UPDATED PICS : Well **** me in the goat ass...
 

Well im oficially going to kill my 240, if its not 100% dead already. Listen to this crock of ****. For the past month or so, my 240 has been running fine, cept timing chain rattle. Pulls strong, doesnt overheat and what not. Well 2 days ago me and 4 of my friends pile into my 240 (yeah we just about doubled the weight limit) and take a ride to a car show... well as i park, theres a storm drain that is almost like a dome, about 6 inches tall, and it scrapes the bottom of my 240... no biggie, just messed with my exhaust hanger and made a dent in the gas tank bout 1 inch by 1 inch by about an 1/8in deep. Looked underneath the front of the car to check the oil pan and radiator for leaks/dents and there were none to be found, and so i drove it for another couple days till today. No coolant leaks in the driveway or anything like that. SO this morning i go to check my schedule at pizza hut (where i deliver) and she runs fine, no sputters, misses or overheating. About an hour later i leave to go to where my dad works so i can pick up some parts to be delivered. Well i stop at the light right before the interstate and she dies. Seemed like a typical 240 low idle/decelerating idle problem... which mine has. So, it took a second to start, which seemed odd to me, and headed to the interstate. She pulled fine and dint die between shifts or anything, but when i took the offramp (which is almost cloverleaf style) i stuck it in neutral, and she died... so i clutch kick it back to life, and when i push the clutch in she dies....so at this point im like wtf.. .look at my gas gauge---fine Temp---Fine, no dummy lights, so i figure that again its low idle crap. Well i make it to the shop, about 3 blocks away, and pop the hood to discover chocolate foam spewing from my pcv valve on my valve cover... joy. And no coolant left... also joy!:tear: now where the hell did my coolant go? well through the oil and out of my valve cover (which isnt hooked to my intake at the moment thank god, cuz the hose is cracked). I just dont understand why my damn headgasket blew so suddenly or if my head is cracked... which i fear, because as i inspected the projectile exorcist style spewing of the choco-foam motor i noticed what looked like boiling moasses somewhere around the no 1 and 2 intake runners where they meet the head....so **** me in the goat ass. First the timing, then other crap, then this? **** on toast. What should i do? tear apart and find out whats wrong with the KA and repair it? Or try to save for an rb20 or ca18 swap and part out what i can on the KA? Mind you this is MY only car...

Oh yeah and for the rest of my story. So i fill up the radiator (probably a stupid move) once the motor is cool enough to touch, hoping to get it home... when it starts to rain.. not just rain, but storm... like a godly act of spite, soaking me and my interior. So i start er up, the tmp gauge reading on the first line from the bottom, thinking itll be okay till i get home (not far away) and i turn onto the next road from the parking lot, only to make it about 100 feet. Shifted first, second, third all at about 2000 rpm, then at about 35-40 mph, she lost all power. So i downshifted, hoping to get it to move a bit further to the gas station about 400 feet up the road, and she just doesnt want to go. So i steer her toward the side of the road, which has no shoulder, just a ditch, and get the front pass. tire stuck in the mud. Great. So i get my friend david, who was riding with me to help me puch it, and its no use. The rain is coming down like ive never been in before. Im soaked... fresh cigarettes, ruined; Motorola Razr, drenched; wallet, soaked; day, ****ed. SO yeah... **** my 240.. kicked the **** out of it a few times and walked away... hoping someone would hit it by accident and have it blow up into a fireball and get it out of my hair...

that sucks. a friend of mine has a similar problem with his 240 and we cant figure out if it a blown head gasket or cracked head. if you take the head out yourself the intake manifold is gonna be a pain to get out, lol. good luck with it tho.

damn that really sucks=((

if i were you id get a used ka but if you dont worry about smog and willing to spend the xtra dough, sr20

bah i dont want an sr... everyone has it and theres a few things about it i cant stand... ca all the way.. or rb

Ill probably end up getting another KA for the time being... sux like hell...

lol i here what your saying...i would go with the CA mrahhhh i just like them for some reason lol.

Sounds like the timing chain ate through the front cover. Very possible since guides were never replaced. Coolant leaks into the oil pan. Idle dies from hydrostatic locking.

...what? can you explain that in a little more detail? so because i didnt fix the lower timing chain, it ate through part of the motor and killed it? How would that explain oil in the radiator when i filled it back up... and wouldnt i have seen some sort of smoke or something in the exhaust?

your supposed to replace the guides?. i thought you just take em out.

youre supposed to replace the lower guides if they are worn out.

Yes. The chain has to much slack and eats through the cover between were the coolant passage is. Allowing water from the coolant passage to run into the oil pan. I bet you if you drain your oil, there will be a shiat load of water in it. I use to get the problem alot more with the napsz 2.4 engines than the ka engines. The naps z engines only used one tensioner and no guides, and were to be replaced every 100,000 miles. Technically in theory people have felt that the KA timing chains would never need replacement due to being dual rowed timing chains, this is false. Guides, tensioners and chains should still be changed at the recomended 100,000miles. If your guides were never changed I know that the tensioners had never been replaced, just shows that it had all been ignored since entire timing assembly should be replaced.
It could also be possible that the head was warped and leaking, but if that was the case you wouldn't get any power, and you wiould see coolant dripping from the head and gasket.
You could fix your ka by replacing the chain assembly and getting a new front cover, although the wear and tear from water on the piston rings probably dropped your compression.

Yep... sounds like what happened to the rings... though if water were to get into the oil, could that water theoretically cause my head to warp?

Okay, BigVin i have a question for you, being the god of the KA. Do you think it would be a rebuildable motor? Or is it shot to hell. Also, if i were to rebuild it, do you think that i should go with lower comp pistons and your basic rebuild-for-turbo parts, like forged rods (not sure if the kas has em stock) and such? Because i WANT a turbo motor, but im wondering if at this point (being broke and all) if it would be in my best interest to rebuild the motor and turbo it when i have the money, or just borrow the money to drop an rb20 or ca18 in there right now?

Well with the way prices in gas are heading these days I would just do high compression. My V6 Nissan Murano gets better gas mileage than my 240sx KA24de 4 banger. My murano has a 10.0:1 CR same as the 350z and gets an estimated 27MPG freeway with it's automatic CVT transmission.
You can clover leaf weld the head by taking it into a reputable head shop and reuse all stock internals(just get new rings, and bearings, and of corse a timing chain kit), or you can get arias pistons in 10.5:1 pistons for under $400 I believe. You can keep the rods stock. if you want to spens like $50 more on some great quality pistons i would get some super tech pistons.
Then all you would need to do is upgrade the injection, you can still use the stock tune and I would use 300cc injectors. thats good to go for 200Crank Horse power without bolt on's.
Turbo charging is getting much to expensive and after market parts are getting more expensive as well.
But to make a long story short your block is rebuildable.

...yeah i guess it IS rebuildable, BUT the only problem i have with that is i dont have the necessary equipment at my disposal anymore... My garage is messy as hell and full of stuff, so i cant do it there. THAT and ive been looking at prices for different stuff to rebuild my motor for high CR and its looking to be about as expensive (if not more than) as the cost of a decent CA18.

Down the road you spend more money on a CA18det anyways. When you run boost you need controller and blow off valve, as well as a good intercooler to suffice for boost. Also increasing the boost will also use more fuel since the inlet boost charge becomes hotter and less dense, more fuel is needed to control A/F ratio. Although the energy potential increases as boost does, air is crammed into a small cylinder space making it hotter on compression, so in order to control the energy output more fuel is needed to cool the cylinder charge to prevent knock. CA18det's are known to be engines that run hot, or overheat when boosted. From what I understand a CA18det uses a 8bit mother board, and doesn't tune well to A/F ratio's as does OBD1 and OBD2 16bit ecu's. CA's are truely outdated, and parts are becoming much more scarce to come by.

By the time you install a CA, get all the parts you want to run boost, and go through a years supply of fuel you would of spent more, and had gotten less gas mileage at WOT, then if you were to run a high compression 2.4 litre setup that produces more energy output on NO boost, and conserves fuel much better on a much better regulated fuel output (smaller pulse width and CC injection).

It takes about 9psi on stock turbo to have a CA18det make 200Crank HP, While it takes a 2.4 litre 10.5:1 CR set up to achieve the same power output on less fuel. This is also running both engines on 91Octane pump gas.

I also wouldn't go with an RB20det just because it's an old engine, and I have heard nothing but complaints about it's transmission and the power you can actually make on boost. It's gear ratio's are horrible for the high reving that the RB20 makes, and makes no where near the amount of power that an RB25det NEO can produce, with it's gear ratio and stronger transmission. supplementing parts for an RB20det is just one big fU^&ing headache.

KA parts are becoming abundantly cheaper as well since Brian Crower sells performance cams that are better than Jim Wolfe for $250.00. Since the KA is a USDM parts are also easier to find. If you want to stretch the power band on a KA use some adjustable cam sprockets for $150... The list goes on with the KA and the parts and affordability are out there.

Where do I get the timing chain kit mentioned above?

my guides are dead and what a day it would be if this happened to me....

Zilvia and NICO members claim that this is one of the best for OEM components. It's at the bottom of the list of items for $164.99...
http://www.bmaparts.com/epcvsoapimc....entid=bmaparts

Pshh....

Get it right.... $164.79 ;)


And thanks....

Yeah, but currently im looking into getting a CA for 600 shipped from somebody. That alone is less than the cost to get another ka, and slightly more than rebuilding (i hope)

...well i thought about it, and 200hp NA is much better than 200hp FI, BUT i started sourcing and pricing parts to build a high CR KA, and there's no way in hell im spending that much to rebuild my motor for high compression. Found some pistons, 10.7:1 CR form Arias for 479 + shipping, PDM Racing ka24de cams $620 a set. Also wanted to have my crank knife edged and balanced, wanted to do port and polish job myself, wanted to get a header, and good valve springs. THEN i would upgrade ECU. Now just to build the motor for high CR and get it to running condition would still be well over 600 dollars.

Who said that you would have to spend that much?
Arias pistons $400
Brian Crower cams (better than PDM are $250).
Ported TB $150
SAFC used $150
I would call that done for well over 200WHP

....200hp with no header? Seems like exhaust is a very important part of making power. Also, there are a lot of other costs that need to be added in, like my front cover, which my chain so gracefully destroyed. A new timing chain and guides, Oils, possibly a headgasket, studs (if i replace the hg)

Also, please explain how the SAFC works, nobody has been able to tell me. Is it like a piggyback? It says it modifies the airflow meter's signal to change the amount of fuel injected. So.... wtf. Im lost. Why would i need that anyways? Is it really going to suck in that much more air? Also, wouldnt i need a wideband o2 sensor to monitor the A/F ratio so i dont royally bone my motor with the SAFC?

Also, what would i have to do to get my ka to rev higher without screwing it up, i know that i would need better valve springs, but is the KA's crank up to the task to rev to, lets say, 7500RPM?

First off rev isn't anything you should care about it's more about peak HP and where it is made in the power band.
Secondly an SAFC lies to the ecu. By cheating the ecu to claim that more or less air has travelled through the maf and to the engine depending on the position of throttle and opening. Air determines how much fuel will or will not be used to the amount of air that was given to part of it's throttle.
This means although the ecu is meant to function on one particular way to it's programming (MAP), you can trick the ecu to move from one part of it's map sooner than later by lieng about it's air percentage. So when the fuel map changes you are also changing the ignition timing depending on it's laocation in RPM and how much fuel you have decided to deliver.
Mostly in the case of an NA engine you would want to increase leaness in the ratio this overall increases the engines VE.

I understand about revs not being a huge concern, the only reason i would want to do that is to stretch out the gears a little more. But i have another question i thought of at work. Why would i need to trick the ECU? Im not increasing the bore or stroke, but would going from 9:1 (IIRC) to 10.7:1 make that much difference in the A/F ratio? And if you want to make it more lean, and by increasing the compression you need more fuel, then wouldnt the stock fuel map be sufficient to make it more lean? Also, running leaner means hotter internal combustion temperatures, right? With that in mind, that would put much more strain on the motor's internals heat-wise? I wouldnt wanna melt a piston or 4...

Also "This overall increases the engines VE"

Whats VE?

Volumetric Efficiency.....

...okay... is that like getting more power from the same volume of air/fuel mixture?

Yeah, something like that

so increasing the CR increases VE?

Hopefully this can get you to understand VE a bit.
http://en.wikipedia.org/wiki/Volumetric_efficiency

Yes Badazz 240 hit it on the button, it's called volumetric efficiency.
O.K tomorrow I am hitting up my 1/4mile against my friends 1999 Prelude H22a with a 10.0:1 CR ratio. His engine only needs to run stoich (14.7.1) maybe a little leaner in order to produce a power output of 200HP to the flywheel or the equivlant of 172HP to the front wheels.
I am running my 240sx with a 9.5:1 CR which means in order for me to compete I am going to have to adjust the A/F ratio through the SAFC and run it leaner than stoich at about an (11.2:1) with my 9.5:1 compression in order to match the energy potential his engine can make stoich. So I am only given so much litre's and in those litres I can configure a ratio that will best suit my engines VE, usually using less fuel charge in order to produce a greater air charge. Increasing the air charge is going to produce the majority of the power I will need but it becomes dangerous as it increases the EGT (Exhaust Gas Temprature), this will make my engine more suseptable to knock and ping although increasing it's energy output to the equivelant of the 200HP that I would need at the crank, most of the power that is made in changing this ratio will take place mostly after 4000RPM when overlap between the intake and exhaust valves occur allowing for a stronger vacuum of air charge to be used at my engines disposal.
So I am defenitely going to need a higher than normal octane I will probably get 98Octane to prevent early ignition.

Now since the SAFC shrinks pulse width by saying there is less air than what there really is, at that RPM the ecu ignition timing will advance further, only increasing my scavaging. Scavaging, and valve overlap have to both work in conjunction with each other. The advanced ignition timing only further increases the scavaging effect, which will further increase inlet air through the valve overlap, this in all works to increase volumetric effeciency by FORCING more air than normal into the combustion chamber (basically making a stronger vacuum or air pump than at stock specs or tune).
That is why tricking the ecu is important to increasing power an SAFC is just cheap.
In your case using the stock injectors you will want to slightly increase fuel to the ratio in order to make up the additional air that a 10.5:1CR engine consumes, the engine would now make enough streetable power that you would want to run your ratio closer to stoich, than ultra lean. Just the reverse situation that I am doing using a lower CR engine.

yea that exact same shiot happened to me goin to nopi lol ironic my sotry is about the same in detail also but my head is done, and as for where my coolant went when we were setting the timing to tdc to tear down the motor it spewed out the #3 spark plug hole like old faithful lol it sucks we found a ka w/ 70,000 for $300 so we're just throwin that in since we already done all the work for the e-de swap for the motor that just messed up, and as for the one in there we're putting it to the side and building it for turbo. good luck with whichever route you chose

meh... you said your head is done? Whats that supposed to mean? Lucky find. What year KA? See if i had the skills to rebuild the motor the way i want it, i would have no problem using my KA. Did you tear down the motor and see what the culprit was? Id like to see a pic to show my dad if you have one. He doesnt believe me. He thinks i was negligent and let it get hot and didnt watch the temp gauge. He's an idiot at times.

BigVin... how the hell did you know what went wrong with my motor? That was amazing are you a psychic or a psycho? Where do you live, ima send you a stripper. You hit the timing chain dead on the head AFAIK. I took off the upper timing cover, and low and behold, no guide left, and a few fragments on the slope tapering down from the top of the front cover, toward the water pump. Now i just need to figure out if it jumped time (likely with this much play in it. So now can you tell me if i can tell (without pulling the head) if i bent the valves? If not, then it should be a not-so-expensive thing to fix. Headwork = ho. SOHC pistons and rods here i come.

Oh and bigvin, what do you think about this setup im thinking of.
Okay, first order of business, SOHC rods and pistons and rings to bring compression up to approx the same as those expensive-ass arias pistons. New SOHC pistons ($124 from summit, "Sealed power" brand) and rods(???) Thats cheaper and arias pistons ($400+) and new rods (???), and a header (DC or Hotshot), along with re-doing my timing chain and water pump stuff. Later on i would have the TB bored, the itnake runners extrude honed, i would pull the head off and do the DIY port/polish, and get better cams, though not int hat order.

Heres some pics!
Chocolate milk, nature's lubricant!
Attachment 26494

Gotta check the Chocolate Milk level in my crankcase. Look, its full.
Attachment 26495

A wonderful thing to find on your upper timing cover....
Attachment 26496

And for my final trick, the amazing disappearing timing chain guide act!

Now you see it...
http://i5.photobucket.com/albums/y15...0/P6220055.jpg

Presto Change-o!!!
Now its gone!
Attachment 26497


...noisy bastard:naughty:

People say that I anylize things too much, I guess I'm pshyco.

Heres the conflict of using a SOHC piston over the arias piston. SOHC KA piston is raised above deck heith this means that there will be complications running high lift cams (JWT,Brian Crower,PDM). Arias pistons are designed to take higher valve lift than the SOHC pistons. There is another alternative that I don't like to give out since this is knowledge handed to me by some well respected Datsun/Nissan tuners at the dime. You can use the NAPSZ 24piston which was manufactured from 1986-1990 for the Z24 engines in the hardbody trucks.
Here are the differences in compression
KA SOHCS 1990 pistons yield 11.1:1
Arias pistons yield 10.5:1
NAPSZ24 pistons yield 10.5:1, (or so I think)
The NAPSZ pistons have fly cuts in the pistons that would allow for higher lift cams, 10.5:1 is pretty standard when you want to run higher lift cams and is much more beneficial. I don't really like 11.1:1 cr for streetable pump gas. 10.5:1 would be much better, and if you could look for a much higher head gasket, to possibly drop compression just a tad more, especially if you plan on using the stock ecu tune. Topline is where I would go to get the pistons they are the biggest bang for your buck. I would ask devious KA if he has a raised head gasket available.
The head will need to come off and I can't determine valve damage I have no idea what happened just the basic formalities.
Looking at those cams though I would put them in oil immediatly to prevent any more corrosion or rust from occuring.
I would order new bucket hydraulics, and springs.
The block should be torn down and checked for stress fractures around the cylinder walls, chances are you are fine, but I would take the block into a shop and have it checked before ordering the piston size in stock size,.010,.020, .030, or.040.....
Then I would have the crank journals checked, if all is well get new beaqring and all new seals.
Sohc rods are fine, compiling together this high compression OEM build should cost under $1000 in parts.
SOHC rods are fine to use.

...okay, so i need the napsz z24 pistons that came out of the hardbody pickup? z24 is the motor code right? 11.1 CR is no problem here in the south, we have 93 octane. ha. Hey vin, on ebay i saw these pistons, what do you think about the price and stuff? good deal? http://cgi.ebay.com/ebaymotors/NISSA...QQcmdZViewItem
Also, what rods would i need for that? How much do you think it would cost to have the crank balanced or knife edged or whatever? Any opinions on the windage tray and crank scrapers that were discussed on the forums here? My dad knows a lot about motors, espeically nissans. he used to have so many of those damn little datsun trucks you wouldnt believe. Anyways, um in not sending the block anywhere. Period. I dont have the kind of money to have someone take a look at it and say "yup, she's good to go" and fork out a hundred bucks. Besides, thats what i have a machine shop at my disposal for =D. Instead of having higher comp pistons i COULD have the machine shop mill my head down a bit. How do i calculate how much milling my head will raise CR? Like so many .xx mm = xx:1 CR?

I would contact the seller. That looks like a pretty lowered dish and no flycut. The KA rods work. I use to take KA sohc pistons to the NAPSZ block to raise CR. See if the seller would have any info on compression specs for the NAPSZ engine then I can do some math.
It would be a great purchase if I knew it ran a high enough CR, I also haven't heard of the company that makes those pistons.
You can mill the head to about .015 clearance in order not to interfear with valve clearance, that is also dependant on the gasket that you use. Milled heads show good results if done right, I've also seen some hack work with warped heads from doing that as well, all depends on how good the machinist is.
You can also try cloverleaf welding the head to raise the CR and still use the stock dohc pistons and not mill the head. There are so many different ways to raise the CR of the engine.
Crank scraper and windage trays are great, HP increase, lower oil tempratures, better lubrication of engine parts. Your dad would know what I am talking about.....

I Could try to cloverleaf weld on the head? lol. 1st off, i dont like ruining parts cuz i cant weld for crap. and 2nd, its aluminum.... a PITA to weld. Ill go to a couple sites for the pistons and see what they look like compared to the celvite pistons. Clevite has been around for a long time. Theyre not like a uberjdm performance company, just oem spec stuff for the most part.

I wasn't trying to insinuate that you should weld the head, I was insisting that a professional should do it. I can't weld a head worth a crap either....LOLS

...though i could have the machinists weld it solid and have them use the mill to cut out what i dont want welded... of course i wouldnt have them weld over the valve openings lol.

Also, there are like 4 z24 engines.. which pistons am i looking for? z24, z24i, z24l, z24i/s?

Alright, it looks as if those pistons on ebay ARE the correct z24 pistons. Looked on advanceautoparts.com and looked up pistons for an 89 d21 (hardbody) pickup. Heres what advace shows.
http://www.partsamerica.com/product_...le/2242332.jpg
Im probably going to get the ebay pistons in this case. What do you think bigvin?
These are the ones on ebay:
http://i10.ebayimg.com/05/i/07/b8/5f/aa_1.JPG