UPDATE 2/17: Shepherd Engine Saga Continues - third drive - about the same

[rv_safetyman]

Could the cold temps create an environment for this problem?

.  It sure as heck causes a problem for ME .  We were supposed to be in Yuma enjoying the sun!!

Ed, we were typing about the same time.  I am pretty sure that the stainless hose I am using is Aeroquip with AQP tubing.  That is said to be resistant to almost any fuels.  It is used in racing applications where racing fuels are really tough on hose.  The problem I am dealing with in my mind is whether I put both hoses on or just the supply to the filter.  I will try to check my records when I get a chance. 

I think the Holley pump test will sort out any problems.

Jim

[Don4107]

Boy that thing has sure put you through the mill.  No pun intended. 

There is one sure way to eliminate the fuel lines and that is to actually eliminate them.  It may be a little too redneck but a 5 gallon can hooked up to the filter and return line would eliminate the guess work.  It would also give you or a helper a chance to see if fuel is still returning under full power, such as it is.  I am certainly no expert but the fuel flow you got out of the restricter sounds low to me. 

Hope the weather and your luck improves,
Don 4107

[Busted Knuckle]

Jim,
I am like Don on this (while I am no expert) but it was said (when they first came out, and has been proven wrong many times over) that the 60 Series engines are "supposedly" returning enough hot fuel to the tanks to keep the tanks from having "gelling problems" yeah right, tell that to all the truckers we used to pull in off the interstate & hwy's "to thaw out" when I drove big wrecker!

But I still feel it might be a low amount on the return. (don't ask me why, cause I have no clue)

Now as for the 3 piece exhaust manifold on 60 series. I have been down that road before too! When we replaced a turbo 2 yrs ago we found that the manifold had cracks in one section. I called the place we buy a lot of parts from and was told by the girl I deal with (yes girl) "if the one is all you want, I'll sell you just the one, but we generally find if one has cracks all 3 have cracks or will crack trying to separate them or will crack soon after re-installing them , I do have all 3 in stock. It's your choice!"
Well upon better inspection dad & I saw that yes 2 of the 3 had obvious cracks. So we bought all 3! Once it was back together and producing so much boost I was blowing hoses of the charge air cooler system (different issue! ), I took the old manifold apart and sure enough if the 3rd one wasn't cracked before I started, it was when I finished!
FWIW   BK   

[blue_goose]

Jim
You have found your problem, the little puff of smoke when you started the engine is enough to kill your boost.  I know you said it cleared up, but so dose the exhaust after it starts.  Any small leek at the exhaust will kill the boost.  I don't think it will ever fix it's self with rust.  I haven't had any experience with the 3 piece exhaust but I am sure it shouldn't leak.
Jack

[rv_safetyman]

2/21/10 Well, I thought I would go out in the 20* (max) and snow crappy weather conditions to the unheated shop and test the fuel flow.  This weather is really getting to me.  Been this way on and off for the past several weeks and will be for a few more days at least.  Down into the low teens and sub 10 most nights.  Been a terrible winter.  Global warming, my A$$ .

I uncoupled the braided stainless hose from the Series 60 fuel pump and adapted it to my Holly (red) electric fuel pump.  I pumped one gallon in 55 seconds.  That equates to over 60 GPH which I would think would be plenty.  Definitely suggests that there is no blockage between the tank and the pump (including the filter).  There is no filter after the pump - goes directly to the head.

It looks like we might have a window on Wednesday or thursday (assuming we don't get too much snow) to do some more testing.  I plan to install the ECM that came with the engine to see if there is any issue there.  On the next test drive, I will be sure to check my mechanical boost gauge against the DDEC reading to make sure I don't have a boost sensor issue.

In the mean time I am trying to psyche myself for the terrible job of changing the turbo and checking the exhaust manifold.  In Eagles, the engine is offset to that side and there is really not much room to work.  I might see if I can pull the exhaust blankets for the next test so that Pat can get a better look for any area of exhaust leak and when I can put a listening tube on the joints.


Jim

[Bob Belter]

Ahoy, Jim,

And  ----  while you are being 'entertained' by your engine, a few other experiences which I have 'enjoyed'.  Probably nothing to do you're your problem,  but maybe of interest to others.

Last summer, on a trip to OR, WA, a problem with my Eagle -01 and
Cummins M-11. 

Cruising up a mountain pass, I saw my EGT was at 1100f +   !!!!!!  --  and increasing!!!    So, I reduced power.  I'd never seen it above ~~1100f before.  My EGT sensor is plugged into the manifold  --  (if installed below the turbo in the exhaust pipe, it would be a lot lower because of the 'work' that is taken out by the turbo).   As I looked at my readings, I realized that my boost was down  --  best at ~~2000 rpm was about 10 -12 psi, and the EGT was climbing until I powered down.  Power was down too, but I was able to continue, with one eye in the road, and the other on the EGT gage.

I checked and found no fault --  all the hoses and clamps were OK.  I suspected that my charge cooler had 'blown', and was leaking, or maybe my turbo was bad.   If I didn't have my boost/EGT gage (Westach), I'd probably not have known until it was too late, and I'm sure that I would have blown my engine!!!  EGT running wild as I saw would have fried the valves right out of the engine.

I was able to continue my trip.  The mountain passes were a slow ride, to hold the EGT down to no more than 1100f.  I was over there with the 80,000 lb loaded trucks.  Cummins has available 'maps' of EGT/RPM/Boost combinations, but one gets used to normal ranges and limits for different conditions.

Got home, and (finally) found the fault.  On the (hot) compressed air discharge 4" aluminum tubing from the turbo to the charge cooler, I had a 1/8" pipe thread port with a phenolic plug with a thermocouple sensor imbedded in it to check discharge temps.  (Yuh, hot,  ~~as high as 325f at full boost of ~~29 psi).  When I was through with my engineering work, I just clipped the wire and left the phenolic plug in the system. The plug could obviously not take the temps and blew out.  A brass plug is now doing the job OK.


Another 'event':  Two months ago, in LA country, a slight 'pop', no boost, and EGT going wild!!!!  I was able to crawl over the pass with an eye on the EGT without hurting the engine.  Stopped, and found that I had blown off a hose.  At least I'd not lost the 'T' bolt hose clamp, and the 4" silicon hose was OK.  Went to re-install the hose, and it would not slide together.  So, I said to my wife "Please bring me some KY jelly".  "Well, OK, but I thought that you were working on the bus".  Worked just fine.

For all you bus guys out there, as far as I'm concerned, a turbo diesel engine without an EGT gage plugged into the exhaust manifold, and a turbo boost gage is NOT fit to be driven.  I can think of no more important instruments than these items.  The oil  / coolant temps, pressures are also vital, but usually don't change that quickly.

With this instrument, you are able to 'press on' with knowledge that you are not hurting your engine.  Absent an EGT, you are constrained to being a philosopher.       

Enjoy   /s/   Bob
     

[rv_safetyman]

Bob, you have preached this subject to me many times and I knew that I need to get and EGT. These stories really drive home the point.  I even welded a bung close to the turbo (no good place to put it in the manifold ahead of the turbo for the gauge.  I would think I will get good relative data.

Folks have said that a small leak will kill your boost and your story reinforces that. 

I have been trying to make my plans for the next test run.  I did just find out that my turbo (the by-pass unit that came with the replacement engine) did not make it to Denver.  Thus I will have to delay that test.

So, here is what I plan to do. 

1)  I will retest the whole charge air system for leaks.  I had done a quick test looking for "big leaks" that I could hear.  You guys have convinced me that a small leak can kill me.  So this time I will make liberal use of soapy water to see if maybe I have several small leaks or one big one I missed.

2) Do another fuel flow test - just cause it is easy (and fun ).

3)  Switch the ECM with the one that was on the replacement engine.

4)  Pull the exhaust blanket so that we can better check for manifold leaks.

Then we will will take her for a drive and see what happens.

Bob, I am would not call my adventures "entertaining".  Lots of other terms come to mind .  Especially with all the terrible weather I have had to endure .   Perhaps others are entertained .  If nothing else, it has resulted in some good dialogue and troubleshooting thoughts.

I have said it many times before, but I really appreciate all of the input.  Some things that I was tending to ignore or dismiss, are getting back on the "must check" list thanks to good logical discussions.

Jim

[Just Dallas]

Removed

[buswarrior]

Jim, you gotta get that thing working!

The thread is becoming a whole garment!

I have nothing more to offer but respect for tenacity and a hearty "Good Luck"!

happy coaching!
buswarrior

[RTS/Daytona]

Dallas

Our boost guages measure:

Gauge pressure is zero referenced against ambient air pressure, so it is equal to absolute pressure minus atmospheric pressure.

not

Absolute pressure is zero referenced against a perfect vacuum, so it is equal to gauge pressure plus atmospheric pressure.


SO 20 PSI boost means 20 PSI over atmospheric pressure

Pete RTS/Daytona - Once and instructor - always and instructor

You can take the instructor out of the classroom - but you can't take the classroom out of the instructor

Pete - Senior Advisory Engineer / Instructor  30 years IBM retired
     

Y

[Bob Belter]

Ahoy, All,

We old BIG ROUND ENGINE airplane guys used manifold  pressure which was defined in absolute inches of mercury.  I flew about the last of the high performance high altitude airplanes --  the 'infamous' AJ-2 Savage.  (Google will tell you "all").  It was a veritable turbo charged  'flying steam calliope'!!!!  Like for instance 61" of manifold pressure  --  sea level power  --   at 42,000'.  Our turbo diesels are done as 'gage' pressure  --  that is --  above ambient in psi  as noted in the previous listing.  MAN_O_ MANNO, you climbed out of that airplane into a jet and you thought that you were wrapped in your mother's arms.

OK, WE bus guys all run BIG ENGINES  Not  many other people do, and so this is for all we 'Big Engine' guys.  Maybe not 'round', but at least big, and need to be paid attention.

This is a 'cultural artifact' left over from a good while ago!!!

DEDICATED TO ALL WHO FLEW BEHIND ROUND ENGINES

We gotta get rid of those turbines, they're ruining aviation and our
hearing...

A turbine is too simple minded, it has no mystery. The air travels through
it in a straight line and doesn't pick up any of the pungent fragrance of
engine oil or pilot sweat.

Anybody can start a turbine. You just need to move a switch from "OFF" to
"START" and then remember to move it back to "ON" after a while. My PC is
harder to start.

Cranking a round engine requires skill, finesse and style. You have to
seduce it into starting. It's like waking up a horny mistress. On some
planes, the pilots aren't even allowed to do it...

Turbines start by whining for a while, then give a lady-like poof and start
whining a little louder.

Round engines give a satisfying rattle-rattle, click-click, BANG, more
rattles, another BANG, a big macho FART or two, more clicks, a lot more
smoke and finally a serious low pitched roar. We like that. It's a GUY
thing...

When you start a round engine, your mind is engaged and you can concentrate
on the flight ahead. Starting a turbine is like flicking on a ceiling fan:
Useful, but, hardly exciting.

When you have started his round engine successfully your crew chief looks up

at you like he'd let you kiss his girl too!

Turbines don't break or catch fire often enough, leading to aircrew boredom,

complacency and inattention.

A round engine at speed looks and sounds like it's going to blow any minute.

This helps concentrate the mind!

Turbines don't have enough control levers or gauges to keep a pilot's
attention. There's nothing to fiddle with during long flights.

Turbines smell like a Boy Scout camp full of Coleman Lamps. Round engines
smell like God intended machines to smell.

Pass this on to an old WWII pilot (or his son who flew them in Vietnam) in
remembrance of that "Greatest Generation."

Enjoy   /s   Bob

[Just Dallas]

Removed

[bevans6]

Tire gauges work the same way, referenced to current atmospheric pressure.  One failing of digital gauges, when you are trying for 1/4 psi accuracy the way you sometimes do on race cars, is they don't reference atmospheric pressure very well.  Analog gauges do better at that.

Brian

[rv_safetyman]

A quick update in a minute.

I have kept the thread going because it contains a lot of information on what I have done in the trouble shooting process and all of the great input I have gotten for you great folks.   After this post, I will start another thread when I have something significant to report (as BW said this one is getting a bit long).

Now for today's update.  I repeated the fuel flow test and got a gallon of fuel in about 50 seconds according to the stop watch.  That is a bit quicker than the first test.  It also suggests that the fuel system is capable of flowing 60 GPH to the pump.  I think we can eliminate that factor.

I again installed my plugs in the charge air system so that I could pressure test all tubes, hose connections, and the charge air cooler.  This time I applied a lot of soapy water every where.  In the previous test I was looking for gross leaks, but a lot of you told me that small leaks could cause the problem.  I found several SMALL leaks.  A couple of connections were worse than the others, but there was not huge loss.  I got all of the tube/hose leaks eliminated. On one connection I had to use two clamps to get it to seal.  A good friend is sending me more clamps and I will double clamp all of the connections. 

I have two very small leaks in the charge air cooler.  At 30 PSI, I am getting continuous bubbles, but not at high frequency or large size. 

I will take a test drive tomorrow to see if getting the leaks sealed up makes much of a difference.  I will also have Pat start the engine and I will watch the exhaust manifold to see if I can see any signals of a leak.  One person called and suggest putting a piece of plywood in front of the tailpipe to create a bit of back pressure.  The thought is that will magnify any leak in the manifold area. 

Jim

[Bob Belter]

Ahoy, Jim, All,

One factor of possible interest would be the pressure in the exhaust manifold before the turbo.  I don't have the faintest notion of what typical pressures are under various load conditions.  A significant leak causing low pressure would see the turbo not getting proper flow and would cause the low boost pressures that you are seeing.

If I were doing a 'cold start' engine installation I would install TWO ports in the exhaust manifold.  One for the EGT, and another for a pressure port.  Be very useful for trouble shooting.

Does anyone know what typical pressures are?  DD must certainly have such info available.  If no one knows, I'll check with Cummins.  Couldn't be much different.

Enjoy   /s/   Bob