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Discussion Starter #1
Looking at dooing something here and wonder if any of you have used a 6.300 rod in an ls with a 3.622 stroke and a 1.115 c.h. piston in a 9.230 deck 6.0 block. Looks like the piston will be .003 in the hole but will the rod acually fit as far as cyl. and cam clearance. I have the block, stock crank and the 1.115 pistons and eagle has a 6.300 rod. Will it work. thanks......
 

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sure as long as boost isn't in your plans, it won't want shit for advance on timing and likely VE will suffer. but it will work.
 

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A lot of hang time there but yeah, it works. To me, a 3.622 stroke engine should start with a 6.200" rod minimum unless needing more meat on the piston for N20 or boost.
 

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Discussion Starter #4
Looking more at spraying it and it a dish piston -8cc. would be roughly 10.2:1 with the heads. Didnt think the tdc time would cause much of a timing issue?
 

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Looking more at spraying it and it a dish piston -8cc. would be roughly 10.2:1 with the heads. Didnt think the tdc time would cause much of a timing issue?
What kind of ring pack do those pistons have and how much crown?
 

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Discussion Starter #6
They are the wiseco n2o / blower pistons with the gfx rings. think the top is .260 down.
 

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All in the tune eh? It will be a safe start on the timing for sure.
 

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Discussion Starter #9
What problems do you forsee with the setup? Its a 317 head and a 256/260 cam on a 111 ls. As i said its just stuff that is here in front of me.
 

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As Sean mentioned, you're not going to be able run a bunch of timing in it but if you're spraying it then there's no need to. Pay extra attention to your P2V upon assembly...........remember, that piston is hanging up top for a little while. Cam selection should be a little different to help overcome the increased pumping losses due to the longer rod.
 

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As Sean mentioned, you're not going to be able run a bunch of timing in it but if you're spraying it then there's no need to. Pay extra attention to your P2V upon assembly...........remember, that piston is hanging up top for a little while. Cam selection should be a little different to help overcome the increased pumping losses due to the longer rod.
Ok so trying to learn something. Will this combo make less power than a shorter rod. If my thinking is correct this should be a 1.739:1 rod ratio. Is this better or worse than say 1.531:1 in a 4" stroke with a 6.125 rod?
 

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Ok so trying to learn something. Will this combo make less power than a shorter rod. If my thinking is correct this should be a 1.739:1 rod ratio. Is this better or worse than say 1.531:1 in a 4" stroke with a 6.125 rod?
Long rod will make less power down low but more power in upper RPM's.

One rod ratio isn't necessarily "better" than another. It depends on what the engine is expected to do.
 

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Discussion Starter #13
Im really looking for power from 4k or so and up. The longer rod will just make it easier to make a lil more power up top. i think......
 

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It's like everything thing else. There are causes and effects............some positive some negative.

The long rod pulls hard on the intake port on down stroke. It causes the engines breathing to "think" it has a larger intake port than it does and is partially why you get the upper RPM advantage. However about half of the pistons travel downward, the piston slows down so as it's coming back up it's just as slow. What is sacrificed is the full assault charge to push the exhaust out of the cylinder and chamber. The piston speed to do so comes a tad late in the upstroke to clear the chamber as efficiently as the short rod. Cammed accordingly, pumping losses can be cut to a minimum. The hang time of the piston with the long sits longer as more of the air/fuel mixture is being burned. This makes it more prone to detonation. But, oddly enough, more power is usually achieved with the lesser timing amount as the timing isn't needed. Since the timing isn't needed, one can actually run higher compression ratio's without fear of detonation.

I'll also add the longer rod takes a lot of side loading out of the picture.
 

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Discussion Starter #15 (Edited)
Any ideals on the camshaft? i may can work a change on the budget... Ill list the specs on mine in a few.
 

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Discussion Starter #16
Dur at .050 256/260 lift .589/.589 lobe sep 111. Intake open19 intake close 57 exhopen 63 exh close 17 .... Its just here and new.....
 

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Gotta get all the info or it's just guesswork and much different that precision guess work.

 

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It's like everything thing else. There are causes and effects............some positive some negative.

The long rod pulls hard on the intake port on down stroke. It causes the engines breathing to "think" it has a larger intake port than it does and is partially why you get the upper RPM advantage. However about half of the pistons travel downward, the piston slows down so as it's coming back up it's just as slow. What is sacrificed is the full assault charge to push the exhaust out of the cylinder and chamber. The piston speed to do so comes a tad late in the upstroke to clear the chamber as efficiently as the short rod. Cammed accordingly, pumping losses can be cut to a minimum. The hang time of the piston with the long sits longer as more of the air/fuel mixture is being burned. This makes it more prone to detonation. But, oddly enough, more power is usually achieved with the lesser timing amount as the timing isn't needed. Since the timing isn't needed, one can actually run higher compression ratio's without fear of detonation.

I'll also add the longer rod takes a lot of side loading out of the picture.
Ha!:smt115 I did learn something. Thanks.
 

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Im no expert but cutting down on dwell time at tdc was very important in our build... The tuning window is wider with more piston speed and less time at tdc. IMHO.FYI I only know nitrous.
 

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Discussion Starter #20 (Edited)
Hey Billy i dont have any flow #s on the heads, it would only be a guess. As i said its just a shitpot of parts to put together and try to go some 5.9x's in a 3200# truck with two .065 or so jets......

If im thinking correctly thissetup will want a leaner tune due to the dwell time correct?
 
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