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My bad, misread that one...  So,.. how much longer would the rod have to be to have a noticeable performance gain?
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You have to make an in crease in the ratio between the rod length and the piston stroke, so it would be different for different engines.
Likely 2 or more inches.
"When I take action, I'm not going to fire a $2 million missile at a $10 empty tent and hit a camel in the butt. It's going to be decisive." - President George W. Bush
95 Contour SE ATX V6
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2 or more inches? That's wack man. Chevy long rod 400's get a difference of around 30 HP/TQ depending on state of mods from going from 5.7" to 6" rods... and the rise starts earlier in the RPM band too. Not saying we'll get that much, but it won't take nearly 2 inches to make any difference.
Brad Noon '99 SE MTX 3 point oh my God H.O. 179HP/178TQ BNMotorsports Floormats, powder coating, TB optimizing, Gutted cats, etc BNMotorsports is now the preferred distributor of Contour/SVT/Mystique Indiglo style gauges!!!bnmotorsports@msn.com
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Originally posted by bnoon:
2 or more inches? That's wack man. Chevy long rod 400's get a difference of around 30 HP/TQ depending on state of mods from going from 5.7" to 6" rods... and the rise starts earlier in the RPM band too. Not saying we'll get that much, but it won't take nearly 2 inches to make any difference. I'm saying that this is what is possible with what I have in mind. Any estimates on what kind of power gains might be had with this level of mods?
"When I take action, I'm not going to fire a $2 million missile at a $10 empty tent and hit a camel in the butt. It's going to be decisive." - President George W. Bush
95 Contour SE ATX V6
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DMD Installed
SVT Brakes
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...and you have to account for the crank and rod length in your rod ratio. Going to a longer rod only means 1.) you add more weight 2.) you have to run a piston with the wrist pin closer to or in, the oil rings,(heat) Yeah, The stroke on the crank doesn't change. Deflection in the cylinder walls and piston/skirts might decrease.
I may be wrong [flame suit on] I don't see how a 1-8mm rod length increase would be benificial. Except to lower the rod ratio by .02-.05%, if that's the goal. Piston speed doesnt increase because you havent changed the throw on the crankshaft.
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You're right, piston speed doesn't increase... it decreases because of the change in angle while the crank is between 90 and 270 degrees of rotation. This increases time at BDC and TDC. A longer rod gains greater force against the crank not only from it's increased length, but also from the decreased angle of deflection. 0.0xxx% doesn't apply directly without first doing the math. I'll see if I can find it somewhere online after my bidding on Ebay for parts...
Brad Noon '99 SE MTX 3 point oh my God H.O. 179HP/178TQ BNMotorsports Floormats, powder coating, TB optimizing, Gutted cats, etc BNMotorsports is now the preferred distributor of Contour/SVT/Mystique Indiglo style gauges!!!bnmotorsports@msn.com
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Bnoon- Good call. I would think negligable on any performance gains. Hows that 3.0L been doing? You happy with it? I'm seriously concidering it very soon.
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Originally posted by 4mula1:
Bnoon- Good call. I would think negligable on any performance gains. Hows that 3.0L been doing? You happy with it? I'm seriously concidering it very soon. It's running fine, but stil not up to it's potential. Wish I had the money to finish her up in one swoop... Next will be figuring out fuel control, then spark control, then increased exhaust flow...
Brad Noon '99 SE MTX 3 point oh my God H.O. 179HP/178TQ BNMotorsports Floormats, powder coating, TB optimizing, Gutted cats, etc BNMotorsports is now the preferred distributor of Contour/SVT/Mystique Indiglo style gauges!!!bnmotorsports@msn.com
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Originally posted by 4mula1:
...and you have to account for the crank and rod length in your rod ratio. Going to a longer rod only means 1.) you add more weight 2.) you have to run a piston with the wrist pin closer to or in, the oil rings,(heat) Yeah, The stroke on the crank doesn't change. Deflection in the cylinder walls and piston/skirts might decrease.
I may be wrong [flame suit on] I don't see how a 1-8mm rod length increase would be benificial. Except to lower the rod ratio by .02-.05%, if that's the goal. Piston speed doesnt increase because you havent changed the throw on the crankshaft. Well, heres a hint: There is no wrist pin in my design..... 
"When I take action, I'm not going to fire a $2 million missile at a $10 empty tent and hit a camel in the butt. It's going to be decisive." - President George W. Bush
95 Contour SE ATX V6
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DMD Installed
SVT Brakes
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Joined: Aug 2001
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Bnoon- BTW are you going for a specific HP number?
I just want the added TQ.
Good luck with the mods.
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93RX7
86GT 377ci
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