ka26e/ka26de omg has anyone else seen this?

[Bigvinnie]

What is the average cost to get the KA crank knifeedged and how much of a higher RPM will it allow?

Depends on the shop and how ANAL they are. I've seen shops charge from $300~$800.Or you can do an alternative and use a crank scraper $50.Crank scrapers are not knife edging though there is a big difference. Knife edging actually drops weight from the crank. Reducing the weight will increase HP and decrease windage, and pressure. A scraper just reduces windage. People have claimed depending on the weight dropped from the crank upto a 8~12HP gain, and a significant increase in acceleration as well as a smoother power band.depends on the shop and how much weight they chose to drop from the crank. Some shops can drop 3LB.s, and some shops get risky to drop almost 10LB's. Personally I wouldn't recomend dropping to much weight because it can weaken the actual forge of the crank.

[TrueSlide]

A crank scraper only reduces windage, so the pressure is still there.

Goal right now is a bottom end that will support a 8k redline. A lighter crank sounds tempting but of course not too lite.

[TrueSlide]

If anyone else wants to read about the crank scrapers here is a good link:

http://www.crank-scrapers.com/

amazing to find out how old this technology really is and how much it can actually help.

Anyone have experience with these?

[Reno]

stfu im sexy!

[Bigvinnie]

If anyone else wants to read about the crank scrapers here is a good link:

http://www.crank-scrapers.com/

amazing to find out how old this technology really is and how much it can actually help.

Anyone have experience with these?

It's really not that bad. Looking at those results for the 2.4 litre dodge it made 3hp 6000RPM.So since the KA makes peak power at almost 6000RPM it will make almost 3 HP and almost a good 4LB.S of torque. For $50 that sounds like a pretty good deal.It's amazing what a piece of metal can do....

[deviousKA]

2.5l would not be good for turbo, at least not at that bore diameter.

Crankshaft knife-edging is overrated. This knife edging process alone is not going to allow for any major changes in harmonic properties of the assembly, its going to have problems at same level as stock crank weight (and possibly a bit sooner) not going to "rev higher" maybe quicker, but not much. Consider this engine at 96mm stroke is using no balancing shafts, and very heavy rod/piston.

The crank scrapers are great, I have two of the IJ scrapers for L/Z series. Imho, go with semi-stock weight crankshafts cleaned up and properly prepped, reduced windage and extra baffling via scrapers and custom low sump gated pan (or dry sump). Concentrate on the little things that are commongly looked over like oil pump/timing system drag and crankshaft oiling passages.

[Bigvinnie]

2.5l would not be good for turbo, at least not at that bore diameter.

91.1 mm piston isn't that good, but you must admit that being at 90mm(.040 bore) is pretty decent for the KA. It doesn't effect coolant passages, the cylinder walls are still thick, it is just right for that slight bump in compression. especially if there are aftermarket piston's for an 8.5:1CR.IMO perfect for boosting, and a little under 2.5L...........The 8.5:1 are offered by wiseco, and Super Tech in .020 and .040 over......................

[Ajax]

Question:If my block is bored .050" over (90.375mm?), is my final displacement 2482cc? Just trying to check my math here.

[Chezedik]

compression ratio raised from 8.6:1 to 10.5:1

Pistons i used are .060" taller than ka24 pistons (34mm).

This was with sohc head, this would not work in dohc pistons would hit chambers.

How is this, I have seen engine kits for the DOHC available in 1.5mm oversize, which is almost .060", how can .010" on either side of the piston make that kind of difference?

[deviousKA]

The pistons are 2mm taller than the ka, and come .060" above the deck surface, I wasnt clear in that qoute.

This with a machined edge for clearance is essentially dome volume if compared to a 34mm flat top. The increase in bore does help raise the ratio, but the main factor is increase in piston dome volume.

My ratio is actually closer to 10.7:1 but since I have mentioned 10.5 earlier, I just say 10.5.

The pistons would hit ka24de chambers because the headgasket is only .045" thick, these come .060" above the deck and are only marginally clearanced for a 90.2mm bore headgasket (open chamber sohc).

[Chezedik]

You NA guys are good, damn good. But the prob is that power doesn't reflect that.

[InsanityInc]

You NA guys are good, damn good. But the prob is that power doesn't reflect that.

Uh. You do realize that these high end NA KAs are making more power than a stock (or even mildly modified) SR20 or KAT, right? Plus, apparently you're forgetting that they're doing mainly road racing, where 300hp NA > 400hp turbo. Big turbos and high boost may look great on a dyno or at a drag strip, but real racing is a whole other story. Smooth power delivery is the name of the game there, and turbos don't give you that.

[Chezedik]

No, I wasn't trying to be insulting, I was genuinely impressed. I understand that they are road racing. I also understand why they are N/A. I was just suggesting that it was injust that they can work so much harder to understand and modify their motors and not get the numbers.

[SimpleEnigma]

So, lemme get this straight...increasing the cylinder bore will also increase the motor's compression ratio?

If that is so, what would the compression ratio be if I were to do a .040" overbore on the DE block and drop in a set of matching oversized E pistons?

Instead of developing a stroker kit for a motor whose stroke is already very long, i think time may have been better spent developing a fully counterweighted crankshaft or a true aftermarket intake manifold, not just a modified stock one; or better yet, a bolt-on ITB Kit, or supercharger kit (someone call up Paxton and complain). :-)

[Chezedik]

It affects dynamic compression. That is to say, it does not change the ratio itself, but it does increase combustion chamber pressure. The compression ratio would be 11.7:1 but the combustion chamber pressure would be higher than that, probably in the 230-240psi range. Big power, if you can keep it from pinging.

[SimpleEnigma]

So i would have to retard the timing a bit, say to something like 15 deg before TDC or else keep factory timing and go to race gas? They have 93 octane fuel here, and that in combination with good tune....perhaps you would be able to get away with the 11.7:1 compression?

Sorry to threadjack BTW.

[Chezedik]

Oh yeah, if you adjust timing you would be good. There was a guy here in town that had them in, plus he had squeeze. With the juice it was supposed to have made 200whp.

[Chezedik]

Of course, the NOS was just for track day, since all we have is 91.

[InsanityInc]

So, lemme get this straight...increasing the cylinder bore will also increase the motor's compression ratio?

Yes. Your STATIC compression ratio is increased by boring an engine. That's because compression ratio is the mathematical expression of the cylinder volume at BDC to the volume at TDC. Your cylinder volume at BDC is the volume of your combustion chamber (I'll call it CCVol for short), plus Pi*(bore/2)*Stroke, so CCVol+Pi*((bore/2)^2)*Stroke. When you're at TDC, your volume is just CCVol, so obviously if you increase Stroke or Bore, your compression ratio also goes up, as the equation for compression ratio would be:

(CCVol+Pi*((bore/2)^2)*Stroke)/CCVol

Quote »If that is so, what would the compression ratio be if I were to do a .040" overbore on the DE block and drop in a set of matching oversized E pistons?[/quote]Higher than you would ever want unless you piss race gas.

[LasVegas240sx]

Ok, if you guys want some real power I've got the stroker kit

http://www.todaracing.com/prod....html This is SIIICCCCKKKK I don't think I've seen anything like this before.

This could probably make 500 on the SR. (By the way, I know this is a KA forum)

[whitekoop]

hey I have a ka24e and I rebuilt it bored it .040 over and the crank .010 what would my compression be also how much of a jump in HP is that if any??? lol

[liquid_cool]

i know alot of people choose the fast turbo aplication for a qwick power adder to be cool..and that SR's are so popular..but one has to concider the style of driving they will be doing before building there power plant...the stroker kit mentiond is desighned for a target HP range within a certian RPM range...it responce that this kit is made for/and quikness out of corners..perfect for togue or autocross/road..not so good for the freeway battle or Autobahn style race ..lets face it,,,the ka has a nasty weekness in its limited rpm range..but it allso has a stregth...torque!...its best to reaserch your target HP goals..find the style or styles of racing you like and build to that profile..and remeber.."sometimes slowing down,makes you go faster"