CONTEST : Guess the HP and WIN!
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-Boosted-
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Yes, flat tops in a decked block (+ .004). I’m kinda second guessing the duration and thinking I should have gone with more but this is what the expert specced out…. lol
There is a math problem that can get you to your optimum intake duration. I had to have Tim run the numbers for me but found out I could use between 272-275 @ .050 depending on rpm peak I'd like but I am at the moment 8 degrees of duration under according to the math.
Jim@ Racer Brown taught me the magic of duration. Lots of it and then a little more when he found out I wasn’t afraid of high stall.
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Good thing a cam swap isn’t too difficult if I decide I want more…. lol
dusterbing the peace
FABO pyrite member
Gambling on this thought process myself for the new build…hoping it pays off Won’t know for quite a few months as I just got the block and heads back and like to take my time with stuff.
If you give me your bore and stroke, compression ratio and the rpm where you want to make peak torque and I can run a math program I use. If you give me your intake valve size and I can get you close on lift.
I may be able to give you an LSA with those numbers but I have to find that math.
It would be interesting to see what my math says compared to what you are thinking as far as duration goes.
Edit: to calculate an LSA I’d also need your rod length.
dusterbing the peace
FABO pyrite member
4.09x4.0, 13.6:1, 6k for torque/7.2k for hp, 2.15 valve
Rod length is 6.125 (Chevy rods)
Any provision for altitude? I’m up at 5,400, although our DA is usually 7-9,000.
I’d love to see it too!!!
Many thanks!
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Can you do all that with a slant 6?
dusterbing the peace
FABO pyrite member
Nice!
I was in the ballpark with 284/292 on 109, straight up.
Thank you for running the numbers, I always like seeing other perspectives, especially when they’re in line with mine;) I should add that I picked lobes with a little less intensity to ease the transition to 750 lift, so the duration is just a touch longer to compensate.
3.445 x 4.125
10.52:1
4000 RPM, BUT I need to run on pump gas.
1.780 318 intake valves.
7.005" connecting rod length.
Needing to run on pump gas is more important than "where" the peak torque will be.
According to D.V., the "optimum" LSA for the 225 is 106, but I don't hold that as gospel, necessarily.
Thank you kindly.
-Boosted-
Hard Member
I’m on my way to the dyno. If you haven’t made your guess, do it now for a chance to win.
dusterbing the peace
FABO pyrite member
486 rwhp, sorry if it’s already taken
justinp61
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What did I win!!! 
439 hp
Updates????
-Boosted-
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And we have a winner! @jimjimjimmy got it on the money with his guess of 429!
Not quite what I was hoping for but it’s a good baseline to work off of and it will only get better.
Jim, message me your t-shirt size and address and I’ll get your prize shipped ASAP!
Not quite what I was hoping for but it’s a good baseline to work off of and it will only get better.
Jim, message me your t-shirt size and address and I’ll get your prize shipped ASAP!
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