SDodd993

So... I bought an 04 civic SI a few weeks ago and the questions are mounting... I've done a lot of reading but to no avail. its certainly a good car that has a nice ride, good mileage, but is just depressing when I floor it. it actually pulls hardest between 2500 and 4K rpms which very unusual to me and needs to be addressed.

First and foremost. I have read that this model runs the k20a3... is this correct? if not how can I find out what I am running? what tell tale signs are there on the actual engine.

Second. if that is the correct engine, can I run stage 1 cam? I've only read about stage 1 cams for the d series engines.

And third. I have read that the a3 is the worst of the k series due to a poorly flowing head. so is a head swap feasible? say to an a2 head or something better?

Well those are my main concerns... just some side thoughts/ questions
WHERE'S THE V-TECH!? haha... I always thought that v-tech was the pride of the Honda community but I have had no such experience. with all the times I've heard "when that v-tech kicks in" I thought I would notice it... but like I stated earlier the car pulls hardest between 2500 and 4k rpm, I don't even send it up past 5k if im really trying to accelerate for that reason. I think my v-tech is broken haha. so when is it that this v-tech is suppose to kick in?

Some other things Im planning for in addition to a stage 1 cam and possible head swap; a nice set of wheels and coils, header and down pipe to compliment the cam in addition with my intake, and an upgraded clutch and light weight flywheel. all that should make for a great driving experience, and learning experience as I have never installed a cam or have done a head swap. I will be documenting the process of my build as I go so a build thread will arise soon.

Thanks to all that actually read this. any help or input will be much appreciated. links to threads I may have missed regarding this info will be a great help. thank you

Poopies

iTrader: (4)

1.) Yes, it's a K20A3. Should also be visible on the front of the engine block somewhere. On the D17 it is to the left of the header. http://en.wikipedia.org/wiki/Honda_K_engine#K20A3
2.) No, Crower doesn't make one for the Si. You would need two anyway, what with the DOHC and all...
3.) I have no clue.. search around!

It doesn't exist. VTEC, on the other hand...
http://en.wikipedia.org/wiki/Honda_K_engine#K20A3

ezone

If you want a great driving experience, fix the base problem before trying to do anything else.
If it won't pull hard above 4k, that's a huge problem on that engine.
If you floor it it should pull hard all the way to redline.


Check engine light on?

SDodd993

no check engine light, engine should be in great condition, only 130k, maintenance kept up, no reported problems. but ill bring it back to the dealer and tell him about it... the power curve just dies off very quick. its not like it cuts off or anything. I gatta check out a dyno sheet to see if the power curve is consistent to what im feeling.

no cam is a bummer... the mazda 3 also has a DOHC and that has a few performance options for just the intake cam with great results. I wonder why this engine is different.

are there any k20a3 build threads out there? I need ideas of something to do to this engine that has been tried and tested with positive results. whenever I search all I get are threads about what you need to know, not what has been done and all regarding engines I don't have or ever typed into the search function... its irritating... I guess ill just have to contact companies directly. it all seems to be very kept information.

ezone

Should. ... You might not believe how quickly some people can ruin your theory.
Except for your reported problem?
A good one will pull hard all the way to redline.
No sense dumping money in go faster parts until this is fixed.

Floormats wedged under the gas pedal?
When you floor the gas pedal, does the throttle open all the way?
Exhaust restriction?

SDodd993

not exactly a theory, only 130k miles, all serviced by the same dealer at required intervals... oil changes have been kept up regularly.

car fax and vehicle history reports have nothing bad to say... I don't necessarily have a problem to report. just trying figure out this engine.

had it checked out, good compression in all four cylinders... apparently my engine is very healthy. I guess i'm just not use to the little 2.0. I just find it peculiar how it can chirp 3rd with what? maybe 120 whp? while the 185whp 2.3L I had hardly broke traction in 2nd.

ill pop off the intake to check the throttle plate... make sure it fully opens, probably clean the whole tb real well and MAF sensor if I can figure out how to remove them (looked like it might have had a special bit for the MAF)... ill also try to clean the vtec solenoid (hope i got that right), but other than that I don't know where a problem could be.

ezone

Ok but what's the problem?


A good report is worthless.
At least with a bad report you know something somewhere happened to it.

What's "good"? My compression gauge doesn't have that on it.

Weight, a tight clutch, and traction coefficient all combine to make tires chirp. Not a great indicator of performance.


See spec list below


I'd just have someone floor the gas pedal, then pull on the exposed cable by hand to see if it isn't tight. If the gas pedal is holding the throttle wide open, you won't be able to pull the throttle open any further by hand.

It doesn't use a MAF sensor. WTF are you looking at?

If there's a real problem there, there should be codes related to it.

Got codes? I know you said the CEL isn't on but see if there are codes anyway.

Backpressure test
Intake restriction checks

Professional help.



K20A3

• Found In
  • 2002-2006 RSX Base model
  • 2002-2005 Civic Si
  • 2002-2005 Civic Type S (UKDM)
    • Displacement: 1,998 cc (121.9 cu in)
    • Compression: 9.8:1
    • Power: 160 hp (120 kW) @ 6500 rpm (SAE net J1349 Rev 8/04)
    • Torque: 141 lb%u00B7ft (191 N%u00B7m)* (191 N%u00B7m) @ 5000 rpm (SAE net J1349 Rev 8/04) for Base RSX, 132 lb ft from 02-05 Civic Si/Type S.
    • Redline: 6800 rpm
    • i-VTEC Engagement Window: 2200 rpm
    • VTC Timing Shift: 4700 rpm

oqjoi

have an 02 Si. For being the shot end of k series, it sure does better that a lot of other cars....

There is no drop in power. I can feel a definite gain in power around 3.5k around 2.2 is the lower end, when i shift like just cruising i end up there. When hauling butt, i shift around 5k and run it. Sounds to me like your vtec is fuvked up. It should be i-vtec, which means it's always adjusting, hence there's no hard pull so to speak.It sounds to me like you were lied to. Mine has 160k miles on it.

SDodd993

there seems to be some confusion so let me clear that up. there is no "drop" in power, I only stated it pulls hardest from about 2500rpm (vtec engagement which now makes sense) to about 4K... and its actually quite impressive. it still accelerates all the way to red line just decreases that "in your seat" feeling. I do notice the vtc shift though which adds some pep. I just want to find a way to open up the top end a bit cause well... it is annoyingly slow. but not by throwing loud, huge piping all around it that will kill the torque.

what about? the affect of the vtec? most likely... people by me would hype up the dirt on the ground. but about it actually being messed up, I think there would be a much more significant indication of such.

haha. dealer just said compression was within spec... took it to a personal mechanic and he literally said the same thing. i was at a buddies shop and he offered to do one just for the heck of it and his response was "looking good" he too is a certified mechanic. i guess i should have asked what that meant. im guessing compression ratio?? meaning im at or close to 9.8:1??

thank you for that suggestion. still use to the stupid electronic throttles.

what? how does it measure the incoming air? i could have swore i saw what looked like a MAF sensor attached to the tb.

anyways i appreciate the inputs. iv gotten the ok from two different mechanics so im not worried about the actual health of the engine. one of them even said any problems were all in my head as i kept asking him to check things. (i do get paranoid when it comes to my vehicle) so now its on to personalizing it... wheels are up first, coils will follow. and i think iv read that many of the parts from the rsx engine will bolt on directly to mine so i will find out as much as i can about that.

ezone

That must have been the MAP sensor.

Look up the definition of "speed density" fuel injection.

A compression tester gives a reading in pounds per square inch of pressure (PSI). You can't really determine a static compression ratio by that, but one can guess.
I'd expect a minimum of 180 PSI, and depending on the engine maybe upwards of 220ish.... when I use my own equipment and methods. There are some other external factors that can influence the readings too.

But if everyone agrees it's ok, then it's probably ok.

When the VTEC kicks on it should give a slight increase in power along with a change in engine sound, but it's certainly nothing like a turbo or anything.

I'm gonna suggest you find someone with an identical car to test drive for comparison, maybe even swap cars so the other person may be able to notice if yours is 'off a bit'.
Or have someone intimately familiar with the cars give yours a test drive and an opinion.


HTH