High RPM short block
04-26-2013, 12:41 PM
#1
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High RPM short block Hello all.
I got all the upgraded top end, but I'm pretty sure I just blew a rod bearing revving out the stock bottom end to 7200 for a long period of time. Ooops.
Already swapped a stock engine back in, but was wondering what you guys recommend for building up the bottom end to handle high RPM. (7500 rpm)
Thanks!
I got all the upgraded top end, but I'm pretty sure I just blew a rod bearing revving out the stock bottom end to 7200 for a long period of time. Ooops.
Already swapped a stock engine back in, but was wondering what you guys recommend for building up the bottom end to handle high RPM. (7500 rpm)
Thanks!
04-26-2013, 01:12 PM
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I got a 3 stage dry sump, so the oil is good.
Just wondering what are some good light rods, good strong rod bolts, good journal machining people recommend.
Thanks.
04-26-2013, 02:18 PM
#4
7500 isnt that high. Katech/arp rod bolts on stock rods should do the trick. Some coated bearings will help too, and turn the stock crank down a little. If it were me I'd go higher (8K rpm) with some BME forged ally rods and a magnum XL crank!! Im guessing you swapped out your rotor's for an LS...welcome to torque. FYI, not many aftermarket steel rods are as light as the factory rod. LS2 floating pin is 639.565 grams and LS1 press pin is 616.886 grams. I think the lightweight K1 rod is 640 grams and the newer callies pro is a little less maybe.
04-26-2013, 04:09 PM
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7500 isnt that high. Katech/arp rod bolts on stock rods should do the trick. Some coated bearings will help too, and turn the stock crank down a little. If it were me I'd go higher (8K rpm) with some BME forged ally rods and a magnum XL crank!! Im guessing you swapped out your rotor's for an LS...welcome to torque. FYI, not many aftermarket steel rods are as light as the factory rod. LS2 floating pin is 639.565 grams and LS1 press pin is 616.886 grams. I think the lightweight K1 rod is 640 grams and the newer callies pro is a little less maybe.
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04-29-2013, 12:05 PM
#9
Depends on how much money you want to spend. Bullet proof to 8500+ would be the BME/GRP Al rods, Callies Magnum XL crank, light weight pins and pistons. That would live forever at 7500 with your dry sump. Once you have the heads/cam/valvetrain/ECM to rev past 8000 rpm then you can really see what it does. I'd be willing to bet you just starved your old motor for oil. Ive taken my stock 01 bottom end to 7500 no problem when it had a 5X3 cam.
04-29-2013, 01:09 PM
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Yeah I starved it for oil, I used all 6 gallons of oil. XD
I didn't just take it to 7200 and hit limiter and stop, I carried it for long period of time, bouncing limiter, multiple times.
Here is a video of when the limiter was at 6800.
http://www.youtube.com/watch?v=5B7TF...ature=youtu.be
But thanks for your recommendation.
I guess the first thing I need to figure out is, what to do with the old motor.
I am thinking about either keeping the same ls1 stroke, or dropping down to a 4.8 L crank. That should drop the piston speed back down. 8000 at a 4 inch stroke, would be like 5333 feet per minute, I don't think I could build anything that could handle that.
I didn't just take it to 7200 and hit limiter and stop, I carried it for long period of time, bouncing limiter, multiple times.
Here is a video of when the limiter was at 6800.
http://www.youtube.com/watch?v=5B7TF...ature=youtu.be
But thanks for your recommendation.
I guess the first thing I need to figure out is, what to do with the old motor.
I am thinking about either keeping the same ls1 stroke, or dropping down to a 4.8 L crank. That should drop the piston speed back down. 8000 at a 4 inch stroke, would be like 5333 feet per minute, I don't think I could build anything that could handle that.
Last edited by tweakgames; 04-29-2013 at 01:17 PM.
04-29-2013, 01:37 PM
#11
Beware that when piston speed is highest, acceleration relative to the cylinder wall is practically zero, and since f=ma, the force the piston on its own puts on everything is nill. Its at tdc & bdc where piston speed is zero but acceleration is crazy.Thats why I keep focusing on weight more than stroke.
04-29-2013, 02:14 PM
#12
We can build you a bottom end that will turn 7500 all day with our TMS 4340 crank and H-beam rods along with diamond pistons for $3999. We even have a 1 year warranty on the motor. Give us a call with any questions. 972-853-0518.
04-29-2013, 02:20 PM
#13
Yeah I starved it for oil, I used all 6 gallons of oil. XD
I didn't just take it to 7200 and hit limiter and stop, I carried it for long period of time, bouncing limiter, multiple times.
Here is a video of when the limiter was at 6800.
http://www.youtube.com/watch?v=5B7TF...ature=youtu.be
But thanks for your recommendation.
I guess the first thing I need to figure out is, what to do with the old motor.
I am thinking about either keeping the same ls1 stroke, or dropping down to a 4.8 L crank. That should drop the piston speed back down. 8000 at a 4 inch stroke, would be like 5333 feet per minute, I don't think I could build anything that could handle that.
I didn't just take it to 7200 and hit limiter and stop, I carried it for long period of time, bouncing limiter, multiple times.
Here is a video of when the limiter was at 6800.
http://www.youtube.com/watch?v=5B7TF...ature=youtu.be
But thanks for your recommendation.
I guess the first thing I need to figure out is, what to do with the old motor.
I am thinking about either keeping the same ls1 stroke, or dropping down to a 4.8 L crank. That should drop the piston speed back down. 8000 at a 4 inch stroke, would be like 5333 feet per minute, I don't think I could build anything that could handle that.
04-29-2013, 02:39 PM
#14
Yeah I starved it for oil, I used all 6 gallons of oil. XD
I didn't just take it to 7200 and hit limiter and stop, I carried it for long period of time, bouncing limiter, multiple times.
Here is a video of when the limiter was at 6800.
http://www.youtube.com/watch?v=5B7TF...ature=youtu.be
But thanks for your recommendation.
I guess the first thing I need to figure out is, what to do with the old motor.
I am thinking about either keeping the same ls1 stroke, or dropping down to a 4.8 L crank. That should drop the piston speed back down. 8000 at a 4 inch stroke, would be like 5333 feet per minute, I don't think I could build anything that could handle that.
I didn't just take it to 7200 and hit limiter and stop, I carried it for long period of time, bouncing limiter, multiple times.
Here is a video of when the limiter was at 6800.
http://www.youtube.com/watch?v=5B7TF...ature=youtu.be
But thanks for your recommendation.
I guess the first thing I need to figure out is, what to do with the old motor.
I am thinking about either keeping the same ls1 stroke, or dropping down to a 4.8 L crank. That should drop the piston speed back down. 8000 at a 4 inch stroke, would be like 5333 feet per minute, I don't think I could build anything that could handle that.
Yea, I figured, I tell my buddy not to hang out on the limiter all the time, same thing happened to his engine. He's also going dry sump now. Stupid drifters
Nice run BTW. You should also look into a HUC lobe for this engine and some J2K's. Especially if you want to rev to 8K. At 5333 FPM, your in Nascar territory, where J2K's become to heavy and it would take some time and development to get it to work properly. Nascar engine=big bore/small stroke=lots of rpm. 4.8L crank should treat you right for that. It sounds like you want to build the motor I have spec'd out to build for myself this winter. I want to do a 440 that revs to at least 7500 rpm. Last edited by Jenson; 04-29-2013 at 03:03 PM.
