Old school SBC/BBC to LS family comparo.

Discussion in 'High Tech Retrofits' started by newschool72, Sep 23, 2013.

  1. 71RS/SS396

    71RS/SS396 Veteran Member

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    Tom, I think you've become thinned skinned about this and are quick to jump down people throats as soon as they disagree with you a little bit, you're off on some tangent about torque management that had nothing to do with the discussion we were having. I think you have a lot to offer to this board but you're starting to become white noise to me because you start attacking people the minute they say something negative about LT1's. Do you really think calling someone a ricer helps your argument?
     
  2. sbca96

    sbca96 Veteran Member

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    I didn't ... I was told that. Just take a truck LS engine, toss a cam at it and you
    will get 500 hp. I question that since Leonard built a NICE LS truck engine and it
    doesn't make 500 hp ... what did he do wrong?

    If you only need a cam to get 500 out of truck motor rated lower than an LT1, it
    seems that the LS2, LS6 and LS3 arent needed?

    GTO LS1 made 350 hp, GTO LS2 made 400 hp, why not just put the 500 hp cam
    in the LS1 and not bother making an LS2 at all?

    Tom
     
  3. 71RS/SS396

    71RS/SS396 Veteran Member

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    I think GM went to the LS2 so they could produce 1 less engine since it shares the same displacement as the LQ4/LQ9 and the LS3 is the same displacement as the L92, it boils down to the economics of lower production costs with fewer engines.
     
  4. sbca96

    sbca96 Veteran Member

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    I have grown tired of the BS, the only one that I jumped down the throat of on
    accident was Knuckle Dragger and I apologized. I said "sound like ricers", which
    I supported the reasoning, you ever talk to a VTEC guy? Same noise. "You are
    stupid to consider anything else". Torque management was from another thread
    and it was deleted, I was making a point on that.

    This board is turning into an LS-only club that force feeds bloated BS to those
    that don't NEED it or WANT the expense and could get a VERY good running
    car with less expense by installing an LT1 instead. Its not even suggested on
    here anymore except by me, and when its brought up on a thread, 10 LS-ers
    jump on the thread to tell the guy he is basically stupid if he doesn't put in an
    LSx engine. I get PM's from people telling me they just lurk for fear of you guys.

    Think about it ... how is that good??

    As I mentioned .. MANY times .. I have TWO LS1s ... this is not coming from a
    person thats never been exposed to them, I have worked on them too! A buddy
    installed one is his '69 Camaro, I am looking forward to a local guys attempt at
    a California Legal LS1 swap into a Firebird that we can run apples to apples.

    Tom
     
  5. 71RS/SS396

    71RS/SS396 Veteran Member

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    I've never posted bloated numbers, I've only posted about what I personally own and had on the dyno. This is precisely what I meant when I said when I said you've become thin skinned you're lumping everyone together that has an LS, as I stated in my first post I have LT1 cars including 1 that is highly modified, they're a good engine.
     
  6. 351maverick

    351maverick full time Ebay seller/hustler/car killer

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    can a guy buy a tunnel ram intake for a LS motor? roots blower manifold? if not then no thanks
     
  7. newschool72

    newschool72 Veteran Member

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    OK, let me pick through this one for you, Tom. First off, if you had read my post on the way HP is rated differently, you would see that there is no 40% increase in HP with the 6.0 truck engine. Using the Hot Rod method of engine dyno, the 6.0 truck engine regularly makes 400+HP wit the dyno room headers installed. The swap to a healthy cam is often worth 70-80HP, there for making as much as 500HP "on the engine dyno" with just a cam swap and free flowing exhaust. So do you see now that no one is claiming 40% increase with a cam swap. Is that "cheating in any way", NO, that is the same way a modded LT1, BBC, SBC, Stud paxton engine ,etc, etc is tested. The low ratings from the factory can not be used in the comparison of before and after with any cam swap, because it is very difficult to match the way the factory tests for the rated HP.
    On the head debate, No porter can turn your 23* heads into 15* heads. The big difference in the SBC head and the LS head is the way the intake runners line up with the cylinder bores. The runner has a much straighter shot to the piston and that creates much improved flow to the combustion chamber. You can do the same thing with a SBC, but the price to play is high to say the least. RHS made a 14* head a few years back for the SBC, but everything had to be a one off custom piece . The headers, pistons, and intake had to be custom built to work with it. There are companies that offer 18* heads as well, but it is the same deal on specialty parts for those as well. Point is, no porters trick will give you the benefits of the LS head. If you notice, the modern hemi, new 5.0 ford and the GM LS all have very straight shots to the piston. They all do this because it is a far superior design and is the reason these modern engines respond so well to induction, exhaust, and camshaft changes. The technology is borrowed from the good ol boys in Nascar.
    I too have owned a couple LS factory equipped cars, a 05 LS2 GTO M6 and a 99 Z28 M6. The engines do rock back and forth at idle, but my tolerance for shake must be way more than yours, because I never noticed the issue you speak of. I guess we can chalk that up to different sensitivity to vibration.
    The difference in low end torque between the two engines is an elusion ,IMO. I have an old issue of GM High Tech mag here at the house somewhere for the maiden voyage and test of the LS1 when it was first introduced. They compared it to the LT1, naturally, because it was THE engine of the time. In a road test the author made the comment that the LT Camaro had much more torque down low, but the LS charged ahead soon after the cars got moving good. They claimed "all hail" the LT1 for its low end grunt. They then raced the 2 cars and the LS Camaro owned the run ,start to finish. They then put them both on the chassis dyno. The LT car made all its grunt down low and the torque curve was impressive. They ran the LS car next and the torque curve continued to climb as the rpms climbed making you believe the torque curve was lazy in the LS car. They superimposed the 2 curves over each other , and the LT car peaked at around 3200 on torque, the LS car peaked at around 4600 on torque, but although the LT car peaked earlier, the LS car had more torque than the LT did AT the LTs peak. The LS continued to climb on torque and peaked well above the LT. They all said the LT car felt better down low, but it was because it moved to its peak almost instantly. I will have to see if I can find the mag to verify the end result, but Im feeling pretty sure the torque #s finished at 275RWTQ for the LT and 335RWTQ for the LS. The LS torque was at 280RWTQ at the LTs peak. I will see if I can find that issue to double verify the numbers but Im at about 95% sure the #s are spot on.
     
    Last edited: Sep 26, 2013
  8. newschool72

    newschool72 Veteran Member

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    Yep on both. Eddy makes a hi ram you can get a dual carb top plate for and the Blower Shop make an LS lower manifold for a roots blower.
     
  9. 5spd540

    5spd540 Veteran Member Lifetime Gold Member

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    To me that takes the reason for a LS motor out. IMO the LS is for efi and drivability if I was going to drive my car a lot it would have a LS. If you want a carb motor go with a BBC
     
  10. newschool72

    newschool72 Veteran Member

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    Carbs work out very well on an LS. I have a carb intake on my LS3, but with Fast EZ efi. The carb style intake really lets the LS shine. You get the advantages of the 15* heads, but the simplicity of an old school engine. Its like building a max effort SBC ( 18* heads and intake, roller cam, 1.7 rocker ratio, aluminum block) with junk yard parts. That is the stuff the average gear head could only dream about being able to build, back before the LS engine showed up.
    I think a lot of people dont look at the engine for what it is. They assume its too complicated with all the wiring and EFI, ECU, high pressure fuel system, bla, bla...all the crap that comes on them from the factory. Strip that sucker down, throw a carb intake on it, throw a camshaft in it that's matched to what you are going to do with the car, wire up the very simple MSD box to control the coils , leave the old fuel system in place, and go haul a$$ for not much $$$s. If you don't believe these engines will flat haul the mail w a simple carb set up for dirt cheap, go to LS1Tech and pull up the Carbed LSX forum. Mid to low 7 sec 1/8th mile times are the norm at 90 to 100mph w junk yard long blocks and a few choice aftermarket parts.
     
    Last edited: Sep 26, 2013

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