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View Full Version : my weakest link: k20a3 block



jeffgeezer
07-16-2008, 05:37 PM
hi everyone! i just want to ask a few questions before i proceed on doing the set-up below. any ideas are welcome.

current engine/tranny set up is:

k20a3 stock
jrsc-r 3.8' pulley 10psi
k-pro
rc 440cc inj
cai/short header/random tech/exhaust
stock ep3 5 speed tranny
exedy stg2 clutch/flywheel
quaife lsd
esmm
ingalls etd

nitto neo-gens

plan:

k24a1 head swap
bc stg 2 cams
bc spring/retainers/valves
replace oem guides/seats/tct/chain (full valvetrain upgrade) i want to start fresh (like what sinister mary did. thanks by the way for your help, mary!)
hondata img
86mm cometic head gasket
arp head studs

afterwards:
maxbore tb

For the meantime i will leave the k20a3 block untouched.



my questions are:

what's the stock k20a3 block's limit? i heard after 300hp, it starts falling apart, the pistons begin to move elliptically instead of vertical, would the pistons, rods, crank be ok? i'm not increasing compression, am i?

will my block hold on to the set-up i'm planning? i doubt i'm gonna reach 300hp

would the axles last too? im not gonna race it everyday. on the weekends maybe, at the track. md bbq? hehe!

since i'm increasing airflow, should i expect a drop in boost?

could i just street tune the pro tune i have right now and smoothen the a/f around 11.5-12:1, make sure there're no knocks, and inj duty cycle is <80%

any ideas how much this set-up's gonna pull?

any other suggestions?

I did search a lil bit, i mean not for a whole day, but enough. i'll make sure i'll search some more. Thanks everyone!

AliG-EP3
07-16-2008, 07:14 PM
Usually there is crank walk past that magic mark, but then again, tuning is a very important aspect so you should make sure you have it tuned right the first time

illusionsoflife
07-17-2008, 02:47 AM
tune is key!!! there are many guys over 300 whp and still going after a year. one guy had 370ish whp on the stock a3. your setup is fine. id stick with it.

Gilmour
07-17-2008, 06:41 AM
The most important thing would be setting your redline. If you left it at the stock limit I'd say you'd be fine for a long time. :coffee:

jeffgeezer
07-17-2008, 08:36 AM
Usually there is crank walk past that magic mark, but then again, tuning is a very important aspect so you should make sure you have it tuned right the first time


tune is key!!! there are many guys over 300 whp and still going after a year. one guy had 370ish whp on the stock a3. your setup is fine. id stick with it.


The most important thing would be setting your redline. If you left it at the stock limit I'd say you'd be fine for a long time. :coffee:

tuning, you mean pro-tuning? when i got tuned before, all they did to me was a/f and a lil bit of ignition and cam angle which looked like it was copy pasted. cost me $700. if i knew kpro a lil bit better before, i would have done it myself. but i wanted to be on the safe side like what im doin right now. i'm not a kpro expert by any sense but i think i know how to ensure i'm in the right boosted a/f range, and i'm aware of the precautions. i watched and learned from jpax's vidoes as well as the hondata ones and also i read the notes in kpro. i also already applied what i learned to the tune i got from the pro's and modified it based on additional mods that i put after my session and everything seems ok ( killed an o2 sensor before though..hehe!) any comments? i'm not being arrogant. i just want to ask why i should get pro-tuning? i guess i'm just paranoid

seems from what you guys say, the k20a3 engine kinda holds on pretty good

i have my redline right now up to 7500. i'm intending to raise it to 8000 after i break it in a couple of miles. do you think it's ok, since i just upgraded valvetrain anyway?

AliG-EP3
07-22-2008, 06:55 PM
I mean, if you feel your tuning is up to par, then by all means, go at it. it's just most people are interested in getting big numbers and slap on the biggest baddest FI parts, and overlook how important dyno tuning time is, and end up f'ing up the A3 because they only took 1. peak power and 2. quality FI parts into consideration, not how the stock A3 would deal with those type of parts / hp figures. Try to keep it conservative if you want longevity, but 8000 shouldn't be too bad

jeffgeezer
07-23-2008, 04:45 PM
I mean, if you feel your tuning is up to par, then by all means, go at it. it's just most people are interested in getting big numbers and slap on the biggest baddest FI parts, and overlook how important dyno tuning time is, and end up f'ing up the A3 because they only took 1. peak power and 2. quality FI parts into consideration, not how the stock A3 would deal with those type of parts / hp figures. Try to keep it conservative if you want longevity, but 8000 shouldn't be too bad
I see what you mean, bro. Thank you very much! Power is important to me too, but how am I going to use this power if my engine's prone to blowing up, right. That's also why I ask if the stock block would be able to handle it. So yes, i will stay on the conservative side of tuning, the safe side. By the way, any ideas how the cams are supposed to be tuned?

03ep3 stapel
07-26-2008, 03:32 AM
my friend put down 327 a few months ago on 11 psi

jeffgeezer
07-26-2008, 10:22 PM
my friend put down 327 a few months ago on 11 psi
wow, nice numbers! what set-up?

talonXracer
07-27-2008, 09:34 AM
Usually there is crank walk past that magic mark, but then again, tuning is a very important aspect so you should make sure you have it tuned right the first time

Crank walk has absolutely nothing to do with WHP figures, it has to do with pressure plate forces and lightweight engine oil.

kon
07-27-2008, 03:03 PM
make sure your A/F is on par and your not knocking. I wouldn't go over 7700 on the revs unless you plan to switch to an A2 oil pump.

dobbs02si
07-27-2008, 04:30 PM
Z3's spin to 8k no problem with balance shafts. No balance shafts=annoying vibes

classiccelica
08-03-2008, 11:27 AM
How hard is it to put in an a2 oil pump?

jaeguyoon
08-03-2008, 01:24 PM
hey jeff, I'm swapping out the a3 block for k24, if you want you can buy my block for cheap and build it.

boliviasi
08-03-2008, 01:28 PM
hey jeff, I'm swapping out the a3 block for k24, if you want you can buy my block for cheap and build it.
how cheap