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

[HRH]

Further mileage update.  It's been about 20 degrees during the day lately, I have the Firestone Winterforce snow tires on which are extremely squishy and siped.  Not nice and hard like the BFGs.  Anyway, took a trip to Lewiston today.  Got 19.5 on the way down, got 17.7 on the way up.  Lewiston grade sucks.  Pinned in 4th, then in 3rd, then in 4th, all the way up.  That wastes fuel like crazy.  And as I suspected it's slightly downhill all the way to Lewiston from Spokane.

 

Anyway, average mileage was 18.6, which, for studless snow tires on a heavy 4x4, really isn't all that bad.  Granted there were some lower speed sections where I was going 55 instead of 62.  I haven't installed the vacuum gauge yet.  When I do, I may see if going to 8 degrees BTDC does worse or better.

[HRH]

Here's an update:  I began thinking about oil weights.  Considering all my previous motors have been L derived or early KA derived and 15w40 does fine in them.  Big oil journals, what have you.  However, I began thinking about the fact that this KADE is 2002 vintage.  Meaning I may have been thinking too old.  Checked Mitchell's and sure enough, it specs 5w30 oil.  I know it can run 15w40, but I have noticed a long time for that oil light to go off when it's cold.  Like a full 3-4 seconds.  So last night I changed the oil and put in 5w30.  Makes a noticeable difference in cold starting easiness and the oil pressure light goes out almost instantaneously, which is good.  Doesn't make any weird noises.

 

Consequently, we'll see what kind of mileage increase we get with the thinner weight, but I wouldn't be surprised if it goes up by 1 mpg.  The Maxima will still get 15w40 because I beat the piss out of her, the new Maxima, maybe 10w30.

[mhub91]

Honestly, I use 5w30 in my s13 KA24DE in my '79 A10. I have had zero problems. I get around 24 mpg. I'm also thrashing on it too. Probably not the best idea to use thin oil when I abuse the engine, but ....oh well.

 

Considering my A10 only weighs 2000ish pounds with 195/50/15 and 3.54 rear end it really loves the free way drives. with all that weight you pack around + 4x4 components 18mpg really sounds perfect to be totally honest.

 

 

Edit: This is my 1000 th post. Yay for internet life.

[HRH]

Yeah, if I can get 18 in the winter, I'm fine with that considering the weight.  Since I put the new motor in though, I've noticed I'm down about 1 mpg all over the spectrum vs. the old single cam.  In the summer I doubt 40w vs. 30w will matter, but in colder temps, especially on startup, I think 5w30 is the way to go for these newer motors with smaller journals and what not.  I'm driving over to CDA today, we'll see if the mileage improves.  I have a feeling it will.

 

It's no secret that's why the newest cars are taking 0w20 and crap like that.  Trying to maximize mileage.  I'm not into running water in an older motor, but 5w30 even for banging around on is perfectly acceptable for 90 percent of our Nissan blocks.

[mhub91]

Exactly. 

 

Even the new large V8 engines (talkin' specifics to Toyota here...) Take 0W20. Crazy, if you ask me. 

[HRH]

Yup, it helped!  Just did 128 miles, getting 17.7 mpg.  That's while going 65 mph into a headwind and probably 100 miles of highway, 40 of which had the headwind, and the rest was in-town, country road driving.  Pretty good mix, I'm fairly happy getting almost 18 with mixed driving and with the wind.  Also had a couple of short trips to the store and back during which the engine hadn't warmed up completely before shut off.  We all know how that sucks the mileage down.  Hopefully sustained highway without wind will yield in the 20-21 mpg range with the sticky snow tires on.

[mhub91]

Hey this just came to mind, my Dad lives over in Couer d' Alene and I visit him from time to time. Maybe we could meet up sometime and talk datsuns.

[HRH]

Cool beans!  I'm down for that!

[HRH]

 

There was a bit of a warming trend lately. However the last two tanks have been 18.4 MPG. Readjusted the timing to 9 degrees from 11 ish, we'll see if that improves the mileage at all. I have noticed less pick up at 3500, its more seamless, previously it was like hitting the secondaries on a Weber. If this doesn't up the mileage, I'm probably at the limits of the system. Either way I'm getting about the same mileage as the 2wd d21 did in winter so I'd say that's pretty good.

[mhub91]

Bah, you're over thinking it at this point. Your mileage is spot on what it should be!

 

Warming trend, as in ... temp gauge shooting a little high?

[HRH]

Nope, like it was 55 degrees here last week, fing weird.  And yes, I may be over thinking it, but we'll try the 9 degrees for a bit, see if I can't squeak out just a liiiiiiiitttttle more mileage.

[HRH]

Did a little more fiddling with the truck today.  Decided to wire in a heated O2 sensor like I planned.  Got one from a '98 Frontier.  Found an extra 3 prong connector on the Altima harness I've already borrowed a number of connectors off of.  This should keep the O2 sensor heated during idle and should help it start sensing sooner on cold mornings, thus leading to better mileage.  In summer it won't increase, but if I can get closer to summer mileage in winter, I'll be extremely happy.  I've gone back to getting semi-crappy 16.5-17.5 mpg in regular conditions.  Half of it's the squishy snow tires, they suck mileage due to their softness, whereas the BFGs are rock hard.  It's not unheard of mileage for a 4 cyinder 4x4, but again, I want to squeak out every little bit I can and adding a heated o2 is pretty easy.

 

For the connector, I ended up using the power source for the vacuum switch for the air valve dump to the exhaust (not hooked up anymore).  Sense wire was wired to an old o2 sensor end to plug into where it did previously.  Ground was a borrowed ground from the electric fan relay.  Removed the fans for ease of installation and just ran the stock clutch fan on the new motor.

 

 

 

 

 

 

Molly helping

 

 

 

I don't think it matters which path you assign power or ground, but I wired it like it was supposed to be per the Hayne's manual.

[HRH]

Well it may just be a fluke, too early to tell, but so far the mileage has already increased and it's pretty obvious.  I'm liking this, but I only have 35 miles on the odo, so need a few more to get a good test in.

[HRH]

So this week which was back and forth to work on the freeway, fighting winds in Airway Heights as usual, and some fair amount of driving around Cheney.  17.96 mpg!  Booyah!  3 wire O2 definitely helps the mileage!  Heading to mom and dad's today, we'll see if it improves on steady-state cruising.

[HRH]

19.56 mpg over Christmas.  Mostly freeway with one trip into town visiting some friends on Christmas day and back to the parent's for dinner before heading back to Spokane.

[]2eDeYe]

That's really good in a 4x4. Do you know what gears you have in the axles? 

[HRH]

4.375, the "highest" of the D21 4x4s.  V6 models got the 4.62s or something close to that ratio, can't remember.  Here's an odd one.  Horn went out the other day.  Odd.  Replaced the horn, worked just fine.  Left mom and dad's tonight, did a little bee* before I left. That's it, just a smidge, horn went out again.  Not something that usually goes out.  On the way home I noticed my auxiliary fog lights were also out, but they're on the running light circuit.  So I'll be digging into that tomorrow.  Can't be a coincidence, or could it?  I can hear the relay for the horn clicking too, but no go.

[HRH]

The other thing I've noticed with the addition of the 3 wire O2 is it gets a bit hotter at cruise now.  Don't think it will be an issue in the heat because there will be less dense air, but it does seem as though it compensates a bit more.

[mhub91]

Unsure if you know, but if an engine is leaned out it can "over heat" or run warmer in terms of coolant. This would make total sense, considering you're getting better mileage but running hotter... I think 

you must be pretty lean.

[HRH]

Yeah, I was thinking that.  However, if it's just reading the O2, it can't really over-lean.  And I'd prefer lean burn anyway on steady state cruise.  If I get on it, the temp goes back down, which indicates it's just right off throttle.  Considering I don't have the air pump for the cat hooked up, it's probably good it's doing that function via the O2.  It's not overheating, just getting hotter.  In the summer there won't be enough air to worry about anyway, it's just the cold temps right now.  The only difference is the O2 is heated, so it could also be just a fluke that I'm noticing it now.  Either way, it seems to be working just fine, haven't noticed any issues.

[HRH]

Sonofabitch.  So when you remove the ground wire from the relay thinking it's the relay for the electric fan which has been removed, and borrow it for the three wire O2, you find out that it's actually the relay for the fog lights, and that probably has something to do with why your fog lights don't work and you've been blowing horns.  Think it was stealing the ground from the horn circuit or something, not sure.  Either way, the relay has now been re-grounded and I'll soon have yet another new horn in place.  This time it shouldn't fry itself.

[HRH]

I'm going to do a mean thing.  I'm going to bait you guys, but I'm not going to pull you out of the water just yet!  :)  Suffice to say, I'm playing around with the double cam again.  I should have some meaningful test results and more pictures for you guys later tonight.

 

[HRH]

So here's the deal:  I was talking to my old roommate Buddy and he mentioned how he was managing 20 mpg in the lifted Cherokee with 33's and lockers front and rear by switching out from 1 hole injectors to 4 hole injectors from a Ford or something.  That got me thinking about the hardbody.

 

In case you're new to the story, we have a 2001 KA24DE from a 2wd Frontier in my '93 4wd Hardbody.  I'm running the '93 ecu because I couldn't figure out how to wire the 01 ecu.  Just not that good with wires.  '01 injectors are green.  We're also running the '93 intake manifold and either the '95 or '93 throttle body, can't remember on that one.  Exhaust manifold is a '98 Frontier manifold because the '01 has a pre-cat that gets in the way.

 

The '93 hardbody red injectors aren't as fat as the green '01 and red '95+ hardbody.  So I ran red '95 hardbody injectors in the '93 rail as that worked just fine.  BUT, they're all 1 hole injector, whereas the 93-99 Altima and 91-95 240sx run red 4 hole injectors of slightly differing variety.

 

In the heat of the summer, if I ran at 60-63 mph I could pull 21-22 mpg.  Pretty decent.  Still didn't get that great around town, but respectable.  With the KA24DE running on the original KAE system, I've had about the same hot highway mileage.  But colder temps usually just suck.  In the winter I'm still getting 16, without the hubs engaged.  Which sucks!  She's a heavy pig, btw, 3800 pounds without me in it.  Compounding the problem is not a tall enough 5th gear as 65 mph on the speedo is about 2850-2900 rpm, which is pretty high for cruising.  I'd like to have a custom 5th gear that put it around 2500 rpm at the same speed.  That's not happening, and I've checked about all the gear tables to see if it's possible, and it doesn't seem to be.  It would be easier to put in an additional transfer case that had super high gearing like a 2 speed rear end.  Yeah, that probably won't happen.

 

So fast forward to today.  I filled up the truck after I finished this project.  17.2 mpg.  Suck.  After this project and 106 miles, 10-15 of city, the rest highway, but at least 4 full speed runs up to 90 mph that sucked the mileage down, I managed 19.5 mpg.  Pretty good.  Looking positive so far.  Especially because its 56 degrees here right now.  Usually as soon as it drops below 70, my mileage drops.  So that cold and getting decent mileage while doing full throttle acceleration runs from the lights during the in-town and full throttle runs on the highway, I'm thinking it's going to make a pretty good difference.

 

I'll have to watch the mileage this next week and see if it's really improved or just a fluke.  In which case it's going to be an expensive test. ;)  However, I have found it idles smoother and runs smoother at all rpm ranges.  I'm liking that.  And now, I'll post some pics.

[HRH]

 

 

 

 

 

 

 

[HRH]

 

The Altima rail is a tapered barrel and the ridge is recessed so the injector fits even.  That ridge doesn't exist on the hardbody injectors, so it sits up higher.  The barrel is shorter though, so don't grind off the ridge.  Tried that with the spare crappy one. ;)  Sits the same regardless.

 

 

 

 

 

 

 

Oh yeah, don't forget you have to change the injector pigtails.  Fortunately I had an extra '93 Altima engine harness in the garage from a pull and save excursion a few years back.