New pistons or a rebuild kit???

[S13_RB25]

Long story short i was looking for a shell to replace my rusty DD s13. Well i came across a 93 s13 for $600. It had lost compression in 4th cylinder. IDK the year and the mileage of the motor, the PO said it was swapped out to replace his old KA24de.

So would it be better for me to buy aftermarket pistons and see if it solves the problem or buy a rebuild kit. http://www.rpmmachine.com/shop/index.ph ... ail&p=5302

On a side note i do plan to turbo the ka. SO with that in mind i know i don't need new connecting rods since there already forged.

[Drakelee]

rebuild, unless you can physicly see the piston is cracked or damaged

[S13_RB25]

rebuild, unless you can physicly see the piston is cracked or damaged

Well the top of the pistons seems to be fine but it could be the rings... I'll take a pic of all four cylinders and upload them later today... Maybe guys and girls can spot something i can't...

[NismoS13Ks]

if you plan on going turbo, i would suggest doing a rebuild.

[S13_RB25]

Here are pic's i took, there going to be in order:
Cylinder 1

Cylinder 2

Cylinder 3

Cylinder 4 ( The one PO said lost compression)

[S13_RB25]

if you plan on going turbo, i would suggest doing a rebuild.

Well ill be fine with that but should i go with the rpm machine rebuild kit or get something off of egay, i hope not, or some other resources??. Also I'll use ARP head and main studs now instead of getting them when i get the turbo...

[Drakelee]

Clean the s*** out of it and do the rings, bearings, ect basic rebuild and I think youll be fine. Im rebuilding my KA in August as well. getting all the parts from FRSport.com

[S13_RB25]

Clean the s*** out of it and do the rings, bearings, ect basic rebuild and I think youll be fine. Im rebuilding my KA in August as well. getting all the parts from FRSport.com

Yea im going to get my rebuild kit either off of egay or rpm machine. But just the basic: pistons, rings, bearings and i might end up getting a new water and oil pump too.

But i need to find a shop, in NJ or somewhere in PA, that can deck and hone the block and also pressure test the head and do a valve job...

[s13drifter88]

OE rebuild should suffice just fine. I have a friend beating the piss out of a stock KA with a 60-1 running on megasquirt. Engine management is the key to KA-T success

[motoman399]

i bought a full gasket set, bearings, rings, and pistons from ebay as cheap as i could find them. i bought it all for 300 including oil and filter. i also turbo'd that engine (only for 4 days for the last drags of the season). car still runs great! got 32.4 mpg with that rebuild after i had the turbo on it. good luck

[S13_RB25]

i bought a full gasket set, bearings, rings, and pistons from ebay as cheap as i could find them. i bought it all for 300 including oil and filter. i also turbo'd that engine (only for 4 days for the last drags of the season). car still runs great! got 32.4 mpg with that rebuild after i had the turbo on it. good luck

OK so if i get a OE rebuild kit from ebay and turbo the engine, assuming i get a good tune, would i be able to DD it?? I want to run around 300whp.

[s13drifter88]

an oe rebuild, machine to factory specs, and if ur OCD like me a.r.p. head studs. add an s15 t28 (t25's choke in the midrange on ka) or even a 2860, n60 maf, sr 370's, and a tune, ie Jim Wolf, Megasquirt ect (safc will work if youre good with one) and youll be more than ready for 300whp. theres a vid on youtube of a t28 ka-t doing like 275whp and 300wtq on 10psi. thats very respectable

[s13drifter88]

t28 - $750
ARP studs - $100
N60 maf - $50
SR 370s - $100 (most i would pay)
Apexi SAFC - $150
Jim Wolf or MS - $4-500ish (recomended)
Ebay FMIC - $180
Ebay 3" turbo back exhaust -$200
Spec stage 2 clutch - $250
It will be fun, it will be reliable, it will perform past the expectations of a "daily driver", and it will be done right. after the build is completed, fill with cheap oil, start and shut off then drain, fill again with cheap oil, drive 4-500 miles then change, fill with cheap oil AGAIN and drive for about 1000 miles then drain. Add a quality synthetic and enjoy your new KA-T. its important to use a basic conventional oil for break-in seeing as how the lubricating properties of synthetic oils reduce engine wear to the pont that it would probably take u 10k miles or more to actually break it (mildly exaggerating).

[S13_RB25]

t28 - $750
ARP studs - $100
N60 maf - $50
SR 370s - $100 (most i would pay)
Apexi SAFC - $150
Jim Wolf or MS - $4-500ish (recomended)
Ebay FMIC - $180
Ebay 3" turbo back exhaust -$200
Spec stage 2 clutch - $250
It will be fun, it will be reliable, it will perform past the expectations of a "daily driver", and it will be done right. after the build is completed, fill with cheap oil, start and shut off then drain, fill again with cheap oil, drive 4-500 miles then change, fill with cheap oil AGAIN and drive for about 1000 miles then drain. Add a quality synthetic and enjoy your new KA-T. its important to use a basic conventional oil for break-in seeing as how the lubricating properties of synthetic oils reduce engine wear to the pont that it would probably take u 10k miles or more to actually break it (mildly exaggerating).

So i use the cheap oil after i turbo the KA or when i get done with the OE spec rebuild?? Also what amount of WHP is safe on the stock pistons?? Would 300whp to 350 be fine?? I also wanted to go with 550cc injectors just so if i want some more power in the future ...

[-RJ-]

I read that a stock KA can handle 300whp fine, also you use conventional oil after the rebuild. Thats what I did and what I'm doing, I got ARP studs, clevite bearings and such but I left the pistons and rods stock. If I had the money at the time I would have got better internals.

[motoman399]

i bought a full gasket set, bearings, rings, and pistons from ebay as cheap as i could find them. i bought it all for 300 including oil and filter. i also turbo'd that engine (only for 4 days for the last drags of the season). car still runs great! got 32.4 mpg with that rebuild after i had the turbo on it. good luck

OK so if i get a OE rebuild kit from ebay and turbo the engine, assuming i get a good tune, would i be able to DD it?? I want to run around 300whp.

im not going to say yes, because if you blow your engine you will hunt me down lol. but i would do it. if you have a good tune it should be good. the stock KA in good condition is good for about 350 +/- a few. if you havent already, go over to the KA-T section on nico. there is some great info there. good luck

oh and stated above that 370's will make 300 reliably.. i dont think so. i would think they would be at around 100% duty cycle which in no way reliable...

[s13drifter88]

use a cheap oil just for break in, synthetic should only be used after the break in period is complete. i dont entirely agree with the statement that 370s wont make 300 reliably. yea they will be operating at a higher duty cycle but also keep this in mind, theyre side feed. the injectors are constantly bathed in the fuel will cool them where top feeds are prone to cutting out being that the fuel just shoots straight through them and they dont cool as well as the side feeds. i made 277whp on my ca18 with my stock 370 top feeds, i turned my fuel pressure up 5 psi and corrected with my afc then retarded my timing 2-3 deg.

[s13drifter88]

but if ur concerned with 370s cutting out then grab a set of s15 440s or 460s whichever one they are, i cant remember, and tune for them. if u get Jim Wolf (what i run) youll have to send the injectors with the ecu so they can test and flow match them.

[S13_RB25]

Thanks for the info and replies guys, but -RJ- aren't the connecting rods forged from the factory for the ka?? The only weak party is the pistons. But it also depends on the tune I or we get, and aren't the internals are good to 400hp, except the pistons?

[motoman399]

but if ur concerned with 370s cutting out then grab a set of s15 440s or 460s whichever one they are, i cant remember, and tune for them. if u get Jim Wolf (what i run) youll have to send the injectors with the ecu so they can test and flow match them.

you cant really get the 440's for much cheaper than brand new injectors. you might as well get some 660's (i think they are, well they are somewhere the 650's) if you are eventually wanting to go with more power. the 550's you want wont get you that much more power. everyone says buy injectors once, you can always take away fuel.

now if your power goals were 250 and less i would tell you to get a set of 370's for $60. but you want 300 so go big or go home

[S13_RB25]

Yup im going to go with bigger injectors. I might go 750cc's if i can get good deal on them.

[s13drifter88]

idk i think 750s are a lil bit big but if u get a good deal then hell why not, id get them

[motoman399]

idk i think 750s are a lil bit big but if u get a good deal then hell why not, id get them

what makes them too big. why did you come to that conclusion?

[s13drifter88]

i just kinda see it as a bit of overkill. when buying injectors, the bigger the size cost goes up. if ur getting a good deal then i guess yeah go for it but as far as buying a set of 4 flat out i wouldnt just go straight for 750s. Deatschwerks 440s would more than easily suffice for his power goals but if you would like to allow for room to grow then pick up a set of 550s. A friend of mine has RC 550s in his red top sr with and hks solid lift valvetrain and hks step 2 cams with a 2871rs and he layed down 421whp on a dyno dynamics all wheel dyno. 550s - 413whp so for 300ish - ... 440s? You dont build a 5x7 picture frame using a 32oz framing hammer lol

[s13drifter88]

Im running rx7 440s in my ca with a 2860 and i blow the 300 mark away every time i switch my EVC6 from low to high and thats just with a jim wolf tuned ecu and an n62 maf

[s13drifter88]

ok, i went to deatschwerks website and used their fuel calculator to size up your injectors. i figured you in a 330hp goal, .43bsfc, 4 injectors, operating at 85% duty cycle and it gives that youll need 41.7 lb hr or 438.2cc min of fuel. thats if you run a 3 bar fuel system (43.5psi). now here is the great thing about the jimwolf computers. its going to be the same price to tune your ecu no matter what. save your self the money and pick up a set of 440s and when u send them the injectors with the ecu to have them flow matched inform them that u are operating them on a 4 bar fuel system. then your 440s will spray 504.6cc min and will also allow them to operate at a lower duty cycle which will still "leave you room to grow". with this being a DD how much room do u really need to grow tho honestly. is it going to be a DD or become another project or big build? K.I.S.S. = keep it stupid simple. btw, deatschwerks 440s are under 300 from enjuku, now idk about u but i havnt found a good set of 750s for anywhere near that price.

[motoman399]

You dont build a 5x7 picture frame using a 32oz framing hammer lol

now what if your going to build a house. you will need that 32oz framing hammer. see my point (room to grow). if you have to spend an extra 100 bux to get some 6XX cc's its worth it if you ever plan to grow. i wish i would have thought of it when i bought mine. i bought 550's and now i want to sell them for some bigger ones. so i have 550's for sale lol 200 obo hahaha.

[s13drifter88]

im not disagreeing with u, if going on a big build like me and my friends vg30et going for over 500 then yeah. but for a DD i think theyre overkill unless u score them for the low low. i think for a DD that 440s, a gt28 (or a 2860), and a flashed ecu with n60 maf will give him his 300. leave the big stuff for the big project. dont lose sight of the project and its simplicity

[S13_RB25]

Well the reason i want to go with 750cc's is because in the near future i plan on buying forged pistons and upping the boost. So that's why i might as well get big injectors now other then buying new ones in the future. I want 300whp just to begin with, but as we get used to that we want more after that and i know i definitely do. So that's why I'd rather not spend money on the same thing twice...

[-RJ-]

Thanks for the info and replies guys, but -RJ- aren't the connecting rods forged from the factory for the ka?? The only weak party is the pistons. But it also depends on the tune I or we get, and aren't the internals are good to 400hp, except the pistons?

That sounds about right. For me, I'm trying to get about 250 - 300whp so I'm fine with the stock internals. If your going to reinforce your bottom end then why not spend just a little bit more and get better rods too and get everything out of the way. Nothing beats peace of mind.