Wich pistons!

[BellicoseBanshee]

I have seen two banshees with Vito's run like crazy. However, I always have and always will use Wiseco Prolite pistons. :cool:

[shanYE west]

I have seen two banshees with Vito's run like crazy. However, I always have and always will use Wiseco Prolite pistons. :cool:

 

Vito's forged SuperStock and Power pistons are made by wiseco.

[BellicoseBanshee]

Vito's forged SuperStock and Power pistons are made by wiseco.

 

I have also heard that Wiseco manufactures them. Super Stock, Power Pistons, and Prolites are all different types of pistons, correct? I know that the Super Stock have the notch on the exhaust side, but are the Power Pistons exactly the same as the Prolites?

[RNBRAD]

You have to weigh the benefits and disadvantages of piston types, ie forged (wideco) and cast (pro-x). For me it's like this. I'm not going to put a lockout clutch on a stock banshee or 35mm carbs, there's no reason and it creates a disadvantage. But there comes a point in motor mods to where the advantages outweigh the disadvantages. Same way with cast and forged pistons. I would not run a forged piston on a stock stroke motor unless you were running alky with drag porting etc... You will have more advantages with a cast. With a stroked and ported motor, cub etc.. you will have better reliability with a stronger piston under those circumstances. What I'm saying is there is a point in motor mods where a cast piston will outperform a forged and vice-a-versa. One piston type is not the best for all motors.

[Justintoxicated]

You have to weigh the benefits and disadvantages of piston types, ie forged (wideco) and cast (pro-x). For me it's like this. I'm not going to put a lockout clutch on a stock banshee or 35mm carbs, there's no reason and it creates a disadvantage. But there comes a point in motor mods to where the advantages outweigh the disadvantages. Same way with cast and forged pistons. I would not run a forged piston on a stock stroke motor unless you were running alky with drag porting etc... You will have more advantages with a cast. With a stroked and ported motor, cub etc.. you will have better reliability with a stronger piston under those circumstances. What I'm saying is there is a point in motor mods where a cast piston will outperform a forged and vice-a-versa. One piston type is not the best for all motors.

 

I'm not following, what is the disadvantage to running weisco? You should ALWAYS warm up your bike wether using cast or forged pistons, forged pistons just expand at a different rate than the cylinders (which are cast)...Other than that I see absolutly NO disadvantage, they are stronger which is most important part of a piston, and lighter weight as well (next most important factor). Since when is cast stronger than forged?

 

Don't port your pistons. theres not much reason to, you might get another HP or two but it will likely make them weaker, they already have the necessary size holes and there is a reason for this...Look for another way to add the HP.

 

Also not sure I'm following the logic on having to have a stroked motor to run weiscos, so if I have a non stroked Cub I should stick with forged? Even on a ported bike I would run Forged pistons, as your already making nearly double the power from the factory. Makes no sense to me! I ran stock pistons for 3 years and weiscos for 3 years on my ported bike, I have not had problems with either setup in terms of reliability.

 

I read about some pisons made in some part of europe that were also forged and had some special Molybdenum Bisulphide coating or something but I don't know much about them (not even the name).

Edited May 25, 2007 by Justintoxicated

[snaddrag]

I seem to have very good luck the WSM/TDR pistons from Tony Doukas Racing. You can check them out at http://www.bansheedepot.com/default.asp I Know about 7 people with them and no problems. Just my 2cents

[FireHead]

I'm not following, what is the disadvantage to running weisco? You should ALWAYS warm up your bike wether using cast or forged pistons, forged pistons just expand at a different rate than the cylinders (which are cast)...Other than that I see absolutly NO disadvantage, they are stronger which is most important part of a piston, and lighter weight as well (next most important factor). Since when is cast stronger than forged?

 

Don't port your pistons. theres not much reason to, you might get another HP or two but it will likely make them weaker, they already have the necessary size holes and there is a reason for this...Look for another way to add the HP.

 

Also not sure I'm following the logic on having to have a stroked motor to run weiscos, so if I have a non stroked Cub I should stick with forged? Even on a ported bike I would run Forged pistons, as your already making nearly double the power from the factory. Makes no sense to me! I ran stock pistons for 3 years and weiscos for 3 years on my ported bike, I have not had problems with either setup in terms of reliability.

 

I read about some pisons made in some part of europe that were also forged and had some special Molybdenum Bisulphide coating or something but I don't know much about them (not even the name).

 

European pistons you are thinking of are probably made by Mahle. The coating I am sure is made by Balzers.

 

Beyond that, I had a crappy day at work and do not feel like getting in a forged vs. cast piston arguement. If RNBrad wasn't such a nice guy, I would probably get up on my soap box a bit more. Pistons made from a forging are always better if your cylinder bores are machine correctly to accept them. If you do not do any machine work and are looking to throw pistons in a bike engine that had OEM cast pistons, then you need to put cast pistons back in there. If you do shitty machine work, then, again, cast pistons are your friends as they are more forgiving. If you put value in reliability and performance, then a quality forged condtruction or billet CNC machined piston is the only way to go.

 

I am sure someone will dig up an internet article to contradict me, but if you really need to do that, you may also feel free to send me a PM containing your favorite vehicle magazine and I will figure out a way to get an article authored by me or atleast written on the subject using me as a noted reference, published......................I apparently have that kind of free time on my hands. :ohmy:

[RNBRAD]

You have to ask yourself, why do some of the top engine manufacturers in the world use forged in some motors and cast in others? There's definite reasons and probably tons more than I even know about. If a forged was the best piston in all engines, there would be no need for a cast design at all and it certainly would not still be around. But to state that a cast piston is more forgiving, not at all the case. The nature of the cast pistons brittleness makes them failure prone when they are not within their specif tight tolerances. One of the reasons forged is such a popular aftermarket replacement piston and they do so well because of their strength and forgiving tolerances. This is not so with a cast, you will brake a skirt real quick if they are just slightly out of tolerance. So in a world of non-exact tolerances from thousands of small mechanics, forged strength is a great attribute for them and it allows those to have great success and reliability. This is the reason cast units get a bad rap as an oem replacement piston in many cases.

 

So what are the benefits and disadvantages to each design? Does a cast pistons tighter tolerances improve performance and longevity when the threat of fracture from high compression high horsepower motors are not a threat? Absolutely!!! Does a cast piston have better antiwear properties and less friction due to it's higher silicon content than a forged? Absolutely!!! Is this a benefit? You tell me. If your cast piston cannot tolerate and is not recommended for the output of your motor due to high risk of fracture, then obviously the forged will be more beneficial than a cast unit. Also why do forged piston manufacturers use all these exotic coatings? To try and add the benefits of a cast piston break-in and antiwear properties without it's disadvantages. Does it work? not as well because they don't last long. I also don't look at warming up a forged piston as a disadvantage and saying a forged piston is lighter than a cast is not true as well, in some cases yes.

 

Anyway I'm not trying to start a pissing match between the two pistons designs. I use both but people need to understand each design has specefic benefits and disadvantages. No one design is the best, just as no one pipe is the best or tire, or suspension, so on and so forth. That's why the market supports both designs so well.

[FireHead]

You have to ask yourself, why do some of the top engine manufacturers in the world use forged in some motors and cast in others? There's definite reasons and probably tons more than I even know about. If a forged was the best piston in all engines, there would be no need for a cast design at all and it certainly would not still be around. But to state that a cast piston is more forgiving, not at all the case. The nature of the cast pistons brittleness makes them failure prone when they are not within their specif tight tolerances. One of the reasons forged is such a popular aftermarket replacement piston and they do so well because of their strength and forgiving tolerances. This is not so with a cast, you will brake a skirt real quick if they are just slightly out of tolerance. So in a world of non-exact tolerances from thousands of small mechanics, forged strength is a great attribute for them and it allows those to have great success and reliability. This is the reason cast units get a bad rap as an oem replacement piston in many cases.

 

So what are the benefits and disadvantages to each design? Does a cast pistons tighter tolerances improve performance and longevity when the threat of fracture from high compression high horsepower motors are not a threat? Absolutely!!! Does a cast piston have better antiwear properties and less friction due to it's higher silicon content than a forged? Absolutely!!! Is this a benefit? You tell me. If your cast piston cannot tolerate and is not recommended for the output of your motor due to high risk of fracture, then obviously the forged will be more beneficial than a cast unit. Also why do forged piston manufacturers use all these exotic coatings? To try and add the benefits of a cast piston break-in and antiwear properties without it's disadvantages. Does it work? not as well because they don't last long. I also don't look at warming up a forged piston as a disadvantage and saying a forged piston is lighter than a cast is not true as well, in some cases yes.

 

Anyway I'm not trying to start a pissing match between the two pistons designs. I use both but people need to understand each design has specefic benefits and disadvantages. No one design is the best, just as no one pipe is the best or tire, or suspension, so on and so forth. That's why the market supports both designs so well.

 

Alright, I have to throw a couple of rocks back at ya here:

 

1.) A piston that is made from a casting is not more brittle, nor than a forged piston. Simple strength of materials stuff. The universal " no free lunch" rule applies here. A cast piston generally is less dense than a forged piston material. With aluminum, lower density you ge maleability. I would venture to say that piston cracking might be more common with a cast piston, but it's not because it brittle. I would say that it is because you generally cannot achieve the same sectional thickness with a casting as you can with a forging.

 

2.) Cast pistons exist for and have existed for a long time for several reasons. The classic scenario is that it used to be the better way to make a piston as forging and machining equipment used to not be the as they are today. I would venture to say that this was the case up until the 1970's (I pulled that decade out of my butt). Now, if you are mass producing a piston in a volume similair to that of bullets, then it is cheaper to cast them. A vacuum degassed cast piston used to be a better piston type than a forging, when forgings were just a mechanically smashed piece of aluminum, but that simply isn;t the case any more.

 

Now, in 99% percent of piston design scenarios, you look towards casting as being the less expensive option for mass production if you can make the rest of your engine suit that choice.

 

3.) Tighter tolerances seems to be used as a blanket term here. If you are talking about the piston itself, then a forging is always more dimensionally stable than a casting. If were are talking about bore tolerances, then they need to be of a higher tolerance for a forging.

 

4.) The higher silicon content of a cast piston is bogus. With the current state of material technology, you can have a wide range of alloy material in either piston construction type. That arguement is about 30 years older than I am.

 

Ok, past all of that, both piston design have there place in many industries. I am also not interested in starting a piston contstruction pissing match. I tend to go a bit overboard when speaking on this subject, but please keep in mind that when I am saying a forged piston is always better, I am speaking to a higher performance engine application. Which is still slightly BS as it's only true in 99.8% of such applications. It really all depends on what you are trying to do with an engine.

 

As Brad says, if you have an OEM set of cylinders on a Banshee and simply have bolt on stuff, then go get Jim-Bob at the local Napa to bore your cylinders and throw a set of Pro-X pistons in there. That makes the most sense.

[RNBRAD]

Just a few corrections.

 

 

 

1.) A piston that is made from a casting is not more brittle, nor than a forged piston. Simple strength of materials stuff. The universal " no free lunch" rule applies here. A cast piston generally is less dense than a forged piston material. With aluminum, lower density you ge maleability. I would venture to say that piston cracking might be more common with a cast piston, but it's not because it brittle. I would say that it is because you generally cannot achieve the same sectional thickness with a casting as you can with a forging.

 

Yes it is simple strength of material. Drop a cast piston and then drop a forged from varying heights, tell me which one breaks 1st. You are confused on the term malleability. A forged piston will deform before it cracks and exhibits more malleability than a cast piston.

 

 

 

3.) Tighter tolerances seems to be used as a blanket term here. If you are talking about the piston itself, then a forging is always more dimensionally stable than a casting. If were are talking about bore tolerances, then they need to be of a higher tolerance for a forging.

 

 

Your kidding right? So a forging is more dimensionally stable, meaning less expansion when heated than a cast piston?

[chevy7398]

wow!!! a few of you need to do some actuall research on the differences between a cast and a forged piston, of a cast and a forged anything for that matter!!! not saying who though cause i dont want to get into a pissing match, but now ive heard everything

[FireHead]

Just a few corrections.

Yes it is simple strength of material. Drop a cast piston and then drop a forged from varying heights, tell me which one breaks 1st. You are confused on the term malleability. A forged piston will deform before it cracks and exhibits more malleability than a cast piston.

Your kidding right? So a forging is more dimensionally stable, meaning less expansion when heated than a cast piston?

Nope not really. An aluminum casting will always expand more unevenly than a forging..............not sure how you could think otherwise.

[RNBRAD]

Nope not really. An aluminum casting will always expand more unevenly than a forging..............not sure how you could think otherwise.

 

If they expand more unevenly or more, then everyone needs an explanation of why cast pistons in a banshee can have a tighter piston to bore clearance than a forged wiseco? Honestly, you have your forged and cast properties backwards.

[FireHead]

If they expand more unevenly or more, then everyone needs an explanation of why cast pistons in a banshee can have a tighter piston to bore clearance than a forged wiseco? Honestly, you have your forged and cast properties backwards.

No, I really don't have them backwards.

 

I am not really sure how to offer a non-metrological explanantion for this, but I will give it a shot.

 

First we must make a few assumptions / state a couple of general rules.

 

1.) A cast piston requires a bore that is not as large as would be required for a forged piston of the same size.

2.)The cast piston is made via a vacuum degassed die casting process (there are several processed out there, this is the most commonfor this genre of discussion)

3.) Post casting turning is done with a relatively simple cam turning setup on en engine lathe.

4.)The engine creates a eutopian heat cycle profile for the piston (not really possible, but it keeps a lid on a can of worms).

5.)The cast piston is made of a 4000 series, 5000 series, or tenzalloy material.

6.)All pistons go through a proper stress relieving process.

 

All that said a cast piston will change shape much less uniformally during a heating cycle than a forged piston. A forged piston may expand and contract more than a cast piston, but it does it in a uniform nature. This is what is important to someone developing a race engine. As long as the gorwth is consistant and repeatable, it really doesn't matter how much it changes dimensionally. Thus, in the spirit of racing engine development, a forged piston is always better (there are exceptions to this, but they are a whole other topic). A cast piston may expand and contract less from a general outside diameter, but along the entire outside diameter the gradient of change is ver inconsistant when compared to it's forged counterpart. This is due to elements of the metal alloy concentrating in certain areas as opposed to staying evenly blended. In lamens terms like elements like to hang out with each other as opposed to staying evenly mixed in the crowd (I know that was corny, but it could have been racist too). I am sure someone is going to mention grain structure of the material, but with a piston, it doesn't matter within reason. All of this is a generally know stumbling block with casting.

 

I am sure I need to put more into this post, but I am tired and typing doesn't seem fun right now. Please point out what doesn't make sense I will be happy to explain and/or repair it.

 

I hate to do this as it generally annoys me when people do it to me, but I have spent more time than I would like to talk about designing, machining, developing, race engine parts. Pistons are a big deal past a certain point, as are engine blocks, and crankshafts. I am sure the time I spent hacking aways at several piston issues will boggle my mind if I were to keep track of it. On top of that, I would like to note that piston manufacturing is a weird business. Compare and contrast, JE, Mahle, Arias, and CP...............none of them use exactly the same process for anything. CP and JE are particularly entertaining. IF anyone is really interested in this stuff, JE has an open house at their facility in SoCal. It's worth the time to go on if you are an engine geek. It will definitely make you say "what the hell?" more than once. Think about all of the operations, QC, fixtures, deburring, and programming that is required to make a family of bore sizes for one engine. Multiply that by all the applications they make pistons for...............................................and like I said you will say "what the hell?," all that work for a price competitive product that usually has nothing more to differentiate itself from a competitor than it's brand name.

[jayzx10r]

Here is why I like forged pistons over cast. See how the forged Wiseco didn't shatter like a cast piston would have under extreme over-rev? It stayed together and folded into itself instead of grenadeing...

This piston is exactly as I found it. I pulled the exhaust...the piston pin fell out of the chamber onto the garage floor. I pulled the head, reached into the cylinder and pulled this out of my RD350. The rod was broken in half and wedged into the cylinder wall. :: Ouch!! ::

 

 

 

 

 

 

Let see YOUR BEST piston pics!!

 

Jay From SanD.