Weisco Pistond for Rebuild

[Milan]

In the Craigslist / Ebay section there area few Daytona's listed.


One of them has the engine rebuilt using the Weisco Forged pistons.
I know there have been some discussions about these here & on AC Club.
Some fights about them as well.

Has anyone here used these and had longevity with them.

M

[soonerbillz]

Don't know about longevity because I've not finished the build as yet but my  R5 build and top end has been designed around Wiseco forged pistons.
This is what was decided on after lots of discussion with John Ritter.
I'm hoping for a long, happy top end life.

[Milan]

Most of the discussions I have read, have to do with the tolerances of the bore due to the pistons being forged.
Due to their different expansion properties

M

[m in sc]

i dont like them personally but no issues with longevity as long, as mentioned, the cyls were bored correclty.. 

[rodneya]

Will also depend on if you allow the motor to warm up well every time before riding.

[1976RD400C]

I've been using Wiscco 513 RZ350 pistons for 10 years. They are lighter than the ones listed for RD350. I replaced them once when the clearance got to .005" and I think the second set may be that much now. I'm going for a rebore soon. They are a little lighter than OEM and seem wicked strong.

[Alain2]

I've been using Wiscco 513 RZ350 pistons for 10 years. They are lighter than the ones listed for RD350. I replaced them once when the clearance got to .005" and I think the second set may be that much now. I'm going for a rebore soon. They are a little lighter than OEM and seem wicked strong.

How many miles did you get out of the pistons before hitting 0.005" of clearance?

[1976RD400C]

[/quote]

How many miles did you get out of the pistons before hitting 0.005" of clearance?
[/quote]

I can only estimate, 6 years, 2000 miles, 4 track days, with a hot rod motor that has big ports. I would call it very hard use. The fresh bore had the clearance set to .003" to be on the safe side.

[Striker1423]

On a bad chamfer job (from next reputable engine builder who assessed it) with a fresh bore at 3 thou, the Wiseco's got me just past 2000 miles before I killed it on the freeway at 75-85mph for 40 miles.

Note to self: RD250 (350 top end) does not like that.

[Milan]

So possible solution:

Find some Yamaha pistons & replace the Wisecos.

M

[m in sc]

i'll be honest, ive never been a fan of wisecos. you hear them making noise: they are wearing. period. and yes, i have bikes with them unfortunately.  I get it on a race bike. but most people will be just fine with art cast pistons, or if you have to go forged, vertex is a better option IMHO.   

[Milan]

So in a perfect scenario:

Remove the Wiseco pistons.
Measure
If OK
swap in a 1'st overbore yamaha piston & rings

M

[m in sc]

depends on personal preference.  wiseco and oem cast pistons have different tolerances so you cant just 'swap' them, the bores need to be set for that piston.

[soonerbillz]

depends on personal preference.  wiseco and oem cast pistons have different tolerances so you cant just 'swap' them, the bores need to be set for that piston.

Fact. It took special work to make John happy with the ones he set up for my R5.

[Hawaii-Mike]

Gary at Spec2 preferred Wiseco as well and then he found out Fast From the Past sells Wossner and he did some work for the owner.  My H2 motor is running great with 2000+ miles, no piston slap.  More than I can say for Wiseco.

For RD's Gary still prefers Pro-X unless you're racing.