!!! LET Motorsports Pulley Failure !!!
Re: !!! LET Motorsports Pulley Failure !!!
Originally Posted by SRT6-Man
Quote:
Originally Posted by BlUEMDsrt6
CERAMIC BEARING
1. RMADERMAN
2. tighed1
3. distantpulse
4. moparrbust
5. AMA FIRE
6. SRT6-Man
7.
STAINLESS BEARING
1. Bulldogger
2.Waldig - Woody
3. Bluemdsrt6
4.MDSRT6
5.Cruzinquick
6.
7.
8.
9.
Originally Posted by BlUEMDsrt6
CERAMIC BEARING
1. RMADERMAN
2. tighed1
3. distantpulse
4. moparrbust
5. AMA FIRE
6. SRT6-Man
7.
STAINLESS BEARING
1. Bulldogger
2.Waldig - Woody
3. Bluemdsrt6
4.MDSRT6
5.Cruzinquick
6.
7.
8.
9.
Re: !!! LET Motorsports Pulley Failure !!!
Originally Posted by SLK32Germany
Thanks for your good points in the discussion!!
Is this solution in your opinion better than the ASP-Idler ? Is there an additional risk to open the old idler and put the new bearing in?
The part is ss6303-2rs sealed with oil. 20,000 RPM max.
Stainless races and retainer with rubber seals.
$21.50 is my cost at 50-100 units. I'm going to need 100.
Thanks for your thoughts!
Best Regards.
Is this solution in your opinion better than the ASP-Idler ? Is there an additional risk to open the old idler and put the new bearing in?
The part is ss6303-2rs sealed with oil. 20,000 RPM max.
Stainless races and retainer with rubber seals.
$21.50 is my cost at 50-100 units. I'm going to need 100.
Thanks for your thoughts!
Best Regards.
Re: !!! LET Motorsports Pulley Failure !!!
20,000 RPM OK but what is its Dynamic Load Rating compared to the basic 6303 bearing?
Stainless steel in my past experience is not good at speed and loads.
At 20k RPM oil is thrown about and surely will escape the seals, the 20k figure is in ideal conditions, not exactly what you have. Seals do dot keep everything in and everything out, there is a gap.
Stainless steel in my past experience is not good at speed and loads.
At 20k RPM oil is thrown about and surely will escape the seals, the 20k figure is in ideal conditions, not exactly what you have. Seals do dot keep everything in and everything out, there is a gap.
Re: !!! LET Motorsports Pulley Failure !!!
Originally Posted by onehundred80
20,000 RPM OK but what is its Dynamic Load Rating compared to the basic 6303 bearing?
Stainless steel in my past experience is not good at speed and loads.
At 20k RPM oil is thrown about and surely will escape the seals, the 20k figure is in ideal conditions, not exactly what you have. Seals do dot keep everything in and everything out, there is a gap.
Stainless steel in my past experience is not good at speed and loads.
At 20k RPM oil is thrown about and surely will escape the seals, the 20k figure is in ideal conditions, not exactly what you have. Seals do dot keep everything in and everything out, there is a gap.
<--- Huge Horsepower
Re: !!! LET Motorsports Pulley Failure !!!
USA Bearings and Belts lists this bearing at $11.06 on its web site.
http://usabearingsandbelts.com/index...products_id=60
If I did not know the dynamic rating at 20,000 RPM I would not install it. It may cause lots of damage, far in excess of the bearigs cost.
http://usabearingsandbelts.com/index...products_id=60
If I did not know the dynamic rating at 20,000 RPM I would not install it. It may cause lots of damage, far in excess of the bearigs cost.
Re: !!! LET Motorsports Pulley Failure !!!
OneHundred80 ... With 50 years designing experience and bearing knowledge. Why haven't you totally redesigned us the ultimate performance pulley kit for the long term duration? I'm totally lost at this point as to who's pulley kit to purchase this March with my tax return!!! Squirrel
Re: !!! LET Motorsports Pulley Failure !!!
Originally Posted by Squirrel Crusher
OneHundred80 ... With 50 years designing experience and bearing knowledge. Why haven't you totally redesigned us the ultimate performance pulley kit for the long term duration? I'm totally lost at this point as to who's pulley kit to purchase this March with my tax return!!! Squirrel
From what I have found on the web, I would not be using stainless steel bearings, people seem to be going for them because of rust. The problem with SS is that it can only take 80-85% of the load of a steel bearing. The RS seal is not recomended at the higher revs of the basic seal,it is rubber and fails at these speeds. It is better to use Z or v types, but I would not use this S.Steel bearing at all no matter what seal.
The result here would be it would fail sooner but look nice and shiny, not a strong reason to go to SS.
All the rust in the first thread may have caused it to fail but I doubt it. My first thought here would have been what caused the rust and solve that problem first.
My immediate solution would be to use two bearings not one and use a longer stud if required.
I cannot find a solid answer on the use of ceramic bearigs, they look like Gods gift but can they take the load as well. Ceramics come in three types, all ceramic, and hybrids; ceramic ***** with races of steel and ceramic for ***** and one race with the other race of steel.
My basic question is why increase the crank pulley diameter thereby increasing the speed and stress on every compoonent attached to the belt
Why not decrease the pulley sizes on those components you want to speed up, this could have led to the idler pulley being increased in size.
For example how fast can a water pump spin before it gets inefficient?Surely spinning the alternator faster than is needed wastes power?
Not the cheapest initial cost but? ......
Last edited by onehundred80; 11-23-2008 at 11:48 AM.
Re: !!! LET Motorsports Pulley Failure !!!
Originally Posted by onehundred80
I have been designing for 50 years, bearings are a specific field and I have used bearings in that time, but I am not an expert on bearings. When I had to use bearings I got expertise from a bearing manufacturers rep. and picked his brains, as that was his job.
From what I have found on the web, I would not be using stainless steel bearings, people seem to be going for them because of rust. The problem with SS is that it can only take 80-85% of the load of a steel bearing.
The result here would be it would fail sooner but look nice and shiny, not a strong reason to go to SS.
All the rust in the first thread may have caused it to fail but I doubt it. My first thought here would have been what caused the rust and solve that problem first.
My immediate solution would be to use two bearings not one and use a longer stud if required.
I cannot find a solid answer on the use of ceramic bearigs, they look like Gods gift but can they take the load as well. Ceramics come in three types, all ceramic, and hybrids; ceramic ***** with races of steel and ceramic for ***** and one race with the other race of steel.
My basic question is why increase the crank pulley diameter thereby increasing the speed and stress on every compoonent attached to the belt
Why not decrease the pulley sizes on those components you want to speed up, this could have led to the idler pulley being increased in size.
For example how fast can a water pump spin before it gets inefficient?Surely spinning the alternator faster than is needed wastes power?
Not the cheapest initial cost but? ......
From what I have found on the web, I would not be using stainless steel bearings, people seem to be going for them because of rust. The problem with SS is that it can only take 80-85% of the load of a steel bearing.
The result here would be it would fail sooner but look nice and shiny, not a strong reason to go to SS.
All the rust in the first thread may have caused it to fail but I doubt it. My first thought here would have been what caused the rust and solve that problem first.
My immediate solution would be to use two bearings not one and use a longer stud if required.
I cannot find a solid answer on the use of ceramic bearigs, they look like Gods gift but can they take the load as well. Ceramics come in three types, all ceramic, and hybrids; ceramic ***** with races of steel and ceramic for ***** and one race with the other race of steel.
My basic question is why increase the crank pulley diameter thereby increasing the speed and stress on every compoonent attached to the belt
Why not decrease the pulley sizes on those components you want to speed up, this could have led to the idler pulley being increased in size.
For example how fast can a water pump spin before it gets inefficient?Surely spinning the alternator faster than is needed wastes power?
Not the cheapest initial cost but? ......
FWIW, the ASP idler pulley pictured (i.e. the rusty one) was never installed on my car - it was the replacement part LET sent initially to help get me back on the road (only wound up using the bearing from it to replace my seized bearing).
Re: !!! LET Motorsports Pulley Failure !!!
Reply to c32AMG-DTM
I see, thanks.
I am only looking at this problem from an engineering viewpoint, I see the posts and read them for what I can learn and then add comments.
The differences between the various tuners approach to the speed increases were not known to me. The Code3Performance idea would seem the soundest approach at first glance. Adding stresses were they are not needed is asking for earlier failure of some components.
I see, thanks.
I am only looking at this problem from an engineering viewpoint, I see the posts and read them for what I can learn and then add comments.
The differences between the various tuners approach to the speed increases were not known to me. The Code3Performance idea would seem the soundest approach at first glance. Adding stresses were they are not needed is asking for earlier failure of some components.
Last edited by onehundred80; 11-23-2008 at 12:02 PM.
Re: !!! LET Motorsports Pulley Failure !!!
Originally Posted by BrianBrave
CERAMIC BEARING
1. RMADERMAN
2. tighed1
3. distantpulse
4. moparrbust
5. AMA FIRE
6. SRT6-Man
7.
8.
9.
STAINLESS BEARING
1. Bulldogger
2. Waldig - Woody
3. Bluemdsrt6
4. MDSRT6
5. Cruzinquick
6. PA/ XFIRE
7. BrianBrave
8.
9.
1. RMADERMAN
2. tighed1
3. distantpulse
4. moparrbust
5. AMA FIRE
6. SRT6-Man
7.
8.
9.
STAINLESS BEARING
1. Bulldogger
2. Waldig - Woody
3. Bluemdsrt6
4. MDSRT6
5. Cruzinquick
6. PA/ XFIRE
7. BrianBrave
8.
9.
1, It can only take 80-85% of an equivalent steel bearing load
2, The RS seal is good only at 35% less speed than a Z seal (20,000 less 35% = 13,000 rpm) 2RS means it has two seals, one on each side.
3, The cage the ***** run in also has to be correct for the highest speeds
These limitations make it worse than the stock seal fitted with Z or V seals.
Last edited by onehundred80; 11-23-2008 at 03:58 PM.
<--- Huge Horsepower
Re: !!! LET Motorsports Pulley Failure !!!
Originally Posted by onehundred80
My basic question is why increase the crank pulley diameter thereby increasing the speed and stress on every compoonent attached to the belt
Why not decrease the pulley sizes on those components you want to speed up, this could have led to the idler pulley being increased in size.
For example how fast can a water pump spin before it gets inefficient?Surely spinning the alternator faster than is needed wastes power?
Not the cheapest initial cost but? ......
Why not decrease the pulley sizes on those components you want to speed up, this could have led to the idler pulley being increased in size.
For example how fast can a water pump spin before it gets inefficient?Surely spinning the alternator faster than is needed wastes power?
Not the cheapest initial cost but? ......
Installing a new pulley on my electrically clutched supercharger that only provides 7HP in gains - - is just not worth the cost or the risk. Not saying it's a bad product - just not enough gains for the price and possibility of damaging my SC.
The largest crank pulley (185mm) increases the other pulley ratios (except the WP and Idler) by 20%. So you really only begin to overdrive them VS a stock crank pulley when your driving above 5K RPM. Your usually in the "sport" mode of driving at those RPM's - during normal driving there really is no issue. Example: 2,500 RPM with a 185mm is the same as 2,000 RPM with a stock crank pulley. No big deal.
That's well worth the risk and cost for the potential gains in PSI - - IMO.
A proper bearing will solve one issue, unfortunately the WP had to be reduced in size to clear the larger pulley. I've had to replace failed WP on my stock truck, so if I have to replace the WP on my SRT6 a little sooner as a cost of more performace -- OK.
Re: !!! LET Motorsports Pulley Failure !!!
Originally Posted by BrianBrave
Six-of-one -- half-a-dozen of the other.
Installing a new pulley on my electrically clutched supercharger that only provides 7HP in gains - - is just not worth the cost or the risk. Not saying it's a bad product - just not enough gains for the price and possibility of damaging my SC.
The largest crank pulley (185mm) increases the other pulley ratios (except the WP and Idler) by 20%. So you really only begin to overdrive them VS a stock crank pulley when your driving above 5K RPM. Your usually in the "sport" mode of driving at those RPM's - during normal driving there really is no issue. Example: 2,500 RPM with a 185mm is the same as 2,000 RPM with a stock crank pulley. No big deal.
That's well worth the risk and cost for the potential gains in PSI - - IMO.
A proper bearing will solve one issue, unfortunately the WP had to be reduced in size to clear the larger pulley. I've had to replace failed WP on my stock truck, so if I have to replace the WP on my SRT6 a little sooner as a cost of more performace -- OK.
Installing a new pulley on my electrically clutched supercharger that only provides 7HP in gains - - is just not worth the cost or the risk. Not saying it's a bad product - just not enough gains for the price and possibility of damaging my SC.
The largest crank pulley (185mm) increases the other pulley ratios (except the WP and Idler) by 20%. So you really only begin to overdrive them VS a stock crank pulley when your driving above 5K RPM. Your usually in the "sport" mode of driving at those RPM's - during normal driving there really is no issue. Example: 2,500 RPM with a 185mm is the same as 2,000 RPM with a stock crank pulley. No big deal.
That's well worth the risk and cost for the potential gains in PSI - - IMO.
A proper bearing will solve one issue, unfortunately the WP had to be reduced in size to clear the larger pulley. I've had to replace failed WP on my stock truck, so if I have to replace the WP on my SRT6 a little sooner as a cost of more performace -- OK.
Go for it, its your car and if you can get it towed home for nothing all the better. Good luck.
Re: !!! LET Motorsports Pulley Failure !!!
Originally Posted by BrianBrave
Six-of-one -- half-a-dozen of the other.
Installing a new pulley on my electrically clutched supercharger that only provides 7HP in gains - - is just not worth the cost or the risk. Not saying it's a bad product - just not enough gains for the price and possibility of damaging my SC.
The largest crank pulley (185mm) increases the other pulley ratios (except the WP and Idler) by 20%. So you really only begin to overdrive them VS a stock crank pulley when your driving above 5K RPM. Your usually in the "sport" mode of driving at those RPM's - during normal driving there really is no issue. Example: 2,500 RPM with a 185mm is the same as 2,000 RPM with a stock crank pulley. No big deal.
That's well worth the risk and cost for the potential gains in PSI - - IMO.
A proper bearing will solve one issue, unfortunately the WP had to be reduced in size to clear the larger pulley. I've had to replace failed WP on my stock truck, so if I have to replace the WP on my SRT6 a little sooner as a cost of more performace -- OK.
Installing a new pulley on my electrically clutched supercharger that only provides 7HP in gains - - is just not worth the cost or the risk. Not saying it's a bad product - just not enough gains for the price and possibility of damaging my SC.
The largest crank pulley (185mm) increases the other pulley ratios (except the WP and Idler) by 20%. So you really only begin to overdrive them VS a stock crank pulley when your driving above 5K RPM. Your usually in the "sport" mode of driving at those RPM's - during normal driving there really is no issue. Example: 2,500 RPM with a 185mm is the same as 2,000 RPM with a stock crank pulley. No big deal.
That's well worth the risk and cost for the potential gains in PSI - - IMO.
A proper bearing will solve one issue, unfortunately the WP had to be reduced in size to clear the larger pulley. I've had to replace failed WP on my stock truck, so if I have to replace the WP on my SRT6 a little sooner as a cost of more performace -- OK.
Smaller pulleys spin faster, that would include the WP and the Idler.
All pulleys will spin faster at a given rpm using a 185mm over the stock pulley, making them smaller makes them spin even faster.
I see you are thinking of using the Stainless Steel bearing .... I see how you get the name BrianBrave.
I have one word for you ....Don't
I think my opinions are falling on deaf ears anyway, they are sound though and based on some research on the web and books etc. The trouble is that they see 20,000 rpm and are seduced by it. Load for load this S.Stl. bearing rates lower than the stock 6303 bearing. At the most optimistic it is no better than the stock bearing at worst it will fail much much sooner and when it fails there will be no warning at all.
Last edited by onehundred80; 11-23-2008 at 09:03 PM.
<--- Huge Horsepower
Re: !!! LET Motorsports Pulley Failure !!!
Originally Posted by onehundred80
I missed this when I read it first, can you explain what you mean? Do you mean the opposite of how it reads?
A proper example would have been:
When operating at 2,000 engine RPM's; an SRT6 engine equipped with 185mm ODPS (Over Drive Pulley System) will drive the accessory components (except the WP and Idler) at the same rate as a stock SRT6 engine operating at 2,400 RPM.
Re: !!! LET Motorsports Pulley Failure !!!
Originally Posted by amg-jerry
Just to clarify, here are the old and new water pump pulleys side by side. I reduced the size of the pulley to aid in belt tension.
The original problem was caused by the sidewall flexing under load, this lead to the aluminum work hardening and getting brittle. Shortening the sidewall increased the rigidity of the sidewall. The forces are now concentrated more on the inside radius, this radius should be bigger, as big as possible and free from machining marks as much as possible.
Aluminum is not good at taking loads like this and ideally it should be steel, failing that the radius must be bigger in the aluminum. A thicker sidewall with counterbores for the existing screws or longer screws would be much better as well.
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Re: !!! LET Motorsports Pulley Failure !!!
Originally Posted by MikeR
The upgraded WP pulley has thicker material and a larger radius at the angle. None of the upgraded pulleys have reported any failures. I will be redundant;
Anyone who did not upgrade their WP pulley should do it IMMEDIATELY.
MikeR
Anyone who did not upgrade their WP pulley should do it IMMEDIATELY.
MikeR