500 Beetle.....

[EZ]

After I blew up the 482 C.I. Big Block Chevy engine in my Camaro door slammer drag car I put a second mortgage
on the house and bought an LS-7 454 Crate motor from the local Chebby dealer.  It has 12.5:1 compression, steel
rods, steel crank, 4 bolt mains, 7/16" rod bolts,  big square port heads.  The thing was bullit proof.  All I did was
install a .780 lift cam with about .320 duration in it and go racing. 

You're right.  The old LS-7's were awesome! 

[guidematic]

LS-7? So far as I know they were rhetoric of legend. It was never installed in any car, but may have been available over the counter in parts or even less likely as a crate engine. The LS-7, according to an article I read many years ago was a 454cid version of either the L-88 or the tri-carb 427, can't remember which at the moment.

The LS-6 was a high zoot version of the 454 installed most commonly in the 1970 Chevelle SS454, then in a few 1971 Corvettes. It was essentially a 454 verwsion of the L-72 427 and rated at 450 HP in 1970 only. Lower compression in 1971 dropped the rating to 425HP.

Mike

[EZ]

LS-7 was a crate engine only. I don't think it was in any production cars.  Maybe a prototype or two.
It had 12.5:1 compression and a bigger cam than the LS-6
which could also be bought over the counter through the parts dept but it only had 10:1 compression
and a smaller cam.

I bought mine in the mid 80's for about $3400.  It was expensive back then but looking back it was a steal!!!
I should have bought several!!!   

[trvlr480]

It's true that LS-7's were a crate only engine.  The very early LS-7's had quite a bit more power than the later LS-7's.  I "think" the very first had aluminum heads as well and when they de-tuned them slightly they put cast iron heads on them and a much milder cam but they were still brutally powerful for that era.  I do remember that it was right around 1976 give or take a year when I worked at that corvette shop and the engine that accountant put in his '66 was one of the earlier hot ones.  It would absolutely not idle under 2000 rpm and even at 2000 rpm it had a serious lope to it.  It was extremely fast.  Fast enough to get him killed.  He was driving an Impala with a 283 in it at the time.  I do remember now that after driving around in it he realized it just had way more power than he felt comfortable with and was getting ready to pull the LS-7 and put in a small block.  The night he got killed was going to be the last drive with that engine. It was coming out the next day.

[guidematic]

The aluminum heads would likely mean it was a 454cid version of the L-88. The explosive power and idle characteristics also suggest that to me. L-88's were routinely dynoed at around 525HP. The LS-7 likely would have made in the vicinity of 550-575HP.

Then there was the L-89. That was the aluminum head version of the L-78 and L-72 and the tri-carb version of the L-72 (Can't remember the RPO on that one) It's also rumoured that a few Chevelles in 1970 had the LS-6 with aluminum heads. Apparently a documented SS454 convertible has surfaced some time ago. These are the cars of legend.

Mike

[trvlr480]

The LS-7 likely would have made in the vicinity of 550-575HP.

You're right. I believe they were rated at 600hp.  By the standards back then.  They would probably only have about 400 today.  They did put the LS-6's in the Chevelles.  Trying to find one of those would probably almost be as difficult as finding a factory 426 Hemi in a Dodge Dart.  I actually saw one of those one time.  What they did to shoe-horn that 426 in there was amazing.

[EZ]

If anyone wants to do the math my '67 Camaro weighed 2550 lbs with the steel headed LS-7.  It ran the 1/8 mile in 6.12 seconds.  This is well below the 9.90 index for Super Gas in the 1/4 mile.  Super Gas index was 6.40 in the 1/8 mile.  All I did to the motor was change to a huge solid lift cam, add a high rise intake and an 850 double pumper carb.  I believe if I could have afforded a 1050 Dominator carb the car would have run the 5.99 Super Comp index or at least real close.

[guidematic]

The LS-7 likely would have made in the vicinity of 550-575HP.

You're right. I believe they were rated at 600hp.  By the standards back then.  They would probably only have about 400 today.  They did put the LS-6's in the Chevelles.  Trying to find one of those would probably almost be as difficult as finding a factory 426 Hemi in a Dodge Dart.  I actually saw one of those one time.  What they did to shoe-horn that 426 in there was amazing.

LS-6 powered Chevelle SS454's are not that rare. I think the option cost about $400 over the base LS-5 in the SS454. So about half of the SS454's were LS-6 equipped.

Also I think the 450HP rating is a bit shy of what they actually made. Essentially it was a 454 cid version of the 425HP L-72 427. When that engine was released in 1966 it carried a factory rating of 450HP, but part way through the year it was dropped to 425HP. This was part of a gentleman's agreement between the manufacturers to not post outputs more than 425HP. That's why you see 425HP ratings on the Hemi and Ford 427's. A couple ratings did go to 430, the L-88 and the tri-carb version of the L-72.

So, if the 450HP rating of the L-72 is correct, then I would expect the LS-6 to produce somewhat north of that.

It was quite common for engines to be underrated through the 60's. For differant reasons. Pontiac started it with the SD421's in 1962 to get them into a more advantagous class in Super Stock drag racing. Until the NHRA caught on and began dynoing engines themselves to get the true outputs. They were rated at 406HP@5600RPM but they would spin to 6500 and higher at which point they were around the 500HP point.

Then it was for insurance reasons. Lower ratings meant lower rates, even thiugh that in itself only worked for a period of time. A few of those engines were the Pontiac Ram Air IV 366HP, Chev L-78 396 375HP, Z-28 and Boss 302's 290HP and the winner the 428 CJ rated at a paltry 335HP.

Mike