LS2/LS7 Based engine.
Thread Starter
Teching In
Joined: Sep 2005
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LS2/LS7 Based engine. Hey Everyone 
After some information on LS2/LS1 Based engines. I am from Australia, and going to do an engine conversion using a LS1/LS2 Based engine.
For the vehicle to be street legal, The largest engine I am allowed would 6.0litre based engine / block.
My questions are as follows:
- I know the LS2 364cu runs a 4.000 bore. Could the LS2 be bored out to run the 4.125 bore that the LS7 uses?
- Will the 4.000 stroke crank from the LS7 fit into the LS2, or is the bore spacing different?
- I belive the LS7 heads share the same stud pattern as the LS2 Heads / Block. Am I correct? With the correct bore size, these heads should work ala LS7.
What I am aiming to build here is a LS7 engine, using a LS2 Block.
Constuctive criticisim accepted.
Andrew
After some information on LS2/LS1 Based engines. I am from Australia, and going to do an engine conversion using a LS1/LS2 Based engine.
For the vehicle to be street legal, The largest engine I am allowed would 6.0litre based engine / block.
My questions are as follows:
- I know the LS2 364cu runs a 4.000 bore. Could the LS2 be bored out to run the 4.125 bore that the LS7 uses?
- Will the 4.000 stroke crank from the LS7 fit into the LS2, or is the bore spacing different?
- I belive the LS7 heads share the same stud pattern as the LS2 Heads / Block. Am I correct? With the correct bore size, these heads should work ala LS7.
What I am aiming to build here is a LS7 engine, using a LS2 Block.
Constuctive criticisim accepted.
Andrew
The LS2 block would have to be re-sleeved but it's a dry sleeving process so it's not AS involved. It can be done up to a 4.160" bore and yes, you can definitely do just up to a 4.125". From what I've heard the LS7 heads bolt to other LSx blocks but I've heard doubts on whether or not the coolant passages line up perfectly. Personally I believe they would given the gen IV nature of it. Yes the LS7 crank will fit. Is there a reason you want to use an LS7 crank over any aftermarket crank? The only problem I can think of is the pistons. The LS7 heads use an 11 degree valve angle so your pistons would need notched accordingly. You would also need to run the LS7 intake manifold because of its unique port size and shape.
Thread Starter
Teching In
Joined: Sep 2005
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Thanks.
The reason behind using the factory crank etc was due to the fact that I am toying with the IDEA of buying a LS7 crate motor, and putting everything from the LS7 block into the LS2 block. As I have said before, the only reason I am doing this is so the car will pass for registration.
Does anyone have specs on what the LS7 heads flow at?
Regarding the pistons being notched accordingly, Off-the-shelf LS7 items wouldn't work in the LS2 block due to the valve angle being different?
The C5R heads are based on a LS6 correct?
OT: When are the 3valve LS7 heads due for release?
Andrew
The reason behind using the factory crank etc was due to the fact that I am toying with the IDEA of buying a LS7 crate motor, and putting everything from the LS7 block into the LS2 block. As I have said before, the only reason I am doing this is so the car will pass for registration.
Does anyone have specs on what the LS7 heads flow at?
Regarding the pistons being notched accordingly, Off-the-shelf LS7 items wouldn't work in the LS2 block due to the valve angle being different?
The C5R heads are based on a LS6 correct?
OT: When are the 3valve LS7 heads due for release?
Andrew
Last edited by drew-; Sep 23, 2005 at 05:41 AM. Reason: The C5R heads are based on a LS6 correct?
Oh, if you wanted to use LS7 pistons then yes, they should work but I believe they are still cast so if you wanted to put more power into it than stock then you might be bnetter off spending a little more if not the same on some aftermarket ones. The C5R heads are entirely new castings. I realize, as you said, it was just an idea but what are you looking to gain by purchasing an LS7 crate and an LS2 block and swapping blocks? Do you plan to sell the LS7 bare block when completed? I don't know the rules of street legality but it could be built for much cheaper because an LS7 crate motor is IMO not worth the price if in the end you won't have a true LS7. Just my .02 cents.
Staging Lane
Joined: Aug 2005
Posts: 50
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From: Melbourne, Oz
Originally Posted by drew-
...snip...: - I know the LS2 364cu runs a 4.000 bore. Could the LS2 be bored out to run the 4.125 bore that the LS7 uses?
Originally Posted by drew-
...snip...: - Will the 4.000 stroke crank from the LS7 fit into the LS2, or is the bore spacing different?
Call damian ... 03.9474-0900
I believe the LS7 crank uses a different reluctor wheel than the other gen4 cranks, and you wont be able to use it unless you have some sort of signal translator for your pcm or the ls7 pcm.
