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A few 20/2 assembly questions

Started by Jens, September 30, 2010, 01:51:44 PM

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Ronmar

Quote from: Jens on November 11, 2010, 03:39:27 PM
is there an easy way to verify camshaft timing with respect to the crankshaft with a minimum of disassembly ?

Last I recall, the intake valve should just start to open at about 5 degrees BTDC, and will be open around .020" at TDC.  This is easy to measure with a dial indicator resting on top of the valve spring cap...

As for spill timing, it is the point where the rising IP piston just closes the inlet port that feeds fuel into the IP bore.  This is the point where the IP piston starts building hydraulic pressure to pop the injector.  To measure this, roll the crank till the IP plunger is all the way up(port closed).  Remove the hardline to the injector and the fitting on top of the IP.  This has a spring under it that holds the little check valve on the top of the IP closed.  Remove the spring and vave and re-install the fitting.  Tighten it with a wrench as it holds the bore sleeve in place.  Rotate the flywheel backwards till fuel starts to flow up and out of the fitting where the hard line would normally be bolted.  Slowly rotate the wheel forward till the fuel flow just stops.  The flywheel timing mark should be just at the spill timing point.  You may have to rock back and forth a few times very slowly, wiping away fuel with a rag to get a feel for the exact point where the flow stops.  Remember that if you are rotating forward, the IP piston is comming up and will push fuel upward and out of that fitting.  If you rotate the flywheel thru the port closing too rapidly, fuel will continue to flow pushed by the IP piston, masking the actual closing point of the inlet port.  The adjuster nut under the IP will of course allow you to change the port closing to flywheel relationship.

Good luck.   
Ron
"It ain't broke till I Can't make parts for it"

billswan

Quote from: Jens on November 11, 2010, 10:43:16 PM
Is my thinking that I should be in the ballpark with the plunger adjustment as it was when the engine last operated not correct ?

Jens
If you have the cam shaft back where it was in relation to the crankshaft then the plunger lifter length should be very close.

Are you positive of the marks that you have that indicate TDC for each cylinder. Could they be off. Did you put them on during your rebuild?

Did you check spill timing before the failure to confirm it was correctly assembled from India.

Be careful I got my 10/1 running but I have never worked on a listeroid twin so my advise might be questionable.

Billswan
16/1 Metro DI at work 900rpm and 7000watts

10/1 Omega in a state of failure

Ronmar

I agree with Bill, are you sure your TDC marks are correct?  I guess if they are not, then your comfirmation of the intake valve starting to open at around 5 degrees BTDC would also be off, which would really confuse things.  If your head is on, you can pull an injector and put a rod down against the piston top and have it push against a dial indicator to confirm the actual TDC point on the flywheel.  Since the IP inlet port needs to close by about 19-20 degrees BTDC, the plunger should start to move upward before that...  The upward travel of your plunger stopping at 40 degrees after, sounds a little late to me.  I don't think I have never measured mine, so have no actual reference to compare to.  But since the injector actually fires right around TDC, a IP plunger still rising after TDC dosn't make much sense to me.  I will look at mine this afternoon and get you some numbers when I get home, as I need to run the engine for this month anyway:)
   
Ron
"It ain't broke till I Can't make parts for it"

billswan

ronmar and jens

The diesel injection event is not like a spark in a spark ignition engine. There is a point that injection begins and then some degrees later the event ends. how many degrees I also cannot say without checking. The upward travel ending of the IP lifter at about 40 degrees after tdc does sound wrong but who knows? If it is rising it would have to be pumping or so it would seem to me........ :o

Just thinking out loud not trying to stir up a stink.

Billswan

16/1 Metro DI at work 900rpm and 7000watts

10/1 Omega in a state of failure

Ronmar

#34
I went and looked at my 6/1 this afternoon before I started it up.  The plunger/tappet begins to rise at around 80 degrees BTDC.  The port closed around 19 degrees and the actual injector pop is within a degree of TDC as measured with my audio pickup and timing light.  The plunger however continues to rise till nearly 45 degrees after TDC.  I didn't think it went that far, but it does  

IF you are cranking the flywheel really slowly, you will hear multiple tinks at the injector as it has time to vent fuel to the nozzle and close several times.  As you speed up, they will blend into one.  If you have a little air in the system, this will also cause this as the air spring absorbs and releases energy right around the injector firing point...

And yes, spill timing can be a very messy evolution:)
Ron
"It ain't broke till I Can't make parts for it"

billswan

Well guys I seam to learn something every day. After rereading the last few posts I learned that the injection pump is more complex than I thought it was.

Jens points out  " With the input port opening up again as the plunger travels up, it would seem irrelevant that the plunger doesn't start it's downward journey until well after TDC - the injection event happened at the very beginning of the plunger rise and any pressure remaining is quickly bled off, likely even before TDC"

Makes perfect sense explains the lifter traveling up so late after tdc.

I have never had to take my pump apart because i only use diesel and wmo I have never experenced the gum up you guys on veggie have to fight. And so have never seen the inner workings of the unit.

Good luck jens.

Billswan
16/1 Metro DI at work 900rpm and 7000watts

10/1 Omega in a state of failure

luv2weld

Jens
It really sounds to me like the inner workings of your #1 injector pump are 180 degrees
out.
I did the same thing on my 8/1. The effect was I could not shut the engine down!!!
Since yours is not running yet, you don't have that symptom yet.
Also when I flipped the stop lever down (the run position), the engine slowed a little.
When I put the lever in the up position, (stop position), it started speeding up.
The only way to shut it down was to disconnect the fuel line at the injector.
I could have shoved a rag into the air inlet, but I was afraid it would swallow it.

But I can guarantee that I really pay attention now when I pull the IP apart!!

Ralph
6/1 with 5 kw ST       
8/1 with 7.5kw ST
28/2 with 24kw ST

I wouldn't need to manage my anger if people would learn to manage their stupidity!!

The best way to "kill time" is to work it to death!

XYZER

I see you have worked through the Injection timing and are onto other new events :o. I have fought the same IP timing issues and became suspect of the rack position while adjusting the spill timing. I never had time to go back and experement with it because I had way more of a diesel puddle on the floor than I cared. I would always wrap a rag around the pump to catch the spill and that would close the rack and cause me to hunt for spill no spill! I always spilled more than was nessary and the rag would become soaked. I would then loose the rag and walla it would time like it says in the book. I still don't know if the rack position affects the spill timing process.....anybody know? 
Vidhata 6/1, Power Solutions 6/1, Kubota Z482

rl71459

Nice Job Jens!

I like your "pusher tool"

Do you think the damage to the shaft will cause you any trouble?

Rob

mobile_bob

if i might make a suggestion, before you file away anything

take a look at where the excess metal came from, it might be (likely is) displaced from somewhere else that it is needed.

if this is the case, as i believe it is, you can often times carefully move it back to where it came from.

i do this a lot on large machines, shafts and pulleys, theaded holes etc.

it goes something like this,
if the metal was lifted up out of the sidewall of a keyway, you can with very little effort put it back into place with careful
hammer work, using many dozens of small pecks basically doing what moved it out of place to start with.

it generally isn't a single event that causes the problem, but hundreds of smaller events.

so just take a small ball peen hammer and carefully work the high spot down in the direction of where the metal came from, do it slowly and you won't cause any problems, it also leaves very little file work and often times no other welding is necessary.

you might find a carefully ground cape chisel sized to fit the groove helpful as well.

welding should be a last resort in my opinion, its generally my last choice.

fwiw

bob g

veggie

IT'S ALIVE !!............IT'S ALIVE !!!  :o

Congratulations !

Quite normal to have lots of smoke after a rebuild.
There's a lot of assembly oil to get burned off.

veggie

billswan

Yes CONGRATULATIONS Jens

Have been here reading about your challenges, it sure takes a lot of time but someday when you finally get it settled down it will have been worth it.

I started mine up a few days ago as it is finally cool enough in minnesota to start heating the shop and so far it has been running about 14 hours a day with no trouble. This year when it gets real cold I hope to run it 24/7. I have roughly 600 hours on my 10/1 and am gaining confidence that most of the bugs have been discovered........

Billswan
16/1 Metro DI at work 900rpm and 7000watts

10/1 Omega in a state of failure

rl71459

Congratulations Jens!

You Did it! I think you will see "Thumper" power up as the ring's seat in. I wonder what other differences you are going to see also.

Good Job!
Rob

vdubnut62

Jen's I bet that the fluctuation in crankcase pressure is causing the oil too be "sucked"as it were from the sight glass.
If  you could connect the top of the glass to a source of crankcase pressure with out too much trouble, just to find out for sure.
Ron
When governments fear the people, there is liberty. When the people fear the government, there is tyranny -- Thomas Jefferson

"Remember, every time a child is responsibly introduced to the best tools for the protection of freedoms, a liberal weeps for the safety of a criminal." Anonymous

veggie


Well done !
Good to hear that all is generally in order.
Don't forget to re-torque the heads and check the valve clearances after a few hours.

BTW....When are you officially opening your Listeroid rebuild shop ?  ;D

veggie