Author Topic: Piston options  (Read 1141 times)

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SDWE61988

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Piston options
« on: November 21, 2011, 07:41:48 AM »
Thank you to all of you that have commented and helped out with troubleshooting my engine under the valve train toublshootng topic.  After I dropped the oil pan Friday and dicovered the # 2 piston skirt had dropped, I am now looking at replacing the pistons.  I have looked at Summit Racing, Northen Auto Parts, Napa, and a couple other sites so far.  The engine is a 97 2.5l, so I believe they came with Hypereutectic pistons.  Do you think it would worth my time and extra cost to replace them with forged pistons (if available), replace with new hypereutectic, or go with plain cast pistons from the older 2.5 liter engines?  The hypereutectic pistons are harder then the traditional cast, but apparently more brittle.  I really don't feel like repeating this repair evolution a couple years down the road, so I would like to get it fixed and not worry about it again.

Nicks92jeeper

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Re: Piston options
« Reply #1 on: November 21, 2011, 08:08:57 AM »
Out of curiosity, is there a piston for the jeep that will create a higher compression. In my Honda Civic there are many types of pistons you can use that will give a bunch more compression due to the shape and thus giving more HP. I know nothing of the Jeep pistons except that they have a flat face. Well, mine do.

SDWE61988

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Re: Piston options
« Reply #2 on: November 21, 2011, 08:17:19 AM »
I am not sure. It looks like the pistons in the 2.5l engines are the same as the ones from the 4.0 liter engines.  Maybe some the gear heads here can comfirm that for us.

Offline sharpxmen

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Re: Piston options
« Reply #3 on: November 21, 2011, 09:05:30 AM »
Thank you to all of you that have commented and helped out with troubleshooting my engine under the valve train toublshootng topic.  After I dropped the oil pan Friday and dicovered the # 2 piston skirt had dropped, I am now looking at replacing the pistons.  I have looked at Summit Racing, Northen Auto Parts, Napa, and a couple other sites so far.  The engine is a 97 2.5l, so I believe they came with Hypereutectic pistons.  Do you think it would worth my time and extra cost to replace them with forged pistons (if available), replace with new hypereutectic, or go with plain cast pistons from the older 2.5 liter engines?  The hypereutectic pistons are harder then the traditional cast, but apparently more brittle.  I really don't feel like repeating this repair evolution a couple years down the road, so I would like to get it fixed and not worry about it again.

as far as i know stock were not hypereutectic. Sealed Power hypereutectic would be my recommendation. Keith Black makes forged ones, they are very expensive about $120/piston.

Out of curiosity, is there a piston for the jeep that will create a higher compression. In my Honda Civic there are many types of pistons you can use that will give a bunch more compression due to the shape and thus giving more HP. I know nothing of the Jeep pistons except that they have a flat face. Well, mine do.


yes, there are differences in compression with different pistons, however the difference is at most 0.3 in think (or 0.2) I can't remember on top of my head, something like 9.2 vs 9.4
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Offline dwtaylorpdx

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Re: Piston options
« Reply #4 on: November 22, 2011, 12:16:15 AM »
My engine builder did not find any decent priced units when I did my motor,
but late late model 2.5's do use coated hyper pistons stock ( to stop the "rattle"
that many 2.5 and 4.0 engines were recalled for.) So my 95 has like 98 pistons in it.

Wiseco will make a set for about 1200 bucks..

It is possible to use 305 Chevy pistons, with special rods and a special crank grind job.
Dave
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SDWE61988

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Re: Piston options
« Reply #5 on: November 22, 2011, 07:12:20 AM »
$1200, is that for custom forged pistons?  It looked light Northern Autohada set of 4 SealedPower hypereutectic pistons for@ $120.  I think Summet Racing had something similar from Kieth black.  I have not called and talked to anyone though. That was just on the web.  I guess I better call and find out availablilty and prices.