a3 build plans i know dont do it !! lol

[los]

before anyone talks all this trash about how much a of a waste of time it is or how pointless of a build it is lol ill have u know i dont care imma do all the work my self its more for personal experience. i wouldnt wanna invest a whole lot of money on a k24 or other engines and just break them. if imma break anything i rather it be a cheaper a3. i have some experiance with it now but im not too sure on some stuff like specs but ill get those later. keep in mind this is a build plan so im open to suggestions but like i said i dont wanna go crazy expensive.


- a3 block sleeved with darton sleeves
-a2 crank with rods to fit since the mains are diffrent than the a3s
- type r pistons/ cps not too sure as far as pistons (need help)
-upgraded valvetrain to a2
-will be running vtec killer set up

ok now anything (not negative) you wanna suggest is welcome lol
-

[1GR8EP3]

The only thing I see wrong is the use of Darton Sleeves... You only need those if you plan on making over 700whp which you wont see on stock rods or pistons. I say save your self the money and use the funds on upgrades that will benefit you.

What are your goals or route you want to go for example N/A, Nitrous, Forced induction?? That will help us help you :)

Quick point dont start a thread how you did, this is not clubrsx and people wont bash you here on ephatch lol... other than that cheers

[Ba82Ep3]

The k20a3 block is the same as the k20a2... minus the oil squirters. As a base platform, the a3 block is a great place to start. Sleeves are really a waste of money unless youre going for BIG boost, or you wanna do a 2.2 build.

My setup starts with a k20a3 block... i even retained the a3 crank and rods. I dont try and spin her up to 8500rpm, nor will i run more than 10psi of boost... so theres nothing wrong with retaining the "weaker" crank and rods. Being realistic about your use and abuse can save you big bucks that you can spread elsewhere.

As far as valvetrain goes... stick with OEM. Use yellow outer springs, red inner springs, dual spring seats and retainers... and cotters that match your spring retainer source. That setup will run any stg 3 cam to 8500rpm and under... so once its built the head can go from one setup to another without needing any additional upgrades.

As far as slugs... i would source a set of 86.5mm RRC pistons/rings. Theyre 11.5cr. Bore your a3 block to match OE specs for the slugs, buy all new OE crank/rod bearings and thrust washers, reuse your a3 crank and rods, set your rev limit to 7800rpm... and let her eat. Budget HP and you still have the experience of building it yourself (minus the bore job).

[los]

thanks guys ! im looking for a budget build cuz it really is for the building experience i and this engine isnt gonna go into my ep this is for a lighter chassis a crx to be exact. my idea for crank and rods upgrade came from reading over and over that the a3 internals are weak. as realistic horsepower im not sure how much i can really make with that set up since ive never built a k before. but if you guys are running a3 internal and small boost with no problems than that will save me a lot of money. the darton sleeves idea came from boost. lol i want to make the rex a track car really since they are already super light and cheap. but if the sleeves are over kill then i guesse ill put that money aside for a turbo set up.


i started this thread the way i did cuz i know a lot of people arnt big fans of they a3 and first thing they would say would be to swap ! anyone can swap an engine or pay a shop to do it but its a different feeling of accomplishment when you build it with your own to hands. im a hands on person and im pretty sure this would be a fun experience.

[Ba82Ep3]

There are quite a few people that have spent plenty of time on stock bottom end a3's, NA and boosted, and revved to 8k on a long term basis. The potential is there, and using the right OEM components, even more can be untapped.

Im the same way... hands on and would rather do it all myself so i know it was done right... and if it was messed up then i learn how to resolve the issue and never repeat it again.

I really want a budget 2.1 build. 87mm 11.0cr OEM k24 slugs, k20a3 block bored to 87mm, and use a k20a2/z1 crank and rods. There is debate over the longevity of the build, since Honda doesnt recommend boring the 2L sleeve more than 86.5mm. my guess is it just needs to be done, documented, and passed on down to those willing to try.

A 2.2 build requires a modded AP2 crank, custom pistons, and custom rods in a k20a3/a3/z1 block. Aint nothin budget about that.

Dont be afraid to make the best of what you have... youll be pleasantly surprised.:mwink:

[los]

sounds good thanks for the advice if possible since ive never bought parts for a whole build at once, off the top of your head what do you think i will be spending to get this kind of a build going? and for the pistons i would want to upgrade them what would you suggest upgrade to after marcket or upgrade to other oems. also yellow and red springs your talking about the a2s right and theye would run dual springs on both intake and exhaust ? cuz dont they come with single spring on intake side on a2 ?

[Ba82Ep3]

sounds good thanks for the advice if possible since ive never bought parts for a whole build at once, off the top of your head what do you think i will be spending to get this kind of a build going? and for the pistons i would want to upgrade them what would you suggest upgrade to after marcket or upgrade to other oems. also yellow and red springs your talking about the a2s right and theye would run dual springs on both intake and exhaust ? cuz dont they come with single spring on intake side on a2 ?

For pistons i would ust go the OEM route. Compare the pistons currently in your block (86mm, A or B size) to know what you need to shop for to replace them. Once they are out you mic them across the skirts to check for comparative size. If you can source pistons the same size as what was in there... and the cylinder bores still have visible crosshatching with no full length scratches... then all you need to do is set the ring gaps permanual and drop them in. No need to take the block to be honed.

The yellow outer and red inner combo is OEM dual spring, and for both sides of the head. Earlier model k20a2 heads had dual spring or mixed dual/single spring setups. I can get you part numbers off of my build lists to make it easier for ya... but im in the hospital again, so it will be faster fo me to track the info down on k20a.org.

[los]

ok mic the piston skirts gotcha and as for the springs ill look around see if i can find that parts number still ig you can get it send it but ill look it up

[Ba82Ep3]

Will do. You need to DL the Honda repair manual that covers both the RSX and the RSX-S side by side. It compares k20a2 and k20a3 engine rebuild specs side by side... so it can help ya correlate the two when youre building a combined or mixed parts engine. Computer PDF's are the shizz...

[los]

i have one og the is it the one with the green cover ?

[Ba82Ep3]

Dunno bro... never owned a hard copy of any of them... i always got them off the net in PDF format. But if you scroll through sections like piston install for instance, it shows you ring gap for both the k20a3 and the k20a2, or bearing clearance for both engines concerning rod journals or crank journals, even TQ differences between the two models... like axle nut TQ is higher on the k20a2 model versus the k20a3... etc.

I have all of them, including the CSX which covers k20z3 engine and trans information... but they are at home on a flash drive and im back in the hospital again. : (

[los]

yeah i i have one on a pdf i think it might be the haynes one not sure your in the hospital a lot i take it your a DR. or something in the medical field ?

[Ba82Ep3]

lol nah ive been in and out the past month. Im having biopsies done today... theyre not sure but think i have Lymphoma. So its just been a bunch of tests to figure out whats wrong with me.

[los]

oh wow man thats crazy i thought you were a dr or nurse or something