NemeSS

iTrader: (127)

man,
this thread is heating up.
i can agree that a bbc will beat a lsx hands down inthe ci dept.
but seriously, nowadays, can u drive up to a jy and go in ther and have your pick of any bbc, the way it is with an iron lsx engine?
im not talking about, way back then, but now. heck even the 90's vortec motors are hard to find in salvage yards. now.
and if u did find one say a 454, out of a 90's dually. lets a guy on a budget. that wants to work with the oem heads, intake and block. how much power realisticly can be made with oem 454 iron heads and perhaps and aftermarket manifold. with a rebuilt motor using beter parts. and cam with supporting mods, lt. etc.
i have no pesonal exp. with this bbc type of build, but it seems like alot of opinions and examples are given here. so i assume the person posting about said motors have exp. with such builds.
in my exp. a jy 6.0 bored .060 with vj heads, oem 317 heads milled, ls6, intake, lt, etc. this was with replacement hyper. pistons pinned to stock rods and stock crank with 235 cam i made around 460rwhp thru an m6 and stock rockers with upgraded springs. keep in mind that this was a originally equipped ls vehicle, so a bbc is not an option. a ls motor bolts right in, no fabbing, to fit etc. with proper calibration.
another example in my exp., a 3rd gen. fbody
a 3rd gen needs serious parts just to accomodate a bbc, not saying it cant be done, but its not a bolt in swap. neither is a lsx, however.
imo a lsx is easier to swap into 3rd gen over a bbc, and i can find most any main engine component in a jy if i have to work on a budget.
imo this is the reason i beleive the lsx engine is a better platform to work with. keep in mind that this imo and my exp., i cannot say the same for any one else.
this is racing engines aside bought from big time race shops and so forth.

Super Speed

iTrader: (8)

The tall deck lsx block should be out soon
Either way I'll take a turbo'd lsx motor over a BBC ANY day

capn smokey

iTrader: (1)

Dont worry about pissing me off, thats really not possible Zane First of all I think we need to clarify this argument. I know a BBC has alot more potential than a lsx but what im saying is that is only because of displacement and the inherent strength of its size. I am only stating that a lsx will make more power at the same displacement as a bbc. I have seen bbcs in action my whole life and know very well what they are capable of, I have also owned a few myself. I have also witnessed ls7s make over 700fwhp on many occasions http://www.youtube.com/watch?v=bQ_iElSvmG4
A friend of mine made 592whp in a C6Z06 with cam-only, stock heads and everything. Please find me a N/A pump gas 427BBC making that kind of power, I dont think they are out there is why i am arguing this point. If a BBC could make more power at the same cubes then all of GMs R&D would have been a waste and they would have just copied the design.

LS6427

iTrader: (2)

C6 Z06 427ci engines make a certain amount of power from the factory.....people port the heads so they flow MUCH better and change the cam and exhaust and they make between 580-620 RWHP. WHY???? Because the engine can breath better and utilize theose 427 cubic inches better, no need to increase the CI's to add 100 HP.

A 454ci BBC has much better breathing options (top ends) than any LSx engine has available and ever will, therefore a 454 BBC will kill a 454ci LSx engine. And if someone tried to hang with a 454 BBC engine using a 454ci LSx engine, they would need to spend a ton of money, all aftermarket top of the line parts and use pure race gas, huge cams and high compression, while the 454 BBC would be using pump gas and NOT be an all out race engine that could be a nice daily driver.

Its that simple.

capn smokey

iTrader: (1)

^I dont agree and i dont see any proof of this, you dont need an all out race 454ls to hang with a pump gas 454bbc. What kind of power do you think a 454bbc can make?

capn smokey

iTrader: (1)

Maybe im just ignorant but can someone please prove to me that a bbc can have better VE than a ls motor.

ZONES89RS

iTrader: (25)

Yes, it is EASIER and CHEAPER to put a BBC in a third gen, the BBC has been around forever, the headers are 500$ for the BBC and 800$ for the LSX swap. Everything else pretty much bolts into place, even the factory trans(not that it will last) Factory BBC oval port heads can br ground out to flow their asses off, the rectangle port BBC heads have been proven to be TOO much on some street engine builds.

Also, i still see BBC **** EVERYWHERE for cheap, complete engines and all, i can get a 454 right now complete with ACC brackets for 300$.


That is the problem again Jeremy, you have to spin the 454 LSX higher for the same power the BBC can make at lower revs because of the bore allowing the bigger valves. The aluminum 427 in the ZL1 camaro made over 500 HP in the old days, the LS7 is just on par with it, but yes, i have seen 427 big blocks make high numbers just like the LS7, been there. As stated, the AFTERMARKET is there to support it thru and thru.


I was debating doing a LSx swap in my 89, but this thread just locked in a 496 in the bitch now, thanks

capn smokey

iTrader: (1)

Damnit Zane, join me on the darkside!! Your gonna be upset when your getting drug on the freeway by me and Ill be laughing, all the while getting 25mpg and looking clean! I know the bore spacing argument but how about the difference in rotating mass? Remember the test Hot Rod mag did between a 454sbc and 454bbc? The SBC came out on top by a large margin and also weighed alot less and cost about the same price to build. LS motors have the same bore spacing as a sbc and have even better head design. The BBC has its downfalls, most of which are weight, such as rotating mass and valvetrain weight which is precisely the reason the sbc came out on top. Oh well this is an argument that could go on for ages and never end....there is one way to settle this though.....my cam-only 6.2l w/ a lil spray VS. your BBC build. Get your **** ready Zane and bring your door screws with you

capn smokey

iTrader: (1)

Oh and we know the ZL1 wasnt a streetable motor like the ls7 is and didnt really have much room for improvement.

hangslo

I dont post here much, but had to on this topic ...

The long and short of it is decide what you want ... mileage? lower cost? ultimate power?

I have a TBSS, and have owned several vehicles with LSx based powerplants and I am well aware of what has been done with them, along with the power that they are capable of while also still pulling down pretty decent mileage numbers. Having said that, my 06 TBSS struggles to maintain 16 mpg on the open road, while my big block truck gets 13 ... they both have 4.10 gears and identical height tires, with the BB being 90 cubes bigger, but the truck does not have as good of an overdrive gear (4L80) compared to the TBSS (4l70) so it also spins just a little higher. Mileage and efficiency are all about the total combination, and you can never get the same mileage from two different engines with a 100 ci difference.

That being said, if streetable power is the goal while building as cheaply and safely as possible then the BBC will win hands down. There is just too much difference in the bore size and heads to make up comparing the two. The LSx engines do have some inherent advantages over the BB like a larger cam core, rotating mass, etc., but if we are talking about replacing rotating assemblies, then rotating mass becomes much less of a discrepancy.

The heads that I have for my BBC build are aftermarket (AFR) aluminum heads and are nowhere near being considered the upper echelon of what is currently available, but they trounce any LSx head anywhere in the curve until you start talking about a set off canted valve heads. In addition, the stock big block heads already have canted valves from the factory.

For instance, the L92 heads (considered to be some of the best factory heads produced for the price) flow roughly 320 cfm out of the box ... pretty respectable for any head, much less a "small block". My heads flow just over 300/intake, 250/exhaust ... but wait, thats only at .400 lift. If we start looking at peak numbers then my exhaust port flows what the L92 intake flows, while my intake numbers hover around 400 mark. The smaller bore on a BB is also 4.25 and can move up to 4.5 which unshrouds the valves a lot more than a smaller bore.

CI per CI, compression the same with the same camshaft and induction, the BBC will win every time. If you want to start comparing power adders to N/A, then everything changes, but for two "identical" engines, then the main difference comes down to airflow capability, and the BBC excels there. Can you build a NA LSx engine that will outperform a NA BBC chevy? Sure, but the BBC will be cheaper to build to make the same HP and (depending on the specs) will most likely make much more torque across the curve.

It all comes down to priorities. My BB truck will drag a house down the street, but it is not built to go fast. Take an LS engine and try to do that ... it aint happening.

I like turbo LS engines a lot and almost went that way (and still may on my TBSS), but if its my play toy then mileage is not so much of an issue and if I'm going to turbo something, then it might as well be a BBC. And if you want to go "green", then build it to run on E85 and make even more power.

ulakovic22

iTrader: (12)

Look at engine masters, a pump gas 454 using mostly stock parts and 9.5 CR can make 650 fwhp and there is more room in that number as well in terms of higher compression, electric w/p, RPM range too as this only spun up to 6500.

http://www.popularhotrodding.com/eng...out/index.html

http://www.popularhotrodding.com/eng..._bb/index.html

Abdullah

iTrader: (2)

i would say part for part a well prepared BBC engine will make much more power than LSX engine easily, if you aren't concerned with fuel economy.

KCS

iTrader: (20)

It's been a while, but SAM used to run 8's with a 466ci BBC with GM rect port heads in a Malibu, which has the aerodynamic chracteristics of a cracker jack box. It would basically dominate NMCA's pro Stock class.

Oh yeah, and it had flat tappets too.

JUICED96Z

iTrader: (2)

There are quite a few 454 BBC's making 800ho range. I am sure you can build a 454LSX to handle that but both examples are track only.

Smokey, to get a 454 you need an aftermarket LS block, if you are talking aluminum then you will need a Warhawk untill the RHS comes out. So since you are talking aluminum then compare that to a all aluminum BBC. The weight difference might supprise you.

If you guys want to throw in power adders and all out track only then look at all the guys trying to max out a LSX and look at all the issues they are having. Now take say the guys with a 540 and a 114mm turbo and those guys are making 2,600 pretty easy, the guys on big twins even more and they are holding together. There are a lot of twin guys with BBC's are making 3,000 range.
The LSX guys are just trying to get the motors to last at 2,000hp range and a power adder.
In the end the SBC based stuff will allways be held back by CUI.

Granted you CAN make to much power for the application, Id never even try and run over 1,500hp on the street.

RS, yes some guys do runs sticks but not many when it comes to big power.

99 Black Bird T/A

iTrader: (4)

I agree weight is always bad for mpg, 1/4 mile etc and about everything else!

I was refering to the 454's from back in the day when they were often in cars. Adults in the early 70's were always whining about the horrible MPG with those cars after the oil embargo in 73. Lot of them got parked or sold. There were a lot of 396/427/454 Vette's, Chevelles, Nova's & 2nd Gen Camaro's around when I was a kid.

BTW Nelson Racing Engines has some killer BBC and LSX set ups. Both have packages offered that make 2,500+ hp with forced induction. In my book that more power than I'd ever need. You could probably get into the 6's with that kind of power!

2,500hp BBC forced induction package
http://www.nelsonracingengines.com/p..._572bbc_tt.pdf

2,500hp LSX forced induction package
http://www.nelsonracingengines.com/p..._454lsx_tt.pdf

Pretty sick in my book. I like how the LSX makes the same power with about 120 less CID.

I think NA the BBC will win because it can go to like 700 CID. I think an LSX can go what ~500 CID. Very hard to make up for 200 CID NA regardless of how good the LSX head is vs the BBC head, I'd think.

I'm sticking with my more afforable mild 383 SBC and LS6 383 engines...

KCS

iTrader: (20)

Is the Tall Deck LSX even out yet??? $20 says that the 572 could run larger turbos than the twin 88's, make more power, and spool up faster than the LSX and it's twin 88's....

COPO9560

What would be interesting is to build a 427 BBC and compare results with a built LS7. A set of AFR 315 CNC heads matches pretty close with CNC LS7 ones on intake but the raised port BBC flows better on exhaust - costs a lot less too. This, coupled with the larger bore on the BBC might give it an edge. The LS with fuel injection will behave much better on the street but at WOT either would be a fun ride.

ZONES89RS

iTrader: (25)

You are smoking rocks bro, a aluminum headed BBC weighs te same as a al iron SBC, so, weight will not be an issue, not to mention, i will be making a bit over 700 HP and a 300 hit of dope, if you seriously think a cam only BS motor you are going to put together, you are just needing to stay out of the sun for a while, i will be murdering supras with a bit over 1000 FWHP on 93 octane, you are not even going to be in my league.


But whatever you think.

Yes it was streetable, ran on pump gas, made about 550 HP, and if you think there was no room for improvement, once again, you dont know **** about big block chevys.

ZONES89RS

iTrader: (25)

Oh yea, Dollar for Dollar, the BBC is where it is at no matter what you do.

NemeSS

iTrader: (127)

perhaps u mean some bolt in headers, the headers kit i used previously was diy kit that came with 1 3/4 tubes and 3 in. collectors, i went ahead and vband flanged the collectors, since they were designed for slip fit. i cut and weld to fit. they also have a 1 7/8 headrs and when i called to get mine, they had some 2in. with 3.25 or 3.5 collectors in the works for ls engines.
i payed 450$ for my exhaust that i installed and fab. with vband flange sealing. with 3 in. y pipe and bullet, exit just before rear end. i dont think i would pay 800$ for headers, i can make a turbo manifold and for less than that out of stainless and i did,
see sig. that manifold is especifically designed for a ls engine in a 3rd gen car.