sr20 bore taper - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

ricardo.benin · 07-31-2015, 01:17 PM

Hi I am doing a stock rebuild on my sr20det blacktop and my two inner bores 2 and 3 have about .0025 taper and my outer bores 1 and 4 have .0005 taper, so my question is this can I get away with the inner taper on stock pistons, BTW my fsm does not give me a max allowable taper so we're could I find it.
Thanks

jedi03 · 01-03-2016, 10:35 AM

Talking with my local machine shop thus is normal wear, but it needs to be evened out with Hine and measure the largest bore for piston and ring size

Kingtal0n · 01-09-2016, 06:10 PM

How many miles were on the engine when you tore it down?

Did the cylinder walls exhibit any egg shaping? You just going to hone them and use brand new rings on OEM pistons?

jedi03 · 01-11-2016, 02:18 PM

I assume maybe 50k on mine...goin aftermarket...his buddy sold me a set of larger pistons at a great deal, but it was cheaper to bore than get new oe size pistons...

Kingtal0n · 01-11-2016, 05:13 PM

Quote:

Originally Posted by jedi03

I assume maybe 50k on mine...goin aftermarket...his buddy sold me a set of larger pistons at a great deal, but it was cheaper to bore than get new oe size pistons...

but did you check the OEM bore after 50k miles to see if new OEM pistons would have been ok first with a hone, by any chance

jedi03 · 01-12-2016, 04:30 PM

I did not actually measure, but based on wear and I could still see the home marks from before I would have run oem size if I had it...I may have run a slight risk of a bit of blow by at the top compared to the bottom

07-31-2015, 01:17 PM	#1
ricardo.benin Leaky Injector Join Date: Dec 2012 Location: us Posts: 69 Trader Rating: (0) Feedback Score: 0 reviews	sr20 bore taper Hi I am doing a stock rebuild on my sr20det blacktop and my two inner bores 2 and 3 have about .0025 taper and my outer bores 1 and 4 have .0005 taper, so my question is this can I get away with the inner taper on stock pistons, BTW my fsm does not give me a max allowable taper so we're could I find it. Thanks

01-09-2016, 06:10 PM	#3
Kingtal0n Post Whore! Join Date: Jul 2005 Location: South Florida Age: 38 Posts: 4,649 Trader Rating: (17) Feedback Score: 17 reviews	How many miles were on the engine when you tore it down? Did the cylinder walls exhibit any egg shaping? You just going to hone them and use brand new rings on OEM pistons? __________________ 5.3/4l80e/turbo 240sx playthrough: https://tinyurl.com/turbo240

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01-03-2016, 10:35 AM	#2
jedi03 Nissanaholic! Join Date: Jul 2008 Location: albuquerque Posts: 1,786 Trader Rating: (8) Feedback Score: 8 reviews	Talking with my local machine shop thus is normal wear, but it needs to be evened out with Hine and measure the largest bore for piston and ring size

01-11-2016, 02:18 PM	#4
jedi03 Nissanaholic! Join Date: Jul 2008 Location: albuquerque Posts: 1,786 Trader Rating: (8) Feedback Score: 8 reviews	I assume maybe 50k on mine...goin aftermarket...his buddy sold me a set of larger pistons at a great deal, but it was cheaper to bore than get new oe size pistons...

01-12-2016, 04:30 PM	#6
jedi03 Nissanaholic! Join Date: Jul 2008 Location: albuquerque Posts: 1,786 Trader Rating: (8) Feedback Score: 8 reviews	I did not actually measure, but based on wear and I could still see the home marks from before I would have run oem size if I had it...I may have run a slight risk of a bit of blow by at the top compared to the bottom