ls vs sbc

[Intragration]

I think the LS wins on maintenance too. There is none. Change the oil. A buddy of mine has one, bone stock, 350 horsepower, nothing but oil and gas for 105k+ miles. Probably due for plugs. They require almost no thought once running and tuned. Even still, they just don't do it for me. I want something with flavor, and idiosyncrasies. A belching, shaking gasoline engine, not an appliance. But I am a dinosaur. 😀

 

[DRIVEN]

^^Well said^^. I totally get that. I've been thinking about an engine upgrade on my Cutlass. It has a 305 so a traditional 350/383/400 would be the obvious "easy" upgrade. An LS would be the "smart" upgrade. But I'm with you, I like engines, not appliances. That's why it'll probably get a 403. It just seems "right".

 

[78MC-BBC]

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.

all LS & LQ engines have the mounts in the same location. there are quite a few guys running the 6.0 block in GTO's and F-bodys for the displacement and strength of the iron block

 

[dogsht]

"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."

Same heads/cam you would get the same ish 400HP but you would get at least another 100 foot pounds of torque from the displacement change. This is a very common misconception please take no offence I point it out only for your info and the benefit of the readers.

I am about high power but low maintenance even drive-ability & reasonable mpg which is part of why I have liked the big blocks for street builds. The LS being like an appliance though is an interesting comment. I have never thought of that but I know exactly what you are saying. For a hot rod driver you can cam it and uncork it even carb it if you want and you should be able to come up with some sound and maybe even some thump. I don't just mean at wot but at cruise and idle. LS still doesn't conjure up in your mind the lusty sound of a well cammed big block.

I agree with the square architecture being better even undersquare providing you can get it to breath. As well as the variable valve timing cams, superior electronics, head designs, valvetrains, etc. Talking about LS series & big blocks interesting to me anyway was that the then standard of the world 68 to 76 Cadillac big block not only had superior block castings & crank strength they also had the combustion chamber design and fireing order that the LS series now use. They also used a perfectly square 4.300 bore by 4.300 stroke. They even pioneered the now due to superior computers & electronics successful cylinder shut down economy systems. LOL Hindsight also shows that they had broomstick sized cam shafts and a head to intake relationship that makes airflow move through a checkmark design which doesn't take a rocket scientist to figure out isn't going to work well beyond a point.

 

[Clone TIE Pilot]

I know everyone keeps saying the price of LSs keep going down, but I have yet to see it in person. In my area go to any junkyard and they want alot more $$$ for an LS over a gen 1 SBC, with no guarantees on either. Also all the LS motor parts seem to cost alot more than SBC parts, often two to three times as much as an SBC's. Then there are all the adapters needed to retrofit an LS into a car not designed for it. Most LS swaps I have seen are usually not legally done swaps, ie lack the LS's factory emission systems. So if one lives in a strict area like CA or NJ, count on retrofitting the LS's OBD2 emission system into your car which is going to add more costs.

The problem I see is that LS engines are just so different from SBCs, that it's hard to compare the two. This is also why LS engine cost more to swap in. But when it comes to low cost, SBCs still win. Not all LS engines are aluminum blocks, most of the truck ones are cast iron I believe (besides being illegal to swap a truck motor into a car or vice versa). Aluminum blocks do have cons, they cost more, they are weaker (which is why LS motor have 6 bolt mains), and are more prone to warping and cracking. I have seen in person where it doesn't take much of a tap to punch a hole in an aluminum LS block. IMHO I rather have an iron block version of the LS.

As for older engines like SBCs not getting good MPGs, an Carbed SBC with the CCC and an overdrive trans gets into the 20s without problems, then there's also TBI and TPI setups and even vortech heads. Of course many ditch the CCC Qjets for a gas dumping aftermarket carb which are not designed for MPGs. Often put together mismatching powertrain parts, such as not having a TC with a stall speed that matchs the camshaft's RPM range, etc.


It's really just comparing apples to oranges really.

 

[Intragration]

Same heads/cam you would get the same ish 400HP but you would get at least another 100 foot pounds of torque from the displacement change. This is a very common misconception please take no offence I point it out only for your info and the benefit of the readers.

This makes sense, and I don't necessarily disagree. I was being very general, but I guess what I was saying was, if you built a 454 LS motor with a larger cam and better heads that matched it the way the stock LS1 parts match the 346, you would have a pretty massively powerful motor that was extremely docile. But you're right, just changing displacement would not change horsepower much.

I am a fan of big displacement, and this discussion does make me wonder about how a big displacement LS motor might behave... But it's such a different world than the one where you go to the junkyard and pull a 450+ cubic inch motor out of a station wagon and throw it in your intermediate car for under $1,000. How much would you spend to put an LS motor of similar displacement in your car? And what would that station wagon motor be like if you spent a similar amount of money building it? Hmm...

 

[dogsht]

Having put a 509ci motor in an intermediate car you could say I am also a fan. :lol: I think a 500+ ci LS motor would not just be cool but fantastic to drive. I skipped the bling and the forged aftermarket parts where I didn't need them and built toward the safe edges of the factory parts trying to spend money and work just where it was needed and prudent. I think 600 cubes or a 4.5+" stroke would be overkill and beyond the useful limits of a practical suspension & tire. I am talking an upgraded suspension with say up to 29 tall drag radials. Back to practical doing much of the work myself and through relationships I still ended up with just over $3,500 in a completely fresh motor carb & distributor that dialed in could have made 500HP & 600TQ. It would be equivalent to the 502/502 crate without the warranty. You would have that in parts to do a 500ci LS motor. Would it be a better overall package make more power and more fuel efficient? Yep. but lots more coin plus the additional costs & work of the swap.

Earlier they mentioned the 600HP level comparisons. Which were great but never even got to what you were going to spend on that especially gen 1 small block package/car to make it live and work vs the BB. Your talking high end aftermarket valvetrain to hold together while spining the snot out of it. You are only buying that high end Harland Sharp etc valvetrain cheaper than another motor IF you have to buy it for both. Big stall converters and steep gears that are not practical or street friendly let alone fuel efficient. Not to mention what cooling system upgrades it will require to support it. Aftermarket heads, girdles, oil pans, scrapers, where it would be needed for one but not yet the other.