Knife Edging and crank weight reduction
Thread Starter
Joined: Nov 2001
Posts: 10,060
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From: Canton, GA
Knife Edging and crank weight reduction Has anyone attempted to lessen the weight of the rotating internals by knife edging the crank weights or some other method. It seems with the advent of all the solid roller combos lately that this may be the next step?
Launching!
Joined: Sep 2002
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From: Clinton Twp. Mi
Knife edging a crank is generally done for windage purposes. To help it lower windage in the crank case. As a weight reduction, I am not sure how much it would take off the crank. As for lightning cranks, i am all for it as long as you don't hurt the strength of the crank. Sometimes people have a tendacy to get carried away and by doing that reduce the strength of the part. If strength is equal, the lighter the better.
Chris
Chris
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Joined: Dec 2002
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From: Bring it........ b*tch
Originally Posted by Reckless
Has anyone attempted to lessen the weight of the rotating internals by knife edging the crank weights or some other method. It seems with the advent of all the solid roller combos lately that this may be the next step?
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the Lunati cranks have rounded edges and the weights are not true knife edges.. Knife Edging is costly .. when i ran gen1 SBC's i Knife edged all of my cranks ..But with the LS1's i havent felt it was needed. As Far as lighning hole or Direct feed holes i am all for that, just have someone that is good do it if the Crank didnt already come that way.
I currently have a 6.0 crank in my LQ9 6.0 in the Z28.. We recently tore several engines down and weighed the cranks.. The LS1 crank generally weighed 50 lbs.. The 6.0 cranks weighed 51-51.5 lbs.. Assumming the LS1 crank was balanced with the stock 4.00" 6.0 pistons/rods etc., how much power would that extra 1-1.5 lb lighter crank be worth in your opinion? I mean that's an extra 1.5 lbs spinning to 6900 rpms I've got right now.. I've always wondered this? Probably hard to put a number on. but has to be worth something right? 
Staging Lane
Joined: Dec 2003
Posts: 54
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From: Bettendorf, IA
Originally Posted by bigeller
I currently have a 6.0 crank in my LQ9 6.0 in the Z28.. We recently tore several engines down and weighed the cranks.. The LS1 crank generally weighed 50 lbs.. The 6.0 cranks weighed 51-51.5 lbs.. Assumming the LS1 crank was balanced with the stock 4.00" 6.0 pistons/rods etc., how much power would that extra 1-1.5 lb lighter crank be worth in your opinion? I mean that's an extra 1.5 lbs spinning to 6900 rpms I've got right now.. I've always wondered this? Probably hard to put a number on. but has to be worth something right?
Launching!
Joined: Sep 2002
Posts: 297
Likes: 0
From: Clinton Twp. Mi
Also remember that with the LS1's the crank is up in the block. It does not hang below the oil pan rail like a gen 1 SBC. By the crank being up in the block helps with windage in the crank case. I am not sure if most people on this board with what they are doing with there LSx engines, would benefit from knife edging a crank.
Chris
Chris
Originally Posted by bigeller
I currently have a 6.0 crank in my LQ9 6.0 in the Z28.. We recently tore several engines down and weighed the cranks.. The LS1 crank generally weighed 50 lbs.. The 6.0 cranks weighed 51-51.5 lbs.. Assumming the LS1 crank was balanced with the stock 4.00" 6.0 pistons/rods etc., how much power would that extra 1-1.5 lb lighter crank be worth in your opinion? I mean that's an extra 1.5 lbs spinning to 6900 rpms I've got right now.. I've always wondered this? Probably hard to put a number on. but has to be worth something right?
In the case of the 6.0 crank... It may be heavier due to being solid and not driiled through the main, but you also have to remember that the extra weight of the 6.0 crank is in the center which is neutral when rotating. People try to stay away from the 6.0 cranks because they are supposedly heavier because they are solid, but the weight is neutral because of it being in the center
while i am not sure about the overall performance of knife edging as in refreance to weight i do know that it was benical in the SBC in the drag but i dont believe it is an issue in the LS1's with how the crank is so high. Light weight cranks are great but ours isn't that heavy to begin with.. An Aluminum rod it great if you plan on changing them every 100 passes or say 7k-10k miles.. The Aluminum rods Strech, now when you order a set of pistons you need to let them know they are for Aluminum rods and they will figure in the strech of the rod when they make the piston but you will still need to replace them in the 100 pass and 7-10k mile range
Staging Lane
Joined: Dec 2003
Posts: 54
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From: Bettendorf, IA
Originally Posted by KHShapiro
while i am not sure about the overall performance of knife edging as in refreance to weight i do know that it was benical in the SBC in the drag but i dont believe it is an issue in the LS1's with how the crank is so high. Light weight cranks are great but ours isn't that heavy to begin with.. An Aluminum rod it great if you plan on changing them every 100 passes or say 7k-10k miles.. The Aluminum rods Strech, now when you order a set of pistons you need to let them know they are for Aluminum rods and they will figure in the strech of the rod when they make the piston but you will still need to replace them in the 100 pass and 7-10k mile range
these days you can get 250 passes out of a set of aluminum rods..back in the day 100 passes was pretty normal, but you can get a lot more passes. I am building a full race motor so maitenance isn't an issue.
If you want an aluminum rod that has the life expectancy of a steel rod you can PM me. A 6.125" long rod is around 430gms. The technology is patented and 2 of the big three are looking at it along with Cummins. Cycle testing was done at the Dept of Energy in Oakridge, TN.
Cstraub
Cstraub
Launching!
Joined: Sep 2002
Posts: 297
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From: Clinton Twp. Mi
If you want a good aluminum rod, I would say to you....use GRP. I have always used their rods and have had no problems. They are very friendly to deal with and seem to always deliver on time.
Chris
Chris