MMR OPG's

[Kahboom]

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[Kahboom]

Don't think I'm going to use there brand again. Switched to MMR opg and ctg will see how it goes with the new motor.

 

[bankyf]

Failed boundary crank sprocket

Do you have a pic from the side? Curios if it broke in the same place that the stock sprockets are breaking. Could anything else have lead to this failure? Having held the stock and boundary in my hands, I don't see how it couldn't be stronger than stock

 

[80FoxCoupe]

Don't think I'm going to use there brand again. Switched to MMR opg and ctg will see how it goes with the new motor.

Can you post a picture of the mating surfaces between the inner and outer portions of the OPG?

 

[80FoxCoupe]

Do you have a pic from the side? Curios if it broke in the same place that the stock sprockets are breaking. Could anything else have lead to this failure? Having held the stock and boundary in my hands, I don't see how it couldn't be stronger than stock

So you can hold two crank sprockets in your hand and make that determination? Nice.

 

[bankyf]

So you can hold two crank sprockets in your hand and make that determination? Nice.

How did I know that that was coming... I'm certainly no metallurgist and have no way to determine the composition of either, but the stock is extremely thin in the area of the keyway and boundary has done a good job of addressing that.

 

[DougS550]

How did I know that that was coming... I'm certainly no metallurgist and have no way to determine the composition of either, but the stock is extremely thin in the area of the keyway and boundary has done a good job of addressing that.

Does the amount of thickness boundary added above the keyway really make any difference if they too are cracking? To nip this at the Bud so to speak, I am sure we could take up a Fund to pay for sending both a failed OEM and a failed Boundary OPG/CS to a Metallurgist Lab and have a Complete Failure Analysis Test done as to why they failed and exactly what are the differences between the two as far as metal composition, harness ETC . This would clear up everything which has to due with the sprockets. Just My Opinion. Good Luck

 

[bankyf]

Does the amount of thickness boundary added above the keyway really make any difference if they too are cracking? To nip this at the Bud so to speak, I am sure we could take up a Fund to pay for sending both a failed OEM and a failed Boundary OPG/CS to a Metallurgist Lab and have a Complete Failure Analysis Test done as to why they failed and exactly what are the differences between the two as far as metal composition, harness ETC . This would clear up everything which has to due with the sprockets. Just My Opinion. Good Luck

I suppose that would depend on why it broke. I've seen plenty of pics of stock sprockets broken, but this is the first boundary I've seen a pic of. I'd absolutely be down to contribute to a failure analysis. After looking at his pic again though, the current Boundary crank gear has a much more significant anti-burst ring around the center.

 

[DougS550]

I suppose that would depend on why it broke. I've seen plenty of pics of stock sprockets broken, but this is the first boundary I've seen a pic of. I'd absolutely be down to contribute to a failure analysis. After looking at his pic again though, the current Boundary crank gear has a much more significant anti-burst ring around the center.

Yes I agree. But material alone is not really the defining factor with metal parts. Metal Composition, Metal Impurities, Incorrect Heat treatment, machining or casting creating an inherent structural material deficiency. Are Boundary parts made in China, if so that would most likely be the issue. China is known for metal impurities, machining inconsistencies. Just Saying

 

[bankyf]

Yes I agree. But material alone is not really the defining factor with metal parts. Metal Composition, Metal Impurities, Incorrect Heat treatment, machining or casting creating an inherent structural material deficiency. Are Boundary parts made in China, if so that would most likely be the issue. China is known for metal impurities, machining inconsistencies. Just Saying

They claim to be machined in house from US sourced heat treated 4340 chromoly billets hardened to Rockwell C scale hardness of 50-55. They also claim 50% stronger which I would like to believe was verified through actual testing, but perhaps they just randomly made that number up. I've found some older pics on retailers websites showing the less significant anti-burst ring. Perhaps they realized the original design was still experiencing failures.

 

[shogun32]

yeah please post an axial view. I didn't see mentioned the proximity of the keyway to the split.
US sourced material can be fraudulent too, as the US Navy had to learn the hard way.

 

[DougS550]

They claim to be machined in house from US sourced heat treated 4340 chromoly billets hardened to Rockwell C scale hardness of 50-55. They also claim 50% stronger which I would like to believe was verified through actual testing, but perhaps they just randomly made that number up. I've found some older pics on retailers websites showing the less significant anti-burst ring. Perhaps they realized the original design was still experiencing failures.

Well, all of this will be verified from the test.

 

[80FoxCoupe]

Thank you for putting this together. This should bring forth many needed answers!

 

[Kahboom]

When the crank timing gear was on the end of the crank the crack was open quite a bit. It was a very snug fit when they went on. If I had to guess they are cracking due to it being too tight and when the metal expands from heat and it's running at a high rpm they crack. They do look beefier then stock but don't seem to hold up any better. As far as the Oil pump gears they make it did turn fine when it was installed and was greased and oiled before being run but it did rub the oil pump housing pretty bad. Bad enough that I had to replace the oil pump housing. Not trying to brand bash just letting people know my experience.

 

[shogun32]

Isn't there a nut keeping it on? A hard press fit seems like a mistake.

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