Things Your Mother never Told you about Wideband (Harley related )

[afterburn 549]

Things Your Mother never Told you about Wideband (Harley related )

All things are done on this engine and almost 300 miles on this latest adventure in attempting a 1.25 HP to one C.I.

I have been chasing my tail with this HSR42 carb and the AFR.
Between AFR, and timing Daytona TT dual plug,- what a fiasco.
I am used to AFR and Daytons as I have been running them last 4 years or so, just different head/valve configuration now.
The timing has had to be retarded even more this round. That would impose the idea the ceramic is helping the ignition process to be more efficient.

So, getting the numbers on that, and the AFR -OMG

It is all OK cold, as it gets hot it goes lean, especially near idle and OAT related.

This is very concerning as it would sometimes come down off RPM and hang over the leanest number of 17 AFR (AEM meter)
So lean the meter is just dotting.............................SCARY.

This is now what Mom never told you, and I will share after much research.
Free air.
Weeeeeeeeeeeeeee
Big cam and lobe separation causes havoc of course at Low RPM but it also will make the meter read leaner!!
Leaner numbers then what the truth is.

Swapping air!

WOW!

I wish I had known all this, and thought I would share.
So -the meter is a reference point underneath the cam and AFR more to be judged on the dyno with pull numbers.
I have 250 miles or so to go B4 I dare dyno it and do the final tune.

This would have been great information had it been included the directions.
Now I have less hair to deal with as I have spent a LOT of time looking for air leaks, tank venting ETC.

Pix show 10lbs on one cyl and 11 lbs drag on the other. (reallow low numbers)

[Jeff Higgins]

I assume you are reading AFR at the exhaust. So, it's going lean on decell or trailing throttle? I'm not sure I would be concerned at all with that. The only numbers that really matter are steady state throttle and under load. How do these look?

Not quite the same animal, but my 3.0 liter MFI motor, with its very healthy cams, goes to 17:1 or higher under trailing throttle. As soon as you even tickle the throttle, however, it goes right back to 12.5:1 or so. With 85,000 miles and God knows how many track days, it's still going strong.

[afterburn 549]

This is the very first time I have used the proverbial Holy Grail - the HSR.

They have another problem -they do lean out as they warm up.!
I am so used to the CV and just love it.
But it is getting too small for the air volume.
The HSR has a futter noise with the reversion too, I can't say that is very appealing. yet said to be normal.
People do make larger CV carbs now, even Scream Eagle offers a 44.
I have a distinct feeling that is where I will end up back at, a version of the larger CV.

The AFR numbers loafing along at 55 MPH run out past super lean at times.
Or like you stated at idle and coast they can go off the scale -no big deal....
albeit I am not used to this.
There have been so many changes, it is a getting used to, and , finding what also is the new norm for this application.

Seeing it idle very lean concerned me being I do go into very HOT climates.
I keep working with it.
With OAT in low 60 it is now under control bouncing around 13.
I can live with that at idle.
Extra heat and extra holes I cant.
Plus separating the AFR lies from truth.

The real truth here is understanding what is going on in application and not so much what the gauge is reading at all times.

[rfuerst911sc]

What are the known acceptable temp readings for things like oil and the jugs or heads ? I am no expert but AFR's are just one piece of the puzzle , yes an important piece but I would rate engine temp's right up there . Are you monitoring any temp's currently ? There has to be a ton of data available for the HD engines , yours is highly altered so take that into consideration . In general how do you think the engine is running ? How does it feel when accelerating ?

[afterburn 549]

The temps are no problem -
Well within limits.
Cylinders are ductile rather than Al.
Plus this time everything is firewalled with ceramics.
Even so, I have not ever in the last 5 years had them give me the fits.
As I stated- the cam overlap is the culprit generating the false reading and biggest problem, and I was jumping through hoops trying to solve that.
The crux is I was trying to make a problem out of a nonproblem.
I never ever thought about the overlap and how fast a wide band is.
Plus I was trying to make an HSR behave like a CV.
That's just not going to happen.
The CV is the closet thing to mechanically FI for a carb that there is.

[spuggy]

Originally Posted by afterburn 549

The HSR has a futter noise with the reversion too,

LOL technology.

Traditional way to detect reversion on an ironhead Sportster is apparently to check if your right knee is wet with fuel after a ride

I've never seen it - but hottest cams I run are P grind and I hate drag pipes, so not really in the demographic...

Originally Posted by afterburn 549

Plus separating the AFR lies from truth.

I can relate; I thought gaining a wideband would be awesome. Which it is, until you encounter one of those pockets that make you think about what they're actually reporting - like when they read lean because the mixture is too rich...

[afterburn 549]

LOL
I remember looking dwn the throat of my iron head and seeing the halos.
That was AWESOME!.


The irony of this is -

The old adage the more I know is the less I know.
One has to be smarter then the tools they are using.
This is where theorums, theory, Smoky Yunick, and Joe Modello all come in handy

[Jeff Higgins]

What are the specs on the cam that you are running? You have mentioned that they have a good deal of overlap. The Andrews R5's I'm running in my Ironhead have some pretty aggressive timing and a good deal of overlap, with lobe centers set at 96 degrees. It was very easy to tune the S&S Super "E" shorty with these cams. Great idle, no flat spots, no lean or rich spots.

[afterburn 549]

That is the most interesting part
DM 530 cam
I have run this cam with my port job for a few years.
It pulled hard!
I know better than using a high RPM race grind and I guess I could move up a little but with that, of course, the engine loses at the bottom.

Then I wanted to go rollers with proper geometry. (less parasitical)
So my friends in portland raised the intakes 1/2 inch up, did the geometry for the lift, and stuck in larger valves.
And then their port secrets.
Not necessarily in that order.

One would think it would not make that much difference.....it would not even idle with my moded CV.

It would fart, gasp, snort, go lean and die.
Yes, hours looking for air leaks and tank venting problems.
none.
I could keep it running at a higher idle but no idle.

*I did know what was happening.
With everything improved, it now was really feeling the overlap a lot.
After some research, I thought I would try the HSR42 I still had in a box I had tried a few years ago.
I did not like it then not so sure I like it now, but the biotch now runs.

A Couple more week it will get on the dyno and see what it does compared to last time






* with a CV the throttle plate needs to be drilled for larger LSA *

[sammyg2]

My first impression is that all your problems can be traced to two and three-letter-acronyms.

[LJ851]

Raw fuel out the exhaust can cause an AFR gauge to incorrectly read lean.

Looking forward to your dyno results.

[afterburn 549]

Originally Posted by LJ851

Raw fuel out the exhaust can cause an AFR gauge to incorrectly read lean.

Looking forward to your dyno results.

The goal, of course, is a spike at near 2K and flat across the top.
Now I am at the point of trying to outguess the "dyno guru" as far as what should be done next B4 it lands in the treadmill.

[KFC911]

Originally Posted by sammyg2

My first impression is that all your problems can be traced to two and three-letter-acronyms.

^^^^ WHS...OK

(what he said...)

[afterburn 549]

Ok
you guy being serious?
What is it you are not understanding>?

[DanielDudley]

You are a braver man that I am. I am always looking for proven combos that will get tried and true predictable results. I have seen too many combinations of various parts bolted together that didn't work, and will never work.

The thing is, you are out there doing your own work, and when you finally get it right, you will have learned a whole lot. When I was working on the Italian engines way back when, we never wanted the exhaust port matched when we were using a lot of overlap. We wanted the header pipes to be bigger than the exhaust ports by a bit, like an eighth of an in or so.

Something about reversion control. Of course, that was with carbs. It seemed to help though.

[afterburn 549]

Thanx
I am limited to the machine work I can do-
I do all my own valve work-started when an old guy said to a very your man "go over there and just do it"
Nowadays I think I have become a bit of an expert...
SO many things to learn and hard to dwn load to another person.

For instance, it goes against all rule of laws to move the seat to the top of the valve.
I will guarantee you some very great results in performance if you do only that, and make them NARROW!

As you said there is a trade-off

I build all my own heads for 20K mile turn around. With almost all high-performance stuff it just doe not last as long.
My last top-end ended when the pinion nut did not hold the drive gear. Thankfully I had just got back from Sturgis ( I refuse to trailer as that is for the poser crowd)

What did I learn and no one ever told me? ( and no one will say to this day anywhere)

The pinion on an EVO is the weak link-
It is not tapered shaft like the shovel, (and that is a BIG deal)
It is just around shaft.
It has about a fingernail thickness of a part of a 1/2 moon holding the drive . (not enough)
All is well until a person installs a large bump stick and HIPO springs -the continual rocking back and forth at low RPM will make that skinny little nut lose its grip, and then?
The exhaust valves will kiss the pistons ..just a little.

After much constipation on NOT ever wanting that to happen again, I installed the new nut (read tiny thin anemic ) to the prescribed 40-foot lbs I think they call for with a quart of the red Loctite .
i still did not think that was gooder enough, and tigged a spot 180 deg from each other . It can al be ground off in a minute when the time comes..
But i gaurantee me it is not going anywhere this time.!

[KFC911]

Originally Posted by afterburn 549

Ok
you guy being serious?

Naw

[afterburn 549]

OK, thanx
back to the grind

Did i mention 50 deg valve seats this time?
The devil is in the details.

[asphaltgambler]

.........I'd like to add a few thoughts.

1) Regarding ignition timing with dual plug HD's - that generally you can back off total timing 2 -3 degrees and make the same power. Also if you increase cranking compression you need less total timing as well. But to dial it in - the engine needs to loaded on a dyno and the AFR already dialed in.

2) HD's are under-squared engine designs - not big news. What is news though is the air flow requirements for a long stroke set-up. Add compression, increased cam timing and port flow and those air flow numbers (requirements) go up substantially. In order to properly load the cylinders with adequate fuel the fuel 'map' looks like the side of a mountain.

As in: from start to rpm limit the amount of fuel needed cannot be supplied from a standard 2-speed fuel jet circuit carb. Further, there may need to be air correction jet(s) either changed or added where there was a fixed jet prior.

While the Mikuni is a good carb (as well as a few others including stock CV) there is a real solution. Zipper's Performance ( Jessup Maryland) sells / modifies S&S carbs. They add a 3rd fuel circuit that atomized for top end fuel supply. Now you can tailor the fuel curve with 3 circuits ( sometimes a 4th ) tuning your main jet for midrange and using their patented Thunderjet for 4200+ RPMs.

Also, depending on your combination - they will add air correction jets and or bore the venturi and extend the main jet emulsion tube up into the air flow. In the end - the fuel loading the cylinders will match the airflow requirements of the engine through-out the RPM range.

[afterburn 549]

Thanx !
The Dyno Guru (Scott at Hillside Harley) will do the final treadmill load and tune.
He is also a racers racer from way back .
He is a pretty smart cookie and will not just push for big numbers but knows what this is for, and will ascribe to that purpose.
I am sort of thinking this HSR will get me to the ring break-in, but I have a feeling it will be going in the trash.
It is very annoying to hear the slide flutter at idle. I kind of hate it.

Also and perhaps I might try about the same cam juts a wider lobe separation
With the dyno, results are a lot more measurable and consistent.
As of now, i am fighting 1600 feet and cooler temps.