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Cat 3208 Injector Pump Bench Testing

Coaldust

Senior Member
Joined
May 9, 2011
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6,088
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Subarctic Backwoods Trailer Park
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Big trucks is what I know. HAZMAT is what I tow.
Oh, and those sheet metal oil pans soaking in the salt water bilge brine. R&R engines just to replace an oil pan, many times. Labor intensive jobs. And, while we are here, let’s do this and this and this, since we have access. lol
 

Shimmy1

Senior Member
Joined
Aug 14, 2014
Messages
5,571
Location
North Dakota
Oh, and those sheet metal oil pans soaking in the salt water bilge brine. R&R engines just to replace an oil pan, many times. Labor intensive jobs. And, while we are here, let’s do this and this and this, since we have access. lol
Holy shlt, this sounds like misery times a million...
 

Coaldust

Senior Member
Joined
May 9, 2011
Messages
6,088
Location
Subarctic Backwoods Trailer Park
Occupation
Big trucks is what I know. HAZMAT is what I tow.
Holy shlt, this sounds like misery times a million...
A young feller doesn’t know any better. Soaking up that over-time and double-time on Sundays.

Sometimes, the tricky part was aligning the shafts and dealing with the inevitable new vibrations. Waiting for the hull to settle, weather, humidity. Making shims, sea trials. That soaks up the labor.
 

DieselFit

Well-Known Member
Joined
Nov 27, 2023
Messages
68
Location
Australia
Just to rule any differences out, maybe it's worthwhile swapping injectors between the lines to see if the outputs stay the same. I've had some new pencil injectors recently that didn't work properly.
 

CrispyCritter

Member
Joined
Nov 8, 2019
Messages
24
Location
Seattle
Just to rule any differences out, maybe it's worthwhile swapping injectors between the lines to see if the outputs stay the same. I've had some new pencil injectors recently that didn't work properly.
I did swap 3 of the injectors around between high and low delivery ports. Numbers changed and became more balanced. So .....
Just researching what 'Pop Testing' is all about. Going to get a simple tester and compare these 'new' injectors for adjustment. Hopefully won't destroy them altogether, but, heck; just gotta FAFO.
It's never too late to learn! (good stuff I hope)
 

DieselFit

Well-Known Member
Joined
Nov 27, 2023
Messages
68
Location
Australia
When testing the pencil injectors if they are the ones with the caps on top, they need to be removed while testing or on other types, the little screw on the side needs to be removed, otherwise the injectors hydraulic lock and the needles won't open. I never worked out why they don't do that while running normally, must all happen too quickly I suppose.
 

CrispyCritter

Member
Joined
Nov 8, 2019
Messages
24
Location
Seattle
When testing the pencil injectors if they are the ones with the caps on top, they need to be removed while testing or on other types, the little screw on the side needs to be removed, otherwise the injectors hydraulic lock and the needles won't open. I never worked out why they don't do that while running normally, must all happen too quickly I suppose.
Update. Thanks for the injector suggestion. I got a Pop Tester and sure enough ...... couldn't figure why they hydraulic locked after a few pumps. Must have missed your last message about removing the caps when testing. DOH!
Had to adjust a couple , but not by much. My CAT book says to set the 1W5829 injector to 2500psi then open the 'stop' 3/4 turn ....... generally found them all originally opening around ~2300psi but several had the stop setting way over 3/4turn! Anyways, they all pop n chatter 'lovely' with good spray pattern.

Back on the pump, I've got pretty good at stripping down to set the sleeve levers and swapping pumps around to test whether my bench runs change. No significant difference tho. except #5 seemed to result in the lowest volume dispensed even after swapping pumps around.
So, moving onto the cam and followers, checking dimensions of cam follower lift revealed no significant difference (+-.0005") between #5 and adjacent pump followers (measured to pump seat).
Checking and re-checking sleeve lever adjustment didn't solve the different volume dispensed (all within .0005" of each other)
Tried re-setting the levers with the shaft play pressed down then up etc. etc.
However, and this is a tad strange, depending on the rpm's and govenor position of the bench test, the % variance of fuel delivery between between pumps changed. Repeatability at the same settings also does not appear constant (i.e. 400rpm at 1/3 govenor for 4 minutes ..... not exactly same results each time!).
Anyway, I got the TMI for the application this pump was assigned to (from CAT) and have checked the Fuel Setting (0.157") and Air/Fuel Ratio (0.122") as per CAT data.
It's going in a 1984 Thomas School Bus which is reported as a 3208T-250hp. This pump came from a Ford Truck also a (3208T-250hp) so ............ should be ok??? (please correct me if I'm wrong tho)
(Bus motor has no Valve Cover tag and I haven't found a stamped s/n anyplace yet so cannot research Arrangement.)
I'll follow up how it runs when this years snow has gone.

To conclude ..... maybe parts in this pump have too much wear? Sleeves and pump shafts all look good, as does the camshaft and followers. I did read someplace however that the cams can get a little 'hollow' on the lifting face , but I don't see any significant wear here.
Maybe ..... and this may be the answer about different fuel delivery versus rpm, is wear on the sleeve operating levers. There is a fair amount of 'play' in all of the lever-to-sleeve grooves ...... and although the levers are adjusted to press on the bottom of the sleeve groove, maybe the sleeves kind of 'rattle around' at different rpm's and 'choke-off' the 'bleed port' with some variance?
.....anybody care to comment?
OK .... this old Brown Jersey Cow is done for now :)
 

CrispyCritter

Member
Joined
Nov 8, 2019
Messages
24
Location
Seattle
Update. Thanks for the injector suggestion. I got a Pop Tester and sure enough ...... couldn't figure why they hydraulic locked after a few pumps. Must have missed your last message about removing the caps when testing. DOH!
Had to adjust a couple , but not by much. My CAT book says to set the 1W5829 injector to 2500psi then open the 'stop' 3/4 turn ....... generally found them all originally opening around ~2300psi but several had the stop setting way over 3/4turn! Anyways, they all pop n chatter 'lovely' with good spray pattern.

Back on the pump, I've got pretty good at stripping down to set the sleeve levers and swapping pumps around to test whether my bench runs change. No significant difference tho. except #5 seemed to result in the lowest volume dispensed even after swapping pumps around.
So, moving onto the cam and followers, checking dimensions of cam follower lift revealed no significant difference (+-.0005") between #5 and adjacent pump followers (measured to pump seat).
Checking and re-checking sleeve lever adjustment didn't solve the different volume dispensed (all within .0005" of each other)
Tried re-setting the levers with the shaft play pressed down then up etc. etc.
However, and this is a tad strange, depending on the rpm's and govenor position of the bench test, the % variance of fuel delivery between between pumps changed. Repeatability at the same settings also does not appear constant (i.e. 400rpm at 1/3 govenor for 4 minutes ..... not exactly same results each time!).
Anyway, I got the TMI for the application this pump was assigned to (from CAT) and have checked the Fuel Setting (0.157") and Air/Fuel Ratio (0.122") as per CAT data.
It's going in a 1984 Thomas School Bus which is reported as a 3208T-250hp. This pump came from a Ford Truck also a (3208T-250hp) so ............ should be ok??? (please correct me if I'm wrong tho)
(Bus motor has no Valve Cover tag and I haven't found a stamped s/n anyplace yet so cannot research Arrangement.)
I'll follow up how it runs when this years snow has gone.

To conclude ..... maybe parts in this pump have too much wear? Sleeves and pump shafts all look good, as does the camshaft and followers. I did read someplace however that the cams can get a little 'hollow' on the lifting face , but I don't see any significant wear here.
Maybe ..... and this may be the answer about different fuel delivery versus rpm, is wear on the sleeve operating levers. There is a fair amount of 'play' in all of the lever-to-sleeve grooves ...... and although the levers are adjusted to press on the bottom of the sleeve groove, maybe the sleeves kind of 'rattle around' at different rpm's and 'choke-off' the 'bleed port' with some variance?
.....anybody care to comment?
OK .... this old Brown Jersey Cow is done for now :)
Oh ..... and happy new year!
 

DieselFit

Well-Known Member
Joined
Nov 27, 2023
Messages
68
Location
Australia
From memory, while testing the pumps on the test bench the governor was only held at full throttle. I don't think there was any tests for different throttle positions. This was about 40 years ago, so that may not be the case. I would think that your pump would be fine for your application. Sometimes the sleeve levers on the rack used to wear where they engage with the sleeves & need replacement, but I think that was rare.
Happy New Year to you too.
 
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