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Need stock bore wiseco pistons

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nazthug

15+ Year Contributor
478
8
Dec 24, 2003
livermore, California
Where do I get some? Just stock bore wisecos, something in the 8:2-9:1 comp ratio???
 
nazthug said:
Where do I get some? Just stock bore wisecos, something in the 8:2-9:1 comp ratio???

Unless you have a fresh block from the factory, it's better to bore/hone the engine and run oversized pistons.

Even in good condition, you won't get the rings to seal very well when there's already been wear on the walls. Would you install a fresh clutch without resurfacing the flywheel?
 
seems like everyone talks and says the same thing, when really only a handfull of people have built engines, the rest is just hearsay and based on what some "pro" said

I've pulled a head off a 92 gsx with 120000 miles and it still had the hash marks on the cylinder walls and looked brand new

my compression is still great and im positive my cyl walls will look brand new still, these blocks are amazing

Im planning on simply getting stock bore pistons, pulling out the old ones, file gapping the new rings, possibly a very minor hone and be done with it...no need for fancy words that make a built engine look like god....

I've seen tons of engines go together like this and still run to this day, and have seen proffessionally machined and 20 process machined blocks walk 10 miles after the build...


THe more machining you do, the more chances you have to screw up...thats how I look at it
 
nazthug said:
seems like everyone talks and says the same thing, when really only a handfull of people have built engines, the rest is just hearsay and based on what some "pro" said

I've pulled a head off a 92 gsx with 120000 miles and it still had the hash marks on the cylinder walls and looked brand new

my compression is still great and im positive my cyl walls will look brand new still, these blocks are amazing

Im planning on simply getting stock bore pistons, pulling out the old ones, file gapping the new rings, possibly a very minor hone and be done with it...no need for fancy words that make a built engine look like god....

I've seen tons of engines go together like this and still run to this day, and have seen proffessionally machined and 20 process machined blocks walk 10 miles after the build...


THe more machining you do, the more chances you have to screw up...thats how I look at it

Keep in mind piston rings wear on cylinder walls -- unless you're running the same rings in an identical orientation, you won't get as good of a seal if you don't have a fresh mating surface.

When Mitsubishi or Toyota, or any manufacturer for that matter, rebuilds an engine, the block is bored, honed, and oversized pistons are used. Big companies don't spend extra money for nothing.
 
anytime you put in new pistons, or even reuse the old ones, you get the cylinders bored/honed. its not just what some "pro" says, its common sense engine knowledge.

so get them bored and honed .20 over like everyone else, cause everyone else is using their heads.
 
Nazthug - Just a little info on Wiseco pistons. Our stock bore is 85mm (3.346"). .020 oversize is equal to .5mm. They only offer two different compression ratios for an unmachined block; 8.1:1 and 8.9:1.

I too would recommend the .020 overs on a high mileage rebuild. I have some .020 overs here and can get the standards. PM me if interested.
 
Although I'm not a machinist by any means, it seems reasonable to meassure the cylinders for taper and out of round several times and then compare these numbers to oem specs. If they still fall within spec, give the block a flex hone and drop in new standard sized pistons with properly gapped rings. I'm sure the "right" way to do it is to bore and hone each cylinder for each designated piston, but you most likely could get away with doing it this way as well assuming all is within spec.
 
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