pro x pistons?

[bentvalve]

what do you guys think of pro x pistons??? junk.. verdict please.. don russell

[Sprntr81]

pro-x makes a great cast piston no doubt.

[FireHead]

If given a choice i would rather use a forged Wiseco piston any day. :thumbsup:

[Bansh-eman]

If given a choice i would rather use a forged Wiseco piston any day. :thumbsup:

ill second that...

[bentvalve]

thanks gents! don

[blaster668]

Not me, I'll take an oem or a pro-x anyday over a wiseco....I seem to be in the minority on this one. I like forged pistons in 4 strokes, but prefer cast in two strokes. I'm not the only one with this opinion either, some very reputable engine builders tend to agree.

[woodro77]

Not me, I'll take an oem or a pro-x anyday over a wiseco....I seem to be in the minority on this one. I like forged pistons in 4 strokes, but prefer cast in two strokes. I'm not the only one with this opinion either, some very reputable engine builders tend to agree.

 

 

why use cast ? what are the advantages ?

[blaster668]

Easier break in for one. Forged pistons are much more likely to cold seize. I think cast are more forgiving also. I've never had a problem with cast pistons and I've been using them for years. I can't say the same for Wiseco pistons, I had trouble with them on more than one occasion. I've seen many Wiseco pistons with broken skirts from friends quads. I've also seen two wiseco pistons that broke one of there circlips and the pin worked out and ruined the cylinders. I talked to a reputable builder about this when it happened to me once and he said it was fairly common with Wiseco circlips.

[RNBRAD]

Pro-x is probably the best cast piston made for a banshee. If I had a relatively stock bike I'd run them over a Wiseco hands down. A cast piston will seal better and have less bore friction over a forged counterpart. If your motor is capable of running a cast piston over a forged, I would do it. I've never seen the difference in performance on cast vs forged in a banshee but car makers like dodge (viper) changed over to cast and it alone made more power. It's not as cut and dry as many people think. A forged is not the best choice in every situation.

[dynodon]

If your planning on running alky, I would go with the wiseco. We had three sets of pro lites drop the skirts off them, with only 4-5 passes on them.

But if your running gas, then I would go with the pro pistons. Just my opinion though

[FireHead]

Easier break in for one. Forged pistons are much more likely to cold seize. I think cast are more forgiving also. I've never had a problem with cast pistons and I've been using them for years. I can't say the same for Wiseco pistons, I had trouble with them on more than one occasion. I've seen many Wiseco pistons with broken skirts from friends quads.

 

A forged piston is not more likely to cold seize than a cast piston. A cast piston could be considered more forgiving than a forged piston as the are less dense and will plasticly deform when stressed. Therefore, your cylinder bore can be more out of round and tapered, but yet still function with a cast piston compared to a forged piston. Basically, if the machinist and machine tool that creates the the bore is with intolerance ofr position, taper, and concentricity in repect to the piston construction you will never have more problems with a forged piston over a comparable cast piston. In fact it will be the other way around.

 

I am curious as to who these big name builders are that have told you this, as it is quite a load of b.s. :thumbsup:

[blaster668]

A forged piston is not more likely to cold seize than a cast piston. A cast piston could be considered more forgiving than a forged piston as the are less dense and will plasticly deform when stressed. Therefore, your cylinder bore can be more out of round and tapered, but yet still function with a cast piston compared to a forged piston. Basically, if the machinist and machine tool that creates the the bore is with intolerance ofr position, taper, and concentricity in repect to the piston construction you will never have more problems with a forged piston over a comparable cast piston. In fact it will be the other way around.

 

I am curious as to who these big name builders are that have told you this, as it is quite a load of b.s. :thumbsup:

 

 

I absolutely will not back down from my statement about cold seizing! The reason is because forged pistons require more clearance than cast pistons. Any time there is more clearance, cold seizures are more likely.

 

I'm totally sick of you opening your mouth about crap you obviously have no idea about. Do a little research next time.

 

 

And by the way, the engine builder is Rich Hetrick of Hetrick Racing.... you've probably never heard of him, but he is very well known in MX racing. In fact he was named engine builder of the year, mechanic of the year, and race team of the year at the GNC awards banquet a couple years ago. John Natalie even rode for him a couple years back.

[FireHead]

Pro-x is probably the best cast piston made for a banshee. If I had a relatively stock bike I'd run them over a Wiseco hands down. A cast piston will seal better and have less bore friction over a forged counterpart. If your motor is capable of running a cast piston over a forged, I would do it. I've never seen the difference in performance on cast vs forged in a banshee but car makers like dodge (viper) changed over to cast and it alone made more power. It's not as cut and dry as many people think. A forged is not the best choice in every situation.

 

I will agree that Pro-X makes the best cast piston for a Banshee. If I was just replacing pistons in a stock bike that did not require and machine work done (remained at stock bore size) then I would certainly use a cast piston. I say this based on the fact that a cast piston requires a different set of bore dimensions and tolerances versus an identical forged piston.

 

You will probably never see a performance difference between a cast piston versus a forged piston except for in longevity of the engine. With properly machined cylinders and correctly installed pistons, a forged piston will always last longer and stand up to more abuse from high compression, high rpm, detonation, poor fuel quality, etc.

 

In regards to you Dodge Viper example and the piston construction being changed from cast to forged, do you know what engine generation you are referring to? The have changed piston construction two times that I can think of, for different reasons both times. At the moment they are currently running forged pistons from the factory, but you are correct in that not always being the case. One time they changed the pistons inorder to bandaid a problem they were having with the cylinder liners distorting, during normal heat cycling, more than a forged piston could accomodate. The the higher CTE of a cast piston solved that problem until the next generation of their V10 came out. The other time that I can think of that the piston construction was changed from forged to cast was when they changed the piston design which began having sea;ing issue at about 25k miles with spirited driving (I think there was actually a voluntary recall on this). The reason the piston construction was changed at this point was due to the piston supplier availability more than anything else.

 

I apologize for the second long post in this thread, in a row. Like Brad says, it's not the most publicly well understood issue and it is certainly not the most cut and dry. I will also appologize if I happen to come off being an ass. :thumbsup:

[FireHead]

I absolutely will not back down from my statement about cold seizing! The reason is because forged pistons require more clearance than cast pistons. Any time there is more clearance, cold seizures are more likely.

 

I'm totally sick of you opening your mouth about crap you obviously have no idea about. Do a little research next time.

And by the way, the engine builder is Rich Hetrick of Hetrick Racing.... you've probably never heard of him, but he is very well known in MX racing. In fact he was named engine builder of the year, mechanic of the year, and race team of the year at the GNC awards banquet a couple years ago. John Natalie even rode for him a couple years back.

 

I have no idea who Rick Hetrick is or his company. I really don't follow any sort of ATV or MX racing, unless I happen to see something about it in a magazine.

 

I am not asking anyone to back down from their opinion. Everyone is most certainly entitled to one.

 

Back to the issue at hand, cast vs. forged pistons, you seemed to have something confused. The piston bore size depend on not only the piston design and construction, but the cylinder construction as well. A forged piston does not alway require more clearance than a cast piston, that is a misleading generality. However, a forged piston will always require a bore with a higher tolerance when it comes to taper and a position in relation to the crankshaft (a Banshee uses a crank guided piston (otherwise that's not always true)).

 

In regards to me not knowing what I am talking about..............you might want to think that one over a bit. :shoothead:

[RNBRAD]

One of my favorite links that can shed some light on the differences between the two piston types.

 

 

LINK