Replaced POD's--OH MY!!!

[hdm48]

After Piers listened to my truck at BD's dyno days he said it was an injector imbalance. So he sent me a new set and I poped them in today.

MY OH MY!!

The first thing Captain Enteligence [me] did was pull out to the main road an punch it. WRONG! Very bad idea. After one 360 I got it under control and attemped to leave the area before my neighbors convenced themselfs that I'm a total idiot and can't drive.

The next stunt I tried was to stop at the bottom of a hill that everybody uses for testing and stand on it from a dead stop. So I did. Well, the truck just sat there and smoked the tires then started to roll backwards in a cloud of smoke. About that time a Sheriff picked this day to show us our tax dollars at work. well here I am doing the best burnout in 10 years right in front of him. I just pulled over to the side of the road thinking 'how much is this gonna cost me?' As it turns out he was a friend and a horsepower freak also so we talked for a while then he told me to go home with that stinky thing and leave the 'real' performance to gas engines. We argued for a while about that then when neither of us would give in we both left. PHEW!

But anyway, lots of power and I need to do some final tuning to come up with numbers. I'll post what they are.

Just thought I'd share.



--dave--

 

[AlK]

Dave,

I remember you telling us at BD Dyno day that you thought that your injectors were not working properly. Good to hear that Piers came through for you. Maybe at the next BD Dyno days you can get your 'BLACK BEAUTY" on the Dyno and put up some good numbers. Glad to hear that you are happy with the POD's - those poor tires.

---

Al

 

[BushWakr - RIP]

hdm48,



I'm curious, when you got/put in your first set did they come with washers? Did the second set? Was there a difference between the washer?

I went through a similar process and saw a marked difference.

I still have some 'at idle' smoke. Do you?

I'm still impressed with the difference between the POD's and the decent 180 HP inj's I had before.

What kind of boost numbers are you seeing now?

Fill us in on your setting(s) and results.



Thanks,



Bob.

 

[hdm48]

Bushwakr, the first set came with washers. The second did not. There was a set of . 013", . 060", and a set of . 115". I used the . 060" as that was what was in with the 230hp injectors. I have no smoke at idle when it's warm. Anything over 15lbs boost makes a little smoke and WFO makes a LOT of smoke.

Like I said, I need to do a little fine tuning.

My timeing is way up there. I'm not even sure what it is now as I moved it up a little from the 1. 4mm that it was set at before. Some T&E is in order here. The max boost is a problem. My boost guage is acting funny. I need to check it to make sure it's working as it should. It says it's making 28lbs and I know from the way it pulls it is making more than that.

One thing though. My idle is slow. You have PODs right? Did your idle slow when you installed yours?



--dave--

 

[BushWakr - RIP]

BTW guys, someone told me the POD's were larger than the 370 injectors... .



Is that true ???

Is there a comparison between the POD's and any others like DD I's or II's as a reference point??



There also seems to be a wide variety of washer sizes being referred to as well. I thought I heard Piers say that . 020,

. 040, . 060 was the three basic thicknesses. Now your sizes make me wonder about this and very curious about what size is actually under my POD's.

Hmmmmm... ...

Thanks



Bob.

 

[roadhawg]

Hey Bushwkr





I have modified 370s and I can tell you



that if the POD injectors had been around when I had them built; that I wouldn't have wasted my time and $$$ on building them.



If you look at the performance you get out of the PODs, vs what mine with opening pressure of 3400lbs you will agree the PODs represent an excelent value.



I believe my manifold pressure #s are within 2lbs of many of the users of PODs so if you are looking to find huge HP#s in A set of 370s? not!



I think we should look into bigger delivery valves for the VE.



Just my opinion

 

[Don M]

The Lucas injectors do flow more fuel stock than the 370 marine nozzles stock.

I have set of Lucas injectors that I extrude honed to flow about 15% more fuel than stock. They work very well and increased my HP around 35-50. Yes, they smoke. Even at idle a little, but they make more power.



Don~

 

[CrewCabDiesel]

Know what you mean . The POD are a major YEE HA . I have yet to set my pump up, I am at little over stock settings on my injector pump and have shredded a set of Goodyear AT/S 285-75R-16s. The tire dealer has measured my tread depth yesterday and I have ground off 8/32 in 10K miles:--) :{ . It seems I am leaving 2 black marks when I hit 26lbs of boost in 2nd 3rd or 4th gears . I get some smoke at half throttle & a mild fogging at WOT, but none at idle.

Kyle

 

[BushWakr - RIP]

LOL, I understand the term "smoke" now. Kinda reminds me of the old WW II movie were the destroyer captain shouts, ... "make smoke, come about... ... . "

I got the "make smoke" part down pat. .

I just wondered about the idle smoke though. I've seen so many fuel hogged 2nd Gens that don't do this at idle I wondered if it was normal for our trucks with these injectors, or if it was just mine.

Some seem to smoke, some don't.



Don M, thanks for the reference point. I also wondered were in the "food chain" these injectors fit compared to others out there and your answer filled in that blank.



Here's another question for you if you're inclined. I understand that at idle/low RPM the lower fuel pressure results in a slightly coarser fuel cloud = some smoking.

Why can't the pop-off pressure be raised a few 'bar' to help with that? I think the POD's have a 250 bar setting,, why not up it to say... . 255 or 260 bar??

Would that help at lower RPM's or cause other problems elswere?

I have recently learned/heard that the "offset" bowl in the piston and the injector angle can mean that some of the fuel cloud will overshoot the top of the piston and not burn efficiently. Hence the need to tiddle with washer thickness to get the nozzle tip in just the right position without allowing it to get hit.

Would a combination of pop-off adjustment and washer thicknesses be a do-able solution to low end smoke??



Bob.

 

[hdm48]

Bushwakr, I would REALLY like to hear the answer to that question.



--dave--

 

[Don M]

Im not a guru on the first gen engine, but I do know a little something about the Lucas POD's.



Mine poped-off at a clean 260 bar right from the factory. I tested and tested these things on the bench and they are now all balanced or shimmed to within 1%. I used diesel fuel and not test oil though. Test oil seems to give a lower number IMO.

The hole size on the POD is rather large when compared to some of the more emission designed stuff of today. Mine are honed out to a very large size. This just makes it tougher to obtain a smoke free idle and WOT run.

Timing plays more of a part of flame travel and where that flame is propagating. Moving the injector nozzle further and closer does not seem to help very much. I tried varying thickness of washers. Even some custon stuff and the power stay about the same. Smoke too. Heck, I even tried some super custom stuff to help position the nozzle right where I wanted it with a second cylinder head and mock up piston assembly. No power gain or smoke loss to speak of. I now run the thinnest washer I could get made up. (. 017)

There is some flame travel across the top (out of the combustion bowl) of the piston when the timing is advanced.

Raising the pop-off pressure is generally done to help with atomization of the fuel through larger sized holes. It can and will help low end smoke in most cases. Even fuel economy a little.

Another thing that just popped into my head is... the Lucas PODs are a sac hole nozzle and the small amount of fuel that does not get into the cylinder during injection to be burned remains in the sac long enough after combustion to be boiled away and make more smoke. It seems to boil away once the piston is/has already traveled a good way down the cylinder. So, more smoke is produced. Very small amounts.

Yeah, raise the pressure and see what happens. Moving the injector around did little for me.

Remember though, I run these in a second gen engine with a P7100 pump and custom injection lines to make them fit. Your results may vary wildly to mine. Good luck and if you try stuff let me know what happens.





Don~

 

[BushWakr - RIP]

Don, I don't want to monopolize your time but could I ask a couple quick follow-ups here??



>If washer thickness made no diff. why did you go with the thinnest? What was the rationale behind that? Since the spray angle of the POD's is (I think) 145* wouldn't lowering the nozzle tip have the effect of concentrating the spray in a smaller area of the 'bowl' or is that the point, lower the tip till the spray angle just places the cloud into the bowl?



>If timing causes/effects flame propagation across the piston head as timing is advanced, then it's logical to assume there is an

"idea" timing setting for each and every injector when spray angle/bar/hole number/size varies. Is this on the right track?



Man, this place makes you think way too deep.....

edit: see what you started hdm48



Bob

 

[Jim Fulmer]

The next stunt I tried was to stop at the bottom of a hill that everybody uses for testing and stand on it from a dead stop. So I did. Well, the truck just sat there and smoked the tires then started to roll backwards in a cloud of smoke. About that time a Sheriff picked this day to show us our tax dollars at work. well here I am doing the best burnout in 10 years right in front of him.



LMAO... ..... Good story!

 

[Don M]

Bob,



After reading my last post I cant believe anyone could follow it. I was sleepy and the words show it



Ok, I used the thinnest washer I could get to help minimize the effects of the thicker head gasket I used. I went with a . 020 thicker dude. So, I fashioned up some thinner washers to get the nozzle closer to the original position. I also did another trick to get the nozzle closer to the piston bowl, but it is censored. Easy to figure out though.

I did not follow Bosch's "standard" of spray angle. I looked at the 4 nozzle holes from a 0 degree angle and came up a single 43 degree hole, a couple of 30's and a single 5. Looking at the way the injector is tilted in the cylinder head must give a total of 145 on the single hole that is at 45. Just saying this nozzle is 150 and this one 145 does not account for all the spray holes. So I decided to drop that Bosch terminology and come up with what I did.

Changing injectors and the timing you run them at is a good way to tune in more power. As we time in more advance we get flame travel across the top of the piston at lower rpm but get closer to optimum at higher rpm. The rate of discharge curve is important here because you can cause a worse ignition lag of the mixture with the big injector or low pop off pressure. If the needle does not close and open at an optimal time during the curve you can put out the flame some and cause a partial burn or get the fuel in to early or late.



The reason I did not see much gain or loss from different thickness washers was the distance the fuel has to travel. An extra 30 thou or so does not seem to make much difference in top HP numbers. The low end stuff and spool up, etc. I did not test. I assume there is/are gains to be made in that area but I did not care. Just the top number is/was what Im after. Some smoke reduction can be had, but its small. Real small.

timing a static in out trucks with the mechanical system. The reason the 24 vavle trucks can make so much low end torque and good HP numbers up top is the boxes are elcetronically changing the timing at different rpm ranges to get the best of both worlds.



Over the 370 marine injectors with the tweaking I did. I came up with 50 solid HP looking back at the dyno sheets. So, there is power to be found and now Im working back the other direction in injector types.



Don~

 

[BushWakr - RIP]

EXCELLENT !!



Thank you Don. Your last post has uncovered a fair amount of adjacent issues for me to think about.

The last and 'censored' method of placing the nozzle tip closer will likely come to me in an epiphany, either that or while I'm in the head taking care of business

For the moment it eludes me though.

Perhaps I'll tinker with washers a bit as well as timing and, see if it makes any noticable difference.

Again, thanks for the time and sharing of info. ..... censored eh.....

hmmmm... ... .





Bob

 

[BushWakr - RIP]

I stopped in at one of my local fuel inj. hideouts today to talk "washers" oooooo ahhhhhhhh... .

Anyway, the fella hauls out 3 different sizes and tells me that... "these are the 3 standard washers that Bosch uses"

One was 95thou, one was 65thou and the other was... ummmm. . tissue paper thou.

Now he grabbed a digital caliper and took out about 8 of the 65 thou washers.

They all ranged from 64 to 67. 5 thou in size. (thickness) Not exactly high tolerance if you ask me.

Sooooo I told him to take a pot of coffee, some 600 or 800 fine and make me a set EXACTLY 60 thou.

I'm thinking that the mid size is what was put in with my POD's the last time. (the ones that I thought were 40 thou)

I am also going to have them balance my POD's to within 1 bar or less if possible, and raise the pop-off to 270 bar. (assuming they come out and test at 260 bar as Don M mentioned)

Personally I think I'm going to be washing dishes for a very long time before this is done.

There is one other project that I think I'm going to have a try at but I'll save that for later, when I see what comes of this "newbie" experiment first.

Now I know why the guys who've "been there done that" don't wanna tell it all... still, kinda fun when you start "the hunt" for answers.



bob