Who makes the strongest LSx crank???
09-11-2008, 07:22 PM
#2
If you're asking this question... I can only assume that you had a failure.
Callies dragonslayer is a really good crank, the XL one is more for n/a stuff I thought, meaning the bob weights are really light for real lw rotating stuff... probably not a real good option.
The lunati billet cranks is also a good piece for sure. I think that I saw somewhere that there was another company making one too now that was supposed to be a really good piece, saw something in the back of a national dragster I think.
Are you having an issue? Take it to PM if need be.
Callies dragonslayer is a really good crank, the XL one is more for n/a stuff I thought, meaning the bob weights are really light for real lw rotating stuff... probably not a real good option.
The lunati billet cranks is also a good piece for sure. I think that I saw somewhere that there was another company making one too now that was supposed to be a really good piece, saw something in the back of a national dragster I think.
Are you having an issue? Take it to PM if need be.
09-11-2008, 07:29 PM
#4
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You are going to want to look towards a billet peice. As 6speeds inc said, Moldex,bryant, and also LA are some top name companys, just not known in the lsx world.
Be prepared to wait several months after putting money down.
On another note, we went with a lunati billet for our 440in blower motor, not running yet but will drive a huge ATI unit.
Be prepared to wait several months after putting money down.
On another note, we went with a lunati billet for our 440in blower motor, not running yet but will drive a huge ATI unit.
09-11-2008, 08:51 PM
#6
I had problems with my bottom end last year the I could not trace, so I switched to an 8 counterweight billet piece. And the problems seemed to go away, even thought the crank mfg said there was no way that is what it was. Apparent 2500hp is easier on a crank than 10,000 rpm. I know now that I have over 60 runs on the same crank and rod bearings, with less bearing clearence, and less oil pressure than I had last year. Funny how the proof is in the pudding.
09-11-2008, 10:59 PM
#7
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If you want to add options, ie add 1.888 journal. and/ or specified stroke, that is Magnum crankshaft.
Magnum XL, adds machined counterweights
Last edited by Fraser@SpeedInc; 09-12-2008 at 10:20 AM.
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09-12-2008, 10:08 AM
#9
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First Lunati does not make a Billet crankshaft. They are all forged. The Lunati is heavier and we feel therefore a bit stronger. We have not tested back to back so it would be hard to quantify.
We have run several crankshafts. All have been Lunati forgings. Our first was a 4.125 Stroke that used honda 1.88 rod journals. The crank was modified to clear our 6" GRP rods.
We noticed main bearing "wipe" on #2, #3 and #4 main bearings. #3 was the most affected while #2 and #4 were only wiped on the halves towards the center main. We had heard several others complain that the block was unstable. It wasn't the block, it was the crankshaft flexing. We decided to change to a Lunati 4" stroke crankshaft with a 2" rod journal. Dyno testing showed less wear on the main bearings. Also at the same time we increased the main studs from 10MM to 11MM.
We have discussed this situation with engineers at GM Performance Parts as well as many experts in the industry. We are talking about Crank Manufacturers as well as builders of high horsepower small blocks. The consensus is that because of the bore spacing in most small blocks there isn't enough area in the flank area to resist flexing. Also the more stroke that you use the less area you have to aid in rigidity.
As Joe pointed out about 50% of the people we talked with stressed the need for a center counterweighted or 8 counterweight crankshaft. As mentioned by Joe these are custom billet pieces only. None of the current crank manufacturers offers a center counterweighted crankshaft. It's only available on a custom basis. That will take probably 12 to 20 weeks depending on who you use.
We have acquired a center counterweighted crankshaft but have not had the opportunity to test it. The changes we made early on have proven to hold up with a 500 shot of Nitrous.
If you’re going to build a high horsepower LSX there are things that I would recommend.
11MM Main Studs
Billet Center counter weighted crankshaft.
Strokes no larger than 4"
Min 2" rod journals
A little extra clearance in the main bearings.
These are things that an experienced engine builder knows. If they have made 1200+ horsepower with a small block they will tell you. Things are going to move around.
Robin
We have run several crankshafts. All have been Lunati forgings. Our first was a 4.125 Stroke that used honda 1.88 rod journals. The crank was modified to clear our 6" GRP rods.
We noticed main bearing "wipe" on #2, #3 and #4 main bearings. #3 was the most affected while #2 and #4 were only wiped on the halves towards the center main. We had heard several others complain that the block was unstable. It wasn't the block, it was the crankshaft flexing. We decided to change to a Lunati 4" stroke crankshaft with a 2" rod journal. Dyno testing showed less wear on the main bearings. Also at the same time we increased the main studs from 10MM to 11MM.
We have discussed this situation with engineers at GM Performance Parts as well as many experts in the industry. We are talking about Crank Manufacturers as well as builders of high horsepower small blocks. The consensus is that because of the bore spacing in most small blocks there isn't enough area in the flank area to resist flexing. Also the more stroke that you use the less area you have to aid in rigidity.
As Joe pointed out about 50% of the people we talked with stressed the need for a center counterweighted or 8 counterweight crankshaft. As mentioned by Joe these are custom billet pieces only. None of the current crank manufacturers offers a center counterweighted crankshaft. It's only available on a custom basis. That will take probably 12 to 20 weeks depending on who you use.
We have acquired a center counterweighted crankshaft but have not had the opportunity to test it. The changes we made early on have proven to hold up with a 500 shot of Nitrous.
If you’re going to build a high horsepower LSX there are things that I would recommend.
11MM Main Studs
Billet Center counter weighted crankshaft.
Strokes no larger than 4"
Min 2" rod journals
A little extra clearance in the main bearings.
These are things that an experienced engine builder knows. If they have made 1200+ horsepower with a small block they will tell you. Things are going to move around.
Robin
09-12-2008, 11:00 AM
#10
Robin, is there anything that is being done with the alum block that is on the way to address any of these issues, such as making the 11 mm stud standard, or added material to the bottom side of the block to help keep it more stable (as the alum would need anyway)
The bearing clearances that you were seeing the improper wipe patters with, what were they set to @ assembly, just so we have some idea as to what's going to be a problem.
As I am waiting for the alum block, I am aware that the block being alum, is going to require a little more clearnace as they tend to move more anyway, but I'm wondering what a good starting point would be.
Depending on what the reccommended max bore of the alum motor is, will decide on what stroke ends up going in the motor. I'm hoping to see the alum be the tall deck version so that a 4.25 stroke would be possible with the piston well up in the cylinder... but if it's a regular deck height motor I'll stick with a little smaller displacment in favor for better geometry.
The bearing clearances that you were seeing the improper wipe patters with, what were they set to @ assembly, just so we have some idea as to what's going to be a problem.
As I am waiting for the alum block, I am aware that the block being alum, is going to require a little more clearnace as they tend to move more anyway, but I'm wondering what a good starting point would be.
Depending on what the reccommended max bore of the alum motor is, will decide on what stroke ends up going in the motor. I'm hoping to see the alum be the tall deck version so that a 4.25 stroke would be possible with the piston well up in the cylinder... but if it's a regular deck height motor I'll stick with a little smaller displacment in favor for better geometry.
09-15-2008, 01:28 AM
#11
FormerVendor
Center counter weighted cranks are always better for stress reduction in any crankshaft. The object of the center counter weighted crank is to make a crank where every single throw is balanced on its own rather than the extra heavy counterweights on the extreme front and rear ends like your OEM stuff is for economy and easier balancing.
The problem is that almost no one makes center counter weighted cranks at all in a "shelf-part" form since they do add dead weight in the middle and they are usually a billet design which is more expensive. Because of this you have to wait forever which NO racer will usually do and you have a really expensive crank that takes half a year to get so no one wants to stock or order anything like that.
Most of your all out power adder engines are Sonny Bryants with center counterweights. Most NA guys don't want the extra weight and do what it takes to make the crank live and still keep the inertia down with the normal style cranks. I would also agree with Joe and Robin that a high rpm big stroke deal is still better with the CCWs to resist flex if you can live with the weight and the extra build time.
The problem is that almost no one makes center counter weighted cranks at all in a "shelf-part" form since they do add dead weight in the middle and they are usually a billet design which is more expensive. Because of this you have to wait forever which NO racer will usually do and you have a really expensive crank that takes half a year to get so no one wants to stock or order anything like that.
Most of your all out power adder engines are Sonny Bryants with center counterweights. Most NA guys don't want the extra weight and do what it takes to make the crank live and still keep the inertia down with the normal style cranks. I would also agree with Joe and Robin that a high rpm big stroke deal is still better with the CCWs to resist flex if you can live with the weight and the extra build time.
09-15-2008, 01:46 AM
#12
FormerVendor
FWIW, I have seen all those above and more totally FUBAR and in pieces when people didn't know what they were doing and seen el cheapo chinese stuff with no center counterweights like eagles go 7s for 200+ passes. Oil starvation whether from crank or block movement, insufficient clearance or windage problems kills most cranks.
Drag race engines have less issues in general since they don't run too long at any rpm whereas circle track engines can have harmonic problems that kill stuff fast if the situation is not dealt with. RPM seems to be worse than power in general as well.
You need to pull the shortblock down after some initial action and look for yourself what is going on at that power level and rpm. Start big on the clearances and work backwards but you will probably need a real drysump to keep the crank oiled and happy too at higher rpms and clearances.
If you see shiny spots on the bearings look at the crank very closely and run more clearance to keep from touching. Also make sure you have the right harmonic damper and tell them (ATI) exactly what you have and what you are doing with it.
If you really want the best out there though it's a Sonny Bryant CCW Billet with full size journals and extra big radii. That's what people that have big money will buy excluding stuff like Chambon which is probably way out of your budget and timeline.
You will see that some people have massive problems and some people don't even though they are all running the same parts so that should really tell you something. The parts are important but it's not all in the parts. I know many super high rpm guys and they won't run a CCW crank ever because of the weight and they don't have issues.
09-16-2008, 09:34 PM
#13
Phil,
You need to pull the shortblock down after some initial action and look for yourself what is going on at that power level and rpm. Start big on the clearances and work backwards but you will probably need a real drysump to keep the crank oiled and happy too at higher rpms and clearances.
You will see that some people have massive problems and some people don't even though they are all running the same parts so that should really tell you something. The parts are important but it's not all in the parts. I know many super high rpm guys and they won't run a CCW crank ever because of the weight and they don't have issues.
You need to pull the shortblock down after some initial action and look for yourself what is going on at that power level and rpm. Start big on the clearances and work backwards but you will probably need a real drysump to keep the crank oiled and happy too at higher rpms and clearances.
You will see that some people have massive problems and some people don't even though they are all running the same parts so that should really tell you something. The parts are important but it's not all in the parts. I know many super high rpm guys and they won't run a CCW crank ever because of the weight and they don't have issues.
09-17-2008, 10:37 PM
#17
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You could always have Windberg make one as well.
I agree with what Erik stated and can also testify to what Joe had stated after seeing a few trial hits/builds with his RPM screamer.
I know with the block movement on high power motors can definitely be a problem. Seeing the C5R block move around on the Orange car was a testament to that, but luckily lived on without any crank issues.
Phil, what did the bottom end of the motor look like? Bearings burnt/squished/etc? Lose all the mains?
Best of luck to you with the rebuild.
I agree with what Erik stated and can also testify to what Joe had stated after seeing a few trial hits/builds with his RPM screamer.
I know with the block movement on high power motors can definitely be a problem. Seeing the C5R block move around on the Orange car was a testament to that, but luckily lived on without any crank issues.
Phil, what did the bottom end of the motor look like? Bearings burnt/squished/etc? Lose all the mains?
Best of luck to you with the rebuild.
09-20-2008, 01:46 PM
#18
We already have a good dry sump. Its initally setup for a big block chevy, 5 stages, divider pan. We've got more than enough volume and oil pressure. Oil pressure on the big end is 110-120psi.
We're going with a Sonny Bryant crank, 2 custom pieces on the block and a couple other changes to see if we can get it to live @ 2500hp and 8500-9000rpms.
We're going with a Sonny Bryant crank, 2 custom pieces on the block and a couple other changes to see if we can get it to live @ 2500hp and 8500-9000rpms.
