depends on how u get 395 ci ... and how u get 408 ci...
395 versus 408?
395 versus 408? Assume equal compression, equal cylinder head/intake/TB/exhaust/drivetrain. Would the 408 SIGNIFIGANTLY outperform the 395, in either HP or TQ? I am thinking of a aluminum blocked 12:1 395, some good LS6 or AFR heads, and a large (240+) cam. How much more HP/TQ would the 408 produce than the 395, assuming everything above is the same for both motors? Enough to make up for the ~80 lb weight difference? Thanks, shawn
Have you looked into the LS2 block? 900 bucks for a 4.000" bore aluminum block is pretty nice.
I am thinking about it. Just want to wait a little while to see what changes have to be made.
Brad
I am thinking about it. Just want to wait a little while to see what changes have to be made.
Brad
exactly!! Well when he mentioned 80 lb weight difference I assume he is talking a 6.0 l iron block vs an ls1 block which equates to a 4.0 bore 4.0 stroke vs a 3.9 bore 4.125 stroke whick is why I said it won't rev as high.
everything being the same just 13 ci will not be 30 hp it will be less. this is not the same comparison though it is with different strokes so the iron block will rev higher and make more hp that way also with the slight advantage of larger ci. so 30 hp is probibly very realistic numbers probibly even more.
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Originally Posted by 52172
well for starters the 395 wont rev as high as it has a longer stroke.
i dont think the extra weight is worth it even if it could give you
an extra 30hp.
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Joined: Mar 2003
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From: Dallas
Originally Posted by Ragtop 99
Take a look at Fastech. They have a 395 that did pretty well. They also spun it pretty high. I think the dyno is in the dyno forum.
If I put the same heads/cam on a 408, I bet it would make about 530.
Originally Posted by Cstraub
Well if you consider the best NA engines make around 2.37HP per cube the power difference at best would be 2.37 x 13.
Chris
Chris
you realize you are saying that a stock 346 CI motor would make:
346
x 2.37
-----------
820 hp
I dont think so. More like 1.37/CI for the best motors.
Thats not my point. You take the best tuned Cup engines and thats what they make about 2.37 per cube. Now you take a street engine your lucky to to make 1.25 per cube. My point is 13 more cube is not going to make a big difference even if it could make 2.37HP per cube.
Chris
Chris
I believe I would be more worried about things like rod angle and placement of the wrist pin in cunjunction with the oil rings. You will have a more efficent motor with the 408 that will prolly last longer due to the better rod angle and better placement of the oil rings. A 4.125 stroke will wear on the rings faster and crowd your oil rings because the wrist pin is moved up so far. Personally, I'd still build the 395 because I don't mind a little work every now and then and I stll think the motor will last a good while. A just don't think the little bit of added hp would be worth the weight. Now if you do the LS2 block, that's a diffrent story.
