Log Rod 6L build up?
09-09-2006, 08:31 PM
#1
Log Rod 6L build up? I going to be building a 6L for my truck in the near future and another member gave me this idea. I wanted to know what you guy think of it. Idea???
Quote:
Originally Posted by vanillagorilla
I think I should elaborate a little further on what I said earlier, because I've had a few PM's regarding it.
This is all theory and I've never seen or heard of it being done, but it works on paper.
You take a 6.0L block with a standard or 0.030 over bore (9.240" deck height). Stock stroke crank (3.622") and 4.8L rods (6.275"). From there you use and off the shelf 402 or 408 stroker piston and you deck the block accordingly. JE and Wesico offer pistons in dished, flat top or domed with a compression height of 1.115"
Deck Height=9.240"
Rod Length=6.275"
Stroke/2=1.811"
Comp. Height=1.115"
9.240-6.275-1.811-1.150=.039"
So to the piston would be 0.039" in the hole, and you could deck the block accordingly to acheive your desired CR.
The advantages of a longer rod are numerous. Longer dwell at TDC and BDC, which creates more cylinder pressure which equals more power. Slower piston speeds which allows greater rpm capability, and reduces the stress on rod bolts. It decreases wear and tear and increases reliability. Also it decreases side loading on the piston due to a reduces rod angle. You get the idea...
Again, this is all theory with a budget in mind.
Originally Posted by vanillagorilla
I think I should elaborate a little further on what I said earlier, because I've had a few PM's regarding it.
This is all theory and I've never seen or heard of it being done, but it works on paper.
You take a 6.0L block with a standard or 0.030 over bore (9.240" deck height). Stock stroke crank (3.622") and 4.8L rods (6.275"). From there you use and off the shelf 402 or 408 stroker piston and you deck the block accordingly. JE and Wesico offer pistons in dished, flat top or domed with a compression height of 1.115"
Deck Height=9.240"
Rod Length=6.275"
Stroke/2=1.811"
Comp. Height=1.115"
9.240-6.275-1.811-1.150=.039"
So to the piston would be 0.039" in the hole, and you could deck the block accordingly to acheive your desired CR.
The advantages of a longer rod are numerous. Longer dwell at TDC and BDC, which creates more cylinder pressure which equals more power. Slower piston speeds which allows greater rpm capability, and reduces the stress on rod bolts. It decreases wear and tear and increases reliability. Also it decreases side loading on the piston due to a reduces rod angle. You get the idea...
Again, this is all theory with a budget in mind.
09-09-2006, 09:47 PM
#2
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sounds pretty sound to. decent budget build idea.
now that i think of it... that sound more like a torquey motor than mid-upper rpm power unless u rev it out a little more than usual
now that i think of it... that sound more like a torquey motor than mid-upper rpm power unless u rev it out a little more than usual
09-10-2006, 02:45 AM
#3
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No reason to put the pin in the oil ring land and use a short skirt piston, a 6.0" rod is already a "long rod" motor with that stroke.
For a street motor the benefits, or lack of depending upon which side of the fence you sit as far as the long rod motor argument goes, will not be seen.
If you are on a budget and want to cut out the cost of aftermarket rods.....
For a street motor the benefits, or lack of depending upon which side of the fence you sit as far as the long rod motor argument goes, will not be seen.
If you are on a budget and want to cut out the cost of aftermarket rods.....
09-10-2006, 12:02 PM
#4
Originally Posted by machinistone
No reason to put the pin in the oil ring land and use a short skirt piston, a 6.0" rod is already a "long rod" motor with that stroke.
For a street motor the benefits, or lack of depending upon which side of the fence you sit as far as the long rod motor argument goes, will not be seen.
If you are on a budget and want to cut out the cost of aftermarket rods.....
For a street motor the benefits, or lack of depending upon which side of the fence you sit as far as the long rod motor argument goes, will not be seen.
If you are on a budget and want to cut out the cost of aftermarket rods.....
09-10-2006, 02:41 PM
#6
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Originally Posted by kbracing96
The 6L uses the same rods and stroke as a 5.3 and 5.7. I want to put forged pistons in it anyway because I'm turboed, so the price really isn't any more, and 4.8 rods should be cheep. And it's different, haven't seen it done yet. Cost really isn't any more, maybe if I deck the block. I was running the numbers, and with 76cc 317 heads, flat top 2cc pistons and a .040 head gasket, w/out decking the block compression would be just over 9 to 1 which would be just about right for FI. Any more thoughts on this?
09-10-2006, 05:54 PM
#7
Don't go with longer rods in a turbo motor. Only time this exersize you are looking at makes sense is when you are tring to reduce bottom end mass and making a shorter CH piston with a longer rod is usually a easy way to do that. In your situation you want mass and with a dish piston you will be better off with a taller piston in that application.
FWIW your example with a 6.300" rod and slightly decking the block works much better, you can deck the block that much but you don't have too. Besides on a turbo motor lots of quench is not always a bad thing.
Bret
FWIW your example with a 6.300" rod and slightly decking the block works much better, you can deck the block that much but you don't have too. Besides on a turbo motor lots of quench is not always a bad thing.
Bret
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09-11-2006, 03:00 PM
#9
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Originally Posted by kbracing96
I'm looking to make about 500rwhp for DD and maybe bump it to 575-600 for track duty. 
09-11-2006, 03:35 PM
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Originally Posted by Keith
Stock rods with god bolts are usually good to 500-550hp. You might be pushing it.
09-19-2006, 05:04 PM
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I found this thread, but I don't know if this guy actually built the engine.
https://ls1tech.com/forums/showthrea...t=6.0+long+rod
I'm still waiting to hear from JE about the pistons and pin size.
https://ls1tech.com/forums/showthrea...t=6.0+long+rod
I'm still waiting to hear from JE about the pistons and pin size.
09-19-2006, 09:04 PM
#12
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depending on what quench u want u have to watch out how much u wanna mill the block because u will start to have manifold problems. Also id rather mill the heads than the block alot.
