Ls7/gen 4

[stiffy]

Hey Darksiders,


I have heard a rumour taht the GEN 4'S and the LS7'S are interchangeable..... Is this correct???


If this is true would aftermarket heads and Cams be interchangeable?

Help,

STIFFY

[alffie]

The LS7 is a "gen 4" The new 6.2ltr LS3/LS9 have the LS7 heads and manifold. The LS7 heads will fit on the LS2 blocks but have 2.2inch intake valves that will have clearance issues with a 4inch bore, will depend cam lift etc. If you use the LS7 heads you will need the LS7 manifold. Alt,starter etc are the same on the LS7/2.

[stephen low]

So according to Alfie, Stiffy, yes they are interchangeable but perhaps you need to confer with Rohan first to be sure!!

[Plums]

The only factory motor that uses LS7 heads is the LS7.

LS7 heads won't fit on any block with a bore size under 4.100, which effectively means the only block that can use them is the LS7 (4.125) or LSX.

[stiffy]

OK,

Thanks, so it would be better to stay with the GEN 4 with aftermarket heads and Cam than go down the path of a LS7. Less hasstle
and not alot of lost HP???



STIFFY

[sambo]

What are you building now Stiffy? Thought you had an engine for the Daytona?

[stiffy]

SAMBO,


I do....... But I am going to the States next week AND with the $$$ being so good I thought I might look into the LS7 option.... Or just heads and cam for the old GEN 4.


If I could get an LS7 at the right price it would be easy to move the GEN 4 onto someone else......


I was informed that they were interchangeable,,,, But that information seems to be a bit off.

STIFFY

[alffie]

Depends on what your definition of interchangeable is. They use the same mounts,clutch,bellhousing,alternater,pullys,you can use a LS2 sump if you want to wet sump them. The harmonic balancer is differnt but the cams the same (differnt grind) timing chain the same. The differences are dry sump set up, block has 4.125 bores, heads have 2.2I 1.64E valves.
Get a LS7 while your over there you can pick one up for $US12000, you will never look back. See if you can get the LS9 that would be a good motor.

[sambo]

Stiffy, $12k US gets you a ripsnorting L98 without the delivery hassles, the extra duty/GST, customs grief, etc.

[400TT]

LS9 would be sweet. But I expect it will much more expensive than the LS7 is now...that's once it's released.

I'm buying an LS7 for myself soon. It all comes down to cubes and reading the specs of an LS7 is like reading the specs of a race engine...nice.

HSV will also have those 2nd hand LS3 engines for sale in the near future. The LS3 engines they pull out when fitting LS7 upgrade. They could be well priced.

[Plums]

Stiffy,

You can get a 440 cube, LS7 stroker with CNC ported heads, your choice of cam, LS7 intake and throttle body (either cable or electronic, your choice) with 50lb injectors..... the works for only $11500US, add $1000 for a RAM twin plate street clutch and you are flying!!!

[stiffy]

PLUMS,


Where do you get it..........


So a GEN 4 with a cam and heads and tune wouldn't be scary

I am just thinking about the installation hasstle's and so on.....



STIFFY

[Aussie Mike]

LSX Iron block 454 with LS7 heads could be had for the same money or a bit less. The LSX block is rated to 2000HP and is a real tough piece of gear. Probably only 20 or 30KG more than the aluminium block too.

Cheers

[400TT]

Am I missing something, in my books there is a lot more going for an LS7 than just the cubes and HP. So even if you build another engine up to the same HP and/or cubes, it does not equal an LS7.

Plus an LS7 has a lot of potential for more HP with tuning etc.

So I can understand going with say an L76 & doing cam etc or going with an LS3 with a tune. Or the more extreme strokers. But you are getting closer to LS7 price range and wouldn't you be better off just buying an LS7 and be done with it.

Plus you have a compliant engine choice. I can get over 500HP out of an LS7 and still be emissions and noise compliant.

What about reliability? I wonder how reliable the different options are?

Educate me fellas, I'm only new to the darkside.

[Aussie Mike]

The serious differences you are getting in the LS7 crate motor over a built up motor are the titanium rods and the dry sump.

All the parts are available to guys wanting to build a tough darkside motor. Plenty of shops are offering big cube combinations based on the LS7 block or LSX block or even the aftermarket Warhawk block. There are tons of aftermarket heads available now and plenty of CNC ported factory heads to keep you guessing on what combination to use.

What I'm saying is you aren't just restricted to factory crate motors now to build that killer engine. This is handy if you are trying to match up parts with your existing drivetrain i.e manifolds, sumps etc

Cheers

[sambo]

One question - how would you put all this power down in a Cobra/Daytona?

[400TT]

Thanks Mike, they are certainly very attractive as you can get just about any level of engine/HP/reliability that you seem to want these days when you look at both the factory & aftermarket options.

For me and what I want an LS7 still looks like the best choice.

[400TT]

Originally Posted by sambo

One question - how would you put all this power down in a Cobra/Daytona?

Now that's the challenge. Better rubber, better geometry & suspension setups. For the street it becomes just the FUN factor, but for the track, BIG HP can certainly help.

My brothers Harrison Cobra hooks up and grips really well. Amazingly well actually. But it's not always been like that, setup makes a big difference.

[sambo]

Substantial changes to the geometry on John's car Craig? Rubber is "only" money but there's a lot more science (and mystery to me) in geometry. Maybe we should continue this chat on my other thread - sorry Stiffy!

[stiffy]

SAMBO,


A good question, I will only be running 15" rubber.......

Its just a thought, the sump on the 6L is a bit low, I was looking at the LS7 for the dry sump set up originally,,,,, But i think I might stick with the 6Litre and buy some added bits.....next week.


STIFFY