Hey california guy thinking of building a...

[classiccelica]

Hey there I am thinking of building a k24a4 with forged pistons, forged connecting rods, micro polished crank, with ARP everything. How high do you think I could rev it, just curious. I know you don't need to rev the k24's high but I am just wondering.

[Kodeen]

From everything I've heard, 8k would be the maximum you would want to take it. After that the piston travel becomes a bit unstable. You might want to rev it even lower.

[b.r.i.a.n.]

yeah you've got to understand that the stock k24 stroke is 99mm compared to the k20's 86mm stroke. the long stroke is great for torque but as far as spinning it high, you've got to take into consideration the piston speeds at 8k+ rpms.

but remember this

torque x rpm = hp

the k20 lacks torque but with the ability to make power at such high rpm is where the hp out of such small displacement comes. the k24 will make the same power much earlier due to the stroke.

as far as how high you can rev a k24 with aftermarket rotating assembly minus the crank, i'd say 8k is enough.

[ALep3]

Ok i'm going to thread jack real quick, what about a stock k24a4 bottom end with a built head,springs, retainers, cams.... how high should I rev that?

[Kodeen]

The head isn't what's creating the limitation, so probably 8k.

[talonXracer]

I wouldnt spin a K24A4 to 8k,,,that is a very easy way to snap a rod,,,those spindly things are not very strong. You can also spin a rod bearing, as the smallish stock rod bolts will stretch and allow the rod big end to open a bitand allow the bearings to spin 7200-7500 rpms max

[b.r.i.a.n.]

Ok i'm going to thread jack real quick, what about a stock k24a4 bottom end with a built head,springs, retainers, cams.... how high should I rev that?

well the head will be able to handle the high rpm. but the stock bottom end will hold you back.

stick to the oem redline on the k24a2 which is about 7200 rpms. and that's that the k24a2 comes with some slightly beefier rods.

[Deadphishy]

I must be a sissy.

I have a built bottom end in my k24 and i cringe when she spins up over 7k. Rev limit right now is set to 7300.

[ALep3]

Ok i'll stay on the safe side 7200 sounds fine, thanks everyone.

[Deadphishy]

Ok i'll stay on the safe side 7200 sounds fine, thanks everyone.

Your motor will thank you.

Now that you know your no going to be spinning super high, you can pick a slightly smaller exhaust to gain mid-range and low end. A lot of people think the higher it flows the better it is. That might be true if your only looking at peak HP, but in overall performance that isn't the case.

[wishbear]

my k24a2 build i set it at 9500
k24a1 block 9-1 piston with h rods and a2 head

[MOOGEN]

J, your crazy kid! reving high isn't always the best.

[ALL MotoR Ep3]

for a k24a4 I wouldnt rev pass 7500 rpm........but on a built k24 with a k20 my tuner had set my rev limiter to 9500...but i never revd that high maybe to 9300 once or twice but i usually rev to 8700 then shift...