust-valve lift remains unchanged from the LS2. The camshaft timing was revised to optimize performance with the higher-lift intake cam profile.

Ensuring the cylinder heads receive all the air they can handles falls to a new, acoustically tuned intake manifold. The composite design is manufactured with a “lost core” process that improves runner to runner variation and reduces airflow losses. An acoustic foam material is used to reduce radiated engine noise; it is sandwiched between the outer top of the manifold and an additional “skull cap” acoustic shell. Also new beauty covers atop the engine shield the rocker covers and also feature a noise-reducing, acoustically tuned insert to provide a more refined engine sound.

WizeAss

iTrader: (5)

[IMG][/IMG]

Beaflag VonRathburg

iTrader: (176)

If they are the same that's pretty dissapointing to me. I always look forward to new technology from GM, but if they're just mixing and matching individuals have been doing that forever.

fast98

iTrader: (16)

rocker arm bolt

WizeAss

iTrader: (5)

yeah I figured.... extra volume... protruding material to support the rocker arm.... makes sense. and the rest?

WizeAss

iTrader: (5)

why the concern?? 4.8 heads, 5.3 heads, and LS1 heads are all very very similiar. Of course they offered improved heads for the LS6 cars. FYI, the L92/LS3 heads were meant for 4.00 bore cars.... so I dont see the issue in GM producing those same heads for the LS3 and L92.... all this L92/L76 talk is funny to begin with... since these parts are originally Aussie stuff.

We are all used to LT1, LS1, LS4, LS2, LS7 etc etc.... L92 and L76 is a different language..... maybe it is Australian......

I still haven't read that the LS3 and L92 block are the same or different. Is the LS3 just a L92 without the displacement on demand?

fast98

iTrader: (16)

i think it all has to do with how gm wanted the port designed. i think they were looking for some port taper possibly to increase velocity around the valve. thats just my take on it

Checkmate

iTrader: (2)

I thought someone said the block was the same.

What I'd like to know:
To put an ls3 in an ls1 car, are we looking at the same issues putting an ls2 in an ls1 car?
Can the TB be converted to a cable?
Are all the sensors the same so an ls1 PCM can be used?

Nine Ball

iTrader: (38)

LS3 and L92 heads are the same. Valves and valvesprings are different though.

LS3 and L92 block is the same too. The L92 in my 2007 Escalade does not have displacement on demand either. Pistons are supposedly a little different between LS3 and L92, as well as the intake manifold and camshaft (of course)

fenix999

iTrader: (17)

thanks 4 finally clearing that up Nine-ball, u da man good stuff to know, because just when it all makes sense, here comes GM adding another number to the LS family engines lol, but who cares it must be a good thing

WizeAss

iTrader: (5)

thanks for clarifying. BTW, Greg did some additional port work on the intake of my 2.125 intake valve'd L92 Heads.... ended up with 365cfm! Shaaaweet. I will have pics of my heads early next week ready for install!

I changed my sig. I like LS3 better then L92... I am now calling them LS3 heads. Especially since my valves are not stock and the springs are Patriot Extremes.

WizeAss

iTrader: (5)

Tony,

Can you change the L92 Info sticky at the top... and the Thread description on the front page? Since some folks are getting the LS3's in as we speak.

Wnts2Go10O

iTrader: (12)

when did u get the escabus?

as long as they have vvt its all good

the_merv

iTrader: (88)

Now I can go brag to my friends that I got LS3 Heads goin on my new Engine..

Justanotherracecar

so L92's and LS3's are the same head? That must make the L92's worth more cash, right?

Cobraeater

Tony,

The LS3 intake is just a L76 intake with a noise-reducing shell atop of it right?

Steve Bryant

iTrader: (1)

I've always thought that it was wrong to designate the heads by the engine designation (e.g. LS1/LS6/L92/L76). I think that the better way to designate the heads would be by the casting number (e.g. 241/243/035/317/823). That way, you know something about the head, not the engine that it may have been installed on.

Just my 2 cents.

Steve

macky

I read over on the corvette forums that the ls3 intake on the corvette has a heimholtz? (i can't remember the spelling) silencer that actually prevents unwanted frequency reverberations. Apparently you do not want to take that off because it would cause lower airflow at certain rpm's.

Macky

CamaroRick

iTrader: (24)

now you gotta change thoes fuel rail covers to say LS3

so is the intake the same as the l76? if the heads are the same and the intake is different, then the l92 combo has 3 different intakes to choose already

CamaroRick

iTrader: (24)

ohh nm i got it..... heimholtz