Making a rev happy KA!!!

[Chingon]

Well, how hard is it, what would be involved?

I assume you'd at least need lighter-higher compression pistons, lighter valves, lighter rods, lighter flywheel, lighter shaft, more aggressive cams, etc...

Is it possible w/o destroking/shaving head/block?

Say, a safe 8-9k rpm redline?

[yozsi]

you would want stonger valve springs too.

[[s3]]

can you say kaboom?

[sxseguy]

When asked about high-revving KA motors, most people usually say, "It can't be done." Well, it can, it's just expensive. Take a look here, and then start searching around on your own. Make note that probably the most important part of these motors is the guys that know how to build them. The machine work is very important.

[[s3]]

$6800 to prove a point

Its nice to be rich

[Chingon]

haha, you're right..yeah I thought about stronger springs as well, but wasn't sure if the technical term was "springs" so I didn't want to sound noobish... By the way, you mean stiffer "rebound" power I supposed by strong?

[yozsi]

you definitely dont want valve floatation at 9k.

[EnzoRWD]

well i dont know much about making a ka rev to 9k, but ud pulleys and light flywheel will make it rev faster, not higher. thats good enough for me.-Enzo

[Chingon]

well, you are may be right enzo.

Another question, the ka doesn't really lack in the rev department (s13) that is. I mean, a 7000 redline is not too bad, however, does the ka like high revs? Compared to say the ca?

[chmercer]

the first time you said ka, did you mean sr?

[lessthanjakejohn]

IBitsnotworthit

[C-Kwik]

you definitely dont want valve floatation at 9k.

You don't want valve float at any RPM for that matter...

[chmercer]

IBitsnotworthit

:/ i was just trying to make sure, not trying to be a post correcting spellin/grammar *****.

also wth does IB mean?

[lessthanjakejohn]

I believe it's not worth it.

Simple matter of fact that you could build a killer turbo KA for the money it would take for such little (if any) gain.

[lessthanjakejohn]

but not getting into the whole NA vs. supercharger, you could do better things with your money first and the engine would definately need to be restroked. You may be able to get to 9k, but its not going to happily go there, especially with its stock stroke and rods.

[Chingon]

the first time you said ka, did you mean sr?

??

[JustinStrife]

I don't see much point in making the KA be a high revving motor when that's not where it's power band is anyway.

If you want Rev's, just get a CA man.

[p00t]

i can see the practicallity under a decently boosted KA-T. But under low boost or NA its pointless. KA has serious breathing issues at those higher rpms. To make effective use of a high reving KA you would need major valve work not just springs, extremely agressive cams (3k idle anyone :rolleyes), balanced crank and rods, a custom shortened intake manifold (shorter runners), ported as much as possible and after all this you would lose all your low end power. So what your doing in effect is creating a horribly small powerband probably 5-7k, when boosted the stock 3-6.5k band is wayyyy better. im not saying no to cams and stuff but go get a ca, sr, or rb if you want revs, they were designed with different power band behaviors in mind (which is what really matters, not how far you can bury the needle).

i dont understand why people need to rev high, rpm isnt directly linked to how much power you make, so many more factors need to be taken into account. Look at a KA dyno chart and take a cold hard look at what you are fighting! In the upper rev range 6300+ the torque drops fast because the engine is starved for air. Shifting the power band to the right more is fine, but you reach a point of diminishing returns and sacrafice the actuall usability of the car, have fun doing nothing but drag and high end track use.

You want to rev to 8 grand? Fine, but you better be able to accept the fact that you will be making 15 hp at 8k rpm, be down about $6000, and going nowhere fast.

[JustinStrife]

I couldn't say it that good if my life depended on it...

[p00t]

ty, also being an insomniac helps -> 3am on the east coast :oface

theres probably even more info out there since 1/10 of all the posts in the KA section are about this subject...ugh

[JustinStrife]

ya i've seen that.

My problem is i'm torn on what I expect performance wise out of an engine, beyond just hp and torque

I don't know if i want a car that makes it's power lower or higher on the rpm range.

At first I thought I wanted an RB25. Then a CA18.. Then a KAT. Now I'm thinking SR20.

I haven't had the money to do any of them, and i've spent the last year reading and reading about their strengths and weaknesses... I don't feel like I'm any closer to realizing what I want either.

Ain't life a beatch?

But buffing up a KA's RPM range isn't one of them

[C-Kwik]

I couldn't say it that good if my life depended on it...

It should be: "I couldn't say it that well if my life depended on it... "

Who learned you to spoke? :pface

On a more serious note though, If you can move the power band higher and get a motor to rev higher, you can take advantage of gearing and put more torque to the wheels. And for a street car, if you lower the final gearing to put the higher redline shift points at the same road speeds, you may end up with a significantly faster car. VTEC Hondas, despite their 8000-9000 RPM redlines still shift out of first about just above 30 and out of second just past 60. Very few cars have the kind of broad torque band and high enough output to do 0-60 effectively in 1st gear. But if you can build a car that can do this well, the pay off is one less shift. I think at least one Lambroghini can do this. I believe there is at least one Porsche(may not be a US Spec) that can do this as well. The Jun Silvia kept 1st gear through 70 mph IIRC. The two production cars I believe had sub 4 second 0-60's. Though, they may both be AWD as well.

[JustinStrife]

Actually Mr. English Professor, either way is acceptable.

Just depends on how "proper" it has to be.

[Chingon]

haha, so scrap that idea then. I'm just learning on how, and seeing the pros and cons. I would never do it, but it's always good to be informed.

so what's the redline on the ca, sr, or rb?

I mean, the 7k rpm redline on the ka is not the best, but is far from being the worst. Is it only that it doesn't produce much power up top like the other engines what categorizes it as low-reving?

[s86d]

ever wonder why diesels practically last forever? (under decent maitnance) low reving the slower the safer. but i like sr so dont cut my throat just yet.

[Jonny 290]

friction goes up as the cube of RPM.

engine life at lower revs gets exponentially better. reference those 5500 redline big blocks with 300k between rebuilds. also reference diesels, as mentioned above.

[JustinStrife]

From what I've heard.. RB's go to 8k redline.

SR's do 7500, and CA does 8k. But the CA can go up to 9k with the right parts...

I bet diesel engines in general are built like tanks. Near indestructible.

Kinda like an RB

[APEXi240]

I know a guy with a 00 golf TDI with 149k on it. How he put all those miles on it, I don't know. The redline on that thing is like 4500 or something like that?