Disadvantages of a 4.125 bore/4.125 stroke ci LS1 motor....
09-09-2003, 09:57 PM
#1
Disadvantages of a 4.125 bore/4.125 stroke ci LS1 motor.... Was reading the post about comparing different engine options. My car is gonna be 75% track, 25% street.
I just wanted to know what disadvantages there would be to a 4.125 bore / 4.125 stroke motor? It's a square motor, and I thought there was a benefit for that.
I read someone state oil consumption was a problem, can someone explain WHY? So besides not really being able to hone out the cylinder walls in case need to rebuild, what other reason would this not be a good idea?
Thanks
Chris
I just wanted to know what disadvantages there would be to a 4.125 bore / 4.125 stroke motor? It's a square motor, and I thought there was a benefit for that.
I read someone state oil consumption was a problem, can someone explain WHY? So besides not really being able to hone out the cylinder walls in case need to rebuild, what other reason would this not be a good idea?
Thanks
Chris
09-09-2003, 11:24 PM
#2
Re: Disadvantages of a 4.125 bore/4.125 stroke ci LS1 motor.... the big problem is oil consumption.....in order to fit the longer crank, the pin has to be moved up the piston even higher...it gets to the point that the pin is in the middle of the oil controle ring....
I was "thinking" of going 441 (4.125"bore/4.125"stroke) but after that, I think I'm going to stay with a 427 (4.125"bore/4"stroke)....
I was "thinking" of going 441 (4.125"bore/4.125"stroke) but after that, I think I'm going to stay with a 427 (4.125"bore/4"stroke)....
09-10-2003, 07:14 AM
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Re: Disadvantages of a 4.125 bore/4.125 stroke ci LS1 motor.... I would think that one of the major disadvantages is that the jealousy created by running a 427 LS1 makes your ride a target for theft. 
09-10-2003, 08:21 AM
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Re: Disadvantages of a 4.125 bore/4.125 stroke ci LS1 motor.... I personally know of a good friend who went with a brand new 4.125 CALLIES crank in a NEW LS6 motor and after only 2,500.00 miles, the welds on the crank broke and the reluctor wheel came loose, causing the engine to cut out in the higher rpms.
I have been told by the most reliable of sources, that the CALLIES cranks for whatever reason that is way above my comprehension is more likely to do this than a LUNATI crank and to stick with a LUNATI crank and go with no more than a 4.00 crank. Hence my suggetion this gentleman go with a proven bore and stroke size that being 4.125 bore and 4.00 crank for 428 Beatiful cubes rounded off to 427 of course!
I have been told by the most reliable of sources, that the CALLIES cranks for whatever reason that is way above my comprehension is more likely to do this than a LUNATI crank and to stick with a LUNATI crank and go with no more than a 4.00 crank. Hence my suggetion this gentleman go with a proven bore and stroke size that being 4.125 bore and 4.00 crank for 428 Beatiful cubes rounded off to 427 of course!
09-10-2003, 09:47 AM
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Re: Disadvantages of a 4.125 bore/4.125 stroke ci LS1 motor.... I thought Pro-Stock John had a similar broken reluctor weld problem with a Lunati 4.0" crank he installed in an iron 422 Gen 3.
...weird; right?
As far as the Callies go, they have not made gen 3 cranks too long so maybe this is a fist-time production glitch??
...weird; right?
As far as the Callies go, they have not made gen 3 cranks too long so maybe this is a fist-time production glitch??
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09-10-2003, 10:33 AM
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09-10-2003, 10:52 AM
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Re: Disadvantages of a 4.125 bore/4.125 stroke ci LS1 motor.... If you're concerned about the wrist pin being to high on the piston, us a shorter rod. Sure, your rod/stroke ratio won't be quite as good but you're not planning on spinning it up to 8000 RPM and you won't be expecting 150,000 miles (right?) from the engine, so why not?
IMO, the importance of the rod/stroke ratio is generally exagerated. I'll take the extra cubes.
IMO, the importance of the rod/stroke ratio is generally exagerated. I'll take the extra cubes.
09-10-2003, 11:03 AM
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Re: Disadvantages of a 4.125 bore/4.125 stroke ci LS1 motor.... Ditto on what colonel said. I would take the extra cubes as well.
For a motor that sees 7200rpm or less a 4.125 stroke is perfectly fine. You could easily run 8000rpm if you wanted to with 4.125 stroke but you have to pay careful attention to assembly and oiling.
For a motor that sees 7200rpm or less a 4.125 stroke is perfectly fine. You could easily run 8000rpm if you wanted to with 4.125 stroke but you have to pay careful attention to assembly and oiling.
09-10-2003, 12:37 PM
#11
Re: Disadvantages of a 4.125 bore/4.125 stroke ci LS1 motor.... thanks guys.
I wasn't even really planning to spin it past 7k. I just want the extra cubes.
So instead of a 6.125" rod, what would you suggest then? just a 6" rod?
I kinda was hoping to spray the motor a bit, but nothing serious, just for that extra hp if needed. Is this something that I should shy away from with this type of motor?
Thanks again
Chris
I wasn't even really planning to spin it past 7k. I just want the extra cubes.
So instead of a 6.125" rod, what would you suggest then? just a 6" rod?
I kinda was hoping to spray the motor a bit, but nothing serious, just for that extra hp if needed. Is this something that I should shy away from with this type of motor?
Thanks again
Chris
09-10-2003, 04:15 PM
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Re: Disadvantages of a 4.125 bore/4.125 stroke ci LS1 motor.... Question:
If you decreased the rod length from 6.125 inches to 6.0 inches, does the engine displacement also decrease?
If you decreased the rod length from 6.125 inches to 6.0 inches, does the engine displacement also decrease?
09-10-2003, 04:15 PM
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Re: Disadvantages of a 4.125 bore/4.125 stroke ci LS1 motor.... Question:
If you decreased the rod length from 6.125 inches to 6.0 inches, does the engine displacement also decrease?
If you decreased the rod length from 6.125 inches to 6.0 inches, does the engine displacement also decrease?
09-10-2003, 04:26 PM
#16
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Re: Disadvantages of a 4.125 bore/4.125 stroke ci LS1 motor.... No. Your displacement is solely dependent on bore and stroke.
"I kinda was hoping to spray the motor a bit, but nothing serious, just for that extra hp if needed. Is this something that I should shy away from with this type of motor?"
Yes, you could use nitrous with this engine.
"I kinda was hoping to spray the motor a bit, but nothing serious, just for that extra hp if needed. Is this something that I should shy away from with this type of motor?"
Yes, you could use nitrous with this engine.
09-11-2003, 08:37 PM
#20
Re: Disadvantages of a 4.125 bore/4.125 stroke ci LS1 motor.... Sorry to throw this out there, you can not run a shorter rod with a 4.125" stroke crank. 6.125" is the minimum rod length unless you run an offset wrist pin. The reluctor wheel almost touches my pin at 4" stroke. Now if you were running a crank trigger and could remove the wheel....
Ryan K.
Ryan K.