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Discussion Starter #1
I have done a fair amount of searching and read a number of posts in various forums regarding breather gears. There were various posts both supporting continuing to use a plastic gear and then those clearly in favor of replacing with steel. Actually, some of the reason on either side of the discussion made sense. Based upon what I have read though I am planning on replacing the breather when I replace my cam this winter and am inquiring on which breather is the way to go for the quality/design verse the cost (S&S, Jim’s, Ultima, or other)? Thanks for your thoughts and insight.
 

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OEM plastic and you'll not have to worry over wearing out the casing . Change out the breather when you change out the lifters and you'll be fine.
 

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Discussion Starter #4
From everything I had read the big concern of the continued use of the plastic ones, was concern over metal filings becoming imbedded in the plastic and then eating up the casing. Has anyone really ever seen this happen?

I hate to say it but I’m skeptical about that happening, because if you are getting a significant amount of metal particles in your oil, I would tend to believe that either you don’t change your oil and filter on a timely basis or you have another significant problem with your engine. In addition, if there are that many particles in your oil I would have to assume that you would be developing some major issues with the bearings throughout the engine.
 

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From everything I had read the big concern of the continued use of the plastic ones, was concern over metal filings becoming imbedded in the plastic and then eating up the casing. Has anyone really ever seen this happen?

I hate to say it but I’m skeptical about that happening, because if you are getting a significant amount of metal particles in your oil, I would tend to believe that either you don’t change your oil and filter on a timely basis or you have another significant problem with your engine. In addition, if there are that many particles in your oil I would have to assume that you would be developing some major issues with the bearings throughout the engine.
I would agree with you. :thumbsup
 

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The other factor to bear in mind is the breather timing. If you intend to modify the motor to increase revs or capacity then it's best to increase the breathing capability to avoid over-pressurising the crankcase. This can restrict performance and cause oil leaks/overheating. My understanding is that at least some of the after-market breathers are designed to do this rather than just offer a change of material.
There are some awful high-mileage motors out there with OEM breathers - I'm not worrying about mine! If there's swarf in the oil then the breather is last of my worries!
 

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We have a client with over 160,000 on his 80" Evo........plastic breather gear.
If we were building one from scratch, S&S would be what we reach for, and our AHDRA Mod Class bike had an S&S gear.:)
Scott
 

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OEM plastic and you'll not have to worry over wearing out the casing . Change out the breather when you change out the lifters and you'll be fine.


big time wrong! the plastic gears actually accelerate case wear.the plasitic gears are often out of round and score the breather hole,along with not sealing nearly as well as the S&S or JIMS steel gear.by all means go with a quality steel gear
 
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