inline6

February 25, 2013

Did some more testing yesterday and today. With the 57.5 pilots, I am no longer seeing (lean AFR on the meter) or feeling that brief lean spot during light throttle tip in - which felt to me to coincide with the transition off of the pilot circuit and onto the pump circuit.

I also tried hooking up the analog cable today - for RPM input only. Not sure what is going on. I tapped into the negative lead on the coil (Crane PS 9 I think). When I checked it briefly at idle before actually splicing (and after running through the configuration), it seems to read the RPM's. I saw it read 900 or so at idle briefly, so I turned the car off and ran a wire from the neg on the coil into the passenger compartment (the cable that comes with the LM2 is not long enough) and spliced it to the black with white stripe wire on the LM2 analog cable. Now, it will intermittently read like this 50......0.......200........80....... at idle. Each number shows for a few seconds. Anyone have any ideas what the problem is?

Since the engine has enough run time on it now, I decided to get into the revs a bit more and to record some data for the first time. It would have been nice if the RPM hookup had worked, but oh well.

I also put 180 mains in before going for another road test. I did this specifically because during previous testing with the 165s in there, I was seeing 15s after opening the throttle about 60-75% but also holding it in a fixed position for many seconds... the car was accelerating briskly but with no movement of the throttle. I am confident I was completely out of the pilot circuit and I did spend a significant amount of time accelerating after all pump jet effect should have been out of the picture. With the 180s, reproducing this same situation as best I could, I believe I am seeing low 12s to 13s instead of 15s.

The AFR's are ok in most situations. The one thing I know I can't do is give 3/4 to full throttle in high gears at low RPM's... that can cause the AFR into the 9's and the motor will start sputtering. I don't want to wash the cylinder walls with lots of fuel! Other than that scenario, AFR in quite varied situations is almost always between 12 and 16. I was pleased to see that I could rev into 7k territory with no problematic AFRs.

I recorded one run from standstill through 3 gears (still not full throttle). Just finished looking at it on my laptop. Generally, I am seeing that as the throttle opens, the AFR drops quickly to around 12 or even into the 11s, then it climbs out of that into low to mid 12's and then low 13's . Hard to know for sure what the plot on the graph relates to during the run without the RPM's showing.

Definitely some pretty cool stuff. Going to have more fun with this once I get the RPM signal working right.

February 22, 2013

What setting is the pumps on?-What hole?

Where is the power band for that cam? You might need to be around 4k+ hard tip ins to judge jetting. Which may also tie into what you are saying about main air jet selection.

Middle hole. Not positive on the cam power band, but probably something like 3000-7700. Redline from the manufacturer is 7700.

Remember that by opening the pilot screws out further than recommended, instead of getting the larger pilot jet, you SET UP the lean transition!

The transition ports use the pilot jet as fuel source. The recommendation on pilot jet turns out is a calculated annular discharge area that is not exceeded, allowing all additional fuel flowing in through the pilot jet to be available to the transition ports.

It is predicated that if you need a lot of fuel at high vacuum idle, it should be available through a set area and adjustable through a very narrow range of adjustment.

Corollary to that is if you need big fuel at high vacuum, you need it in transition. Open those screws up, beyond recommendations, you rob transition fuel available.

The limit on turns FORCES people to change the jets (for proper operation)

You look at a 1973 GSS Corolla with an 18R-GR making 140HP out of two litres, the Mikuni PHH's from he OEM were set up EXACTLY as stated: pilots barely open, huge pilot jets....but it drove like a Corolla with a single carb, silky smooth no bogs no coughs.

Instead of reinventing the wheel, listen to those guys that designed them! They aren't Rochester YH's, turning the screw out further will not make your job any easier... In fact, thes niggling things show up and confound people repeatedly.

Hear ya. I switched to the biggest pilots I had tonight - 60's. Was able to achieve high 14's, low 15's AFR with 1.25 turns out, but as soon as I cracked the throttle at all, the AFR dropped into the 12's. It sounded fat, and throttle response was noticeably subdued. Switched from those to 57.5's and was able to get the AFR around high 14's low 15's at close to 1.5 turns out. Slight opening of throttle gave me 13's instead of 12's - the engine was clearly happier - throttle response was happier. I didn't get a chance to road test because it started raining. I will do that next to see if the lean spot is subdued to any degree.

In the interest of research, PM me and I will send you pilot jets. I have a slew of them and be willing to let you borrow some to get dialed in. I'm up to 70's now, so I have all the smaller one available. I have 40's(mikunis), but I believe jets are the same.

Thank you! for that offer. I think I have all the pilot jets I need. You wouldn't have any 35 or 30 pump jets would you?

There's a scientific approach to tuning these carbs, jumping from circuit-to-circuit will have you chasing your tail. Take a look at Keith's "White Paper" in the Files section of Sidedraft Central. You'll have to register there first. Although the site is Weber-focused, the approach is the same for any DCOE-like carburetor.

Thanks for the info. I'm all over it - learning so I can make improvements.

February 21, 2013

Took it for two test drives tonight. I also put some miles on it over the weekend, so hopefully it is breaking in nicely. So, the change for the first run was to put in main fuel jets one size smaller - 160's and then see what that did. I went out on the interstate and played with some acceleration runs in 5th, 4th and 3rd, with revs from 3k to around a little south of 6k. The goal was to spend at least a few seconds with throttle open 50% to 80% while looking at AFR. On this outing, during those moments after transitions, when the car was pulling well, I was seeing 16's and 17's.

Another thing I tried was quick and substantial throttle openings. The quicker they were and the deeper they were, the lower the AFR dove. With really quick and really deep throttle applications, even in 3rd at something north of 4k RPM, it would go down into the 10's. With 4th or 5th, it would go down into the 9's. It was dark out, so I couldn't see any smoke. Anyway, as a result of those tests, I decided I would try smaller accel pump jets.

So after that test, I changed back to the 165's (main fuel) I had in there before, and I lowered the accel pumps to 40's.

For test number two, I went out to the same interstate and repeated the tests. Again, depending on how quick and deep I got into the throttle, I was still seeing 10's and even an occasional 9 something just after initial throttle opening, but as RPM's went up, the AFR climbed, only this time it didn't go as high as before. I was seeing low 15's and the engine seemed to be pulling noticeably harder. Perhaps going with 165's was the right move.

And here is something really interesting. On the way back home, I was playing with very slight dips into the throttle and noticed a hesitation that seemed like it was consistently in the transition from pilots to accel pumps - throttle opening had to be "enough" but not more than "a little" - in other words, it felt like it was right around 20% throttle opening. I did it repeatedly and every time the AFR would show a very brief lean spike. I'd be cruising at 70 mph or so, dip just that right amount into the throttle, and then see the AFR spike up with one brief instant to 17 something before blinking back to something more normal like 15. And again, with heavy and quick throttle openings, I could send the AFR down into the 9's and choke the engine up.

Having read quite a bit of what others have posted in various carb tuning threads, I think what is going on is I am too lean on the pilot jets so the transition off of the pilot circuit is causing a brief lean condition. Again, I am running 55's and I am 1 and 3/4 turns out on the pilot screws. The consensus from the experienced seems to be to go with the richest pilot jet you can get away with and keep the turns on the pilot screw to no more than 1. With either 57.5's or 60's, I hope to get down to 1 turn out... and still get the same overall driveability experience from idle to 20% throttle as I am getting now, but to eliminate or minimize that brief lean spot in the transition away from the pilot circuit.

And I think the 40 accel pump jets that I put in are still too dang big. I don't have enough 35's - only have four, so I will have to buy some. With the 165's main fuel jets, I am seeing what looks to be a fairly stable AFR in the 15's. This seems to indicate the need for bigger main fuel jets, so I will give that a try next.

I'm really not sure how the air correction is going to play into this. My basic understanding is that I need to play with that to adjust AFR in the 6k-7.7k rpm "high engine range" (whatever that is) territory. Best to put some more miles on the engine before testing up there.

Also, I need to find a way to check for constant fuel pressure from the pump as Tony said...

February 18, 2013

Rated according to actual flow, not wire diameter hole drilling like Rochesters!

It's why "jet drills" so commonly used on Holley & Rochester stuff, with somewhat repeatable results can be maddening with Webers & the like. I think there is an admonition in the manual against "drilling he jets" due to the "ream-test-stamp based on flow" procedure.

Should I just trust the numbers then - assume the flow was done correctly? I'm having some difficulty with the fact that the flow on the various jets I have differs a lot with the same size hole in them - there isn't much to them except a hole! I've got some 170's and 185's that measure the same size opening. Now that you mention this, I do recall stumbling across an article once about someone measuring flow rates of jets to get everything matched up. I'll switch to my EFI before I get that deep in into it. I have just wanted to have a triple Mikuni engine since my teens... so I am doing it, but will put the EFI on after I have my fun.

So, for me, playing with these carbs is sort of like the moment when you finally get to drive that Exotic car you had posters of in your room. When you actually drive it, you realize that you really shouldn't have because the actual experience can't live up to the dream.

February 18, 2013

Good thread

http://forums.hybridz.org/topic/106649-triple-mikuni-help/?hl=triple mikuni help

Thanks. I read the whole thing. Definitely some things to keep in mind in there like it's ok to run lean (leaner than 14.7) at idle and cruise... if having stumbling during pilot to main transition, go with the largest pilot possible and get the pilot screws dialed in to less than 1.5 turns... big cams require less pilot.

Two things:

Your AFR if not pump squirted should remain stable on the main circuit as RPMs rise, if its leaning out it MAY be your fuel pump is not keeping up. WATCH YOUR FUEL PRESSURE! Even my 70RWHP car was experiencing Fuel feed issues! After fixing the regulator and return setup to backpressure regulation, I picked up HP and my AFR's stayed steady under sustained main jet load.

One thing I usually point out to most people are that the mains in our 300HP L28 Bonneville car were 135's.

You are probably one or two jet sizes large...but make sure you have unchanging fuel pressure at higher RPM's, if it's dropping then so is your effective float level and your jets may need to be even smaller than indicated by this latest test.

This is really where a dyno to hold a load point becomes handy!

Hmmm. My fuel pressure gauge is on the regulator in the engine compartment. I'll have to wait until I can get it on a chassis dyno before I can check that properly.

I've got a full set of 6, 155 main fuel jets. I'll give them a shot. Unfortunately my full set of 160's actually measure out to be the same as my 165's --- they are all 170's! I learned from Tom Howen (driver and engine builder for Malvern Racing) a long time ago that Mikuni jets are often totally different sizes than the number on them - seems to be especially the case with the main fuel jets in my experience.

February 18, 2013

I suggested hard tip ins above 3500 to be above the pilot circuit, so you can read AFRS on the main circuit. What main air jets are you running? Too small of main airs might be bringing the mains in too early.

I currently have 210 air correction jets installed. So, 170 main, 210 air, 55 pilot, and 45 pump.

Today, I drove the car on the interstate some. I did a couple of downshifts to 4th to bring the revs up above 3500, let it stabilize, then squeezed deep into the throttle - not fast and not full throttle. I typically held it there for about 4 or 5 seconds at a time. At the beginning of that 4 or 5 seconds, the AFR would drop down into the 10's and then as rpms would build, AFR would climb with also. In the back half or last part of the 4 or 5 seconds the car would start pulling hard and I could see the AFR was around high 12's, low 13's.

The above is really quite different than from a few nights ago, and nothing really has changed with jetting. I think the float adjustments caused a noticeable difference.

I've got the pilot screws turned out 1 and 3/4 turns exactly right now. I'm thinking about going one size larger on the pilots because the Honsowetz book says to shoot for 1.5 turns. I've got 55's in there right now. Driving around with low throttle applications, here is what I am seeing, generally, in the following three situations:

steady state on flat surface - generally seeing high 14's low to mid 15's
climbing a slight hill where a small amount of throttle is needed - generally seeing 16's and briefly into the low 17's... no hesitation when this is happening.
down hill with no throttle at all - generally much like at idle in the 14's and down into the 13's some if I remember correctly

February 17, 2013

170's are big. What accelerator pumps are you running? What's your ignition timing set at? It will be hard to dial in those carbs doing hard tip-ins at lower rpms. Dial in your mains above 3500rpm - don't do a hard WOT until you are above 3500. Hard tip-ins on my motor at low rpms show rich AFR's also, but above 3500 they are perfect.

Thanks for the advice. The pump jets are 45's. I have an OEM, european distributor (single points instead of dual and possibly a difference advance curve than US spec - and of course, I have replace the points with the optical pickup for the Crane HI-6 ignition) and I have the initial ignition setting at 17* BTDC. On my last motor, total advance was about 36* and it was all in at something less than 3k rpm - haven't checked that with this motor, but it should be identical.

I am confused by the "Setting of Carburetor Main System with Running Test Alone" section in my Mikuni manual. It says "After warming up the engine, bring the engine revolutions up to the maximum rpm through rapid acceleration from around 1,000 rpm." I can't tell if that description is just of just blipping the throttle when the car is stationary, or while driving under load. I can discern nothing really when blipping the throttle heavily. The throttle response is good and the engine revs instantly and high. I don't want to rev it past 6k yet, as the engine only have about 100 miles on it. Thus, the reason I did a road test and was watching the AFR under various instances.

I guess I don't need to make sense of what the manual says since I have the LM2. My plan is to change the main jets lower and then go see what the AFR is with the throttle open more than 20% (to get out of the pilot circuit) and at some RPM that should be sufficiently high as to require operation of the Main circuit. Recording several pulls from 40 to 80 in 3rd gear with half-plus throttle application should do it.

February 16, 2013

I decided to pull the covers off and double check the floats, to eliminate being unsure about that. On thing I didn't pay much attention to last time was making sure that each float in the carb was set. When I pulled them off and checked each one in each carb, I did find one where the floats were different levels - out maybe as much as 2 mm.

So, now that I am confident the float levels are correct, next step will be to fire it up and adjust the pilot screws as necessary to fix any change in mixture the float adjustment caused. Then, I think I will try to record some data.

From just driving it around and watching the AFR, it runs ok at small throttle openings. The more I open the throttle, the worse it seems to run. For example, giving it full throttle in a taller gear, like third, at say, 45 MPH, the AFR quickly nose dives 14... 13... 12... 11... 10... 9 and at 9 the engine actually starts misfiring. I don't have a lot of main fuel jets in my inventory, but my guess at this point is the 170's in there are too big. Will need to see if the float adjustments changed any of that before I change anything else.

February 13, 2013

I had a very similar noise on my car when I over tensioned the belt on my tired alternator. Try backing off the alternator tension to see if it changes. I wouldn't have thought there'd be any noise from the tensioner? Liking this build!

Yeah, it's on my "to do" list to search the forums and elsewhere to see if the noise is to be expected with the special Kameari chain tensioner set up. I also will loosen the bolts on the tensioner and see if it feels right to back it off a tad.

In the meantime, I got the air box cover on... it is super tight to the point of almost breaking it to get it on. Unfortunately, the combo of the Cannon manifold, the rubber carb isolators, and the carbs and the .030" heat shield and the air box mounting plate combine to make it too long. Here is a pic of it installed:

I am still wondering what to do with the air filter... I have it installed in this pic.

I have two things I am thinking about. First, should the filter be pointed up like this? Over a long drive in the rain, I can see the water coming in and pooling in the bottom of the aluminum tube. That wouldn't be good, because eventually, its going to get sucked into the engine. And second, Should I put it in the center like this, in front of the radiator? Seems like I could shorten the run a touch and point it downwards and still get all the flow it needs, but the downside is that it will be exposed even more to water spray coming in the front. Where it is now, it is protected by tucking under the hood a bit. Anyway, still pondering.

February 12, 2013

Sounds really nice!

What flares and wheels are you running? Looks sweet.

Pete

Wheels are Panasport c8's. Rear is 16X9, front is 16X8. The flares were purchases from Motorsport Auto in 1992-3 - they were called "street flares", though they accommodate more wheel and tire than "ZG" flares. I see they are no longer available from there, and maybe nowhere? I saw identical ones in an old Bob Sharp Racing catalog I believe - they were very popular in the 70's and 80's for sure. Seems like ZG is most popular nowadays - just from my point of view.

February 11, 2013

That sounds Awesome!! Is that a 3" exhaust?

Yes, it is. I drove it around the neighborhood today for all of ~ 8 minutes. It was starting to rain... And it isn't registered/licensed just yet. My plan was to get a better video of the exhaust sound. I'm very interested myself... I mean, I have only heard it from the tail pipe end at idle so far. The induction noise is very loud... much louder than expected, but I don't have the air cleaner cover on there, and no filter... and no hood right now either!

I am fairly certain I'll need to wear ear plugs when driving it more than 10 minutes at a time. We'll see.

Here is my exhaust system build thread if you are interested in seeing that:

http://forums.hybridz.org/topic/109185-3-exhaust-for-na-modified-engine-muffler-options/

And another very short video of the car after the 8 minute drive... not running this time.

February 10, 2013

Well, I started a post over in the fuel delivery section because that is more relevant to what I am actually doing right now with the car, but I thought I'd post a video in this thread too. I've got the car idling at about 800 RPM now. Tomorrow, I hope to put it on the ground and get it to move under its own power for the first time in 3 years.

February 10, 2013

I had some time today to work on it and made some good progress. First I updated the firmware on the LM2. The instructions weren't great. Basically, what you need to do is go to the Innovate site and see what version of firmware is available - that latest, of course. You download that file to your laptop. Then you follow the instructions in the manual to get the LM2 into boot mode. Then you fire up LM Programmer, which is the software for the LM2. Then you click the button to "update firmware", select the file that you downloaded, and wait for it to update. Do it in that order, and you'll have no issues.

Now, on to the tuning. I fired the engine up and got it up to operating temp. It still wouldn't idle without some throttle of course. That is pretty much where we left off. This time, I checked the fuel gauge with the engine running and it was showing something less than 3 lbs. The needle wasn't bouncing as much... so I undid the lock nut, adjusted it up between 3 and 3.5 and tightened the lock nut.

So, picking up where I left off... except now I could read the AFR and it was showing between 20 and 30 when I would let go of the throttle for brief instances. Whenever the engine was about to die, I'd open the throttle a bit and keep it alive, and the AFR would drop down to around 13-15. With this info, I started playing with the pilot screws again - backing them out to see what would happen with the AFR. Interestingly, when I backed the screws out (they were at 1/4 turn out) the AFR dropped to the high teens. So, I backed them out some more. Then I was around 16. Then some more... 13. But it STILL wouldn't idle.

It was at this point that I turned off the engine and pulled out the Mikuni manual, again. I was thinking to myself "how could the AFR be that close to the right ratio, and the engine still won't idle?" and "you're supposed to be able to get it to idle without using throttle screws...". Well, I happened to turn right the page in the manual with the instructions on setting the idle speed. And what do you know? It says right there "turn the throttle screws in until they touch the lever, then turn about one turn". I thought, one turn on the throttle is about all I need to get this thing to idle. And something else I had been thinking about clicked as well. I was thinking that you were supposed to get it to idle with just the pilot screws, but if that was the case, there would be absolutely no need for the throttle screws. Clearly they were there for a reason. So, I screwed them in until they touched the lever, and then 1 full turn. then I fired it up again and used the UNI SYN to check carb synchronization. A few little adjustments to each throttle screw and the carbs were in sync and the engine was idling at 1000 RPM. Then I went back to the pilot screws. The AFR was close. At this point, I stopped turning the screws 1/4 turns and went to literally 1/16 turns. Doing this, I was able to get the AFR to around 14.4 to 15.0, with much of the time an indicated 14.6...

Just a side note, there is a reason for the really fine pitch of the threads on the pilot screws. 1/2 turn on the screws was moving the AFR from around 16 down to 13. So, keep that in mind.

So, here is a video - post changes... I've got the idle set at 800-850 here:

February 8, 2013

I remember reading your other thread. I think you need to nail down your fuel pump/regulator issue first. As I have read many times on this site, the Mikuni's are very sensitive to fuel pressure.

Yep. I addressed that before touching the pilot jets again. Needle on the gauge which is on one of the regulator ports is bouncing between 2.8ish and 3.5ish now... hoping that the accurate reading is in the middle of that range.

Are you sure you have the floats dead nuts?

It would seem that you could get that big 2.9 to run fairly close with the 52.'s. I know it has a lot to do with cams , but I run 70's with my 2.5

No smoke and smells like a carbed motor in the garage-umm-yep. Not trying to a smart ass, but I think it is hard to judge anything that way. Not sure you will be able to idle a Mikuni fueled 2.9 in the garage without stinking a bit.

Like Jon said, turn the pilots out a turn and see what your LM2 says.

What's the condition of the carbs-especially the pilot screws?

Hopefully your gauge will be okay. I know for a fact that a blown HG kills the sensor. It will probably act erratic if it is bad.

I am not sure I have the floats set 100% perfect. The way I set them was to trim and sand a nail to the right length, then use that as a gauge for setting the float lever distance from the float cover. I put the nail in position with needle nose pliers, seat the float assembly against it, and then blow (with my mouth) through the fuel inlet. I consider it set correctly when no air gets by the needle and seat assembly. This was done while the carbs were in hand many months ago - they were not on the car. Two of the carbs are essentially new, and the third may be a touch older, but is visibly in the same excellent condition. I totally rebuilt that one with a rebuild kit. Everything is tight, sealed, nice. If I confirm with the LM2 that it is still crazy rich, and the 45 pilots I have on order don't show marked improvement, I'll revisit the float levels.

Run your pilots 1 turn out. If you need more pilot, change the jet rather than adjusting the screws. There have been some pretty good threads on Mikuni tuning recently. Search and you'll find them.

The only reason I turned the pilot screws in that far: I only have 4 sets of pilot jets in my inventory - 52.5, 55, 57.5 and 60's. Since, with the garage door open, my clothes and hair would reek after running it for 10 minutes with both the 60's and 55's, I hypothesized it is running absurdly rich. Honsewetz says in the How to Hot Rod your Nissan book start at 1.5 turns out and that for each turn you have to go in, you need to go down one jet size and also the converse of this (I'm paraphrasing). So, I put in the 52.5's - the smallest in my inventory. then, I set the screws at 1.5 turns out and started it. It still wouldn't idle but didn't die quite as fast as with the 60's or the 55's. So, I turned in the pilot screws one turn, and tried again, hoping that I could at least discern some improvement - to give me some evidence I was on the right track. There seemed to be slight improvement. I turned them in one more quarter... leaving them basically 1/4 turn out at this point. That seemed to help a tiny bit more.

Since I had no smaller jets to try and the screws essentially couldn't be turned in any more, I finally went and grabbed the LM2 off the storage shelf. I wanted to test my hypothesis that it was indeed running really rich. Then I got bogged down in reading the manual and the rest is detailed in my other post.

I pulled the O2 sensor from the pipe tonight, and calibrated it per the instructions - in open air. It reacts to exhaling on it, so hopefully that is a sign that it isn't damaged. We'll see I guess.

Thanks very much for the input. Between that and searching and reading the manual and some experimentation, I'm sure I'll have it running well soon.

February 7, 2013

I got my new engine fired up last Sunday. Instead of getting the LM2 set up right away, I was excited to get it started for the first time and check the usual basic stuff... for leaks and such. After that part went ok, I wanted to play with it a bit just to see if I could get it idling alright. I tried the few pilot jets I have in my inventory. Started with 60's, went to 55's, then went to 52.5's. With each, within a few minutes, my clothes and hair would stink... (car is in the garage with the door completely open while doing this and I let it air out after these episodes - so I am fairly certain I won't die from it... ) There is no smoke to speak of, but man is it running rich. Anyway, the 52.5's are the smallest pilot jets I've got currently, so I have those in there and dialed the pilot screws in to about 1/4 to 1/2 turn out... and it still won't idle without throttle, but it doesn't die as fast as with the other sizes when I close the throttle plates completely.

By this point, I am fairly certain that it is exceedingly rich, and I don't have any smaller jets to try, so I brought out the LM2 to start playing with it. I figured I'd hook it up and get confirmation that I'm running stinky dog rich. Tonight, I proceeded to read through the instructions, and the online manual. And I learned a couple of things I wish I had known before now - clearly I should have looked at this stuff before firing up the engine...

First, it warns to never run the engine with the oxygen sensor installed in the exhaust pipe and not hooked up to the 12 volt power supply (that heats it up) or the 02 sensor will be damaged. Oops. Before the first start on Sunday, I plugged the 02 bung in the exhaust with... the oxygen sensor that cam with the LM2. So much for that. Who knows if I have damaged it? I've started it about 5 times and run it for a collective 30 minutes perhaps - running exceedingly rich in each instance... I guess, I'll just have to try to use it and see if it "works" at this point.

Second thing is more minor, but it is pretty obvious it would be an issue... the manual warns of having absolutely no exhaust leaks or the readings will be inaccurate (leaner than should be). The band clamps I am using on the exhaust joints are not quite sealing a 100% yet. I have used band clamps in the past and have found that they have to be modified by hand to seal completely - they just don't seal 100% right out of the box. So, that is next on my "to do" list before anything else.

Then I have to remove the O2 sensor from the exhaust pipe and "calibrate" it in open air... Then, I can get down to trying to actually use the thing. Judging by what I read through in the manual tonight, it looks like I have a lot of learning ahead of me.

February 6, 2013

FWIW - I'm running 45 pilots in my 44's on a 3.1L. Idles at 13.2 according to the wideband.

Thanks for that info.

I'm running a 17010-A7600 NISMO High Volume fuel pump... The gauge on the aeromotive regulator was showing 4+ but below 5 lbs. So, maybe it was enough pressure to push past the needle and seat and raise the fuel level too high in the carburetor body.

Since 3 to 3.5 lbs is what I see as the recommendation from searching, I adjusted it downward. Only problem is, for some reason, the needle on the pressure gauge is rock steady from 0 to 2.5 lbs and above 3.5 lbs... but adjusting to bring it into the 3 to 3.5 territory, it gets some kind of resonance thing going on and the needle on the gauge bounces up and down like crazy. Go figure.

Haven't had a chance to see if that changes things yet - it is too late to start it up tonight - even though I should to get back at the neighbors with their freaking loud and constantly barking dogs.

February 5, 2013

It runs!

Got it started yesterday. Doesn't idle without the throttle screws set to push the throttle plates open a bit. Not sure what is going on yet. I set the ignition timing at about 17* as with the previous engine. For now, I am using the same "Euro" distributor in combination with a Crane Hi-6 ignition - optical sensor replaces the points. Have tried 55 pilots and 60 pilots thus far and engine doesn't seem to respond to screwing pilot screws in or out with either one... just doesn't idle and makes the whole garage stink, and my clothes stink.

Seems crazy rich. Anyway, here is a short video. Throttle response is nice. The whining coming from the engine is noteworthy. I'm not sure if that is normal with the Kameari timing chain tension set-up, but my guess it that it is. I could have the tension too tight... not really sure. The instructions had some crazy number that didn't make sense.

February 1, 2013

When I did the body work on my car, the roof took a fair amount of work to straighten out... very thin layer of bondo... primer... the usual. I'd examine the spot welds on the seams and verify they are factory... that the roof hasn't been replaced somewhere along the line. If the welds are factory, and from the inside you can't perceive any undulations in the headliner, then it's nothing that can't be addressed by a body shop during a repaint. If factory spot welds are not obvious (in the rain gutter areas) or you have obvious undulations in the headliner, then their could be gobs of bondo in the panel or other nightmares waiting for you.

January 25, 2013

Oh... not the best place for the O2 sensor. It would be better in the 3" section. Did I suggest putting it in the merge itself (I hope not...)?

No, I didn't think to ask. My preference was to put it another eight or twelve inches downstream, but everything after the merge collector is stainless and I had a regular steel fitting... I couldn't put it in the 3" part of the merge collector because the transmission cross member is right there and I didn't move it any further forward because it would be on 3 cylinders only.

So, is this a known, bad thing, or an unknown but certainly wouldn't think it is optimal kind of thing? What is the best solution? I welded the fitting as high up and out of the merge collector as possible to try to minimize obstruction...

Should I put a plug in that one, and grind down the inside as flush as possible... and then buy a stainless fitting and weld that into the 3" stainless pipe a bit further back?

January 24, 2013

Got the header and the merge collector back from Jet Hot. Looks nice:

Now I can put everything back on the engine and get it ready to start.

While I had the welding gas and extra materials, I went ahead and made a "bypass" section so I could see how much of a difference the middle muffler/resonator makes in sound volume.

Still no Maxima diesel pumps in the country. I couldn't even get a used pump... Tried the Nissan Diesel forum, emailed several salvage yards across the country, tried want ads here on hybridz... no luck.

Even though my front engine cover has been modified for a diesel pump, I guess I have no choice but to put a stock water pump on there.

Maybe I can get it fired up this weekend. We shall see. Video will be forthcoming!

January 22, 2013

I've also got one from a truck. Ran it in my Z a while. I upgraded to a R200 LSD of the same ratio. I'm in GA. Let me know if you are still looking for one - I can send pics.

December 28, 2012

I am excited to hear it run too, but it is going to be a while longer before I can start it. I'm still looking for a maxima diesel water pump. Since that is taking forever, I'll send off the header and the merge collector to get them ceramic coated. Maybe by the time I get them back, I will have the water pump.

December 23, 2012

Exhaust is basically done now. A few more pics. Going to send off the header and the merge collector for ceramic coating soon - while I continue looking for an LD28 water pump.

The header still needs some welding. I'll finish that when I pull it off the motor - now that the rest of the exhaust is completely done:

Header to merge collector:

A different view of the resonator in the tunnel:

It's a tight fit:

Then the pipe has to swing back to the slot in the rear crossmember:

A good shot of how close the pipe is to the diff 'tang':

6" round muffler fits with room to spare:

Nothing specific here, but you can get an idea of what kind of road clearance there will be.

Rear diff mount "slot" fit on left side:

Again, showing space to diff:

Rear diff mount "slot" fit on right side:

Resonator to floor/tunnel clearance:

December 15, 2012

I'm in the Holly Springs area. My Z has been off the road for a couple of years but will hopefully have it fired up again in Jan. Putting the finishing touches on an all new 3" exhaust and still need to locate a diesel water pump for the new motor.

Garrett

December 13, 2012

Well, in NZ at least, LD28 diesel and Lxx petrol engines have different part codes and details for their pumps

www.STAParts.co.nz

Product Code : WPN-LD28

Description : Water Pump Nissan LD28 1984/10-86 Laurel

60mm from base to top of flange V3-037

Unit Price NZD : 52.98 Each (Incl Tax)

WPN-05A Water Pump Nissan H20 20 L26 LD28 Z16 Z18 Z20 Z24 1969-On 66mm from base to top of flange Atlas Bluebird Civilian Skyline

(Note: This Item is POA - You cannot add To shopping cart - please call or email for $$$)

I've bolded the differences, so they aren't just the same pump used for both applications, I'm not going to buy any to have a look at the impeller tho, I'm off to China on Thursday and won't be around.

So, I've been looking at sourcing a pump from Australia... emailing a Jimmy at staparts.co.nz. My stock pump (L28) measures 66 mm from the base to the top of the flange. The pump they list as for LD28 is only 60 mm. Part number on that one cross references to a WPN-062... not a WPN-079. My hypothesis is that the 062 pump differs from the 079 pump in this distance from back to front. I wonder if just swapping out the front flange would make it 66 mm. Those just press on/off...

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