no replacement 4 displacement????????? - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

DDSR240 · 08-24-2008, 03:20 PM

Does anyone no if Mahle offers a standard bore for the sr20. Sounds simple and believe me I have searched only to find the smallest bore being 86.5, im worried because I ordered them friday and the shop owner was on the phone with his retailer and told me 3 times I must do a overbore on my block b/c Mahle doesnt offer a stock bore piston. wtf so I told him to get me cp pistons then because I'm going for big numbers and don't want to risk weakening (I heard they tend to oval at 600+)my stock sleeves. Then he said never mind they do have them in stock bore,so I ordered them and thought nothing more of it till I got home and started searching. Every site I saw offered them at a minimum 86.5 bore exept one that was stock bore but the stroke was listed at 86.5?? so I am assuming that site was a typo. I really want to use these pistons for there lightness strength and the coatings they come with so if they arn't availible in 86.0 trim should I go ahead and do the .5 over bore and is it safe on the stock sleeves for 550 -600 hp?

Sileighty_85 · 08-24-2008, 05:10 PM

Your Machinest probably just told you they have them instock in stock bore but really gonna install the 86.5 just so you'd leave him alone.

The reason they dont offer stock bore pistons for our engines is cuz by now every SR has to have the cylinders bored over by this time. Over time the Cylinder wall become uneven \ / or / \ so you need to bore the cylinder walls Ex .20 over to make the walls look like this | |.

If your doing +600 and worried about the Sleves then get these Darton Piston Sleeve Kit

DDSR240 · 08-24-2008, 05:50 PM

well i cant afford to sleeve the block I ran out of money...so i was correct there is no stock bore piston for the sr from mahle? oh and btw I ordered my pistons from a shop not my machinest, damn shops are shady as hell but i'll just have to hope that.20 over won't be my engines downfall

thanks +rep 4u sir any more advise would help if any zilvians have been down this road.

DDSR240 · 08-24-2008, 06:03 PM

well im am a lot more comfortable after looking at what 20 over or .5 actually is on my caliper

Def · 08-24-2008, 06:23 PM

Yea, it's a good idea on a rebuild just to make sure your bore is nice and straight. Plus it will remove any small scratches/wear marks in the bore if there are any.

DDSR240 · 08-24-2008, 07:10 PM

I know but it is a 98 180 sx motor it still has the cross hone marks on the cylinder walls it was practically a new motor.

Def · 08-24-2008, 07:14 PM

What happens if the clearances required for the new pistons means you need an EXACTLY 86.00 mm bore? I doubt it's absolutely pristine - it's over 10 years old.

08-24-2008, 03:20 PM	#1
DDSR240 Zilvia Member Join Date: Dec 2006 Location: South Carolina Age: 34 Posts: 259 Trader Rating: (0) Feedback Score: 0 reviews	no replacement 4 displacement????????? Does anyone no if Mahle offers a standard bore for the sr20. Sounds simple and believe me I have searched only to find the smallest bore being 86.5, im worried because I ordered them friday and the shop owner was on the phone with his retailer and told me 3 times I must do a overbore on my block b/c Mahle doesnt offer a stock bore piston. wtf so I told him to get me cp pistons then because I'm going for big numbers and don't want to risk weakening (I heard they tend to oval at 600+)my stock sleeves. Then he said never mind they do have them in stock bore,so I ordered them and thought nothing more of it till I got home and started searching. Every site I saw offered them at a minimum 86.5 bore exept one that was stock bore but the stroke was listed at 86.5?? so I am assuming that site was a typo. I really want to use these pistons for there lightness strength and the coatings they come with so if they arn't availible in 86.0 trim should I go ahead and do the .5 over bore and is it safe on the stock sleeves for 550 -600 hp? __________________

08-24-2008, 05:10 PM	#2
Sileighty_85 Post Whore! Join Date: Dec 2006 Location: Misawa, Japan Posts: 6,815 Trader Rating: (8) Feedback Score: 8 reviews	Your Machinest probably just told you they have them instock in stock bore but really gonna install the 86.5 just so you'd leave him alone. The reason they dont offer stock bore pistons for our engines is cuz by now every SR has to have the cylinders bored over by this time. Over time the Cylinder wall become uneven \ / or / \ so you need to bore the cylinder walls Ex .20 over to make the walls look like this \| \|. If your doing +600 and worried about the Sleves then get these Darton Piston Sleeve Kit __________________ 後輪駆動車１番 1989 Built SR GT2871R -363whp 1998 S14 W/RB25- 250ish (For Now) 1986 SR86 - 200ish 1990 R32 GTR - 320hp Don't Buy Engines from JDM-Online http://zilvia.net/f/businesses/207457-jdm-online.html Don't Buy XS-Power or SSAC Shit

08-24-2008, 05:50 PM	#3
DDSR240 Zilvia Member Join Date: Dec 2006 Location: South Carolina Age: 34 Posts: 259 Trader Rating: (0) Feedback Score: 0 reviews	well i cant afford to sleeve the block I ran out of money...so i was correct there is no stock bore piston for the sr from mahle? oh and btw I ordered my pistons from a shop not my machinest, damn shops are shady as hell but i'll just have to hope that.20 over won't be my engines downfall thanks +rep 4u sir any more advise would help if any zilvians have been down this road. __________________

08-24-2008, 06:03 PM	#4
DDSR240 Zilvia Member Join Date: Dec 2006 Location: South Carolina Age: 34 Posts: 259 Trader Rating: (0) Feedback Score: 0 reviews	well im am a lot more comfortable after looking at what 20 over or .5 actually is on my caliper __________________

08-24-2008, 07:10 PM	#6
DDSR240 Zilvia Member Join Date: Dec 2006 Location: South Carolina Age: 34 Posts: 259 Trader Rating: (0) Feedback Score: 0 reviews	I know but it is a 98 180 sx motor it still has the cross hone marks on the cylinder walls it was practically a new motor. __________________

08-24-2008, 06:23 PM	#5
Def Post Whore! Join Date: Apr 2004 Location: Houston, TX Posts: 2,701 Trader Rating: (16) Feedback Score: 16 reviews	Yea, it's a good idea on a rebuild just to make sure your bore is nice and straight. Plus it will remove any small scratches/wear marks in the bore if there are any.

08-24-2008, 07:14 PM	#7
Def Post Whore! Join Date: Apr 2004 Location: Houston, TX Posts: 2,701 Trader Rating: (16) Feedback Score: 16 reviews	What happens if the clearances required for the new pistons means you need an EXACTLY 86.00 mm bore? I doubt it's absolutely pristine - it's over 10 years old.

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