Re: Engine?
 

I shoulda been more specific... It was a 3200lb car, solid roller on race gas.. The huge advantage with an LS i that they require waaay less labour to make power... I would say there are more bbc aftermarket parts on the market, but that could be untrue is as little as 5 years.. Who knows...! Bottom line is do your research and build what you want :)
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Re: Engine?
 

Well this would do it easily. :lol:
http://www.hotrod.com/techarticles/e...e/viewall.html

Re: Engine?
 

I'll take one for 10,000

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I will take two for $10,000 :metal:

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Usually when they don't list the price, it costs too much. :lol:

Re: Engine?
 

LS motors are impressive. You can buy a 750hp LS based (LSX454X) crate motor from GM PERFORMANCE PARTS. A 454 cid small block? Ok...it's a small block, GM says so. Not very streetable, not intended to be (13.1:1cr, solid roller cam and a carb, not injected) and not on pump gas. Makes all the hp and torque numbers at "peak RPM" what ever "peak" is. LS motors are impressive, however, with 502 cid big block you can have 502hp @5200 RPM and 567lb.-ft. torque at 4200 RPM, 500+ lb.-ft of torque at 2500 RPM and drive it anywhere/everywhere for a long time with low maintenance on pump gas. You can't do that with a NA "small block". Now... be nice to me with your replies (I'm putting up my umbrella preparing for the sh*t storm I know is coming). Once you go big block you'll never go back.

Re: Engine?
 

All of these motors are impressive but they all got there ups and down. Its like the old saying goes you have three choices when it comes to a motor: cheap, fast, or reliable, but you can only choose two. You can make a gen one small block (350 or 383) crank out 500hp easily and be just as reliable as that 502 as long as you know what you are doing for less. LS motors are great because they are a very efficient design and don't take much to make good power, but they're going to get more expensive as demand grows for them. You can make an old gen one small block perform just as well as an ls motor in performance and "streetability" for the same amount of money if not substantially less than a brand new ls motor from GM. Same applies for a big block, but big blocks are known for making as much power as you want depending on your wallet thanks to the fact that there is no replacement for displacement (but don't expect them to get the gas mileage of an ls motor, but then again I wouldn't complain :metal:).

Re: Engine?
 

Are those engine dyno numbers or chassis dyno numbers? Seems like a short power band, 1k rpm. Bad heads/intake on that combo?

My little 418 pump gas hyd cam low maintenece motor made 521rwhp at 6,950 and 469ftlbs at 5,500. Just putting it out there.
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Re: Engine?
 

I have to guess those are the numbers at the flywheel. Those numbers are from the GM Performance Parts catalog, I haven't had my motor on a dyno. 1k power band? Where do you see that?

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I was reffering to peak TQ (4,200rpm) and peak HP (5,200rpm)..

Re: Engine?
 

I must need an education on what "power band" means. The way I look at the numbers the power starts coming on at 2500 RPM and falls off around 5200 RPM. Sounds like a fairly wide power band to me. If I am wrong please enlighten me. I drove trucks for a living for about 10 years. They had a tight power band: 1600 - 2100 RPM or 1800 - 2100 RPM, 500 and 300 RPM respectively. Now THAT is a short power band.

Re: Engine?
 

Most converter companies will set a converter at Peak TQ or a couple hundred RPM past for max 1/4 mile ET on a NA motor. You will go fastest out of the hole hitting the tires with everything you can TQ wise. So, to me, with a drag racing application, you must consider shift extensions of the transmission you are using. Looking at average power in that rpm range is much more important that what is under the curve. Since most transmissions will create more than a 1k rpm drop having a longer peak to peak rpm band is not a bad thing.

Example:
My motor makes peak TQ at 5,500 rpm and peak HP at 6,950 rpm.
Data logger shows a shift at 7,700rpm with the glide and it comes back in second at 5,600.
Data logger shows another pass I shifted at 6,500 and rode the converter at 5,200ish.

Since I should be shifting the old combo about 7,100, I want the most average power between the converter at 5,200 and 7,100 meaning 1,900rpm.

Now I have a 5,200 rpm verter vs a 5,700 due to using a N20 system.

Does any of that make sense?


Some will argue that riding the converter will help multiply TQ with the gear changes and net a better ET. I think that is dependant on combo.


There is much more to this, it's not that plain and simple, but something to consider. Road cars, street cars and drag cars are all differentand require different things.

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Thank you for the education. I've said this before...great picture of your truck with the left front wheel in the air.

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big block old school for me

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^ That is friggin AWESOME!

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You can not argue BBC vs LS. Like arguing about a 350 vs Flathead. Some will love the old school, some want the new stuff. Technology advancing can not be argued. Only personal preferance. I would be ticked off if a BBC was still better then a LS which was designed over 30 years later. Yea, "No replacement for Displacement" works but like all things, their are exceptions, Forced Induction, Air flow, NOS, Compression, TECHNOLOGY, ECT.....

I love my BBC but can not stop thinking about an LS. Even thought of selling my C-10 and supercharging my Silverado w/5.3 How fun is Daily driving a 550+HP vehicle with all the creature comforts? I like my BBC but driving it daily is a job. I always say, Driving a new vehicle is nice, it is an experience that i enjoy to drive an old school vehicle.

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I agree LS motors make a lot of HP, however, I think you only have to look as far as the NHRA Pro Stock class and see what the Chevrolet guys are running...it ain't an LS motor, it's a Rat motor.

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Tell me why they have 4 cylinders in those classes. Those 4 cylinders are pushing 1400+hp. LS is superior in the design to a BBC. No need for a 454 when the 6.0 makes more power then any stock 454 placed in an engine bay from the factory. NHRA pro stock is not a RAT, it is a kangaroo. Those engines are around $100,000. Like comparing a Ferrari to a new V-6 Camero. Still a sick car just not the $$ into it the Ferrari does.

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The reason they run rat motors in Pro Stock is because the motors have to be NA, thus a need for bigger cubic inches to make power and I'm pretty sure they don't run turbo 4 cylinder motors in NHRA Pro Stock last time I checked but I can be wrong. You can make a lot more power with a turbo big block than a 4 cylinder, but trying to hook up all that power is another story...:lol:

Re: Engine?
 

I was unaware they ran 4 cylinders in pro stock. I know they are limited to 500 cubic inch, 90*, NA V8 motors with no spray and if your car is a Chevrolet you have to run a Chevrolet motor, if a Ford then a Ford motor.

A 6.0 LQ4 makes 325 HP. A LS6 (big block 454) makes 450 HP and was installed at the factory in 1970 SS Chevelles. An L88 (big block 427) made an advertised 430 HP but was later proven to make close to 500 HP and those were installed at the factory in 1967 Corvettes. The LS7 (big block 454) made 465+ HP but could only be had as a crate motor. They all have single carb induction.

Re: Engine?
 

The Head technology that all the race teams are using is far superior to what most of us are running.

Pro stock,Pro mod,Top comp all these classes run 12-14* type of head's. Guess what degree LS based engines run? 12* I believe.

I wonder much like every one here has. Do I build BBC, LS based motor or do I take advantage of the cylinder head technology and convert from 23* to 14*-18*
Can I save in cost? Will it perform like a LS motor?
So many variables.

Re: Engine?
 

Re: Engine?
 

Randy,

Numbers from the 60's and 70's were rated differently than todays motors.
The L88 and old school LS7 were more or less all out factory race motors. Look at todays little C6 ZO6 motor that is 427ci making every bit of 505hp from the factory. Smooth idle, runs vacum brakes, weighs less.. With a set of headers and a cam swap, they have been known to make over 600rwhp on pump gas.

Tony Mamo from AFR recently made 730+hp on an engine dyno with a 454ci LS motor. This was a 91 octane drinking hyd roller motor.

I mean really, things could be argueed for days on this.


I still haven't seen a rough cost for an NA high 11/low 12 second big block in a 36-3800lb truck.

4-5 years ago I remember driving around my buddies big block 69 truck wearing aftermarket heads, decent sized cam with 11-1 compression, converter, gear and tire. I was only running 12.30's in my truck then. He gatted me by 2-3 cars do to my lack of traction, went by him before the 1/8 and strapped close to 5 cars on him. Similar results with a second pass. My guess is it was a high 12 second truck at best.

Now I know DJ's old motor would have drove around me.. But what would that motor take to replicate in todays market?

Re: Engine?
 

My 496 is $8800. It should have me in mid 11's no problem... The same engine in a chevelle is running high tens low 11's. Pump gas, vacuum brakes, and daily driver.

Re: Engine?
 

How much HP would you say you have to make (with the right tire/gear/chassis set up) to go low 12's/high 11's in a 3800 lb truck?