The Engine Rebuild Thread

[LuPix_S15]

Nice1 Toby - so I take it 86.5mm is not standard piston size and even this requires bore and honing?


I was speaking to a very knowledgable mate yesterday about rebuilds and it was interesting to hear that the honing uses cross-thatched type material which makes a rough surface within the cylinder walls. And it's the 'run in' period of the rebuilt engine that actually is meant to create it's own final smooth tight finish of the piston rings against the cylinder walls etc. Also he suggested that one is supposed to use mineral oils to run in the engine cos of all the crap it can flush out during this period (??)

 

[Toby]

Standard Size is 86mm mate, anything larger even .5mm will require boring out.

Yes honing leaves a very faint ridge on the sides of the bores, this also lets oil sit in the ridges to aid with the running in.

Honing doesn't actually increase the cylinder size just cleans it up as so to speak.

Mineral oil is a must for running in, My engine will have 2 - 3 oil changes with mineral oil over the first 1000 miles, 1 oil change at only 50 miles, and probably another at 500, then at 1000 I will swap over to a fully synthetic.

 

[LuPix_S15]

Thanks for confirming mate :thumbs:

 

[AllanOrr]

Lu - reason I am saying defo buy the sleeves is remember its a aluminium block so it will be weakened if there is any boring needing to be done to fit the new pistons, for £500 I would rather have the peace of mind knowing they are there to keep everything solid know what I mean

 

[LuPix_S15]

Allan - yep totally understand your advice and guess at the end of the day it's whether pay more to get peace of mind or take the chance and not do it :wack:

 

[sx-si]

86.5mm-87mm pistons are mainly regarded for use without sleves dude but if you do 87mm then score the bore your only other option is either sleave it with larger pistons or start again with a fresh lump
mind you a big end blown sr20det can be picked up for peanuts

i personally wouldnt bother buying turbo and injectors simply because if you spend a few months/ years building a engine that can take 500-600bhp or more i doubt you would use such a small turbo (its kind of a waste using a gt2871r on a forged or stroked sr in my eyes)
get yourself a engine build book for some toilet reading and a sr20det to rip appart
then go from there

 

[Curryzz]

Hmm i seem to be hearing alot about this rebuild stuff as my engine started tapping,(Bottom end)So my silvia is currently geting its engine removed, once we find out how bad if at all the damage is to the bottom end/little end il make a desicion to rebuild completly or not, problem iv got is i cant really afford a big turbo/injectors all the parts, if i have to pay for a rebuild then i mite aswell get some stonger parts but i dont really fancy a 10k bill, iv already splashed on a front mount and im having a stand alone Link ECU fitted with a boost controller so i can have her remapped, it will actually be set up with lanch controll and anti lag but hey i couldnt say no lol

Paul

 

[DeanS15]

it might just need re-shelling.....that would get it back up and running and you'd have breathing space to plan what you want to do in the long term

 

[LuPix_S15]

Si - I think it's making more sense now... I wasn't sure if the stroker was worthwhile just for more torque and felt it's better to get uprated internals just so I can push the engine hard constantly without worrying about her breaking etc!!

But if the general consensus is that uprated internals and stroker is a waste of money for something that will always be just under or around 400 bhp (and similar torque figure) then I'll leave it and just rebuild an engine by checking all the parts are ok, freshen things up if needs be (or replace with similar to stock items) and work a bit on the head like mild cams and stiffer springs etc

 

[sx-si]

thats what ive done dude
i set myself a e pwer figure or 420bhp and ame toque
then built engine, box, turbo setup, fueling and ecu round it

when its finished i should be running
engine
Arias Piston Kit
Eagle H Beam Rods
ARP Head Stud Kit
Brian Crower Stage 2 Camshafts (IN 264 and EX 264)
Brian Crower Uprated valve springs
Cometic Metal Head Gasket 1.6mm
Head ported and matched intake and exhaust
Polished greddy pletnum

turbo
hks 2835r

drivetrain
jaguar v12 manual box conversion
lightweight fly wheel
sierra rwd paddle clutch
nismo w diff wih 4.rato
r32 gt rearhalfshafts

fueling
SARD 850cc Injectors
twin bosh pumps
tommei fuel pressure regulator

ecu
link g4



obviously theres lots of shiney bits and bobs too
but that "should" be a bullet proof setup, as im trying to build a car too keep a long time with as little trouble as possiable

 

[TurboAL]

james i wil be watching this thread closely, I'll be keen to see what decisions you make as i will at some stage be upgrading the engine to extract more power from it.

I cannot offer too much advice atm as its not some thing i have done. but what i will say is:

For a everyday usable reliable fast s15 i do not think more than 400bhp is required. i would say do not over spec stuff that does not require it.
some things to consider is that more power equals more fuel which could cost big bucks and can effect how often the car gets driven.
There are secondhand parts and secondhand complete tuned engines that sell for nothing close to what they cost to build so this is also worth considering.
Also your considering getting a second engine to tune so the time the car will be off the road will be reduced to a minimium which is a good idea. I've seen a lot of projects which have gone over the top of people and then there enthusiasm wears off and they fail to get completed, so having a car still usable for the majority of the time is a big plus.

 

[EMAGDNIM]

I'm really enjoying the discussion so far in this thread. I'm going to follow it for sure. I was thinking about this over my lunch break today and I have to say that I'm still on the fence on this as I'm not looking for huge HP figures but a smooth powerband with low end grunt. Pairing the kit with a proper turbo will be my big decision as I'm looking for response...

 

[sx-si]

emagdnim
theres tonnes of options available dude it depends on budget as thats the killer
powerband is prettymuch the easy bit as for quicker boost is larger pistons/ stroker with maybe some light headwork
or a longer rev range = heavy cams which rase the rev limit but also you lose low end spool
also depends on what size urbo you want to run as its easy to get a gt3071r before 4k revs
the powerband is just mapping really tbh

 

[tripleJs15]

There's alot of good info here, but to be honest with you, I've ran 450whp with stock rods, and CP pistons, 260 Tomei cams (HLA), for 2 years with no problems.

To hit that 500hp you really dont need a stroker, thats way over kill. A few upgrades and a very good tune will get you there easily.

Also you will get more out a good turbo, little headwork, and cams. than the stroker kit.

 

[Toby]

I've been told 350bhp is the safe limit of std rods.

 

[AllanOrr]

hmm am in two minds now if I should go down the HKS stroker kit line

 

[tripleJs15]

This is my 600hp Mod list, I'm sure there are things missing but thats the main stuff.

Standalone:
Tomei Reytec MAP Based Standalone

Head:
Headgames did the head, Port Polish, Multi Angle Valve Job, Combustion Chamber Clean Up, Port Matching, polished combustion chamber.
Supertech Dual Springs and Ti Retainers
Supertech Locators
Supertech Valves
Supertech Valve Guides
Tomei 270/270 Cams

Block:
CP Pistons (9.0:1) 86.5mm Bore
Eagle Rods
Cosworth HG
Honed
Line Bored, and all new nissan bearings etc.
ATI Crank Pulley (Not Pictured)

Turbo:
Precision Turbo HP6262 Billet Turbo
Peakboost Manifold
Greddy Intercooler
Tial MVS Wastegate
Blitz SBC ID-III Spec R Boost Controller
Custom 3" Downpipe
Custom 3" Exhaust
HKS Muffler

Intake:
Greddy Ver. II Intake
Tomei 70mm Throttle Body Kit
4" Turbo intake pipe and K&N Filter

Iginition:
Spiltfire Coilpack
NGK Iridiums

Fuel:
Injector Dynamics ID-1000cc SAturated High Impedence Injectors
Greddy Fuel Rail
Aeromotive FPR
Walbro Pump In tank
Bosch In Line

Money Shot:

 

[tripleJs15]

I've been told 350bhp is the safe limit of std rods.

I ran stock rods and ran it hard with no problems.

There's no such thing as a safe limit really, too many factors play into the equation. The biggest factor is tuning, this will make or break you. Hwoever if you pulling the engine apart I would go ahead and throw some eagle rods in there at least, ARP everything and you should be safe.

 

[sx-si]

what box you running?

 

[tripleJs15]

have the Mazworx Z32 kit, comes with the box, machined bell housing, adapters, new bolts, driveshaft etc. I switched from my ORC clutch to an Exedy Twin Plate which I hated but didnt have a choice.

Info: http://www.mazworx.com/index.php?l=product_detail&p=2759

I actually sold the ORC to a guy of this forum.