ls vs sbc

[79 drag car]

alright i know this has been discussed before the ls an lq motors against the gen one motors but what really makes the ls/lq so much superior then the gen 1 i know the fuel injection 6 bolt main caps and power make it better but since there were so many chevy 350s produced its hard to compare but lets say we took a 69 caprice 350 sbc rated at 375 hp and put it in a gbody monte carlo then we had 2001 camaro ls1 rated at 315hp and put that in the same g body monte both backed by a 700r4 3.73 rear would the ls1 still get the win because of its power curve and light weight aluminum block basically what i want to know is would a nice 4 bolt 350 chevy stand a chance mod for mod against an ls/lq and what about big blocks against the ls/lq i know the ls/lq has the best daily driver/strip package but right now im just talking about comparing the 2 mod for mod for drag racing and light to light runs all input would be nice

 

[CHRIS.O]

In my opinion the hp/dollar ratio of a gen 1 sbc can never be beaten. However your particular scenario would have the ls1 come out on top. Reason being is most of those are well over the 315 rated hp. Take any ls1 f body and throw it on a chassis dyno and you will see that number to the wheels with no mods. They actually make around 350-360hp. GM really did their homework on the cylinder head design of the ls1. The fuel injection is surely the biggest bonus of the whole set up. In an ls1 f body you can easily pull down mid to high 20's on the highway. Yes I said 20's. Your not going to do that with a carbed gen 1. Ls1's are much more efficient. Although if you had a budget for rebuild of either one and install into a g body the gen 1 would win. Say you had 5k for the engine alone. You could build a 525hp 383 that will drop right into a gbody. Your going to have half that budget just getting an ls1 into a gbody. Either one is a solid choice and I wish I had the cash to drop an ls1 into a gbody.

 

[78MC-BBC]

If i were to do a daily driver G-body it would have an 5.3 or a 6.0 engine out of a early 2000's truck. Reason being is the truck engines can be had with lower miles for a lot less than a typical LS1 or LS2.

LS Series
Light weight for Aluminum block (497lbs)
Good fuel injection
Strong stock engine

SBC
575 lbs
Everyone and there brother has one
Parts are cheap
Typically have to rev

BBC
685 lbs
525 lbs with aluminum heads
Cubic inches!
Weigh alot
Torque monsters
dont need to rev to make power
Can be expensive on parts

But the thing i have come to notice when it comes to a SBC, BBC or LS engine is the price for horsepower.
The difference in price and reliability of a naturally aspirated motor (no turbos or superchargers or nitrous oxide) for lets say a 600hp engine is way different between the 3 engines.

A 600hp sbc is not going to be really a easy engine to have on the street and probably the only thing stock in the engine would be the block. And you are looking at a serious amount of coin. Is also pretty far away from a mild build up.

A 600hp LS Series engine is i believe easier to attain than a SBC for relaibilty concerns and the fact of having fuel injection is a plus. but you are looking at probably a little more money than a similar built SBC.

A 600hp BBC is probably the easiest to get the power out of and remain streetable, the big block i have is a little over 600hp, built to run on pump gas, a single 870cfm carb and with aluminum heads the weight issues are not a factor

 

[dogsht]

I think that is pretty well put 78MC.

My understanding from what I have seen the LS has become cheaper to get HP than a gen 1 and more reliably and fuel efficiently at the same time. That said getting both to X power and getting them on the road in a G tilts that equation in the favor of the gen 1. At least if you are just looking at dollar for dollar and ease & sophistication of the swap.

Chris I think most people give too much credit to fuel injection for fuel economy. More credit especially relative to performance belongs to the overdrive transmission. The lock up torque converter is also normally responsible for at least 1 mpg which is all that fuel injection would typically pick up on the otherwise same setup with a well tuned q-jet. Although the mileage and better driveability is a larger jump if you are comparing FI to a square bore carb. Then there is several other increased efficiencies throughout the engine that combined would also normally be responsible for at least another mpg.

On the opposite side of the coin I believe most people put too much blame on larger displacement for poor mileage. I understand why looking at how most big block engines have been used and were set up. That said it only takes X power to move a vehicle at said speed. If gearing etc is setup to optimize say a 100ci larger displacement engine the actual loses attributed to greater pumping loses & extra weight is minimal.

In fact my 509ci pulled almost the same average mileage as my 307 in the same car with the same trans when both were driven for mileage. It should not have except that it was hand machined, built, and tuned, with more efficiencies such as greater compression than the factoryline assembled 307.

Too many people overlook big blocks for their hot rod project car goals they just follow the herd.

 

[DRIVEN]

lets say we took a 69 caprice 350 sbc rated at 375 hp and put it in a gbody monte carlo then we had 2001 camaro ls1 rated at 315hp and put that in the same g body monte both backed by a 700r4 3.73 rear

That's a flawed comparison from the beginning. As mentioned earlier, the LS engines are proven to be underrated. Also, what '69 Caprice got a 375hp 350? Even the 427 in that car was only rated at 335hp. The LT1 was the only 350 of that vintage with 375hp and it was a pretty rare engine in the grand scheme. Also, you are aware of the difference in the rating system from gross to net in the early 70's? A pretty clear explanation here:
http://ateupwithmotor.com/automotive-te ... power.html

There is also a few fundamental differences in the overall design trends -- not just for GM but most manufactures. Back in the day, performance oriented engines were normally shorter stroke with bigger bores. They needed the larger bore to accommodate big valves because the heads really didn't flow that great. These engines were good at making PEAK horsepower. Today the trend is more toward a square (equal bore and stroke) and head design is more about air velocity than sheer volume. Newer SB heads breathe like old BB heads. Today's engines make nice BROAD power curves. There's also alloy blocks and heads with more even and efficient cooling. The geometry and roller valvetrain is superior too. That's just addressing the engine itself. The advent of EFI and crank-fired ignition systems just make it better.

I love old small blocks and have several but I can't ignore the obvious advantages with the LS.

 

[78MC-BBC]

ive had plenty of small block and i am on my second big block now. but between the two i'd rather have the big block. Even a mild built 454 with lower compression can pull down some nice hp and tq numbers, if you did a similar build with a small block you wouldn't have near the hp/tq numbers of a big block. There is that saying "no replacement for displacement" well when you compare small to big blocks its true. Now days i think the only replacement for displacement is turbos and superchargers. Which basically make a small engine act like a larger one.

 

[DRIVEN]

Displacement is another great point where the LS wins. The LSX can go to 480cid. There are aftermarket LS-based engines in excess of 500cid. Again, these are more of a square-ish engine. The old BBC were oversquare and some of the bores were huge. I bet a BBC 454 (4.250 bore / 4.00 stroke) and an LS-based 454 (4.200 bore / 4.100 stroke) would in the same neighborhood given the same cam specs. I have a suspicion that the LS would have more average torque though.

 

[kornball426]

Hey quick question, since this is an LS thread... Are the engine mounts the same on LS and LQ engines? I have an opportunity to pick up a 2006 GTO with no engine in it for a decent price, and I'd like to get it on the road quick and cheap so I'd just drop a truck motor in it until I could get something better... Assuming that it would bolt right in.

 

[Intragration]

I bet a BBC 454 (4.250 bore / 4.00 stroke) and an LS-based 454 (4.200 bore / 4.100 stroke) would in the same neighborhood given the same cam specs. I have a suspicion that the LS would have more average torque though.

I don't know man, you even said it beofore about the differences in architecture in the modern engines. You can build a lazy bolt-on-only stock heads/cam 346 CID LS1 to make over 400 horsepower and get high-20s MPG. I've done it. Not too many people doing it, but if you were to build an equally lazy 454 LS1, I think you'd be talking in the neighborhood of 500 horsepower. Then you could do things like heads and mild cam and wake that up ha ha. You'd need a heck of a valvetrain and heads on a big block, not to mention a pretty big cam to match a super-mild heads/cam 454 LS1.

I'm personally an old big block guy, that's what I love, that's what I prefer. I like lazy massive torque, and I really don't care about efficiency. But there's something to be said for the LS motors. They have advantages that make them impossible to ignore for guys who want power. But if you still just love lazy torque, they are no replacement. I own both, and they each have their specific purpose. My big blocks get the wheels driven off of them, and my LS1 sits.

 

[84cutlassjuggalo]

i'm glad you made this thread because it allows me to learn a lot abotut both motors. personally though for dollar to dollar and the easy of maintance and part accebility i would go with first gen because as metioned before every one and their brother has one. I also think Ls are over rated and over used. there are more ls swaps than asains (not to be racist). also they even have people putitng them in cars like rx7s and even 240sx's. I'm a little sick of seeing ls motors. I will not argue the fact that reliability and power of the ls but carberated are much simpler to maintain and cost less find. but that's just my.02