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.

[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!!!

[sambo]

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

[sambo]

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

[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

[sambo]

Let us know if you see any billet rocker covers for the 6.0L mate.

[400TT]

Sambo, billet rocker covers, are you trying to go for the nice clean look that Tenrocca has achieved.

Yes, John's Cobra has had quite a few suspension changes front & rear. Plus we originally built it a bit different than the norm to start with. The Cobra is faster than ever at the moment. I guess it will up for sale soon or dressed up, de-tuned and made into a street car.

[sambo]

Yes mate, after looking at that "302 in situ" thread I'm really envious of the oldschool look. Relocating coil packs is a good start, followed by some dressy rocker covers and whatever else can be done to help. These non-carby engines will never look as good though...

[alffie]

The advantage of the LS7 is it is factory so it passes emissions etc and MVR/RTA are happy for it to be regod. Putting a big cam and heads on any engine to get the power can cause a lot of greif with rego if they dont like what youve done. When you look at the prices, by the time youve done the mods it wont work out much cheaper at all.
Phil would have spent the best part of 15k on his engine to get similler hp numbers as the LS7 but will not pass rego now. One question off topic, do you guys have to go over the pits every year? How do you keep them regod with the engine mods?

[stiffy]

I suppose I should have started the post with what I had and the outcome I was wanting.

I have a new 6 Litre 6 speed from WASP. The car will go through rego
as is. Then I will add the cam/heads while painting the engine bay and getting Aussie Mike to mod the gearbox.

I want the all singing all dancing idle sound.

I hope that sorts things out...


STIFFY