Frontier KA24DE to D21 4x4 swap. No more KAZ24.

[HRH]

So I got the truck down to the exhaust shop today and now that it's quiet, the header flange is leaking.  Not to mention, our shortening of the header definitely made it a 3500 rpm and up header, so my torque rather sucks.  I'm thinking I may find a factory manifold and put it on instead.  Anyone have an extra KADE 240sx or truck manifold laying around?

[izzo]

Good job Matt!

[HRH]

Thanks izzo!  I'm so freaking happy to be (mostly) done with this project.  Annoying it took way more of my vacation than I'd planned, but at least she's running now.  A few more tweaks and we can start measuring mileage and seeing if anything bad arises.  Hopefully not.  It is amazing to remember how slow the 4x4 is compared to the Maxima I've been driving around.  I tried to get on it in third and yeah, that didn't happen.  1100 pounds heavier sucks.  But it will be good in the snow.

[]2eDeYe]

Nice work dude. :thumbup:

[HRH]

Okay, here are some pics!  And photophucket is being a turd.

 

 

 

 

So the stainless header is much prettier, but due to the problem of my shortening it, my low-end torque is non-existent.  I can feel the exhaust tumble.  The '02 Frontier manifold was cracked for one, for two, it has a giant pre-cat attached to it's bottom.  After driving the truck this morning, I found not only that, but even though it has a nice big thick flange, it was bowed enough to make a leak on the very back edge.  I thought it was Ron welding up my pipe and he missed a spot so I took it back to the muffler shop.  And he informed me, nope, I heard that, whenever it's a tick, it's at the head.  He brought out some rubber hose and sure enough found it right at the end and had me listen.  I got schooled, but in a good way! :)  I thought I was hearing it down at the joint he welded, pretty easy to find with a piece of hose, really isolates it when you find the spot.

 

Anyway, I drove the truck home and changed the oil, and then decided I would try to find a different manifold.  What is plentiful in pull and saves?  Altimas!  I got a manifold off a '94 Altima as shown above which looks to not only have the same original flange attachment as the D21, but it looks like it will clear just fine and be a nice cast-iron non-leaking manifold with decent torque characteristics.  We shall see.  I've decided I'm taking a day trip to Seattle tomorrow, so maybe Sunday I'll get around to trying to put that on.

[HRH]

Have the idler bracket issue fixed.  Not the finest welding, but solid enough I'm not worried.  Ended up straightening the sohc idler bracket then adding on a few sections.  Worked quite well, just need to find a longer belt now.

 

 

 

[]2eDeYe]

Home made parts ftw! :D

[HRH]

Yep!  The downside is the Altima manifold will not fit.  It exits right at the motor mount.  The truck ones are farther over and at a 45 degree.  I did find, however, that '98 Frontiers didn't have the massive cat hanging off the exhaust, so I have one of those manifolds now (new from NAPA) and have the corresponding connecting pipe coming.  Next weekend I'll be assembling that which should work a lot better for low end torque.  Wish I hadn't cut up the header.  Oh well.  Truck is running well besides having crap flow issues below 3000 rpm.

[HRH]

 

Exhaust pipe from a '96 Honda accord works perfectly.  75mm stud to stud length, 1.72" ID due to double walled pipe.  Frontier aftermarket manifold 1.75"  Close enough.  Not sure what Frontier downpipe size is, don't have it yet.  I suspect it's not any larger.

 

 

The pile of potential parts.

 

 

Remove stupid heat shield that cuts you.  Also, expect to clean up the manifold.  Ground a lot of casting bits due to sharp edges, etc.

 

 

Did I mention cleanup?

 

 

Dorman cheap china manifolds have lots of leftover shit.  Tap/chase all bolt holes.  Tried to just install the studs, that didn't go well.  Note all the leftover crap coming out of the threaded hole.

 

 

Note, sealing ring is supposed to go around pipe extension so it's centered, then seat on the beveled edge and crush to seal.  I'm using the existing Honda gasket since that makes it flat, and I siliconed it to keep it centered during install.

 

 

[HRH]

 

Like so.

 

 

And also so!

 

 

You can't see it from this picture but the hole openings are NOT very good on the aftermarket manifold.  I checked it and roughly all the openings didn't have any overlap so I was lazy and didn't take the burr and make them perfect.

 

 

Overlapped pipe pieces so yes my welds are a little ugly, but more than sufficient to seal the pipe.

 

 

And here's the manifold on the truck.  Didn't take a picture of the completed job, but it works great.  The only bad part was the joint where I had to weld underneath the truck.  I really need a lift.  Welding upside down in the dark with a mirror to try and stab at the top side, yeah, let's just say that joint looks like a pile of bird shit, but I did manage to get it securely welded and only had to re-weld one leak spot.

[HRH]

Did testing today on the truck.  The IAC did a weirdness, idled high after the trip to CDA, adjusted it down to 1000, then it dropped down to 600, and then after the long trip to Wallace it was fine again.  Moved it ever so slightly up just to get it off the stop, and so far it's been right on ever since.  I suppose it might have just gotten pissy due to lack of use.  Hopefully fiddling with the idle adjustment air bleed solved that problem.

 

I have noticed due to the open nature of the DE manifold, the low end is lacking a little until 3000 with the new manifold.  The original sohc uses a flapper valve in the intake to make the air move faster during low speed operation, which does a great job of increasing low-end torque.  Can't remember if the intake manifold gaskets are the same between E and DE, but if they are I may switch back to the '93 manifold.  Mid-range with the double cam is very strong, top end, just so-so.  It's not bad, but not night and day difference.  Still a few little things.

 

On the trip to Wallace, I averaged 17 mpg, which was pretty shitty but I went faster than 2750 rpm (67 or so) and there were lots of over the mountains, but also down the mountains.  Anyway, it occured to me the injectors I had squirreled away for 9 years might have been a little dirty.  So once back in CDA, I topped off with 92 non-ethanol, then ran a can of VP fuel injector cleaner through it.  We just started selling VP products at NAPA.  Don't have race gas in drums, but quart bottles for lawn mowers, etc.  For the record, their fuel cleaner seems to work rather well.

 

The good thing was from CDA to Spokane (which is flat) and up to the Safeway on Wellesley, I averaged 22 mpg.  That was not going above 63 mph indicated on the speedo, which is approx 65.52 mph.  So, things are improving.  I think I'm going to run a few more cans of injector cleaner through her these next few tanks.  It also occurs to me that might have hindered my initial start efforts also.

 

So a few bugs to work out yet, but so far Gracie II is back on the road and ready for winter.

[Farmer Joe]

so i just drove my truck around a bit with the DE, and i noticed the same thing about the bottom end being gone.. 

 

i think the single cam head just inherently has better bottom end.

 

but, its sweet to hear yours is running back to almost normal again. off to shake down the 620!! 

[HRH]

Yeah, I had a brilliant idea while driving home tonight to use an Altima manifold and just cut off the throttle body end and relocate it on the other side.  Alas, there is a problem.  Altima, 93-97 is different intake.  Frontier 98-04 is different intake.  240sx is also different intake.  And of course the KAE is a different intake.  Most noticeably on the Altima conversion, the water port built into the end of the intake manifold is a different shape.  While you can certainly swap a head on the Frontier motor, you can't just swap intakes.

 

Sooooo, that means I'm stuck, unless I can dink around with timing and the cams to get more bottom end.  But yeah, after 3k, it does great, it's just not that great for low end.  I think one of the reasons is that swirl control valve in the runners (the flappy deal that closes at low speeds and opens at top end).  If you were to retrofit that to the Frontier/Altima manifold to essentially close off the intake a little to increase the flow, I think low-rpm torque would increase.  But that would be a lot of work.

 

At the moment, I think I'll go for dinking with the timing, and seeing if retarding it a tad doesn't help the pickup on the bottom end.  That and I still have the random IAC issue.  I brought home a new IAC valve tonight, probably get around to changing that out this weekend.  Didn't do it on the way home, cold seems to annoy it more.

 

You know, that's the next thing I need to look at.  Whether the Altima and 240 and Frontier cams are different or not.  I know the 240 guys had a trick of using two exhaust cams in the stock motor to get power for cheap, can't remember which.  I'll have to check the bro40 forums for that info.  I would think the Frontier would have the torquey-est cam, but I could be mistaken.

[Farmer Joe]

the cams are different!

 

i just found one 248 duration altima cam at the yard on sunday. needs to find another one. i want to do the 248/248 swap. 

 

check this out matt.. 

 

http://forums.nicoclub.com/ka24de-cams-specifications-t169323.html

 

cams in my 2000 frontier engine are 232/216 duration... tiny!! 

[HRH]

Dude!  Nice link!  I think the ECU tuning has quite a bit to do with it.  I remember testing a Stanza ECU in my truck with the previous KAE motor.  It wouldn't idle correctly, way too high, the IAC probably didn't know what to do.  However, the thing was LOADS quicker accelerating.  The only problem was there was a hiccup around 3500 and 4500 or somewhere in there where it's like the ECU cut out for the automatic shift or something.  I don't know.  All I know is I returned it to stock because it wasn't refined enough.  I imagine though, if you swapped the whole intake from the Stanza on there, it wouldn't have a problem.

 

I may go raid some Altima camshafts and try that too.  I have the later model, so 224/224 cams.  However, it appears that 91-93 240sx and 93-95 Altima have the same cam specs.  Instead of trying to find both exhaust, I'm thinking I'll just switch in the cams from an Altima.  It's still a good improvement with more lift and duration.  Plus I only need one Altima motor with good cams.  There are actually quite a few in the pull and save's around here, let me know if you want me to grab another exhaust cam this next weekend.  Subject to non-marred cams of course.

[]2eDeYe]

Cam tech! Nice. 

 

I have an exhaust cam to put into mine, but I haven't had the time or inclination yet. 

 

I find it odd that Nissan would have so many different configurations for the same basic motor. I guess changing the engine to fit the car was cheaper than designing the car to fit around the motor? 

[HRH]

Yeah, I'm surprised, but I think it was due to the trucks being made in Mexico, the cars in Japan.  And probably cheapness had something to do with it.  Don't forget, '98 was the year Nissan got bailed out by Renault because they shit the bed financially.

 

Anyway, I just filled up tonight after going back and forth to work for a couple days.  Not to mention high winds this morning, which didn't help.  My mileage, after correction factor for 30x9.50/15 tires (stock 235/75/15) is 1.04.  Around 70 miles of travel, in not all highway conditions and a quick jaunt the other day which drags mileage even further.  Went to the bank and an account then back to work.  Short trip, 4 miles in town.

 

Enough stalling, I got a paltry 17.09 mpg.  BOOOOOOO!!!!  (And this was pretty much babying it)

 

The lack of bottom end hasn't been seamless either, it's been rather annoying because I know it's not right.  So I investigated fuel injectors and cams and postulated on the potential problems of tricking the ecu into thinking it's still running a single cam when it fact its double.  And I realized I was probably looking in the wrong place besides the known antiquated 93 ecu.

 

By the way, Farmer, which ecu are you running?

 

Anyway, started with the basics tonight, got the new temp sensor in for the gauge so it reads correctly now.  Then went about timing.

 

For those with early D21 KAEs, timing sequence is as follows:  Get engine to operating temp, run at 2000 for a bit, if idle isn't below 1000 rpm, get it below 1000 rpm.  Shut engine off, disconnect TPS connector.  Start engine again.  Set idle at 750 rpm and timing at 10 degrees BTDC, plus or minus 2 degrees.  Adjust idle speed using the idle adjustment portion of the IAC valve.  After desired settings are met, shut off engine and reconnect TPS sensor.  Re-start, see if idle increases 50 rpm.  If not, fix IAC valve issues.

 

So I haven't timed this since first getting it running.  And I timed it without the TPS sensor disconnected.  Not only that, I found an incorrect diagram in the Haynes manual that stated the first position of the 6 crank marks was 0, not -5.  So what did I do?  I believed it.  What I found tonight after initial inspection was that I had indeed timed it at 5 degrees BTDC.  Baaaadd.  It doesn't like that.

 

It is now right at 10-11 degrees BTDC, timed correctly.  Motor actually seems to wind up smoother.  I'm hoping it will have some effect on mileage as the EFI is meant to not be run retarded, unlike that ability with early carbed motors.  We shall see the next two days.

 

I'm still planning on investigating cams and ecus at pull and save.  I'm tempted to put an Altima ECU in it, however, I think I will run into the same problem of the Stanza as the IAC valve is VERY different between truck and car and I don't think it will have enough adjustment to run properly in the hardbody.  I also don't know if the Altima ecu connectors are the same.  I suspect they are, I'll have to try and see.  Don't know if they'll freak out from lack of knock sensor either.

 

In the meantime, we'll see if she runs better now that she's timed correctly and I will let you all know what mileage does.  Keep in mind, unlike Farmer's 2wd, I'm extended cab and 4x4.  She's a heavy pig.  3800 pounds without me in her.  Yeeek!  Built to move mountains the hardbodies are.

 

Side note:  After using the Honda Accord manifold pipe, I finally got the Frontier pipe in today.  Looks big, like 2 1/4 pipe on the outside, but it's double walled and almost exactly the same size as the Honda pipe, so looks like it's fine the way it is.  1.75 ID in case you were wondering.

[Farmer Joe]

dang, that mileage is kinda sucky.. 

 

i dont have an ECU on mine.

 

 

trololololzzzz

 

im using a weber 38 and the truck intake. the single cam was carbed too. 

 

thing is, on the single cam, i had removed the runner blades. even without em, it had noticeably more torque on the bottom end. i really believe it has to deal with the single cam only having 4 exhaust valves. that characteristic has to give it more bottom end right off idle. 

 

ive yet to put a timing light on it either.. but its also running L-series dirstibutor.. im pretty much driving a twin cam L-series.. lol\

 

im not sure what itll run well at. the single cam loved to run at 15* till the timing chain took a shit. im not sure what the twin cam is gonna like. we'll see. 

 

 

 

in any case from what you have going, sounds like alot of variables right now.. 

 

would the fuel pressure have anything to do with it? do the side loader injectors take more pressure to operate than the top loaders the d21 came with from the factory?

 

the milage your getting is like that of the auto version of the fronty.. the 5 speed version says its supposed to be around 21mpg combined.. the frontier of that year weighed 4220lbs.. youd think the 400lbs would help you out.

 

more isolation! 

[]2eDeYe]

I get about 22-25 if I drive like a sane person, but I haven't done any mods to the motor at all. Of course, I don't drive it like that to often :lol: 

[HRH]

SUCCESS!!!  That 5 degrees of timing makes a HUGE difference in runability.  I'm already having way better response, power up to 5500 rpm, and better mileage on the gauge in just today's trip.  I'll wait to average it out for a bit more, but I should be getting back to normal if not slightly better than standard hardbody 4x4 mileage.  Very happy today.  Still going to the wrecking yard and planning on installing Altima cams this weekend.  That should bump the power up a bit more.

 

I like the 38/38 on the KA truck manifold!  Did you have to do any custom welding with the KAE water ports in the manifold mating to the KADE head?  It looked to me like the intake gaskets were different there, but maybe it just looked that way?

[Farmer Joe]

nah, i had to prep a whole new intake. 

 

the d21 and d22 used the same design in the intake, other than the injectors and the DE flange.

 

i did hog out the intake a little bit where the throttle body used to be, to make it more like a single plane 4 barrel intake. 

 

i left the plate that youd connect the PCV to, but made gaskets to block off the port. 

 

built another plate that sits on that, and then a weber adapter bolts to it.... kinda complicated in words, but its really simple. check out my thread in the trucks sections.. i wont hijack the thread here. 

 

ive likes how its ran.. understandably its not gonna run like an injected motor, but it has the same power overall. at low speed under load, like any single plane intake, it looses velocity in the intake if you gas it too much. 

 

it should rip once i get the altima exhaust cams in it. gonna do a 248/248 swap.. 

[mhub91]

Careful, you can't just "throw" in that Altima exhaust cam. First, about 5/16" has to be shaved off the rear of the cam. This is where the distributor drive for the FWD KA in the Altima. 

 

Also, I HIGHLY recommend you check valve lash after installing that cam. Even though the DE has hydraulic lifters, there is still a tolerance between the bucket and cam lobe.

 

Equation for finding proper valve lash w/ a caliper and feeler gauge.

 

 R= thickness of old shim      N=new shim size      M= measured clearance
 

exhaust: N=R + ( m - .37mm )
intake: N=R + ( m - .35mm )

 

Don't forget to always perform order of operations in this equation. That means do what's in the parenthesis first.

 

 

 

Oh, and don't forget to rotate the new exhaust (now on intake) cam counter clock wise 3 teeth now.

[HRH]

Good call!  I knew about cutting off the distributor tang.  Didn't think about measuring the bucket clearance.  Now I'm debating if I want to bother doing it, though I suppose I can gather all the old shims at the wrecking yard as well.

 

At the moment, I'm still having my idle issue of it occasionally wants to idle at 1500 rpm.  Sprayed starting fluid around tonight, didn't find anything.  Not quite sure why it's doing it yet.  Going to have to dig into that this weekend.  Not causing runability problems, just annoying and wastes gas at idle.  Have a new IAC ready, though I whacked it tonight with a screwdriver multiple times and it didn't idle down.  Going to check the fast idle cam plate for sticking and a few other things too.

[HRH]

Well fuck a double duck. You know how you get in your mind something is all better and then it bites you in the ass? 17.33 MPG just now. Something is still not right. Besides the lack of egr which shouldn't matter distilled have to fix the iac mess. Right now I'm half thinking of carbing the damn thing. I'm sure ill figure something out tomorrow, just annoyed. I do have a long hill and winds on the high pains in the am commute to work but I still should be able to pull 18-19 MPG with mixed driving.

[HRH]

Okay, it is Sunday morning, I have a few plans in place:

 

First off, I'm going to attempt to "fix" whatever's broken.  Going to start by checking the ECU for "55" blinky lights indicating that everything is okay.  If not, we'll fix those issues.  Should everything be okay, the next thought I have is perhaps she's just going to get shitty mileage climbing up the Sunset hill every morning then fighting wind on the high plains.  I have a nasty feeling I could go to Coeur d' Alene right now and average 22 mpg on the nice flat freeway with steady load at 63 mph.  However, 17.33 is UNACCEPTABLE.  Especially when a crapbox Jeep Cherokee with a bullet-proof 4.0 liter can get 23 mpg and 18-19 in the winter.  If I can't get this right, I'm going to own a Cherokee.

 

So my plans are this in order of cheapness (money-wise and time-wise)

 

1.  Fix the existing system and make it work correctly.

2.  Try an Altima ecu if it will fit, see if that will help

3.  200sx EFI using a secondary throttle body as a giant choke unit instead of the annoying IAC valve which is just a reed and spring.  I've never liked them, they never seem to work well.

4.  Swapping an Altima or 240sx car harness in.

5.  Dual SU carbs or dual 32/36 carbs.  The one reason I don't like this is because the manifold wasn't designed for fuel.  Just air.  While it would be much easier to replicate Farmer's idea, I'm thinking about taking the manifold off, setting up in a jig, then cutting off the flanges and cutting two L16 manifolds off at the flange, then staggering them to fit.  Not sure if it will work, but I have a few extra manifolds to try.  This of course, would be expensive to have done, and then you have to buy two carbs, but it's still not that expensive.  I like the idea of motorcycle carbs, but I haven't played with them, nor gotten them.  I just calculated that every cylinder would be 600 cc, so I suppose I could hook up 4 600 cc thumper carbs and make that work.  Keep in mind this is in order of most costly.

6.  Standalone ECU such as megasquirt.  I know Icehouse will vouch for this, but I'm still intimidated.

7.  An entire 280zx motor, might mean some more custom pan work and custom core-support work, but it would be soo cool.  But it's also at the last of the list.  And then what would I do with the Frontier motor.

 

I'm still stuck with the fact that the hardbody weighs 3800 pounds without me in it.  She's a heavy pig.  The other thought I have is the EGR not being attached, perhaps missing the extra airflow from that, the ECU is running too rich?  But then, the 02 sensor should see that and compensate for the very little amount the EGR lets in.  And that's only at light load and idle, not WOT and heavy accel.

 

8.  Think I'm going to hook up a vacuum gauge and do some testing also, see if my most fuel efficient point is indeed still 2700 rpm in 5th.