Need help/suggestions on rebuilding my motor

[white90esex]

Allright guys. Basically its time to rebuild this spare motor I picked up. My current motor is buring oil on down shifts whitch is probably caused by vavle seals but I just wanna put a fully fresh motor in the car so....

I guess we will start by what im thinking of getting to start off the build.

- OEM SR20det engine rebuild gasket/seal set- Celvite coated main/con-rod bearings- OEM Sr20det Piston rings

These seem to be the main things to a renewed and fresh motor. I dont wanna go all out with this, Im not even shooting for more than 300hp. This is for my DD that I just want to be relyable and new felling.

So anything else that you guys recomend?

Also Ive see the way to choose bearing sizes (off the block and the crank) but I dont see the option to buy them in different sizes. Is it necesisary to purchase specific size or can you just buy the "standard sized" bearing sets that I see for sale.

Also, when I start the process im going to do a detailed as possible build on this to help other people like myself.

THANKS in advance.

[Justin35ll]

Cool, good luck with it.Are you going to be doing main bearings as well?New head studs since the oem ones are TTY I think.Timing chain, water pump, oil pump, etc.. the list goes on it sucks. when I "rebuilt" mine all I did was the oem gasket rebuild kit. I didn't have enough money to do the rest.I figured if I did bearings I would have to clean, hone, deck block and head new chain, pumps, everything and it would have costed me too much money so I said eff it

[Sil80315]

if your doing rod and main bearings you can go to http://www.enjukuracing.com they have the FYI how to figure out what size you need.

[mRodiek]

You wont make close to 300hp with the T25, if you upgrade to the S15 Spec R on the other hand.. I was doin something similar with my SR then I found the Spec R and ended up going for like 320hp when I was originally planning for 250 lol. The must [or first things] should be water pump, headgasket, pulleys, gaskets everywhere, oil pan if necessary, hoses everywhere...You can even do the timing chain & cover. But if your replacing all these parts anyway, why not upgrade?

This is the problem I ran into but I will feel plenty good when I'm cruisin!

[Sileighty_85]

If you want a fresh bottom end you can't just put in new rings you need to bore and hone the cylinders and get the correct oversized pistons and rings

Have the crank checked and poished, Mil the head get a Metal head gasket (NOT COMETIC), ARP Head studs, New Crank Bolts New Oil pump, New timing chain and Revised guides. ect
Modified by Sileighty_85 at 10:37 PM 1/27/2009

[white90esex]

See, I was also thinking about alot of this stuff but I dont feel its totally necissary.

I dont see why I need a new oil pump or things of that nature unless they really look outta shape.

A new timeing chain is a good idea though.

I know how to figure out what size of bearings I need but I was more wondering if I HAVE to do that. OEM bearings are more than the coated bearings witch are alot better overall. I guess ill have to email the guy to see about getting the sizing I need.

If you want a fresh bottom end you can't just put in new rings you need to bore and hone the cylinders and get the correct oversized pistons and rings

I do want a smooth bottom end, I want to get the crank balanced and everything totally cleaned up. I would like to get the head and block decked for flush mounting surface.

I dont want to go the route of getting new pistons and stuff like you are stateing though.

I seriously have NO goal for HP with this motor, Im running and will continue running my T25 unless my buddy gives me this HKS (cant remeber what it is) but its along the sizing of a T28. He put down like 296 with it and thats the most Id bother with on this car.

I just want like a relyable fresh motor, nothing extravigant.

[Sileighty_85]

Well you need to check the clearance on that 16 year old oil pump if you decide to not drop in a new one if that oil pump goes while your driving that engine will be toast and you wont know it until its too late unless you have an oil pruessure gauge

yes you need to get the correct size bearings if you do not the clearance will be too great you will have low oil pressure and eventually tear up and spin the bearings

You need to bore and hone the cylinders if you want good compression the rings to last another 16 years

Over time the cylinder walls become uneven like / \ or \ / so you need to bore and home them to get them straight again | |

you dont sound like you know much about engines therefore i woud suggest leting a professional put this engine together for you

[mRodiek]

Yeah dude your talking about adding almost 100hp to a car after its been used and abused for the better part of 2 decades. If you dont want to get in so deep I wouldnt reccomend rebuildin the bottom end, start with the head and other parts and see how that goes for you. It sucks when people tell you that your plan is **** but were here to help

[white90esex]

I guess its hard for some people to understand but ****. Ive been working on cars for a long *** time. Ive never had the opportunity to actually build a motor. I have hands on skills and I trust all the work ive ever done.

I will be doing this myself.

I was allready planning on taking the motor to the shop to get everything cleaned up/machined ect.

I know what your are saying about getting it honed just that someone stated getting oversized pistons and **** but thats not in the cards.

your talking about adding almost 100hp to a car

Not at all. Right now my car puts down 242whp. I AM NOT building this motor with any goal to be putting down more power, it may be in the cards later on but Im not planning it.

Thread over.

[white90esex]

yes you need to get the correct size bearings if you do not the clearance will be too great you will have low oil pressure and eventually tear up and spin the bearings

And thank you for telling me straigh up that I DO need to make sure they are all the right size.

Ive seen this as a concern on motors that are going to be raped but wasnt sure on something like a dd that doesnt get driven all that hard.

I was trying to read into this recently closer tollerance means less oil and will actually ride on the bearings wearing everything out prematurely and messing stuff up. While too loose it will allow too much play and then you will get movement and could cause spun bearings ect.

[boro drift]

Make sure the bores are not worn anymore than .005", as long as they're not, you can hone and re-ring the bottom end, using the original pistons. Also, if you go this rout, make sure the rings you buy are .005" over sized.

[white90esex]

So being 86mm is the stock bore, if I go with a 86.2mm (if possible to machine that little) or 86.5mm then id be ok to use the stock pistons.

At the price of new pistons I may as well buy aftermarket ones, and if im buying upgraded pistons id wanna go all the way with it cause if im gonna be spending the money may as well spend it doing it up right.

But thats not the case with this car, I want a modest well runing cheap and easy rebuild.

BTW, thanks for the help.

[boro drift]

So being 86mm is the stock bore, if I go with a 86.2mm (if possible to machine that little) or 86.5mm then id be ok to use the stock pistons.

Bores will probably be worn .003 thousands of an inch. The hone will take the last .001 or .002 thousands. So, converting to metric unit of measure, you will need 86.12mm rings. 86.5mm is .020 over, that's way too much for re-ringing a stock bore! Also, keep in mind your piston clearances will be greater, so you may get a little piston slap on cold start up, but not too bad.

[Justin35ll]

It's just not worth the time to rebuild your motor if you're going to be leaving stock oil pump, etc in. Cause what happens when you put the engine in fire it up and 2 days later you have no oil pressure? Time to rebuild again?

Not trying to discourage you or anything just trying to prevent future screw ups

[corey240]

Well you need to check the clearance on that 16 year old oil pump if you decide to not drop in a new one if that oil pump goes while your driving that engine will be toast and you wont know it until its too late unless you have an oil pruessure gauge

yes you need to get the correct size bearings if you do not the clearance will be too great you will have low oil pressure and eventually tear up and spin the bearings

You need to bore and hone the cylinders if you want good compression the rings to last another 16 years

Over time the cylinder walls become uneven like / \ or \ / so you need to bore and home them to get them straight again | |

you dont sound like you know much about engines therefore i woud suggest leting a professional put this engine together for you

All sounds good, but why are you cracking on Cometic? Ive been running the same Cometic hg for 2 years now. Never had any problems with it. Now im on a spec r turbo and plan on going injectors and mafs this year. And it will probly still hold. No arguments, just wondering what everyone complains about, like Megan coilovers being too stiff or soft, bs. Alot of people talk shiz on Spec. Fck Spec, mine fell apart after 2500 miles. No drifting. lol.

But yea its all been covered. I would replace bearings, and rings, all seals, everything decked, cylinders honed. DO NOT PUT THE ENGINE BACK IN WITHOUT A NEW OIL PUMP! It will be the best 250 you spend ont he whole car, knowing the oil pump isnt gona go out any day now. Im waiting

[Sileighty_85]

All sounds good, but why are you cracking on Cometic? Ive been running the same Cometic hg for 2 years now. Never had any problems with it. Now im on a spec r turbo and plan on going injectors and mafs this year.

I just read/heard alot of stories on them.You'll rarely hear any stories about an Apexi or Power Enterprise H/G blowin out. I've maybe only heard like 1 or 2 of them but it was due to overheating.

And it will probly still hold. No arguments, just wondering what everyone complains about,

I love the confidence haha :P

like Megan coilovers being too stiff or soft, bs. Alot of people talk shiz on Spec. Fck Spec, mine fell apart after 2500 miles. No drifting. lol.

Yeah these are true, I have friends with Megans, they do not recommend them (front coil brackets seized)Spec yeah Fu*k that clutch i had a friend who had one for 2 months before it grenaded on him just DD it

But yea its all been covered. I would replace bearings, and rings, all seals, everything decked, cylinders honed. DO NOT PUT THE ENGINE BACK IN WITHOUT A NEW OIL PUMP! It will be the best 250 you spend ont he whole car, knowing the oil pump isnt gona go out any day now. Im waiting

Well you can get one cheaper herehttp://www.thenismoshop.com/ik...d=284

[white90esex]

Allright, well upon further inspection of this motor I have it seems the pistons are pretty pitted from detonation I sapose.

What once was a quick refresh to get a solid motor in my car is now a total build.

I guess im gonna have to just start getting a few parts here and there.

[corey240]

Sham thats so much cheaper then I have ever found it! Definatly thank you for that one. Make shore you replace that oil pump, 150 will save that motor one day lol. I had no real prior mechanical experience prior to my first rebuild. So dont let people scare you off. If you have money, like most of us dont, then have a shop do it. I did mine in my grandmas driveway in the winter. Built the motor in the bedroom. Put it in over every nice day I had. Search for my thread, it should help you on some things later possibly. Get the FSM and you will be set. Email me if ytou have any problems or questions. [email protected]. good luck