Little Red Wagon...

[troyt]

Your engine bay came out great, very nice and tidy.

[Just Joel]

Thanks :) It's a developing story... Wires will hopefully be gone this winter if I can find time and I'm changing other minor things in an effort to clean things up a bit.

[Swedishcadillac]

When everyone sees his news Shoes and Rearend, it's gonna break the Ratsunet!

 

[Just Joel]

lol...

[anth]

While we're talking about carbs and such, I should add a picture of the finished engine bay...

 

Is there a "bow down" emoticon? Because there needs to be!

[Just Joel]

Haha... Thanks Anth, hopefully I'll get the exterior up to par someday :)

[mrbigtanker]

While we're talking about carbs and such, I should add a picture of the finished engine bay...

 

 

Although I shouldn't say finished as small things have changed ;)

Joel some rubbing compound will get that engine bay to shine up. lol

[Duncan]

Joel,

Somehow, I had not seen your wagon thread before.  Very nice work, and what an awesome wagon!

 

I hope my OzGoon ends up as nice as yours.  Well done,sir   :thumbup:  :thumbup: 

[Just Joel]

Shit... Your on a whole nother level my friend but thanks for the kind words :)

[ATP]

You have done a really nice job, very clean, nice attention to detail! I am curious why you changed your carb settings though? You said it was too lean at cruise? What exactly were you seeing for AFR during cruise before and what do you see now?

 

 

Andrew 

[q-tip]

The big reason for the needle modification is that the never made a jet and needle set for the L20b.  So you were either too rich at idle/cruise to run correct mix /wot or the opposite.

 

 

Still really love the shifter by the way

[ATP]

I love hearing when people love that shifter. I put a ton of time into it so it makes me happy when people tell me that!

 

I may not have asked the question too well, I was mainly wanting to know what the AFR was that made him think he needed to richen it up at cruise? I set up some SU's for a guy with a wideband (as I do with any setup I'm tuning) and was very pleased with the stock setup for the SU's. Nice and lean for cruise, not too rich at heavy loads/WOT and idle was acceptable.

 

People would probably have a heart attack if they knew the values I tune for on all the EFI setups I do. One thing many don't realize is that you won't ever hurt an engine by running it too lean at light loads.

 

 

Andrew

[Just Joel]

My values were extremely high (18's to 19's) at cruise light loads especially when air temperature was cold in the evening. Here in central Oregon (high Desert, 3000' elevation) , we experience temp swings of 50° on a regular basis during a typical day. The car was on the verge of a stumble during the lean state condition... Probably not dangerous (or at least not according to the guru's) but also not optimal in my mind. My goal was to richen the cruise/light load state along with around town values during the coldest part of the day. What I've accomplished was a one to two point reduction in numbers at the targeted state. That means that typically, my numbers at cruise are in the 16's and around town values hover in the 13's and 14's depending on air temperature. Wot was not changed and typically come in rather rich and idle is happiest around 12.5 Like you mentioned, any efi tuner would consider these numbers obscene but for my little L, they seem to work well. I should note that I'm not an expert in any way so please correct me if I'm out of line in my thinking. What values are you used to seeing?

 

I also love the shifter... And can't wait till you make one for my trans ;)

[Just Joel]

Very good you chimed in tho... This is an evolving process for me that I'm very much still developing. Currently, the car tells me she's "fine" with the mixture settings but I've been contemplating more changes in an effort to better optimize the numbers... I would love to think I didn't have too tho :)

[ATP]

The fact that you have installed a wideband O2 makes you more professional than about 95% of the shops I've seen that "tune" carburetor setups. I have seen some of the real old timers that have tons of time and experience with specific carburetors that can do a pretty decent job, but that's more because they have experienced what doesn't work, and have learned a few tricks about what seems to do ok. I prefer to get the data, and make changes based on the data. I have a few carb setups I've done (I much prefer EFI) for customers that either couldn't afford efi, or wanted a more period correct/stock vehicle with the carburetor. And in all cases when I set them up with O2's and set every part of the carburetor the way it should be set, it actually runs quite well and has good drivability and reliability (which as a hardcore EFI guy, is hard to admit!). Anyways, What I am mainly trying to say is you have done a great job by first putting in the wideband in and getting some real data to go off of! That alone gives you so much more authority to say what works and what doesn't and why.

 

18-19:1 AFR, even at cruise is pretty high. If that was a consistent reading at light loads I would have expected at least some random lean misfires or hesitation when cruising. It very much depends on the engine though. Typically when I am tuning, I will lean out low load area until it misfires, then I'll richen it up slightly. For example in my 64 F100 truck I have the 4.6 modular ford V8 running right around 17:1 AFR during cruising. Much leaner and I will start to notice a slight bucking at times when it randomly misfires. Obviously I don't want drivability issues, because that will then reduce efficiency. However you won't ever hurt an engine at light loads. The hard part with a carb, is that you don't typically know where the actual load is at unless you have a vacuum gauge or MAP sensor hooked up. So figuring out if the transition point is too rich or lean is the hard part. Just because you are light on the throttle doesn't necessarily mean its light load. It is typically a fairly close relationship between the two, but there are times when light throttle does not equate to light load. I tend to side with safety in those areas and would rather be a little more rich in and around a transition point rather than lean. But in true light load areas, I lean the crap out of it, until the engine tells me it just doesn't like it.

 

For a N/A engine I will run AFR in the low 13:1 at WOT. I've leaned it out as much as 14.5:1 at WOT though, if that's what the engine wants. Its hard without a dyno to know this, so if I'm street tuning, I will err on the side of caution. 13.0-13.5 AFR is typically a great N/A WOT number to shoot for. I have seen when more performance built engines prefer more fuel though in the 12.5-13.0 range, but typically any N/A engine running below 12.5 AFR you are loosing power. If its a vehicle that is built for endurance or will be subjected long and often WOT runs, I will richen it up even more (which means sacrificing some power) for cooling purposes to stave of detonation issues that can happen on prolonged WOT situations.

 

With idle it can vary, but I find 13.5-14.5 at operating temp is a range most all engines like to be in. Much richer and you just start wasting fuel in my opinion. I have seen a little richer condition pull slightly more vacuum, but I'd say the majority of time around 14:1 is where I land for idle AFR. Bigger cams are the exception because it screws up the O2 reading because of overlap. 

 

This post ended up being pretty long, but hopefully provides something helpful to anyone wanting to setup their carb or efi themselves with not much tuning experience. 

 

 

 

Andrew

[ATP]

I will say your environment is prime for an EFI swap!  :D

 

Temp and altitude changes are brutal on carbs.

 

 

 

 

Andrew

[q-tip]

Joel, you jelly of my shifter bro? :lol:

[Just Joel]

Great info... Everything you mentioned is exactly what I've read to be true and I've based my tuning on those factors. I have actually done extensive work in attempting to lean the idle state and she miss behaves anywhere above 13 AFR.

 

At WOT I'm in high 11's low 12's. Short of adding material out near the tip, this will have to do. I attribute the rich condition largely to the smaller carbs inability to deliver enough air but this is entirely based on "gut feeling" less actual fact. Regardless, this isn't a race car and rarely do I find the skinny pedal tight to the floor :)

 

EFI is always on the table and I've considered it extensively. I've fallen in love with a few Japanese ITB setups that I wouldn't mind having a go at. Once I'm done with my current (expensive) phase of the project, I might re entertain the idea.

[Son_of_a_Datsun_Guy]

I have a similar issue with the SUs on my motor, and I know that I'm getting starved out on the top end. Unfortunately there is only so much you can do to the SUs. I'm not a Mikuni sidedraft fan (especially for street cars). EFI's been on the list for a while (I've got at least a new rear end, more interior, and some more body work in line before that). For a while I really wanted to re-purpose some of the Toyota 4AGE ITBs that came on the silvertop motors in Japan.

 

Recently I've found some cool options from Borla and EFI Hardware (crazy Australians). After having a lot of conversations with a friend of mine that builds spec Miata race cars and rents them out, as well as competing in a lot of time-attack like events, I'm almost convinced that it makes more sense to run to a more standard plenum TB setup. His experience with small displacement 4 cylinder motors is that ITBs are A. a pain to tune and B. very top end happy, leaving little for the lower end (much like Mikunis in carb-land).

 

The trick is finding/building a plenum setup that doesn't look like :poop: .... Just some food for thought when you get to that stage in the build. 

 

I'm very excited to see where you're going with this new winter "overhaul".

                                                 

[ATP]

The work you have done so far is extremely high quality, I assumed you did your research, but was still curious as to your thinking for making your decision to modify them.  

 

The rich idle is kind of common, most likely because of the ignition. The reason so many people (incorrectly) think that rich always means more power, is because back in the 60's and 70's it did mean that. The engines were capable of making more power, the fuel and induction systems were making there way to being more capable, but the ignition was always the limiting factor....many times still is. The nice thing about a rich condition is its easy to "light off", so as you make more heat and combustion pressure, there is less chance for misfire with a nice rich mixture. Too much heat and combustion pressure can cause misfires for weak ignitions, but so can too little heat and combustion pressure, its not so much the engine, but just that the ignition is less than ideal for the conditions. This is one of the reasons I almost always go to COP setup with any EFI swap I do. It allows me to take advantage of programming very lean conditions for maximum efficiency.  

 

I will say I really like your wagon though, super clean, the work is top notch! Looking forward to more updates on this thing!

 

 

 

 

Andrew

[greengoon]

So glad that you updated your thread. Your build quality is amazing... and you're doing it all yourself. My hero!

[Just Joel]

Haha... Thanks man ^^^^ your guna like the next part ;)

[Just Joel]

The work you have done so far is extremely high quality, I assumed you did your research, but was still curious as to your thinking for making your decision to modify them.  

 

The rich idle is kind of common, most likely because of the ignition. The reason so many people (incorrectly) think that rich always means more power, is because back in the 60's and 70's it did mean that. The engines were capable of making more power, the fuel and induction systems were making there way to being more capable, but the ignition was always the limiting factor....many times still is. The nice thing about a rich condition is its easy to "light off", so as you make more heat and combustion pressure, there is less chance for misfire with a nice rich mixture. Too much heat and combustion pressure can cause misfires for weak ignitions, but so can too little heat and combustion pressure, its not so much the engine, but just that the ignition is less than ideal for the conditions. This is one of the reasons I almost always go to COP setup with any EFI swap I do. It allows me to take advantage of programming very lean conditions for maximum efficiency.  

 

I will say I really like your wagon though, super clean, the work is top notch! Looking forward to more updates on this thing!

 

 

 

 

Andrew

Thank you Andrew, the tech conversation is much appreciated... Always learning :)

[Just Joel]

 

Oops...

[q-tip]

 

Oops...

I'll say, look at those spots you forgot to paint!