Quote:
Originally Posted by CC69Rat
I didn't poke at anyone, I'm just trying to understand the hype. If they're that powerful, I'll look harder at the swap.
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It's not that they make THAT much more power, it's the WAY they make it. The valve angle allows for a different flow path of air/fuel for better atomization at higher rpms when the air gets turbulent, which makes for more power and better efficiency. This along with the lighter weight rotating assemblies, will allow for power levels to climb well into 6500-7000rpm ranges. Any old small block is pretty much spent by 5500 unless you start throwing alot of go-fast goodies in it. Keep in mind these are the same "type" of go-fast goodies that LSx motors come with in stock form.
The one advantage old sbc/bbc engines have is low end grunt. The 23 deg valve angle allows for better fuel atomization at low rpms, but is limted at higher rpms, which is still much better for a towing application.
Quote:
Originally Posted by CC69Rat
Do I pull my perfectly good running 350 out of my cruiser to have a good running LS in it, just so I can say I have one?
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To that question, I say no. As you stated before, it would a long time to recoup the costs(as far as fuel mileage). If what you have is efficient and works great, and you don't need the extra power, why would you?
Now, if your engine trans combo is getting tired and weak, and it needs replaced anyway, then the answer would be a big YES!! I say that because you can pick up good, used engine/trans combos for what a machine shop will charge you just in labor to build an engine.
Also, if you have a good running setup, but it's not enough, and you want more, then that's another reason to say yes. The reason is it's very hard to make a sbc make good power and still get good efficiency(I'm not saying it can't be done, I'm just stating that it's not an easy task.). The LSx engines are a great combo of power/efficiency.
All that said, the typical costs of swaps that I have seen run anywhere between $3500-$5000+ depending on which engine/trans you get and how many "upgrades" you put into it. As I stated before, it'll cost $3000+ to get a sbc built to make some decent power, then you have accessory drive system, carb, dist, etc. etc. on top of all that. We haven't even discussed getting a trans built yet.
When I did the L6 to V8 swap in 2000, I went with the stock $1500 GM crate engine, but after I bought everything else, and had the trans built, I was over $4000 for the total and still hadn't touched the rearend.