LS compared to BBC

[SuperBuickGuy]

Originally Posted by Tom

How that has any relevance to a big block vs LS swap is beyond me.

op- 700hp does not require boost, but yes it requires dollars. Same thing with big blocks though. Remember an LS can go to 454cid.

a core BBC 4 bolt main is available to me for $500 (actually, $120 if I simply spend the gas to go get one I have a few miles away); the cheapest 6.0 I've seen 2k and the LSx block required for a 454 build (not including the 10k of machining) is $2500.... dollar for dollar I think can build more power with a BBC.

BBC does have rpm limitations because of their valve train, but weight is almost a wash since the 6.0 iron block about the same as a bare bbc 225 for LS, 250 for bbc.

Not just that, but anywhere about 500 hp and head gaskets tend to be the fuses in BBC and LS motors... so as car flippers say, you make your money when you buy the project. What I'm coming up with between the two is I can get a rebuilt 454 for $3000, heads for another $1500 and everything for another $1500 (intake, etc).... with an LS motor, it's about 2k-3k more.

But fuel economy is a thing that factors in this, and in that the LS rules....

I almost like the implied challenge to see if I can make a bbc get high-teens/low 20s and still make the hp number in a C10 pickup... efi and electronic ignition along with smart head choices.... dunno (thinking out loud more then anything else).... so far about the best I've ever got out of a bbc is 13.... that said, my 2006 GTO with the 6 speed got 14 around town at squeaked 17 on the highway...

[BR3W CITY]

Originally Posted by SuperBuickGuy

I almost like the implied challenge to see if I can make a bbc get high-teens/low 20s and still make the hp number in a C10 pickup... efi and electronic ignition along with smart head choices.... dunno (thinking out loud more then anything else).... so far about the best I've ever got out of a bbc is 13....

That challenge can be cheated if your willing to get into the deep cuts of the GM extended vendor parts catalog, and aim the build towards a primary purpose.

My biz partner has designed and built more than 6 variations on the "last" of the BBC's on the 8.1L platform (GM no longer owns the patents on the 8.1, it was sold to a 3rd party and GM buys back what it needs). GM's change to the "modern" ECM/EFI systems during the final life of the 8.1 was a large leap forward in terms of economy.

The needed heads are a big part of the recipe, and are probably the hardest to get. All of the specialty 8.1's and 8.8's (oooh yeaaa) the company has been making use a specially cast & machined head, and intake manifold; different from anything GM offered on any light/medium duty truck.

These can be paired with a very torque focused cam, and will yield a 15-20mpg 8.1 in a 8k pound truck. You'll be redlining around 3600 rpm, but in a tow pig or lifted beast on 38's it would be cool. The designed purpose was commercial duty trucks which don't have access to diesel fuel.

The same platform is used in an 8.8L variety with either a single, twin, or twin compound turbos. The version with small twins (very small for this size engine) can get around 17 on the highway, but is rated in vehicles over 12k pounds. If you've never seen a ******* schoolbus do a burnout off the footbrake, your missing out.

edit: can't use the company name, the contract is private.

[SuperBuickGuy]

Originally Posted by BR3W CITY

That challenge can be cheated if your willing to get into the deep cuts of the GM extended vendor parts catalog, and aim the build towards a primary purpose.

My biz partner has designed and built more than 6 variations on the "last" of the BBC's on the 8.1L platform (GM no longer owns the patents on the 8.1, it was sold to a 3rd party and GM buys back what it needs). GM's change to the "modern" ECM/EFI systems during the final life of the 8.1 was a large leap forward in terms of economy.

The needed heads are a big part of the recipe, and are probably the hardest to get. All of the specialty 8.1's and 8.8's (oooh yeaaa) the company has been making use a specially cast & machined head, and intake manifold; different from anything GM offered on any light/medium duty truck.

These can be paired with a very torque focused cam, and will yield a 15-20mpg 8.1 in a 8k pound truck. You'll be redlining around 3600 rpm, but in a tow pig or lifted beast on 38's it would be cool. The designed purpose was commercial duty trucks which don't have access to diesel fuel.

The same platform is used in an 8.8L variety with either a single, twin, or twin compound turbos. The version with small twins (very small for this size engine) can get around 17 on the highway, but is rated in vehicles over 12k pounds. If you've never seen a ******* schoolbus do a burnout off the footbrake, your missing out.

edit: can't use the company name, the contract is private.

heh, maybe that's where I should be looking for my FJ40 - I've been disappointed at the torque of the 350 in it, so that might be the right thing... hmmmm....

this really won't be a tow rig (at least not in my mind, more a cruiser with a pickup bed that will haul my dirt bikes/quads)....

[Alex V.]

Originally Posted by '63GENIII

The L29 does have a cam, injectors and a tune so this may be an unfair comparison. I would really like to see what the 7.4 would be like with a 4L80 in a 2wd truck with a decent suspension.

To fill in a couple blanks if I may, that '98 K2500 Suburban (4L80E/4.10's) I mentioned (BIL's dad's rig) supposedly gets around 14 MPG empty/highway - they're a scientific bunch so I'd say that number is more than a guess. My '85 C3500 (TH400/4.10's) tacked down 12.5 highway just like clockwork on numerous trips to the city running 55-65. I've never known it to get less than 9.5 pulling as much as 9,000 lbs. (GCW 14,500). The '98 Suburban has towed a 32 ft. enclosed tri-axle trailer on 1,000 mile trips several times, more often than not loaded with heavy cooking equipment and/or furniture, small cars, etc. - no idea of GCW but I know of at least one occasion where he set the cruise @ 75 MPH and it was downshifting to 2nd on some of the steeper hills through Missouri to hold it. I wish so badly I'd have had a run-by video of that with the dual Flowmaster 40's on it. :O

The 6.0 powered trucks I've driven just seemed like a much different animal than those 454's. Not altogether weaker, but designed more around horsepower than torque with the drivetrain changes to bring that out - higher stall converter, higher shift points, etc. It's probably just what I'm used to, but leaning into a load with a 454 is just more gratifying.

[Alex V.]

Originally Posted by '63GENIII

The L29 does have a cam, injectors and a tune so this may be an unfair comparison. I would really like to see what the 7.4 would be like with a 4L80 in a 2wd truck with a decent suspension.

To fill in a couple blanks if I may, that '98 K2500 Suburban (4L80E/4.10's) I mentioned (BIL's dad's rig) supposedly gets around 14 MPG empty/highway - they're a scientific bunch so I'd say that number is more than a guess. My '85 C3500 (TH400/4.10's) tacked down 12.5 highway just like clockwork on numerous trips to the city running 55-65. I've never known it to get less than 9.5 pulling as much as 9,000 lbs. (GCW 14,500). The '98 Suburban has towed a 32 ft. enclosed tri-axle trailer on 1,000 mile trips several times, more often than not loaded with heavy cooking equipment and/or furniture, small cars, etc. - no idea of GCW but I know of at least one occasion where he set the cruise @ 75 MPH and it was downshifting to 2nd on some of the steeper hills through Missouri to hold it. I wish so badly I'd have had a run-by video of that with the dual Flowmaster 40's on it. :O

[SuperBuickGuy]

Originally Posted by Alex V.

It's probably just what I'm used to, but leaning into a load with a 454 is just more gratifying.

I live near Seattle, this is a very good point, watching greenies hide behind their mommy's skirt when I lean into any of my environmentally sensitive vehicles* is something I get way too much joy from.

*C3 Corvette with side pipes cam/holley, FJ40 with a 350 (flowmaster 40s - they don't muffler more then they tune), H3 Hummer Alpha (v8)... I embrace Mother Earth until she screams.

[Marv D]

The LS motors are the small motor for the millennium. Even though they can be made to BIG HP numbers, built for 1/3 the $ and get 2x the fuel mileage...
I think it REALLY depends on what your doing with the truck!!
I've towed with both the 6.0 and a 454 BBC. Give me the BBC ANY DAY with 10,000 pounds in a trailer. A 454 4l80E or NV4500 with the right gearing is a SWEET tow set up (and that's coming from a hard core SBC guy)

If your not working the crap out of the truck with heavy loads,, LS is the ONLY way to go IMO. You can not beat the simplicity, cost, efficiency and power offered in the LS platform. Like BR3 ad others are telling you,, the BBC was the workhorse of the last 7 decades. But the LS is it's replacement,, get used to it. aPrts and pieces that used to be laying around every GM addicts garage are disappearing at alarming rates. And money follows the trend. As less and less SBCs and BBc are used in custom builds,, the aftermarket is moving away from supplying us with pieces too. The day will come when ALL sbc / bbc parts are 'collectors items' . How far away is that????? I wish I knew

[b454rat]

I don't think the SB/BB are gonna go away or loose too much following. There are people out there that will mess with them no matter what. Look at the flat head, a V-6 makes more power but some people can't get enough of them. IMO, one of the problems with an LS isn't necessarily the motor but the tranny. Not enough gears. I have an 08 Tundra with the 5.7, 370 horse 380 torque or something like that. I has the tow package, 4.30 gears, and think its a 5-6 or 7 speed don't remember. But I've pulled with it, and it does pretty damn good. I think it's comparable to the LS motors, makes power higher in the RPM range. I don't race or really hot rod the truck, it was my late fathers, and want it to outlast me. But get the Rs over 4k and hang on!!!!! It pulls like its' trying to rip your arms off. The truck is lifted with 35s on it too. I think LS engines would do better with more than 4 gears. My 99 crew has a tired 350 and 3.73 gears, and the gear split in the tranny is pathetic. I had 4-500 pounds in the bed and it was a noticeable amount that just killed any type of pulling or acceleration of the truck. And the guy I bought it from pulled a 6k camper, how I don't know. It's a total dog. I know it's not the same, but just saying if it had more tranny gears and more rear end gear, it would do better, and think LS's as well. Hopefully some day I can do the 8.1 swap in my truck, and put a 6.0 or similar in something, just to cure my own curiosity.

[Ironangel]

It's an apples to apple pie no brainer for me. The newest vehicle I own is a 91 Jeep Cherokee with more than half a million miles on the clock. My apple pie is a 1969 L34 396 in one of my 72 C/10's, no computer necessary. And hey, when the lights go out or when an EMP event occurs, I pull a dizzy out of a steel can and we're rollin again. When I see an LS in a 67 -72 or any old Chevy I'm like, "wheres the motor?" Totally out of place and unimpressive in my book. I'm finding them turbo diesels more attractive than LS motors, they fascinate me for some reason. My old KZ still beats the ZO6 in 60ft. 1/8th, and the 1/4 mile, she dont leak oil and neither does that BBC. Guess the short answer is, "no comparison" ~Ghostrider~

[James the III]

Originally Posted by SuperBuickGuy

I live near Seattle, this is a very good point, watching greenies hide behind their mommy's skirt when I lean into any of my environmentally sensitive vehicles* is something I get way too much joy from.

*C3 Corvette with side pipes cam/holley, FJ40 with a 350 (flowmaster 40s - they don't muffler more then they tune), H3 Hummer Alpha (v8)... I embrace Mother Earth until she screams.

You're in the woods, doing volunteer work recovery and such..

1) the ls dies and you need to get it running what do you do
2) the bbc dies and you need to get it running again..

the ls is ecu controlled completely
your bbc most likely will be a carb and a HEI

What one you think you'll get running again.. to continue helping or get the vehicle out of harms way..??

[clinebarger]

Originally Posted by James the III

You're in the woods, doing volunteer work recovery and such..

1) the ls dies and you need to get it running what do you do
2) the bbc dies and you need to get it running again..

the ls is ecu controlled completely
your bbc most likely will be a carb and a HEI

What one you think you'll get running again.. to continue helping or get the vehicle out of harms way..??

I would rely on the LS to not break down over any carbureted engine!

[SuperBuickGuy]

The discussion is cool - but I'm actually more interested in the cost to each motor....

[b454rat]

I had my 454 fully rebuilt for about $3500. ATT, I loosely priced LS, and didn't come close. There are so many "little things" needed with an LS it seems like a pain. Granted if the LS is going in a truck it might be different. I know prices are coming down on the stuff, but to me the lack of power between the two is just too much.

[nlped]

I have a complete 5.3/4L60e that I was going to put into my '68 C10. I also happen to have a complete 468/700r4 combo that I was going to find something for it to live in. But after a personal inflection...I want Walter to have a BiG motor with overdrive. Now, don't get me wrong, it will be EFI. I spoke with the EFITech guys at sema and I think I'm going that route.

[my56chevytruck]

Originally Posted by SuperBuickGuy

Help me make up my mind on which way to go. MPG would be nice, but I'm willing to ignore that to hear that sweet, sweet music of a BBC.

The nutshell is if I were to buy a 6.0 LS motor and trans from one of the ebay-type sellers - what did it cost to put it in a 72 Chev 2wd pickup? I've done 454s, so that question is more - were you sorry you chose a 454... or vice versa.

I've never done an LS motor, and I understand they are good and efficient. Although, I like seeing a carbureted engine far more than seeing runners. just my opinion. I've only got big blocks in my hot rods and have no thoughts of going otherwise.

[slammed57]

yeah I know this is an old tread, thought I'll dig it up again. I do like LS but BBC like this NEVER gets old to look at , much less the sound of it..... As for me this speaks volumes of hot rod and why I love this hobby..... As for cold starts and MPG thats what my daily driver is for. And that is why I went with a BBC this time around. and as for the LS crowd I understand it and respect everyones opinion and we all can still be friends lol, But this is flat out the definition of cool!

[jrusher]

Ive built both in the last 3 years a 496 for my 67 chevelle with pretty much the best of the best parts top to bottom and a ly6 6.0 for my 65 c10 which i freshened up the bottom end and the heads and added a camaro intake, tb, texas speed cam, uprgaded rockers, valve springs etc
The 496 cost me just over 10 grand in parts and machining plus my time to assemble and the ls came in about $6000 with parts and machining plus my time to assemble
I wanted an old school look in my chevelle and never built a big block before so I wanted to see what kind of power and torque it would have. Its a 4 speed car 3:31 posi The thing makes awesome torque it pulls hard to about 5200 then flattens out abit I havnet had it on the dyno yet and it runs abit rich so i know theres more power left on the table. The thing drinks fuel like crazy hopefully after i lean it down and dyno tune it it will be better. I dont drive it much. Then i built an LS for my 65 c10
My c10 with the 6.0 made 380 hp at the wheel , it pulls pretty good off the bottom but nothing like my 496 but its really responsive, quick revving and revs quick and hard up too 6300 rpm . i have a built up 4l80e in it and 3:73 posi rear . I have to add a higher stall yet as the cams abit big. Its fun to drive and good on fuel.
If i were to do it again i would go with another 6.0 in my chevelle and maybe a turbo its hard to beat the price of the ls and the cheap hp you can make with these things. No oil leaks, no jetting and decent fuel economy. I just put a used 4.8 in the wifes 61 apache that i just built up for her. Was a supposedly low km engine/tranny 230km ish that i got off the local classifieds for $600 and the thing runs like a brand new engine. Such a well designed engine luv the ls family

[cadillac_al]

Originally Posted by jrusher

Ive built both in the last 3 years a 496 for my 67 chevelle with pretty much the best of the best parts top to bottom and a ly6 6.0 for my 65 c10 which i freshened up the bottom end and the heads and added a camaro intake, tb, texas speed cam, uprgaded rockers, valve springs etc
The 496 cost me just over 10 grand in parts and machining plus my time to assemble and the ls came in about $6000 with parts and machining plus my time to assemble
I wanted an old school look in my chevelle and never built a big block before so I wanted to see what kind of power and torque it would have. Its a 4 speed car 3:31 posi The thing makes awesome torque it pulls hard to about 5200 then flattens out abit I havnet had it on the dyno yet and it runs abit rich so i know theres more power left on the table. The thing drinks fuel like crazy hopefully after i lean it down and dyno tune it it will be better. I dont drive it much. Then i built an LS for my 65 c10
My c10 with the 6.0 made 380 hp at the wheel , it pulls pretty good off the bottom but nothing like my 496 but its really responsive, quick revving and revs quick and hard up too 6300 rpm . i have a built up 4l80e in it and 3:73 posi rear . I have to add a higher stall yet as the cams abit big. Its fun to drive and good on fuel.
If i were to do it again i would go with another 6.0 in my chevelle and maybe a turbo its hard to beat the price of the ls and the cheap hp you can make with these things. No oil leaks, no jetting and decent fuel economy. I just put a used 4.8 in the wifes 61 apache that i just built up for her. Was a supposedly low km engine/tranny 230km ish that i got off the local classifieds for $600 and the thing runs like a brand new engine. Such a well designed engine luv the ls family

Big block wins the beauty contest hands down.

[YoungPup1977]

I like both and have both. I like my 1967 camaro SS with a original big block.....would I replace the big block with a LS, hell NO !!!

[Ziegelsteinfaust]

Originally Posted by davepl

As much as I like the old big blocks, I don't think you can compare. After all, a big block passenger car, something mild like our trucks or an Impala, will go 100,000 miles if treated well before needing a rebuild.

For whatever reason, LS motors seem to be able to run to 200,000 miles and beyond. I don't know what the difference is - machining processes, materials, I don't know. GM got it right with these though.

Either motor, done right, will serve you for a long time. And either motor, done wrong, will annoy the heck out of you.

The biggest difference in engine life of now vs back in the day is oil pure, and simple. Namely the packet of additives they use now in the synthetic oils.

I had a 325hp estimated 307 I built for a friend who did cell tower installs all over the western US. It lasted 300K miles with very little bearing wear, and very little oil usage. The bores were hammered, but still had life to go. He finally got rid of it because it wasn't going to die when he switched jobs, and wanted to install his 450hp 350 that just sat.

[my56chevytruck]

Originally Posted by jrusher

Ive built both in the last 3 years a 496 for my 67 chevelle with pretty much the best of the best parts top to bottom and a ly6 6.0 for my 65 c10 which i freshened up the bottom end and the heads and added a camaro intake, tb, texas speed cam, uprgaded rockers, valve springs etc
The 496 cost me just over 10 grand in parts and machining plus my time to assemble and the ls came in about $6000 with parts and machining plus my time to assemble
I wanted an old school look in my chevelle and never built a big block before so I wanted to see what kind of power and torque it would have. Its a 4 speed car 3:31 posi The thing makes awesome torque it pulls hard to about 5200 then flattens out abit I havnet had it on the dyno yet and it runs abit rich so i know theres more power left on the table. The thing drinks fuel like crazy hopefully after i lean it down and dyno tune it it will be better. I dont drive it much. Then i built an LS for my 65 c10
My c10 with the 6.0 made 380 hp at the wheel , it pulls pretty good off the bottom but nothing like my 496 but its really responsive, quick revving and revs quick and hard up too 6300 rpm . i have a built up 4l80e in it and 3:73 posi rear . I have to add a higher stall yet as the cams abit big. Its fun to drive and good on fuel.
If i were to do it again i would go with another 6.0 in my chevelle and maybe a turbo its hard to beat the price of the ls and the cheap hp you can make with these things. No oil leaks, no jetting and decent fuel economy. I just put a used 4.8 in the wifes 61 apache that i just built up for her. Was a supposedly low km engine/tranny 230km ish that i got off the local classifieds for $600 and the thing runs like a brand new engine. Such a well designed engine luv the ls family

sorry, but the carb'ed engine is by far the better looking one, it belongs there

[YoungPup1977]

BAck when the big block was introduced GM did not have the overdrive designed as they do today. You can praise the LS engine but the overdrive trans help save the LS engine from constant 3000 rpm cruzin speeds. Just my thoughts...

[The Rocknrod]

Originally Posted by my56chevytruck

sorry, but the carb'ed engine is by far the better looking one, it belongs there

Ya I considered an LS for a second or two. To me they look like a goat at a dinner table, just don't belong there. If it were a fiberglass faux street rod I'd say yes. But again that's the fun of this hobby, everyone can build what 'they' want and it's appreciated by someone. So no matter what you do someone is going to like it and someone will not. Just have fun with it.

[jrusher]

I agree the bbc looks the best under the hood and there’s nothing like the bottom end grunt of that engine it’s a blast to drive. For me I really could care less how one doesn’t look right under the hood compared to the other. I don’t build show cars or factory oem restorations . What matters to me is performance, decent fuel economy , reliability which equates to less wrenching. That’s where the ls wins in my books. Ls efi only way to go I’m going to turbo my 65 this winter can’t wait should be around the 600-700 hp mark. Reliable cheap hp and I don’t have to stop at every gas station I pass.

[Tom]

For work, the big block wins every time. Cubic inches and torque!
For play, the LS is better in just about every way. Less weight and HP.