Engine weights- LSx vs. SBC vs. BBC.

[Todd80Z28]

We've discussed this ad nauseum here, and Brian Callahan has his most excellent weight database with lots of info. However, I was reading this article last night- Hot Rod's GM crate motor shootout.

(5MB file)- http://www.gmperformanceparts.com/_res/pdf/MagazineArticles/49917_eprint.pdf

Take a look at the race weights for the different combos. What struck me as most odd was that the smaller-than-expected different in the engines.

LS7 (alum block, heads)- 3420 lbs.
LS3 (alum block, heads)- 3334 lbs.
LS327 (iron block, alum heads)- 3386 lbs.
ZZ4 & ZZ383 (SBC, iron block, allum heads)- 3360 lbs.
ZZ427 (iron BBC, alum heads)- 3520 lbs.

I'm most surprised that the LS7 is so much heavier than the LS3. I didn't think the dry sump stuff would add that much weight. I'm also very surprised that the ZZ4/ZZ383 SBC is only 25lbs heavier than the LS3, and that the LS327 is actually 25lbs heavier than the standard SBC.

These engines are missing most accessories, of course, but they're all missing them, so the comparison seems pretty valid.

Thoughts?

 

[daniel76309]

I agree. I also would have thought an all aluminum engine (LS-3) would amount to greater weight savings relative to an iron block engine (ZZ383). I intend to replace my existing 350 with an LS 3, and a significant consideration in selecting LS3 over (e.g.) ZZ383 was for reduced weight. My current combination has iron heads and A-6 AC compressor, etc., so I would be reducing weight either way. There are other valid reasons to go the LS route, but still, I would have thought that the alum block would make more difference. Interesting...

 

[TheMeat]

Obviously these engines don't each weigh over 3K lbs. Which car/chassis were they mounted in?
I attempted to open the link you posted but no luck.

 

[Todd80Z28]

The whole file had to download for me before I could see anything.

Yeah, the race weight was the whole car, not just the engine. It was a '71 Chevelle, didn't have the front fenderwells, and all accessories except water pump were left off the engine. In most cases, they used an electric water pump.

 

[Aceshigh]

I'm most surprised that the LS7 is so much heavier than the LS3. I didn't think the dry sump stuff would add that much weight.

I saw the picture with the dry sump cylinder in front.
I have no idea how much it weighs, but it's not small.
An engine compartment-mounted 8-quart reservoir delivers oil to
the engine oil pump under the demanding conditions of cornering loads in excess of 1 g.

I wonder how much bigger the LS7 block is over the ZZ SBC

Obviously these engines don't each weigh over 3K lbs. Which car/chassis were they mounted in?
I attempted to open the link you posted but no luck.

All in the same car. A 1969 Chevelle.

 

[quadriderkyle]

I have this issue of hotrod and was stunned at how fast they got that 327hp 5.3L to run, I think it was something like 12.35 in the 1/4. I guess it is all about traction and matching the converter and gears to the engine.

 

[5spd540]

I cant belive how heavy a ls7 is

 

[BonzoHansen]

An engine compartment-mounted 8-quart reservoir

A case and a half of oil and the tank, lines, etc adds up

 

[Todd80Z28]

I'd forgotten all about this.

 

[BonzoHansen]

LOL I didn't notice the dates!