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Wed Feb 01, 2012 8:02 pm

Does anyone know how to tell which way the wiseco pistons point on a rebuild? From what I can see, there are no identifying marks like the usual arrow. Any help would be appreciated. Marty

Thu Feb 02, 2012 11:37 am

Mine has an arrow on the inside of the piston, on the wrist pin area, mine isn't your standard wiseco, but the same may apply to yours. give it look.

Thu Feb 02, 2012 11:51 am

No arrows uless you stamp one on there yourself. The valve pocket reliefs on the underside just need to be up not down.

Thu Feb 02, 2012 12:13 pm

Good advice there, didn't even think to look there.

Thu Feb 02, 2012 2:27 pm

Just talked to a tech from Wiseco and he told me the pistons are completely symmetrical with no offset. Good to know. A small stamp for next time is definitely a good idea though. Thanks.

Thu Feb 02, 2012 4:03 pm

Valve pockets should go toward the bottom, not the top. That is where the piston gets notched for clearance. If you're not notched, it really doesn't matter.

Thu Feb 02, 2012 4:59 pm

If the piston has a zero offset wrist pin bore it does not matter which way it faces as long as there are no valve reliefs. If it has reliefs then as Eric said they face downward.
If the wrist pin bore has an offset, the manufacturer will normally mark the installation direction.

Thu Feb 02, 2012 10:10 pm

I re-thought about this and I was wrong. Pockets are down. Hey everyone makes mistakes as long as they are not during assembly ha ha.

Fri Feb 03, 2012 1:52 am

Looks like mine was made wrong then...pocket reliefs should def be towards the top on mine. Unless it was numbered wrong. Eric, I may be giving you a call tomorrow...

Fri Feb 03, 2012 7:10 am

Chip B. wrote: Looks like mine was made wrong then...pocket reliefs should def be towards the top on mine. Unless it was numbered wrong. Eric, I may be giving you a call tomorrow...

Squishy's change things a bit. Two will be 'right', two will be 'wrong'. Mine are notched .150" deep for valves, and still fine on the two that are opposite the valve pocket bosses.

Fri Feb 03, 2012 7:56 am

Were yours numbered and marked for to point at flywheel? Not sure if the PO did it to mine. The one marked 4 is definitely upside down. Haven't checked any of the others though. May need to brave the cold and head out to the garage.

Fri Feb 03, 2012 8:25 am

Chip B. wrote: Were yours numbered and marked for to point at flywheel? Not sure if the PO did it to mine. The one marked 4 is definitely upside down. Haven't checked any of the others though. May need to brave the cold and head out to the garage.

The PO marked them. Wiseco doesn't mark them.

Fri Feb 03, 2012 9:08 am

Eaallred wrote: Chip B. wrote: Looks like mine was made wrong then...pocket reliefs should def be towards the top on mine. Unless it was numbered wrong. Eric, I may be giving you a call tomorrow...

Squishy's change things a bit. Two will be 'right', two will be 'wrong'. Mine are notched .150" deep for valves, and still fine on the two that are opposite the valve pocket bosses.
Can you post pics of the front and back?

Fri Feb 03, 2012 9:35 am

The back looks exactly like the ones you have on your build page. For the front, you'll have to contact John C. Not trying to be rude, but I'm trying to protect the interests of my friend. He hasn't published any, and I won't jump in and do it for him. Not my place. Sorry.

Fri Feb 03, 2012 9:43 am

Chip B. wrote: The back looks exactly like the ones you have on your build page. For the front, you'll have to contact John C. Not trying to be rude, but I'm trying to protect the interests of my friend. He hasn't published any, and I won't jump in and do it for him. Not my place. Sorry.

x2.

Fri Feb 03, 2012 12:05 pm

I realized after I asked the question that it did sound like I wanted to see the Squishies but I didn't really mean that. I know John wants the design kept to the purchasing public. Hopefully he only sells them to Americans who don't travel to china.
I just wanted to see them mounted on yous short block for clarity.

Fri Feb 03, 2012 5:15 pm

Cool cool, I actually don't have them mounted to the short block at this time. One is on my desk, the others are in the garage waiting in line patiently for their turn on the engine stand.

Sun Apr 08, 2012 7:53 am

Recently I found myself caught in a quagmire in the middle of a 2276CC engine build. Then discovered that id bought the wrong cylinder and piston set. Needed 82x94 but had 69x94. and with Mahle being on national backorder. I moved in the direction of Wiseco. Which of course I was told could be used with my exisiting new Mahle Cylinders. Last night I was moving in the direction of setting ring gaps etc. I noticed that the wiseco pistons appear to be about a 16th of an inch smaller in diameter than the Mahles. I have not been able to accurately measure them yet.

this has me sweating bullets. Considering what to do? Autocraft cylinders? In my mind the wisecos should fit as snuggly in the cylinders as the mahle's did.

Share your thoughts

Sun Apr 08, 2012 12:08 pm

It usually says what size hole the pistons fit on the box

And also, if the rings gaps are near correct then you have it right, unless the rings and pistons were mis-boxed, which is unlikely

If they don't give me a clearance spec I go by ring gaps and common sense

If you can't afford to have it looked at, you can use feeler gauges to check the skirt clearance. That is how they did it 50 years ago

Mon Apr 09, 2012 7:08 am

DarinNDebra1961VW wrote: Recently I found myself caught in a quagmire in the middle of a 2276CC engine build. Then discovered that id bought the wrong cylinder and piston set. Needed 82x94 but had 69x94. and with Mahle being on national backorder. I moved in the direction of Wiseco. Which of course I was told could be used with my exisiting new Mahle Cylinders. Last night I was moving in the direction of setting ring gaps etc. I noticed that the wiseco pistons appear to be about a 16th of an inch smaller in diameter than the Mahles. I have not been able to accurately measure them yet.

this has me sweating bullets. Considering what to do? Autocraft cylinders? In my mind the wisecos should fit as snuggly in the cylinders as the mahle's did.

Share your thoughts

Since Wiseco is a real forged piston and the Mahle's are not you are going to want the Wiseco a little more loose than the Mahle piston. My wiseco's have a .0055 Piston to cylinder clearance for a turbo application. If you are running NA and on the street you can tighten it up a little and to add to the fact these are air-cooled you cannot translate Wiseco's recommended clearance exactly. Adding .0005-.001 additional clearance over their recommendation is a good rule of thumb for whatever your application is.