Ideal KA24DE Fully Built Engine??

[deviousKA]

the timing curve would not be optimal with the tps, o2, maf and other signals not going to the ecu. It would be much easier to just convert to vacuum advance distributor which is made for carb setup. An l20b distributor will work, you just need a z24i distributor shaft, and modify the distributor mount a tad. The fuel pump is powered by ecu but has its own pressure shutoff internally, as well as the fuel rail regulator. It is designed to put out 40+psi vs. the 4-5psi you need for a carb setup. There are many different pump setups you could use for this.

btw. ka24de 240sx vacuum advance dist. would need to be custom made using various datsun/nissan parts, it has been done many times before.

[C-Kwik]

Why go with a carb when you have a perfectly good FI system? I mean, side drafts aren't good because they use carbs. They are good because of the ITB's and short stack runners. You can build an ITB system with short runners to use FI. And this would be a whole lot better for tunability and consistency. It would be easier to keep running well under a variety of condittions as well. Carbs don't adjust to changes in weather. You have to constantly tune it for the conditions you drive in.

And before someone tries to interject that carbs are used on the GT3 KA's, they are used because the rules require them to.

[deviousKA]

Why go with a carb when you have a perfectly good FI system? I mean, side drafts aren't good because they use carbs. They are good because of the ITB's and short stack runners. You can build an ITB system with short runners to use FI. And this would be a whole lot better for tunability and consistency. It would be easier to keep running well under a variety of condittions as well. Carbs don't adjust to changes in weather. You have to constantly tune it for the conditions you drive in.

And before someone tries to interject that carbs are used on the GT3 KA's, they are used because the rules require them to.

Yeah, but raging panda asked about a carb setup on ka, not an opinion.

btw. most 220+hp naturally aspirated ka setups i know of (non-nasport) are using sidedraft weber dcoe or mikuni carbs, and run very well in a variety of conditions. So i would say they are a viable option when it comes to high hp n/a ka24.

[raging panda]

If you had all that stuff off, wouldn't the timing be set at a base setting because there is nothing telling it to adjust? Then it would just be a matter of setting your timing? Would there be an issue with advancing the timing then?

And yes, the FI is always better, but I'm sure carbs are a cheaper way of achieving 200+ N/A hp. The ITBs would require either tricking the ecu somehow (no one has figured that out yet) or switching to MAP which would cost some major money, unless theres something im missing here. I really want ITBs, but I can't get that unless I drop some major money.

[C-Kwik]

Carbs alone are not going to give you 200+HP. To realistically reach levels along the lines of NASPORT GT3 cars you need to bump up redline. There is only so much you can do with cams and induction tuning alone. Torque can only be increased so much for a given displacement with only the weight of the atmosphere pushing the air into the motor. Given that, you can increase HP by changing where the KA makes it's torque. The problem with the KA is acheiving acceptable harmonics that high up in the RPM band. And I doubt you'll have a KA with HP levels that high that can idle very well under 2000 RPM. The cams would have to be quite aggressive.

[raging panda]

Oh, not GT3 levels, just 200+. I know carbs alone wont do it. I have been following the E+DE head thread and thats where I'm planning to go with this. High comp, carbs, exhaust, cams, little porting, etc.

[C-Kwik]

I am going to assume you are talking about 200+ RWHP. Even if you were to keep the redline stock, you'ld have to move the peak torque point up to a higher RPM. if you are to make 200 RWHP and 6500 RPM, you'ld been 161 lb-ft of torque at that point. So not only do you have to move the torque peak, but you have to significantly increase volumetric efficiency and flow. Particularly in the RPM range where you plan to make that power. In other words all your parts have to work with each other very well. Doing this typically takes some reaseach and testing to achieve. The DOHC KA has litytle support for this. The SOHC KA does have a lot of research done due to it's use in racing. Following the race KA's formulas will help, but I see you have a 93 S13. And the formulas for success the race KA's use make the power up towards 8000 RPM. So it wouldn't necessarily work well for a motor with a lower redline. So you could be back at square one.

I'm all for anyone trying to make more power out of the KA, and I'm not trying to discourage you, but I think it's important that you know what you're getting into.

[Scott McLellan]

Let me start a list of what I would do and reasons:

1) Ram Air- Your car is moving, so why not use it to your advantage? Just please don't waste your $ on a boost gauge;)2)Mass Air mod- Cobra? Of course put a nice intake setup on (would a custom setup on the pass. side w/ battery relocated be better since shorter?)3)Bored tb- more air4)Ported intake- not some kid w/ a dremel. A pro w/ a flowbench and some experience. Porting can decrease power if you don't know what you're doing.5)Ported head- see above6)Race valves- smaller stem and heat coated to reduce det. less weight, better airflow. Possibly oversized slightly7)3 angle valve job- increased flow at low lift8)Perf. springs and titanium retainers- higher revving stability and for bigger cam9)Cams- going radical? expect it not to have any street manners.10)ARP fasteners thruout- increased strength11)Crank- I personally think that factory forged doesn't sound bad so I would stick with that and yes stock stroke. If you are going to rev higher you need all the journal material you've got, right?12)Titanium rods- as strong as steel but lighter for less recip. mass- I found a set that run approx. $2400- yeah or $600 ish for some nice steel ones that weigh a little more13)Forged Pistons w/ total seal rings- I'd say 10.5 for street on pump gas. Lighter weight again reduces recip. mass for higher rpm stability. 14)Header/highflow cat/exhaust- better air flow. maybe get one of those valves so you can have an open exhaust when you want it15)Ignition- MSD/external high output coil/plug wires/iridium plugs16)Grounds- better perf. of all elect. components17)Underdrive pulleys- also has anyone ever done a dry sump or elect. water pump? Might be dumb, though. Maybe remove A/C system and conv. to manual steering18)Cooling system- alluminum rad. so that cooling doesn't take as much draw from alternator for an elect. fan conversion. I'm not sure if you would even want a lower temp thermo. for power?19)Custom crank scaper/louvered oil pan- reduce power robbing windage20)ECM tuning- takes all mods into account21)Lightweight flywheel and driveshaft- less recip. mass22)Synthetic fluids throughout- less friction=more power23)Fuel system- the "right pump", high flow rail, injectors, good filter, and maybe fuel cooler and/or insulate fuel lines24)If your just running a 1/4 mile or for a short time, the "bag of ice" on the intake manifold before the run has been proven to be worth a tenth of a sec. or something like that25)Balance rotating assembly- higher revving engine and smoother everything26)Blueprint- cause it sounds good. No just to make sure everything is in spec and "tight" for precision's reliability factor

Here are a few things I've heard will help:1)Cryro-treat engine and components2)Heat coat pistons on top and coat sides with anti-friction coating(I think it's teflon if I remember right-Speed Pro makes them I think)?3)When boring engine, bore w/ a torque plate and, here is a crazy one to think about, with the engine block @200 degrees F. Yeah, it's been proven that this will make a very small amount of power but hey...

----OR----

Coates Engineering $15,000 Rotary valve setup- hey you said a KA block means it is a KA and this new "cylinder head" will allow you to run 14:1 (or higher-can't remember exact) compression on pump gas, have a 14,000 rpm redline or limited to recip. assembly. If I remember right, a Lincoln V8 engine put out something like 475 hp compared to the stock 220 hp. That's over double, yeah in a 4.6 L engine (I am assuming). Anyways, for 15K they outfit it for your spec. engine and you won't have to spend a dime on cams, valve springs, retainers, porting, valves, ect.

If all else fails, a little laughing gas. Just kidding.

FEEL FREE TO ADD/FIX THIS!

[Scott McLellan]

What would you guess? With "normal engine" w/ above mods like 250 hp? W/ Coates top end and beefed up bottom like 275 hp?

[C-Kwik]

It's not the parts or mods themselves that will get you there. They have to work well together. Most importantly, each mod should stack it's peak torque on or near all the other' modification's peak toque points. This will limit the range where the engine will be usable, but for racing purposes, this is not a big deal since the transmission gears should be matched with a close enough ratio to accomodate this, and the driver should keep the motor in it's powerband at all times. While it's easy enough to through out mods, it's much harder to accomplish them in such a way that they optimize peak power and torque. It requires a very good understanding of flow characteristics of each component and some trial and error.

While the Rotary valves are interesting, I am skeptical still. It does nothing to address the issues of different airflow requirements at different engine speeds. While it may prove to be a viable option providing less frictional losses, it's equivalent to lift and duration is still the same. Sure, a 5.0 L motor made some 480 HP, but what's the rest of the powerband look like? It's not uncommon to see high compression hiigh HP Poppet valve equipped V-8's over 500 HP. They really don't give you any specs on each motor on their site. Frankly, attributing some 200 lb-ft of torque increase to just this is hardly believable.

And as far as 14:1 compression, I doubt it will allow you to magically run that on pump gas. Most of the heating of air and fuel in a combustion chamber comes from compression alone prior to ignition. While it's conceivable that rotary valves can run cooler than poppet valves, I doubt we'll see it to the point where such high compression numbers can be used on pump gas.