LS1s suck.... don't cave 5spd.
And what do you mean that you've never seen a 347 dyno like an LS1? LS1s dyno, like you said, in the neighborhood of 300 rwhp. 500 rwhp is kinda steep. Never seen that from an LS1, but I have seen 400 rwhp from a n/a 302. Could a high revving 347 make that kinda power? probably
For a pushrod, yes I believe they are better.
I have never seen an equally equipped 347 out "dyno" a 346. I am keeping accessories, powerband, goals of the car in mind.
http://guerragroup.com/2000TA.htm (slightly bored ls1)
I have seen 400rwhp from a 302, it used C12 race gas, and 12.25:1 compression.
Want to read about the "recipe" for 500rwhp with "heads and cam" on an ls1?
http://www.ls1tech.com/forums/showthread.php?t=732392
Can't compare a stock 302 to LS1... It just isn't even close. I'm still not really sure what a 346 ci LS1 can do that a 347 can't. The one you show made 510 rwhp, go to AFR's website and they have numerous articles with impressive numbers from any regular displacement chevy engine. How about 750 rwhp from an n/a stroked 302! Not streetable, but there is an example of a 575 hp n/a stroker that looks completely streetable. That's probably more than 500 rwhp (keep in mind that 15% may not be applicable at higher hp levels.
Chris
I am not trying to compare a 302 vs. a 346, but 347 vs. a 346.
I have not seen near the amount of streetable 347's that I do, ls1's.
420rwhp with bolt-ons and a daily driver capable OTS camshaft, without changing heads or intake. I do not see that with similar "flowing" heads on a short block Ford. In fact, most 347's are not even close to that, with, in my opinion, less streetability.
Those examples I have seen, and much are carbed, which will typically always inflate the peak numbers, as compared to fuel injected.
I'm sorry, the AFR tests offer the only objective evidence I can provide. I don't see too many tests that are as thorough as the one shown by your chevy guy.Also, I am going off chassis dynos, not engine dynos, like those AFR test.
I am not saying that the ls1 is some great engine, but as I listed, it has these little details that make it work better than the older generation short block Ford. As you know, it is all in the details...
Because every LS1 starts off streetable.... 347s are not commonly produced
The 575 hp AFR article is about a 347 that uses the Ford AFR205... The combo you show is a chevy guy with AFR205 heads... Very similar numbers. What's streetability? usually that's determined only by cam and tune
Carbs don't inflate numbers. They just don't run out of airflow like smaller long-runner efi intakes do at higher rpm. There's not much point to try run a long-runner to 7000+ rpm. It won't make power there. Put a Vic Jr, TFS R, Systemax II, or Supervictor on there and you'll see the exact same thing you do with carbs... less low end and more high end. Carbs do not offer a hp advantage over the properly sized fuel injected intake. That's an entirely different argument, however.
I'm sorry, the AFR tests offer the only objective evidence I can provide. I don't see too many tests that are as thorough as the one shown by your chevy guy.
You're right, to an extent. The old factory pushrod ford has nothing on the newer technology employed in the LS1.
But lets face it, there's nothing too technologically complex about an engine. You have a cylinder enclosed on both ends by a piston and a combustion chamber with 2 valves. All of the new after market products have similar chevy and ford versions. When you strip away the top-end of the engine it eliminates the performance advantage. Now all you're doing in both camps is putting on aftermarket parts that are nearly identical. I think you generally see combos making more power in the LS1 camp only because billy-bob and his brother can afford to put together a 347 combo with stock 351 heads. That combo just ain't gonna turn the numbers that big spenders will turn with better components.
Spare me the time it would take to go back and disect your list of LS1 advantages. Go back and look at them and consider what is still an advantage when you give the SBF all aftermarket top-end components with a cam.
And for what it's worth, I personally don't buy the concept that square stroke vs. bore is better for performance. I'd rather build a 4.125" bore 347 stroker than a 4.030" bore 347 stroker. The latter may make more torque, but I bet I'd get more average power out of mine. Would probably be able to rev my motor higher, too - consider piston speed. What are you left with in terms of LS1 advantages?
I don't see any. And, FWIW, I hope it doesn't seem like I'm coming down on you. I really enjoy our discussions. I've learned quite a bit about the LS1s from you in this thread, and I already own one! ('97 C5 vette)
Chris
But lets face it, there's nothing too technologically complex about an engine. You have a cylinder enclosed on both ends by a piston and a combustion chamber with 2 valves. All of the new after market products have similar chevy and ford versions. When you strip away the top-end of the engine it eliminates the performance advantage. Now all you're doing in both camps is putting on aftermarket parts that are nearly identical. I think you generally see combos making more power in the LS1 camp only because billy-bob and his brother can afford to put together a 347 combo with stock 351 heads. That combo just ain't gonna turn the numbers that big spenders will turn with better components.
Chris
Now all you're doing in both camps is putting on aftermarket parts that are nearly identical.
Chris
By the way, anyone notice that the new AFR 225/205/185 Ford heads switched to an LS valvetrain?
Yep, 8mm, lighterweight, and smaller diameter...
Spring upgrades are no longer needed for "typical camshafts," as before.
This makes the AFR heads even more valuable, in my opinion.
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