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how about je pistons? they offer 13.5:1 87mm standard and 88mm .040 over.. would either of those be a straight drop in?
 

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i have a question, why in the world would anybody want to just "drop" pistons in without knowing piston to wall clearances or any other clearances for that matter. These are probabaly the same people who take the stock bearings off their rods and place them in the new rods wih out ever measuring anything.
 

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of course u would measure clearances to make sure, but usually u would not expect this type of problem when buying an 87mm piston for an 87mm bore.
 

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So what your saying is that you will measure the piston/wall clearance in your driveway with the engine in the car? What about bearing clearance, what about rod/crank clearances? wrist pin clearances for the pistons and rods? There is so many other things that must be looked at but im sure everybody knows that.

Somebody who just wants to "Drop" in pistons isnt somebody who is aware of what precautions really need to be taken when building an engine. or one who seems to be willing to do it right.

just my $.02
 

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this thread is about 87mm k24 shelf pistons not working in 87mm k24 blocks, not about any of the other stuff u talkin about.. i feel like u takin shots at me now, but i dont even understand why.
 

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im not taking shots at you personally. i am taking shots at all the people who "build" cars and "tune" cars but yet dont have a clue as to what is going on. Everybody wants drop in parts and perfect base maps to make them look like a superstar builder/tuner yet they have no clue as to the simple working of an I.C.E. They cant tell you why pistons needs that type of clearance. They just know what they read online and what there buddy tells them.

As far the .005 piston/wall clearance, why is that to loose for a forged piston? I have run piston/wall clearances alot looser and had very very successful/powerful engines. Im not gonna go into exact detail but .005 is not all that loose.
 

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ok well all my question had to do with was this k24 issue and the fitment/clearance of the pistons into the stock bore. wasnt saying i wanted to close my eyes and just swap the pistons and leave everythign else, as u made it seem
 

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there is no telling if the block is blown out in the center or not until it is apart, so my advice would be to take the engine apart and mic/gauge it up before you buy any pistons.
 

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How can you clean up the top of a used block (send it to a mechine shop to take off a .001 or just a quick shot with a abrasive gun (quick cuz its alluminum))?
 

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i have 87mm je in my k24, never honed the block nothing, it had 27k miles on it, maybe not the wisest thing to do...but i dont have any problem,s no oil consumption nothing....just dropped them in and kept going. I have about 100 plus hard runs and about 1000k on the build
 

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txtypes said:
i have 87mm je in my k24, never honed the block nothing, it had 27k miles on it, maybe not the wisest thing to do...but i dont have any problem,s no oil consumption nothing....just dropped them in and kept going. I have about 100 plus hard runs and about 1000k on the build
Try doing a compression and leakdown test and tell us how it turns out...

All that is being said is, "You should never put in pistons without checking clearances".

Most engine builders will tell you that they always order .25 or .5 OS pistons even for stock sleeves and then have the block slightly bored and honed for best results... I don't know to many builders who would order standard bore pistons and hope that the block isn't out of round...
 

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if the bores are still straight 0.005" piston-wall wont be a problem, it might be a little loud when its cold but we build damn near everything to 0.004, if its gona be making over 600hp we'll go a little looser.
 

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Usually, the vast majority of the time, the cylinders are in spec for stock bore pistons on a motor that has not been abused, overheated, super high miles, etc. Same thing with the mains, if the thing never overheated, or got rod knock or had some abnormality its overwhelmingly going to check out as good. I have checked so many, we are talking a ton.

Out of the multitudes of motors I have done, as in 500+, of all the checking the blocks, the mains were out of alignment where it needed line hone like maybe 8 times? out of 550 or so? And as for the bores being out of round, etc, on motors with less rod angle, and less stroke, they tend to keep shape much better than motors with more rod and angle and more stroke. Per the same RPM use.

On B series, the worst out of round cases are LS blocks, and the best cases are B16A blocks, which are sometimes within spec for stock bore after well over 100k miles. So I would be willing to bet K24's go out of round way easier than K20's or S2000's.

Coatings on pistons help this as well, because they will allow you to clean up hone 3-5 tenths off the old bores to make them a hell of alot more straight, within spec again.

Another reason to get Wiseco, the called for tolerance is .0025 AND its coated, so you have plenty of room to hone a stock bore block with stock bore pistons. Then you install them at .003 or more. Which is no problem for street use at all, not to mention the offset pins quiet the noise from being too loose.

Guys, go here, and buy this:

http://www.gaging.com/toolathon.htm
Part numbers: P54-646-401 Thats a dial bore guage thats like $215
Then get this:
P52-222-444 $115? Thats a digit micrometer set for your crank, pistons.
Then get some green plastiguage for double checking.

That right there folks is the economical way to start out engine building the right away. Once you have those 2 part numbers, and you keep care of them and learn how to use them, you can build a motor the way your supposed to, clearances wise.

You can also check for out of round, taper, etc.

I have these for mobile checking, and I use a $1600 dial bore guage for the blocks and mitytoyo micrometers for piston to wall clearance.

For $350 bucks, you can't possible spend your money any wiser.

Come on guys! Lets get a whole bandwagon of blueprinters out there! Youll have less problems with your motors, and save money in the long run.

Jeff





Jeff
 

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compression tet done,,,i was worried...
195
205
195
205

leak down passed aswell,,,i have element block 27k: je 12.5:1 coated skirt
and i just dropped hem in. as jeff stated low mileage nonabused blocks dont have this problem

under certain circumstances this thread would be true...at the moment wth just dropping them in its running like a champ
 

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Import Builders said:
Usually, the vast majority of the time, the cylinders are in spec for stock bore pistons on a motor that has not been abused, overheated, super high miles, etc.

so a k24 block that has about 6000 miles on it that was driven like normal would probably most likely take a stock bore piston and not require a hone as compared to a k24 that has 50000 miles on it?
 

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xproductionz said:
so a k24 block that has about 6000 miles on it that was driven like normal would probably most likely take a stock bore piston and not require a hone as compared to a k24 that has 50000 miles on it?

i wouldn't worry, my block from an element probably never saw past 4krpm
 

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txtypes said:
compression tet done,,,i was worried...
195
205
195
205

leak down passed aswell,,,i have element block 27k: je 12.5:1 coated skirt
and i just dropped hem in. as jeff stated low mileage nonabused blocks dont have this problem

under certain circumstances this thread would be true...at the moment wth just dropping them in its running like a champ
good to hear...

someone must have been babying that bad boy...

:up: :up: Jeff bringing the hard facts...
 
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