[Zio]

I am looking at a 1970 chevelle. The guy told me he put a 454 LS-6 crate engine in the in 1992. He said he got it from parts unlimited. I was just wondering if anyone knew anything about these engines. He said that the engine has forged pistons and it has a cast iron intake that came with the engine. does anyone know what kind of HP and torque these engine put out. are they a good engine. He also said that he put a LS-7 cam in. Does anyone know if this cam even exists and if so does anyone know the specs of the cam? also does anyone have any idea what kind of heads are on this motor? are they any good? what kind of compression does it have, is this a solid or flat tappet cam in this engine? what kind of internal parts does it have?

Does anyone have any idea of the power this engine is putting out with this cam, headers, 3" exhaust, cast iron intake, holley 850 DP. he said that he ran 12.3 @112 in the quarter on slick with 4.10's and a 4000 stall through a th400 trans.

sorry for all the questions, i just want to see what is really in this engine to see if it is worth the asking price.
thanks for info that you can give me.

thanks
Tom

 

[Guest]

An LS-6 is the 450hp/460hp/454, 11 to 1 CR. motor AND if he put an LS-7 cam in it, imho, it's not going to run all that well b/c the old great big stock, solid GM cams needed at least 12 to 12.5 to 1 CR. to run their best!! And the gas that goes along with it. (The LS-7 was 12.5 to 1 CR., I think)...

The motor is a forged rotating assembly motor, (crank, pistons and of course, stock forged h/d rods), and has a solid lifter, flat-tappet cam in it as well as rect. port heads.

Depending on years of the crate motor, I think they may be both open and closed chambered heads but I may be off here and they may only be open??

pdq67

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[427L88]

LS7 should be a solid, 324 330 duration, 540/600 lift 130+ overlap, LUM_P_I T_Y solid cam. Not bad choice if its feeding 12:1 compression on 94 octane.

If its an 11:1 motor, you'll have a tough time running it on pump fuel unless you use a ridiculous cam like that.

It'd make a good bracket motor. With iron intake ( crazy ), 11:1 +, a good valve job, that cam, ir should make in excess of 500 HP, but with a relatively high torque peak of over 5000 rpms, or thereabouts, $3500-4500?

For the street it needs to shed a pt of compression and a modern camshaft, so figure that in to your price.

Make sure the compression ratio makes sense for your use, and you probably wont like that cam, it big man.

 

[Zio]

thanks guys. i am not buying just the engine. it is in a 70ss. but i would pay more for the car if it had a little better engine in it. The cam did not sound all that big. but you guys would know better. Well i would like to use it on the street. so that means that i have to change heads or pistons to lower the compression? If it is a LS-6 it has 11:1 commpression? can i some how lower the compression with keeping the same heads and pistons? maybe use a thicker head gasket? also can i use a bigger, modern cam that will bleed some of the compression off? would it then be streetable on 93 octane?

sorry for all the questions i just don't want to buy a car with a motor that will not work on the street at all.

thanks
Tom

 

[Mike Feudo]

Chev sold crate LS-6s that they put open chamber heads on to lower the compression when the gas got bad. I am almost certain an LS-7 cam will not clear the stock pistons in an LS-6. Unless he did a lot of work he is BSing you. An engine with an LS-7 cam in it idles like nothing you have ever heard. Sort of at 1200+ RPM. You will be able to tell as soon as it starts. I think I would be very weary of this guy he sounds a little shakey to me.

 

[Zio]

where can i look on the block to tell if it is really a LS-6? the car had a little bit of a lump, but it just sounded like a mild big block to me. So if he has a ls-7 cam it would have a BIG lump to it?
are the open chamber heads on the ls-6 bad? are they worth using or would it be better to get different heads?

thanks
Tom

 

[Zio]

anyone know how to identify the ls6?

thanks
Tom

 

[DN]

Wouldn't it still have suffix on pad? CRV or CRR. This isn't that dealer off 127th St. is it?

 

[Zio]

no the car is located in melrose park. It is a private owner that is selling the car. I just wanted to get all the info i could about this engine because i might be willing to pay a little more for a car that has an engine with steel crank, forged pistons, solid cam etc.

thanks
Tom

 

[dsr]

Hi Tom
My 1990 LS-6 crate engine which I bought new from G.M. came with closed chamber pistons & rec. open chamber heads which gives you 10:23 to 1 according to G.M. specs. It came with an alum. rec. port holley intake #****163 used on 375 horse 396er's. Also has good steel crank & forged pistons. Came with a solid lifter cam 520/520 lift 242 duration, same cam as 375hp 396. Factory rated at 450 hp & 500 lbs/torque. Mine has the code stamped on the engine block in the front behind the water pump just below the intake manifold. I'll have to check the code it's something like XXA or AXX, I can check it for you tomorrow and post tomorrow night. Dave

 

[Bomber '67]

Cast iron rectangular port intake manifold??? Hmmm...I'm not sure I have ever seen one of those. I would say that this is NOT an LS6. I will also say that engine does not have an LS7 camshaft - an LS7 camshaft makes the engine sound like this: "race me, race me, race me".

An amazing thing happens in the buying and selling of performance cars: many times both the buyer and seller are not exactly sure what they have. Kinda like: Somebody told somebody told me so I'm passing on what I believe or wish to be what this car is. Happens all the time that even someone who owns a performance car for a long time will be a bit lacking on actual specifications.

Don't pay a premium for the car, but if you get it I'll bet it will be a good big block driver.

Thomas

 

[dsr]

Tom The code stamped on my 1990 LS-6 crate engine is TK04XAA9, I think the XAA part indicates LS-6 crate engine. Dave

 

[Zio]

DSR thank you very much for taking the time to find that number for me. When i go back to look at the car again i will check for XAA to see if it is really a LS-6.

thanks again
Tom