BannedCR500Riders.com

What piston do you all suggest? I've always used Weisco in the past, but after reading allot on this website it seems most of you consider them to not be so good? Thanks,

Jeff

They have their place....... SEVERE DUTY

90% of all other riders would be better with cast.

OEM period...

I am always amused at so many of the guys on these boards that carry the torch for running honda replacement parts, but are quick to also tell you how rad a wiseco is. drill the special little holes, massage it, carry it to bed with them, whatever.

Honda has by far the most research into the design of thier pistons. why run anything else?

You so often read about these bikes running 10 years on the original motor/top end. Good luck receiving that kind of longevity with a wiseco.

Bob's right however, i am sure for the guys that RACE every weekend, and plan to rebuild two times a season the wiseco is great. As far as i can tell Iggy is the only one on this board that is racing weekly.

if you trail ride, cast is fine and will last. I can tell you after having cast piston skirts explode into a million pieces, I would never run a cast piston. Dune only bike, forged all the way. As long as you get your cylinder bored correctly for a forged piston and you do the proper break in on them, they will last longer and they don't explode. I just hate the fact that Wiesco isn't willing to do any machining on them any more.

I am considering a Wossner piston but they are only single ring and I don't know how I feel about a single ring piston in a non race application.

Probably will just get a boat anchor wiesco and machine it lighter.

i just went thru building my af and chose an oem 89.25 honda piston, my alternative to that is only the vertex. I have a prox in a bridgeless 86 engine and run all my stuff to the nuts, hillclimbing, trail, open field.

Dont let the $ make your decision either, if its 89, 89.5 90 9.5 or 91 I'd be on Vertex when no oem is available quick, NOT pro-x cuz of thier design, and last place i put the 1st+2nd gen wisecos.

LOVEMYCR500 wrote: they will last longer and they don't explode.

Excessive cylinder clearence makes cast pistons crack....

Running a cracked piston will lead to the explosion you mention, but the root cause goes back to the clearences....

i agree bob, and it takes really big clearances over really long periods for the skirt to crack....and for a crack to grenade is pretty damned rare....

poor machining + poor maintanence=excessive clearance

Excessive clearance+time= Kaboom

pretty simple, and not the fault of the piston manufacture process, IMO.

I went to a pull one time and a dude who'd been winning here in his hometown came over to give me the peptalk about how he was going to kick my butt.
I ran my smallblock and 175 rwhp of nitrous and kicked him by a long ways, he complained it wasnt stock, bla bla bla, it had OEM cast hyperutectic pistons from a 95 corvette in it.

If you go through all the "piston issue" posts........

95 % are Wiescos that have either siezed, have " black death", pinched a ring, or have terrible blow by issues.

4.5% are oem cast pistons who have run hard for 8 years and developed the "smile" cracks.


.5% are cast pistons that have fragged.

Its not a huge issue.

Personally im a wiseco fan.

britincali wrote:Personally im a wiseco fan.

Thanks for all the good information. I think I'll go OEM!

dog walker wrote:Thanks for all the good opinions. I think I'll go OEM!

for the most part, its a matter of choice. both pistons work just fine.

dog walker wrote:Thanks for all the good information. I think I'll go OEM!

IMHO vertex cast pistons are better than prox which is OEM
Fit and finish is much better on the vertex

except prox is the ugly step sister and likes it in both holes at the same time