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Discussion Starter #1
Got this information off Hotwheelz:

12.5 Cp 87mm pistons don't work in k24 blocks

k24 blocks have 5 thousands for factory pistons, forge units only allow 3...

So k24 blocks would need 88mm.

87mm will ruin the skirts. in no time
 

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or 87.5mm - bore and hone specifically for piston-wall clearance with new pistons. The stock liners have enough material to get back into round and accomodate these.

We have 3 sets w/ ample intake valve relief for our most aggressive cams. 12.2:1 with a 99mm stroke in a K24A.

-Ron
 

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what edo means is 87.5MM pistons (not honing to 87.5mm and keeping the 87mm pistons)

personally 87.5mm is kinda big for the stock liners, they aren't any bigger than 1/8 thick, then the aluminum deck pretrudes.. not much force left for sidewall loading....

machine shop said 87.25 at most... I don't feel like being a test dummy at 87.5mm I have enough bad luck as it is..

I lesson learned the hardway, waiting on manufacturer to see if he can accomodate a set in a serious hurry.

so 87mm pistons require aftermarket sleeve size to run. OEM sleeves are honed to big for the forged units..... my block was new, no out of roundness also.

from the looks of things it's only Ron and myself doing complicated builds ???
 

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i just havent gotten to that point yet... i would totally share all info... wish people could be more helpful... you guys (edo and hotwheelz) are doing a great job of giving out info and i appreciate it very much..
 

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2fastxeg said:
i just havent gotten to that point yet... i would totally share all info... wish people could be more helpful... you guys (edo and hotwheelz) are doing a great job of giving out info and i appreciate it very much..
:up: :up:

I'll be there one day too...
 

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H2nr said:
So are you saying the 12.5/1 87mm pistons (SC7147X) are useless? I have a set of these pistons ordered for my K24a2 and I am not sleeving the block.
yea... WTF

i have the same set of pistons sitting right beside me, planning on throwing them into an accord block with K20A2 head

they wont fit without a slightly smaller bore? WTF another thing to set me back? :wow: (its been a long day)
 

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sc7147X, my TSX block was at 5thousands, spec requires 3.. get a feeler gauge and mesure it, because i'm pretty certain all k24's will have the same result.. so yeah those who have thos pistons well.. were kinda all SOL.

so those who have these pistons please mesure and provide your feedback aswell.
 

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It's really too bad that CP doesn't offer a 87.25mm shelf application. Perhaps if all those who have the SC7147X complain with the same issue, they might make the change.

-Ron
 

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Discussion Starter #13
edo said:
It's really too bad that CP doesn't offer a 87.25mm shelf application. Perhaps if all those who have the SC7147X complain with the same issue, they might make the change.

-Ron
I talked to camp1320 today that stocks them and does very well selling cp... He told me that it has been addressed already and that they will offer it... Of course for the peopel that want them right now, it is not going to help... but hey.. at least something is being done.. according to Tom from camp1320.com I know he has in stock around 10 sets at least of that same piston.
 

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That's great news. Maybe those who have them can sell to 2.0L guys that want a quality piston. +1mm overbore is doable on the stock liners.

-Ron
 

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edo said:
That's great news. Maybe those who have them can sell to 2.0L guys that want a quality piston. +1mm overbore is doable on the stock liners.

-Ron
i wonder what compression would work out to be... ill figure it out when i get home tonight

also, i will go to my friends house tonight and take a measurement of the accord2.4L bore...
 

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Just sleeve the block you little girls... :D
 

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Our pistons do not have .005" clearance in a stock block. You cannot measure piston to wall clearance with a feeler gauge. The block has to be measured with a dial bore gauge, and a mic for the piston. The piston on that particular part number has to be measured 0.400" up from the bottom of the skirt. Nobody is SOL, if our pistons don't measure to what our specification sheet has printed, return them.

You guys should contact the manufacturer first, it would lead to less headaches.

Darius

CP Pistons
 

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Nick, check to see if your cylinders are out of round. You will need at least a hone to ensure good ring seal.

Measure before and after honing per Darius' instructions to determine if you have proper piston-wall clearance.

CP is one of the few piston makers where you can actually bore your block to size without having the actual piston. Their clearances are built into the piston and precision manufactured to strict tolerances.

-Ron
 
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