Need your opinion really quick! LS3 vs LS7

[djwilk]

Hi,
As per the title.

I can either buy a new LS3 crate for £5.2k or a used 15k mile (allegedly) LS7 for £6k.

Now, that is a good question what to do...

A few important factors:

- will my existing LS3 ancillaries including A/C, power steering, ECU, starter, alternator, etc fit and work?
- will LS3 power flow headers fit?
- is the LS7 cam optimal, or can I do better?
- would a cam that I have been discussing for LS3 (XER273HR) fit into LS7?
- LS7 comes with a dry sump AFAIR? Is it expensive to convert it to Wet sump or simply add the missing items?

Application fror VXR8. I am exctied, but tell me what you think.

[S800VXR]

From a purely aesthetic POV its LS7 all day for me! Think that would make you the only 7ltr VXR8 out there, worth loads of pub points!

[mikeyb1987]

Isn't Ringram running a stoker in his?

[mikeyb1987]

The LS7 runs 1.8 ratio rockers, so that may screw your cam choice.

[anonymous-user]

I'd say LS3 with a tasty cam. Simpler, newer and more power.

What about this? http://shop.partsworldperformance.com/ls376-525-v8...

Edited by anonymous-user on Tuesday 10th June 20:30

[ARAF]

If you can get the LS7 down to £5k (that's approx. 50% of new price) then I'd take a punt on it, if it is genuinely a 15k mile engine.

Not sure how much will need changing though. The engine and ancillaries are assembled under the assumption that the steering column is on the left...

[djwilk]

wormus said:

I'd say LS3 with a tasty cam. Simpler, newer and more power.

What about this? http://shop.partsworldperformance.com/ls376-525-v8...

Edited by wormus on Tuesday 10th June 20:30

It was my first choice, but the ASA cam is not going to be liveable with...

[anonymous-user]

LSA crate engine?

[djwilk]

wormus said:

LSA crate engine?

I am capped to £6k all in.

[ARAF]

wormus said:

LSA crate engine?

The US LSA won't fit under the scuttle on a VXR8.

[jonnM]

If it's a hassle free install, then cammed LS7 would be my choice.

With a 230/240 it would drive like stock but still give 450-ish at the wheel. Nice

[ringram]

It will cost you too much to retrofit IMO. You need all the dry sump plumbing and reservoir etc.
Add to that the LS7 crank is longer and the accessories probably wont line up. Crank is longer for vacuum pump for dry sump etc.
But aside from the sump its a drop in. All sensors etc should bolt up.

As mentioned ls7 is 505bhp rated, though torque is pretty stout too. It also rev to 7200 and runs titanium rods, valves etc..

There was an HSC 427 so you can get it to fit without too much trouble. But it will cost you

[mikeyb1987]

Probably a daft question, but would the LS7 titanium rods fit an LS2?

[ArnieVXR]

Wet sump conversions are relatively cheap IIRC. I'd be concerned about how hard that LS7's been driven, if it's not a straight pull from a Corvette. People only buy these aftermarket to thrash them on the track.

[djwilk]

It came out from a written off 2009 Z06 with 22k kms on it.

The guy is offering the engine together with the dry sump and plumbing + reservoir.

[ArnieVXR]

mikeyb1987 said:

Probably a daft question, but would the LS7 titanium rods fit an LS2?

No...
http://forums.corvetteforum.com/c5-tech/1891231-ls...

[ArnieVXR]

Accessory drive kit listed on eBay is for LS3 or LS7, so maybe the parts will line up

[stevieturbo]

If you have a restricted budget, then stick with the LS3.

You can bet if you move to something that isnt a simple bolt in...you'll blow a lot more £££ trying to adapt it to your car.

[djwilk]

You guys are probably right. I didn't realise there was so much faffing about with ls7 swap.

[mik_ok]

Ooh. I'd love an LS7 engined '8, and obviously it does work since the W427 exists.

Other than that I can offer no useful input. No idea about ancillaries, engine mounts, ecu etc etc.

Worth a question on a US or Oz forum?

Worth calling HSV and asking??