Wiseco, Wossner, or Pro X Or ???

[KXDINO]

thanks dave for clearing that up , a lot of piston failures are from people leaving them in the engine way past there service life , some seem to think i can get more hrs out of mine then yours , while there cylinders are getting more flogged out and there loosing hp.

[alward25]

All good discussion, however, I have never had a Forged piston shatter.  I have had more problems with cast, namely Pro-X and a few OEM shattering the skirt, not holding the the alignment pin for the ring and letting it bounce around the engine, or straight up exploding.  All of them in not very remarkable engines.  After having a bunch of Wiseco piston and ring problems and crappy customer service, not going there if I don't have to.  So, I run only Wossner by process of elimination and I feel they spend more time on the finished product than the other guys.  My 2 cents while we are throwing opinions out there. 

Bike companies also put in the most eco friendly parts they can so they can turn a profit and the parts are sure to last as long as you keep to the schedule they have established.  They are not the best available and there is an overly high opinion in this industry that OEM is the only way to go.  There are a few parts that are made that OEM is a better option.  This is not always the case and to blindly boast " I run only OEM parts", tells me you run the bare minimum to get by for quality and overpay for packaging in many cases.

[sandblaster]

Hey Alex...
Jeff has a year on the top end I built for him.
Ice, Dirt, and street... It's been a good year for him as he just won his 6th Drag championship on his K5.
He will be taking the top end off soon to check it out.
It will be interesting to see how well his Wossner is holding up  

[mun]

Hi sandblaster.

Do you know what RPM is a peak power at short exhaust pipe? Approximately.

[big green]

All good discussion, however, I have never had a Forged piston shatter.  I have had more problems with cast, namely Pro-X and a few OEM shattering the skirt, not holding the the alignment pin for the ring and letting it bounce around the engine, or straight up exploding.  All of them in not very remarkable engines.  After having a bunch of Wiseco piston and ring problems and crappy customer service, not going there if I don't have to.  So, I run only Wossner by process of elimination and I feel they spend more time on the finished product than the other guys.  My 2 cents while we are throwing opinions out there. 

Bike companies also put in the most eco friendly parts they can so they can turn a profit and the parts are sure to last as long as you keep to the schedule they have established.  They are not the best available and there is an overly high opinion in this industry that OEM is the only way to go.  There are a few parts that are made that OEM is a better option.  This is not always the case and to blindly boast " I run only OEM parts", tells me you run the bare minimum to get by for quality and overpay for packaging in many cases.

I could not agree more. However the only time I have ever had a ring pin issue was when I ran wiseco pistons in a snowmobile engine along with another friend. We used to do a lot of grudge racing. Unfortunately piston threads usually turn into the same thing as what oil is best thread or mineral vs synthetic....  I honestly regret even commenting in the first place. I am however extremely grateful for much of the knowledge gained on this site. My original reply to the first post was simply that I would not wait for brand "x" piston as I have had great luck with other pistons and not so good with others. I am not here to wield my almighty knowledge sword just share some experiences. Those that prefer forged should continue to run them and those that prefer cast should do the same but to somehow suggest that a certain racers bike would basically self destruct if it didn't have a forged piston is just ridiculous but again that is my opinion and i have realized I should keep those to my self. I will continue to frequent the forum as my love for the kx 500 is as strong as any other here but will keep my posting to a minimum when it comes to opinion based topics.

Cheers!

[alward25]

Big Green,
If Vertex made a piston for the K5, I would run it in stock to mild engines until it gave me a reason not to.  So, with that being said, what oil u running:)

[big green]

 

[umberto]

All good discussion, however, I have never had a Forged piston shatter.  I have had more problems with cast, namely Pro-X and a few OEM shattering the skirt, not holding the the alignment pin for the ring and letting it bounce around the engine, or straight up exploding.  All of them in not very remarkable engines.  After having a bunch of Wiseco piston and ring problems and crappy customer service, not going there if I don't have to.  So, I run only Wossner by process of elimination and I feel they spend more time on the finished product than the other guys.  My 2 cents while we are throwing opinions out there. 

Bike companies also put in the most eco friendly parts they can so they can turn a profit and the parts are sure to last as long as you keep to the schedule they have established.  They are not the best available and there is an overly high opinion in this industry that OEM is the only way to go.  There are a few parts that are made that OEM is a better option.  This is not always the case and to blindly boast " I run only OEM parts", tells me you run the bare minimum to get by for quality and overpay for packaging in many cases.

I could not agree more. However the only time I have ever had a ring pin issue was when I ran wiseco pistons in a snowmobile engine along with another friend. We used to do a lot of grudge racing. Unfortunately piston threads usually turn into the same thing as what oil is best thread or mineral vs synthetic....  I honestly regret even commenting in the first place. I am however extremely grateful for much of the knowledge gained on this site. My original reply to the first post was simply that I would not wait for brand "x" piston as I have had great luck with other pistons and not so good with others. I am not here to wield my almighty knowledge sword just share some experiences. Those that prefer forged should continue to run them and those that prefer cast should do the same but to somehow suggest that a certain racers bike would basically self destruct if it didn't have a forged piston is just ridiculous but again that is my opinion and i have realized I should keep those to my self. I will continue to frequent the forum as my love for the kx 500 is as strong as any other here but will keep my posting to a minimum when it comes to opinion based topics.

Cheers!

Please keep expressing your opinions.  This site is all about people expressing their love for KXs and sharing experiences and knowledge.  I came from the hot rod world and was biased towards forged pistons, so this was very interesting to read for me and most importantly I learned something.

[sandblaster]

Hi sandblaster.

Do you know what RPM is a peak power at short exhaust pipe? Approximately.

I built Jeff a Crank and a top end.
He assembled the parts and raced it.
I have heard rumors but I'm not allowed say.
I will tell you that there are some that have ran their Wossner K5 cranks and pistons over 12k... with no apparent damage  

[mun]

I built Jeff a Crank and a top end.
He assembled the parts and raced it.
I have heard rumors but I'm not allowed say.
I will tell you that there are some that have ran their Wossner K5 cranks and pistons over 12k... with no apparent damage  

Thanks.
More than 12k is a hell of a lot of 86-mm stroke.

Prior to secure piston speed was approx. 8500> 24.4 m/s 79.9 ft/sec.
12000> 34.4 m/s, 112.9 ft/sec.
http://www.csgnetwork.com/pistonspeedcalc.html

Now I understand the shortness of the exhaust pipe. More than 12k can be obtained from the motor over 100 hp easily.

[big green]

So I wanted to post an update on this thread. As you all may or may not know Tom Morgan is in the process of rebuilding my k5 engine and during our original discussions he said he would be using a oem cast piston. I used a cast piston in my 87 k5 I used to have and had no issues at all but the engine outside of reeds and pipe was stock. I have used cast pistons in stock and modified snowmobile engines without issue as well. However just so you all don't think I was trying to be a over the top opinionated jerk or some kind of know it all I wanted to share with you my most recent conversation with Tom where he informed me that he will be using a wossner piston in my build in part due to the fact it won't be stock. He also stated that he generally prefers wiseco pistons in most of his performance builds but he prefers the wossner in a k5 due to a stronger skirt design. I hope I did not offend anyone or steer anyone in the wrong direction and still believe for most applications that a cast piston will serve you well but in the spirit of this friendly and informative forum I felt compelled to share this information with my k5 friends. Cheers!

[sandblaster]

I know that I didn't take any offense and likely most others did not either.
Sharing is what these forums are all about.
I'm glad to see that Tom is using Wossners in his K5 builds.
I follow some of his builds on Facebook and I know that he does good work.
But since he is using Wossners in his modded K5 builds he just moved up one notch on my list of top K5 builders 

[Foxx4Beaver]

nope...no offense taken here neither big green...there's just some of us that prefer Wossner over anything else....for me personally, it was due to bad experiences with other brands and their craftsmanship/quality.

[reklessj]

Man I'm just offended that Tom put a wiseco in mine and you are getting wossner 😫

[big green]

  well if yours is still running I would say you are just fine with the wiseco