K24 increase compression ratio

[Fredoops]

I've had this idea in my mind for a while. Sorry if I sounded noob

I've been reading k20.org for a bit and I've came by quite a few thread where it's basically:
"I've got mailed TSX pistons instead of my CRV pistons... I'll just swap them out and reflash...bam! compression ratio increased from 9.7:1 to 10.5:1.... goody"

hmm... is it THAT simple? :eek:

If so then can I swap out a set of K24z3 piston's (11:1) onto my CL9 (K24a3, 10.5:1) to get more out of the block?

[fatboyz39]

You can swap out the pistons to the new k24z3 pistons. Did you get the right pistons for your block? There is a A and B set unless you got the over size pistons which won't matter.

Adding slightly more comp will only benefit with other mods done to the car. i.e headers/intake/exhaust and etc.

Is it a worthwhile mod to a stock engine? I would say no... the time and labour isnt worth it.

[Fredoops]

You can swap out the pistons to the new k24z3 pistons. Did you get the right pistons for your block? There is a A and B set unless you got the over size pistons which won't matter.

Adding slightly more comp will only benefit with other mods done to the car. i.e headers/intake/exhaust and etc.

Is it a worthwhile mod to a stock engine? I would say no... the time and labour isnt worth it.

CL9 is K24A3 I believe.... Anyway... So it IS just the piston? I always thought you'll need a new set of cam gears as well or something.

[dougie_504]

CL9 is K24A3 I believe.... Anyway... So it IS just the piston? I always thought you'll need a new set of cam gears as well or something.


Full head build sure wouldn't hurt if you're doing pistons mate.

[Fredoops]

Full head build sure wouldn't hurt if you're doing pistons mate.

You know Im by no means a mechanic, but I do have greasy fingers. So the cam + piston thingy will cost about 1200.. in total.. God bless America
and it's still cheaper than the ECU tune/reflash... lols

[dougie_504]

Pistons + cam gears?

What's the point in getting cam gears alone? I see minimal purpose unless you get shafts too, in order to reap the real benefits. Then a supporting valve train to handle it, a good intake and exhaust setup to help the car breathe. Head work wouldn't hurt while you're in there ---> 3-angle grind, port job, matched manifolds.

Then tune it up, otherwise it's a waste.

Add in labour, then suddenly your $10g worse off and wondering why you didn't just go F/I or buy a different car.

[Fredoops]

Pistons + cam gears?

What's the point in getting cam gears alone? I see minimal purpose unless you get shafts too, in order to reap the real benefits. Then a supporting valve train to handle it, a good intake and exhaust setup to help the car breathe. Head work wouldn't hurt while you're in there ---> 3-angle grind, port job, matched manifolds.

Then tune it up, otherwise it's a waste.

Add in labour, then suddenly your $10g worse off and wondering why you didn't just go F/I or buy a different car.
Good Point.

[dougie_504]

I'm all for modding engines, but I just believe that you go like this (for power):
1. I/H/E
2. Head build (mild) - mildly aggressive cam shafts/gears + tune
3. Head build (aggressive) - more aggressive shafts, supporting valvetrain, head work, TB/IM + tune
4. Block (mild) - larger displacement + tune
5. Block (aggressive) - high comp pistons, lightweight crank maybe, forged internals a good idea + tune

Flywheel upgrade a fun idea. Clutch upgrades as appropriate.

To me personally it just makes more sense to do things this way due to accessibility to head/block for labour, power gains, laws regarding engines swaps (block numbers), being able to put a built head on a bigger block if you need more power later etc.

[stndrd]

the order in which you say to build a motor ends up being a very costly way to build it. i understand where you are coming from but with the way people love to rev to 9000rpm, i would recommend upgrading valve springs/retainers etc when you do your first cam swap because its always better to be safe than sorry. also the majority of valves in modern cars already run 3 angle valve grinds. these days go for a 5 or even 7 angle valve grind and you will make some good power with a good port job and match porting the head with the manifolds.

in regards to your question about bumping up compression ratio, the 0.5 in ratio can be achieved simply by shaving the cylinder head (remember to always check piston to valve clearances) when you go to fit non standard camshafts. also look into the adjustable vct gears instead of 'fixed' adjustable cam gears. this allows you to further shift your power and torque curves when combined with a good aftermarket computer (i recommend using haltech ep3r plug'n'play computer)

[dougie_504]

I agree with your point about the valvetrain, however there are several people that run very mild cam setups without upgrading the valve train. I don't like the idea personally...what I listed is a suggested progressive build.

TBH I would just skip all the 'mild' steps I mentioned. I think if you're opening the head or the block you should just mod it. No point buying OEM replacement internals to me lol. WOTAM.

[Fredoops]

Only reason I ask is because got a friend in the states who can send me some parts for shipping cost only lol

[dougie_504]

Hook me up asap lols

[Fredoops]

Hook me up asap lols

LOL... nah, he just got foreclosed on his car loan.

Got pissed off and took a .45 and shot at the car.... Needless to say, dirty harry won.

And then he took out 1/2 the engine block before the car got towed by the bank.

[jeremydawg]

I'm all for modding engines, but I just believe that you go like this (for power):
1. I/H/E
2. Head build (mild) - mildly aggressive cam shafts/gears + tune
3. Head build (aggressive) - more aggressive shafts, supporting valvetrain, head work, TB/IM + tune
4. Block (mild) - larger displacement + tune
5. Block (aggressive) - high comp pistons, lightweight crank maybe, forged internals a good idea + tune

Flywheel upgrade a fun idea. Clutch upgrades as appropriate.

To me personally it just makes more sense to do things this way due to accessibility to head/block for labour, power gains, laws regarding engines swaps (block numbers), being able to put a built head on a bigger block if you need more power later etc.

Wouldnt it be better to do just one final tune at the end of all your mods? instead of having to do a tune every now and again. Id understand if it was over a long period of time though. Please enlighten me :D

[dougie_504]

Absolutely, but most people aren't prepared to do a bull top/bottom build all at once. They don't have the cash and generally want to get 'a bit more power' rather than go the whole nine yards...then they keep upgrading.

For me I'm in a position like that. Wondering if I should tune now after head build, or do a B20 in case I decide I want one later down the track...

[jeremydawg]

ah i see now. I have a b16 too, i was thinking of building it up but im not going further than i/h/e cause i have other plans now. h22 type s into a dc2...thatll be within the next two years hopefully. Ive thought about b20 but i want something different.
Go b20! If i were you i would

[dougie_504]

Considering it because one day I might want that much power.

But my B16A block has 101,500 genuine KMs on it and is compressing at 215, 210, 215, 220. Super awesome comp.

[jeremydawg]

oh damn! maybe wait a couple years then lol