Higher Redline?

[Perfectd3]

Is there anyway to run the KA24DE to a higher redline if I boost it? How would I go about raising the RPMs?

[UnderPressure]

valves, valve springs,. valve spring retainers, cams, ecu, valve job, ign sys., but theres really no point, you wont make much more power. . . .

[I am Technoman]

Why would you use a KA for high revs? Nissan made a motor called an "SR20DET" its perfect for high reving...

[SSDwellah]

Or better yet, how about the CA18DET. It was designed for high rev. The SR20DE's valvetrain is actually not optimal for high revolutions.

[I am Technoman]

True! When I worked for a Nissan dealer I did a few warranty jobs on the sr20de rocker arms. They used to fly off!

[Perfectd3]

Thanks y'all! one more question tho... Can the higher revving CA18DET make as much power as the SR20DET with similiar mods made? I come from the Honda camp and am having a hard time getting used to the smaller revs.

[Exar-Kun]

heres the breakdown, as I see it:KA=SMOOOOOOOTH torque band, but problems when you reach 350hp or more, as far as mods that "bolt on" go.Sr20DET: higher revving, less low end torque, a WORLD of 400+hp and serious HP products availableCA18DET: even higher revvs, getting hp over 300 sometimes difficult due to smaller displacement, and less aftermarket support than the sr20.

hope that helps.-chet

[WDRacing]

Hmm...In my world we love a thing called torque. Neither the SR or the tiny CA produce either.

The SR does not have a ton of bolt ons that will take you over 400HP. That takes alot of time and money.

The CA isn't worth building in my book.

Then there is godz gift to torque...the KA24DE. The problems with any stroker motor are lack of rpm band. Fortunatly for us, the guys at Nissan didn't build the motor to if fullest potential. A turbo cures the lack of top end pull. So you have low end torque and top end grunt...basically a Honda's dream.

But you want higher revs(which by the way, if built right WILL make more power) to compete with the SR series. So you pull the crank and have it balanced, shotpeened and knife edged. While your in the block you change the rods and pistons. You now have an engine that rev's to 8000 RPM. With a ton of torque and all the topend you'll ever need.

WD

[george]

sorry to rain on your parade WDracing but the stock crank wont spin past 7200rpm it ends up cracking the block, negative harmonics. i had a custom crank constructed for my KA and destroked the motor to 2.2 liter to run anywhere near 8000rpm. this "pull the crank and shot peen and balance crap wont work. sorry

[george]

the crank on the KA is the weak link of the engine just like the head is for the SR. if it was that easy to balance the crank on a KA and spin it too 800rpm then nobody i mean nobody would buy an sr20. cuz the KA would be the ultimate motor.

[george]

also the CA is one hell of a motor for the reason that you can spin that mother AND it has an iron block. what a great kickass motor

[WDRacing]

I'm just not a fan of anything smaller the 2liter's. But thats just a personal preference. As far as cracking the block goes, has anyone tried to go with 4 bolt mains? That might could help quite a bit. How many people do you know who have had the crank lightened and balanced professionally then cracked there block? Not that i'm doubting it happens, I'd just like to know how many try.

[SSDwellah]

I'm just not a fan of anything smaller the 2liter's. But thats just a personal preference. As far as cracking the block goes, has anyone tried to go with 4 bolt mains? That might could help quite a bit. How many people do you know who have had the crank lightened and balanced professionally then cracked there block? Not that i'm doubting it happens, I'd just like to know how many try.

Well if I spent all that time and money I wouldn't try to spin that engine at 8000RPM... that's pretty steep considering the stock redline. The problem is that the stroke and displacement make for a very rough, unbalanced rotation. Reciprocating mass needs to be lightened but then you'd suffer from problems with momentum (the engine would rev higher and faster but also stop revving faster even under a lighter load).

[Exar-Kun]

yeah, I know that you could, supposeing the valvtrain would support it, run 8k rpms out of a KA24DE, sunbelt engines can build one reliably to handle it, it just costs a LOT of money.

and george, not to be a *****, but instead of posting like 3-5 times whenever you think of a new line, you can EDIT your last post, so it doesnt take up that much space, unless your just post whoring.

-chet

[george]

sorry man i didnt know i could edit i will do that in the future

[Exar-Kun]

no problem learn something new every day -chet

[UnderPressure]

good point with all the bottom end part but. . . if you dont upgrade the valves, springs, retainers, cams, then you will def. have whats called valve float, where the valves cant open and close as fast as the RPMS so they "float" and stay about half open. thats bad! alot of damage.

and without the ECU, you wont be able to get past the factory redline

[gyfer]

Originally posted by SSDwellah "]" Well if I spent all that time and money I wouldn't try to spin that engine at 8000RPM... that's pretty steep considering the stock redline. The problem is that the stroke and displacement make for a very rough, unbalanced rotation. Reciprocating mass needs to be lightened but then you'd suffer from problems with momentum (the engine would rev higher and faster but also stop revving faster even under a lighter load). ''

:squint

If I spent the money, I will rev 9000rpm. You gotta love high-rev, if possible mid-torque too....

[big jon's 240]

First off, the valvetrain would be the least of your worries if your were trying to up your redline. The valve train could hanle 8 or 9 g's without to much work, its the stroke that would kill you. The KA24 has a pretty long stroke (everybody likes a long stroke ) But getting up to that many revs wouldnt really be that much fun, youd be out of the engines power curve. Engine / head flow were not designed for high rev power. Why is everyone so bent on getting a higher redline? Power is power no matter what RPM you get it at, 3500 or 7500.If you really must take the needle that high, get an SR.

[I am Technoman]

Yea I dont understand why every one wants high revs 7,200rpms is perfect for the KA.. Do you guys think your going to make that much more power at 8k? verses 7,200?

[gyfer]

Indeed... yes !

HP = RPM x Torque / 5252With same torque, higher the RPM goes, more HP you get.

Power is not just power. In different RPM, you get different torque and hp. Plus, with your gear ratio, and tires configuration ( traction and size ), that determine how many power you put on the ground.

3500 and 7500 is WAY TOO MUCH different.

Still not convince ?

Honda S2000 : Weight : 2800lbs Torque : 153 lbs @7500rpmHP: 240 @8300rpm

240SX 24DE ( Dual-Cam) BIGGER DisplacementWeight : 2750lbsTorque : 160 @4400HP : 155 @5600.

Clearly it explain all.

[WDRacing]

First off, the valvetrain would be the least of your worries if your were trying to up your redline. The valve train could hanle 8 or 9 g's without to much work, its the stroke that would kill you. The KA24 has a pretty long stroke (everybody likes a long stroke ) But getting up to that many revs wouldnt really be that much fun, youd be out of the engines power curve. Engine / head flow were not designed for high rev power. Why is everyone so bent on getting a higher redline? Power is power no matter what RPM you get it at, 3500 or 7500.If you really must take the needle that high, get an SR.

I understand what your saying about the stroke and the valve train. I also understand about the head design as far as forced induction goes.

Thats why you have the head built for high boost. The stroke can be hurdled by reducing the crank weight and balancing everything. If your worried about your rpms dropping do to crank reduction just add a heavier flywheel.

Power is not power, if your power band is between 3500 and 7200 and mine is between 3500 and 8000...You'll lose.

When I get back to the states I'm going to build a high rev, high boost KADET. Just to prove it can be done. I hate SR's...

WD

[george]

a high rev high boost KA can be done and has been done. anything can be done with a lot of money but some things are just not worth doing. like a high reving KA.

[gyfer]

WDRacing, when you going to be here in US ? Remember to bring some real goody from Japan :-)

Can you find me a Spec A 4A-GE Redtop 20valve ?? woooo... 240hp in 1.6L

[WDRacing]

WDRacing, when you going to be here in US ? Remember to bring some real goody from Japan :-)

Can you find me a Spec A 4A-GE Redtop 20valve ?? woooo... 240hp in 1.6L

LoL....not to many of those just lying around. I'll be back next dec.

George, the only reson I want to build a higher revving KADET is because I'm to used to driving Skylines. 8500 on stock internals is just fun.

I'll be doing so much work to the block and internals anyway, I might as well have everything I want. I'm not worried about cash. They pay me decent money and I don't have bills. I've been in Asia for 6 damn years already. I'm ready to come home and dump money into a race car.

WD

[george]

WD racing, if you want the ultimate KA call AEBS in San Diego CA, they built my KA. custom crank, destroked motor, titanium rods to reduce weight of rotating assembly, extensive valve job, and crazy engine management. turbo and nitrous and some sky high revs just the way you want somewhere to the tune of 700bhp. just dont expect it to be too reliable.

[WDRacing]

Do they have a website? If I wanted reliable I'd buy a Honda. This car isn't going to be my DD. It'll be used mostly at the track and a little on the street.

WD

[gyfer]

" ...If I wanted reliable I'd buy a Honda..." :squint

Toyota man. 4A-GE, 2JZ-GTE, 3S-GTE, 7S-GTE... so many to choose.. why a Honda ??

[big jon's 240]

Higher revs do not neccessarily mean higher hp, yes HP=rpm x tq / 5252, but there really is more to factor in than that simple equation. If it were that simple every car around would have an 8000 rpm redline. The torque/hp curve on a KA24 starts to drop after about 6500 rpm. Changing the redline is not going to change this, it is inherent in the engine design. Now im sure it could be changed, but its probably not worth the time and $$$. And i understand that gear ratios also come into play, buy outside of 1st and 2nd gear its probably not enough to make a huge differece. (thats a guess, i have no idea what the gear ratios are in the 240)But go ahead and try, i wish you luck.

Oh, i almost forgot, if your power band was between 3500 and 8000, and mine was between 3500 and 7500, i will still win because i am the better driver!:D

[I am Technoman]

WD your just spoiled on RB20 motors a ka is a good motor but it is not an RB.