DIY: Rebuilding an SR20DET

For the RWD SR20DET cars! Sponsored by Wiring Specialties.
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Hijacker
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86.5mm is equivilant to boring it out .020"


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cartoonlips7
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has anyone used wpc treatment? from what i've read it sounds pretty useful.. also anyone know if I use acl race bearings all aroung if they are the same as using oem bearings in the terms of size from the numbers from the block and counter weights..

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Hijacker
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I should have mentioned in the DIY post, but I must have forgot to. Nissan has all those bearing sizes, but the difference in thicknesses are very minimal. The thinnest bearing is 1.977mm and the thickest is 1.998mm. That's .021mm (or .00083") difference in the extremes. ACL and other aftermarket bearing manufactures make their bearings one size, which is fine. So long as everything is within spec of tollerance, you're fine. If you feel really unsure, you can measure the journals and races, or do plastiguage measuring (which is a PITA IMO) to be triple certain that you're fine. I've put quite a few motors together now using regular old ACL bearings and haven't had any issues. So long as the crank and the block/rods don't have any wear showing on them (say from a spun bearing), the bearings have worked flawlessly.

WPC, from what I saw on their website, is a different form of shot peening. It work hardens the surface of the metal to increase durability. I wouldn't use it on a set of coated pistons. The micro dimples it leaves behind is supposed to help trap oil and keep the surface of the piece lubricated.

tokendog
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I see the part where you recommend cleaning the holes where the head bolts go.

I am not up to making my own thread chaser. What exactly would I look for if I were to go to an auto parts store to get a thread chaser? I definitely want to clean the holes to make sure that the bolts get a good seating and are given the proper torque readings.

Thanks.

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Hijacker
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I used an old head bolt. Nissan used an odd ball size of an M11x1.25 (I think it's 1.25) for the headbolts. A regular tap was impossible to chase down in there far enough, so I just ground down the sides of an old head bolt, then ran a die over it to give the threads their shape back. The flat side catchs all the dirt and pulls it up and out of the hole.

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Coolwhip
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Didn't read the whole thread but VERY well written, props to you for taking the time to even pause and snap pictures of everything as you went.

One addition to where I stopped reading: The removing of the pistons through the cylinder bore. I've always found it benefitial to debur the edge of the bore to prevent the rings from binding against when removing. Usually a recommended step if trying to reuse the rings or bore size.

(forgive me if it was already covered)

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Hijacker
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Deburring is a very good idea. But usually, if you're pulling the pistons out, you should get the block honed (or do it yourself). I didn't really cover honing since, to me, it's a very touch and go type of procedure. The honing process should deburr the top edge of the bore, all things considered.

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grmreapr
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damn great read do you do this for a living or on the side and people pay you cause I would so send you my bottom end for a rebuild while I do the top end

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duffman1278
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Wouldn't you have to know what your doing if you hone it yourself, doesn't seem like a really DIY type of deal there. I ask this because at my old job, I knew the guy who used to hone most of the engines we rebuilt and the guy told me he had to learn how to diamond hone the engines, and other stuff. I know you can buy the stuff but is it safe for someone new to attempt it?

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Hijacker
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I added this yesterday to the DIY:Quote »If you had your block machined for bore diameter, the shop more than likely honed your block. If you didn't send it off to the shop, then you should hone the block yourself, or have someone do it for you. I don't want to cover the actual honing process just because it seems to be a very touch and go process to me. You have to get a feel for how fast the spin the honing stones and to move them up and down in the block. It's not something I feel I can easily convey over the internet.[/quote]I feel you have to learn it from someone, but it's not some mystical voodoo magic that only certain people in the world can do. It's not a time consuming step, it's just something someone has to show you how to do so you can get a feel for it.

Matt, I don't do this for a living or as a side job. I just do it for fun. My friend Jay taught me how to put motors together a few years ago, and I found an evil pleasure in doing it. Normally I don't do a lot of assembly for people, and given that you're in the PA/NJ area, shipping probably wouldn't be cheap for you to send your block and internals to me.

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blackhole1
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this thread has been very helpful considering I am building my sr for the first time, I have read you kept the stock rods, I am on a budget like most nico members want to change pistons and rods, but will the stock rods be safe around 400-450 rwd on a daily driver or should I just replace the rod and save my self from future problems.

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grmreapr
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I would not mind shipping their and back and throwing some money your way for your time and expertise I really just dont trust anyone around here enough to do it I would send you basically everything you need and if you come across something you need Il just send you money to pay for it if your up for it let me know email me

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RCCC_DRiFteR
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blackhole1 wrote:this thread has been very helpful considering I am building my sr for the first time, I have read you kept the stock rods, I am on a budget like most nico members want to change pistons and rods, but will the stock rods be safe around 400-450 rwd on a daily driver or should I just replace the rod and save my self from future problems.
If your gonna put that much money into making power wouldn't you wanna make sure your bottom end can take it!?!? I would definitely make sure I had a reliable bottom end before I made that much power. I've heard that bottom end can hold up to 400HP but every build I've seen with that much power all had built bottom end. I see it as an investment, spend money for a better bottom and it will you give you a sense of safety and peace of mind. just my thought...

Kalypso
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woah I just discovered this I am officially, suscribed


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RCCC_DRiFteR
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yeah, Hijacker is pretty much AWESOMENESS and SEX put together!!

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Hijacker
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RCCC_DRiFteR wrote:yeah, Hijacker is pretty much AWESOMENESS and SEX put together!!


hehe

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RCCC_DRiFteR
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LoL true story!!

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Hijacker
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RCCC_DRiFteR wrote:If your gonna put that much money into making power wouldn't you wanna make sure your bottom end can take it!?!? I would definitely make sure I had a reliable bottom end before I made that much power. I've heard that bottom end can hold up to 400HP but every build I've seen with that much power all had built bottom end. I see it as an investment, spend money for a better bottom and it will you give you a sense of safety and peace of mind. just my thought...
I'm going to chime in on this. Every motor I've opened up that was detonated has been due to pistons. I have yet to see a rod bend or snap a cap bolt. Not to say it can't happen, but the 400 WHP ceiling is due to weak piston design. Sicne my end goal is only 350-400, I felt that leaving the stock rods in would be fine. If I wanted to go over the 400 WHP mark, I would have considered rods.

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Influenced
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i have seen stock rods take well over 400hp, so you are fine

i used cp pistons and they were full of WIN!

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Hijacker
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I love my Mahles. The only thing that you need to be careful with is that the inside castings will contact the squirters under load. The easy fix is to cut off half the locating pin and swivel them closer to the center of the bore. Problem solved.

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RCCC_DRiFteR
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Hijacker wrote:
I'm going to chime in on this. Every motor I've opened up that was detonated has been due to pistons. I have yet to see a rod bend or snap a cap bolt. Not to say it can't happen, but the 400 WHP ceiling is due to weak piston design. Sicne my end goal is only 350-400, I felt that leaving the stock rods in would be fine. If I wanted to go over the 400 WHP mark, I would have considered rods.
Wow I find this interesting seeing as how the SR I bought that was all effed up!! piston #3 take a straight crap and fell apart!! and the other pistons #1,2,4 all had stress marks too. Good call!! (edit) I bought it knowing it needed to be honed and new pistons and rings. Not bad for a full motorset for $950

ntraserz
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incredible write up, my engine is currently in the shop getting bored new pistons (went CP 86.5 9.0:1) and valve job with cleaning of head.

i think the crank is going to get ground, not sure yet since have yet to hear back from the shop on it, hopefully new bearings wont be too confusing to order at that point

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Hijacker
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Oh! I forgot to mention, I was working an Isuzu V6 with Jay, and we had to plastiguage some of the bearings. I snagged some pics, so I'll be integrating that into the write up in the near future. I just need to remember to upload them to photobucket at some point when I'm not in a "I hate sitting in front of my computer" mood after work.

ntraserz
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hopefully you can include information for properly guaging bearing clearances with plastigage as well :Dokay so i asked a friend bout it and realized how simple it was so yeah nevermind
Modified by ntraserz at 11:02 AM 8/7/2008

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RCCC_DRiFteR
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Hijacker I know you may find it alil off topic but I think you should just give a small tutorial for the n00bs like me. But I'm actually gonna be firing the motor up soon and I reember reading about a 1K check up after breaking the motor in and I was curious if you could give a rough idea of what needs to be done at the 1K check up. thanks

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Hijacker
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At 1000, just change the oil again, and retorque the head if you use a metal headgasket.

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RCCC_DRiFteR
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alright, simple enough. thanks

nismostate
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What processes will you take on cranks that were machined?

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Hijacker
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Assembly is assembly. I would just plastiguage the crank's bearings during assembly to be certain that the machine shop was accurate.

nismostate
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when is line boring necessary?


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