The Engine Rebuild Thread

[LuPix_S15]

Ok guys,

Thought it's time we started some proper discussion on engine rebuilds as mine has hit 100k miles and I'm in the process of sourcing a second high mileage SR20DET so can pull her apart and start work on rebuilding. I'm hoping to get this all done before my current block decides she doesn't want to play ball anymore so will take my time to make the right decisions and source the correct parts. There's obviously gonna be bits I'll have to send her off for like head skimming etc but want to do the majority myself (maybe I'll only end up ripping her apart and getting the rest done by experience pros but we'll see haha)

I've always held the belief that I want my car to remain fun and entertaining to drive at lower rpms (fast and twisty roads) so I'm still not looking for 'well above' 400 bhp. However, if I'm gonna rebuild I might as well use internals that can take more abuse/power/torque etc. I'm not gonna go overkill and pay for forged this that and the other but upgrading will be key.

So... I've recently been eyeing up the Mazworx stroker kits. Here's what I can copy and paste:

We are proud to introduce our line of stroker kits. Available in 91mm (turbo applications) 92mm (N/A applications). Our stroker kits will come with the following:

Mazworx 91 or 92mm stroker crank. 91mm crank 4340 billet, full counter-weight, teardrop oil chamfer. 92mm crank 4340 billet, full counter-weight, knife-edged, straight through oiling holes.

Custom CP Pistons. Available in any compression ratio desired. Comes with pistons, rings, locks, wrist pins.

Manley Rods - good for 600hp ( on average). Can be upgraded to bigger, badder rods.

ACL race bearings set ( main, rod , thrust washers). Option available with 19mm wide rod bearing machining, and 5 hole main bearings (GTi-R standard)

Motor displacement:

87mm bore x 91mm stroke - 2.16L
90mm bore x 91mm stroke - 2.32L (Please contact us for this application)

87mm bore x 92mm stroke - 2.19L
90mm bore x 92mm stroke - 2.34L (Please contact us for this application)
92mm bore x 92mm stroke - 2.45L (Please contact us for this application)


My first question is even though I'm not planning on bhp figures like 450 to 500+ would it still be worth me getting a stroker kit that displaces to 2.16 or 2.19 (assuming I'm sticking with 87mm sized pistons)? Will there be more torque at the lower end so even if I was to tune to around 400 bhp combined with .86 AR trim turbo will it be a worthwhile upgrade?

If I keep the pistons to 87mm - will I still need to bore out the original cylinders slightly as I get the impression stock piston sizes are 86.5mm?

I'm also wondering what cams would best suit - Tomei Poncams seem to be around 256 deg but I've also seen 260/260 IIRC... think 275/275 is too aggressive and the whole point is I don't want to have to rag the hell outta her to get all the performance like a true track machine :wack:

Start your debates and opinions!!

Cheers,

James

 

[LuPix_S15]

lol is this too much of a head banger for Friday night?! :wack:

 

[Jay]

i would love to give you an opinion on all of this, but the above descriptions/questions may as well be in mongolian for the knowledge i have on internals :wack:

is it really worth the effort and expense if you are gonna stay below 400?

 

[AllanOrr]

Hey dude I am actually doing the same though I am going down the path of a full D1 Street GP Car I am currently stripping and selling off all the stock parts to get a 2.2 HKS Stroker kit aswell as everything else HKS from full Cam to Head Kit will be looking around the £10k mark just to rebuild the block, though I plan on making it a total animal of a car
Reason I am going down the HKS route rather than Tomie and Brain Crower is mainly a personal choice as I am a bit of a brand slag :rotfl:
only big trouble I can see is reaching my goal of 500bhp+ at the fly with Nismo 740cc Injectors I know the gearbox will need to chucked and either get a PPG Dogbox or get a Close ratio internals kit

 

[AllanOrr]

i would love to give you an opinion on all of this, but the above descriptions/questions may as well be in mongolian for the knowledge i have on internals :wack:

is it really worth the effort and expense if you are gonna stay below 400?

2.2 Stroker Kits are mainly for torque abuse rather than to gain a high BHP figure as with most Drift Spec S15s that still have the SR20DET they dont usualy go above the 550BHP mark but with a torque figure to match, easyer to smoke up the rear with alot of torque :wack:

 

[EMAGDNIM]

My first question is even though I'm not planning on bhp figures like 450 to 500+ would it still be worth me getting a stroker kit that displaces to 2.16 or 2.19 (assuming I'm sticking with 87mm sized pistons)? Will there be more torque at the lower end so even if I was to tune to around 400 bhp combined with .86 AR trim turbo will it be a worthwhile upgrade?

From what I understand, low end torque feels GREAT on the track no matter what. I'm toying with a stroker kit myself as I've been researching it for a while now. Low end grunt with top end boost = full of win on the track. I'll be in this thread for sure for this discussion.

 

[meddler]

92mm bore x 92mm stroke - 2.45L (Please contact us for this application)

now this would be fun I would definatley give the new 2.5L subaru STI guys something to think about :nod:

 

[DeanS15]

for what you want why not just go with a straight rebuild with uprated internals and rod/head bolts, some headwork then spec some cams and a headgasket (ask the person tuning it). run it on a 2871r and you should have an engine that can cope quite comfortably with the turbo and use anything else would probably start to get a big bogged down lower down......

 

[sx-si]

check my engine spec in my build thread also with the hks 2835r ill have over 400bhp before 4krevs

allough you need to be really carfull as your end power or torqe figure with what your using the car do to aka drift or drag will depend on what else you need to upgrade

as if you spent 6k on the engine you would still need 1k worth of clutch then a geabox, rb25 conversion is 1k or ppg boxes are about 4k
then halfshafts if using the car hard and are over 400bhp
also ecu and mapping which i wouldnt pay less than 1.5k for if its a spec like that
and fueling which is proablly another 500quid
then a good turbo is most likly 1.5k i wouldnt bother with a gt2871r or 3071r as theres alot of better and faster turbo's out there

soon becomes a 10k build

 

[Adam L]

It's well known that the stock engine will take the mileage and power.

The stock bore is 86mm, you've got the choice of oversizing to 86.5 or 87mm. going 20thou over is a better choice as if something does happen to the bores with 87mm your block is scrap unless you go even bigger.

A bigger turbo and head work, with cams would be more worthwhile in my opinion.

Like sx-si said, you'll end up going over budget. If you want to build a bomb proof bottom end and replace pretty much everything, you'd be looking at £3k plus on a standard stroke without touching the head.

 

[AllanOrr]

I have to agree with sx-si that builds end up going over budget on these cars veryyyyy easily go over budget :wack: end of the day if your going to tune these cars seriously you might aswell do it right.....and sell your house and live in it :rotfl:
Bride seats or king size bed you decide :wack:

 

[LuPix_S15]

lol Allan I'll take the Bride seats if my two sons are willing to take the stock back seats (soon to be no seats!!)... and fook knows where the wife will sleep?? On my BGW lmao


Loving the replies and opinions guys... keep 'em coming as this should turnout a useful thread for everyone interested in rebuilds and/or upgraded rebuilds etc.

I think at the end of the day the stroker might just put too much cost into the overall package and esp for what I want. I'm deffo a torque addict and more esp at lower end is something I don't mind paying for as long as there will be a noticeable difference. I didn't think adding the stroker would suddenly make the overall cost so high... if I was always planning on stripping a used SR20 block down to ensure everything is in working order then surely it's pretty much my time spent on getting everything apart and then the cost of the stroker kit and cost of honing and possibly experienced garage to put it together, getting the head and block skimmed and all the other stuff which I'd need to do anyways... maybe I'm being a bit too optimistic but I was hoping the whole lot can be done for around £5k max (bearing in mind cost of Mazworx stroker is under £2k). This would also include new cams and all the valve/spring related items replaced/upgraded as well.

The thing is being a second block to work on I can take my time and was gonna spread the cost over 12 months minimum and take my time sourcing parts and learning how to strip and rebuild as much of it myself as possible


Si - I'm deffo getting the RB box conversion and this will be done early next year well before I start this rebuild madness

 

[Toby]

The other cost with the stroker kit (unless you get the baby 87mm diameter one) is I assume anyway you will need to re sleeve the block - bye bye another £500.

 

[GUEST_JDM]

Ive just gone down the hole rebuild road found that nitto stroker kit nailed the rest they quoted me five grand with everything needed to do the bottom end, the manager of the company
garenteed me the kit would handle over 1200hp and rev over 12 grand due to how good there balancing process was. But in the end I just replaced the rings n bearings in the bottom end n went crazy with the head full port n polish over sized valves mild pon cams and general rebuild with new vct gear, lifters, went so far with the hole port n polish thing I sanded n smoothed out my greddy. Intake plenum to the point that there was no cast marks left, baby smooth pritty much did the same with the ex housing on the new 71r I got took it apart n removed every mark till it was smooth did the same on the dump pipe n ex manifold. Massive over kill really but the end result was well worth it with an ultra responsive 260kw on 18 psi just goes to show that flow makes power not really volume

 

[LuPix_S15]

^^^ I'm liking that!! As said I'm not looking for big power or even massive amounts of torque. I just think if I want a fresh engine and I've got the time to pull it apart and try do stuff myself then I might as well get better parts and the small displacement stroker upgrade seems like a good idea to extract a little more torque nearer the lower end of the revs which should = more fun

I think I'm still gonna go for the 91mm stroker with 86.5 or 87mm pistons which means I won't need those expensive sleeves + massive rebore job etc. Believe honing should suffice. Ok might be a little overkill with CP pistons and H-beam conrods plus new crank/ACR bearings but at least I can ensure everything is new and there can't be much of a price difference between the Mazworx uprated crank against an OEM Nissan one. Or will I save loadsa pennies by just getting original crank ground and re-balanced?? :wack:


As Guest says I'm gonna definitely concentrate on the head as well so it all matches up perfectly between head and bottom end...

 

[EMAGDNIM]

The other cost with the stroker kit (unless you get the baby 87mm diameter one) is I assume anyway you will need to re sleeve the block - bye bye another £500.

Yeah, even the smallest diameter pistons in the HKS kit need the sleeves. I've factored that in my overall pricing (I've got a pricing breakdown going in my excel build file). There's lots of little things that can add up quick.

 

[sx-si]

is it worth buying keirons stroker setup from sxoc or dw?
i can see what your saying but its most likely going to turn into a 3 year project to build the engine up and i dont know how much you love your s15 but wouldnt you get board with the project or just fancy a diffrent car in that space of time

if it was me i would forget all about it in like 4months and it would get shoved into a cubbard and forgotten about
which is why im building my s15 to its final spec as soon as i can so i can jst relax and enjoy it

 

[AllanOrr]

Totaly agree with Toby on the cylinder sleeves dont cheap out on them can you think after spending 10grand odd if your not going to do the work yourself to then have a piston dancing on your bonnet after one drift run lol :wack:

Good thing about my wee project is one of my mates and myself are going to do all the work (he has a s14 also going to be getting stripped) and we will use the cars as demo's and in the future maby open up somewhere well thats the dream lol always has a better feeling when you know youv put your own hard work into a build rather than paying a garage to do the dirty work.
Like Guest says would be nice to know your block can handle a crazy amount of abuse up to 1200bhp but will be solid @ around the 500 mark and when you feel like being a little bit crazy you can always crank it up a level :thumbs:
Come on lottery win :wack:

 

[LuPix_S15]

Si - I've seen Keiron's add for the Apex stroker but I'm not sure about the quality of the parts (apart from CP pistons) so didn't really consider them in the end... Maybe when I get round to doing this there's more peeps (probs S13/14) who have fitted Apex strokers and can confirm the quality/reliability.

Won't get bored mate as I'm not like some other types of owners who do a bit and then move on - this is deffo a long term project and it took me 18 months after I got the car to start modding performance/suspension stuff. 3 years down the line I'm only at the point where I'm at which in my mind is about 10 to 20% completed. She's a daily driver but in a couple of years when kids are older I'll just strip her out and get rollcage fitted which is why I wanted to start looking at a stronger engine with more torque potential and go down a slightly different route to the norm with stroker etc.

But before all this or during the initial period of rebuild I'm gonna get the injectors, AFM and GT2871R sorted so there's a mini power/torque upgrade before the rebuilt engine is eventually swapped over lol


Allan - do you think it's essential to get the sleeves fitted regardless of how small the amount of boring/honing is?? Even going from 86.5mm stock piston to 87mm??

 

[Toby]

I would only sleeve the engine if you go over 87mm tbh.

I've not had mine sleeved, and Ive bored it out to 86.5mm with CP's fitted.

I looked at it, labour was about £400, and the liners were £275ish IIRC.