Question for Dieseltech

[tom upton]

Hoping you can help me out with Roosa pump timing on a 310 indirect out of a 1800. ( now with 4 1/4 inch pistons but same 4 3/8 stroke) This is in a pulling tractor that turns about 3500 RPM. I broke the camshaft a year ago and since putting in another cam the darn thing does not seem to lug very well at all. I had Cam ground identical to the old cam and set cam timing the same. What I am not sure of is were I had pump timing? ( To make a long story short I lost the paper I had written it on, but thought it was around 20 degrees before TDC. I have tryed it there, at 17 and at 14 and still does not have anywhere near the lugging power it had before. Ideally I would put on a dyno but dont think thats going to happpen this pulling season as I dont have a PTO shaft in it or the drive hub for same in flywheel. ( PTO clutch might not take it anyway??) So my question to you is were would you suggest a good starting point for pump timing be? Also is there any gain in playing with the tourqe screw?

 

[Janicholson]

If the new reground cam was shaped correctly but not indexed the same as the old one pump timing changes won't help. Degreeing the cam timing might be informative. Jim

 

[Dieseltech]

What is the pump DBGFC number so I can get an idea what the pump is?

 

[tom upton]

What is the pump DBGFC number so I can get an idea what the pump is?

DBGFC631---4DW 2200 This pump was redone by a somewhat reputable shop some 20 years ago who no longer are around. They said it was set up for max fuel, but it never did seem to deliver enough fuel? Ran okish for an indirect, and would lug pretty good, but very little black smoke. Any suggestions sure appreciated. Thanks Tom

 

[Dieseltech]

With or without a turbo?

 

[Tx Jim]

Double check inj pump timing!!! Check for good fuel flow from tank to inj pump. Check to be sure fuel tank is venting.

 

[tom upton]

With or without a turbo?

no turbo

 

[Dieseltech]

no turbo

Pump has a 6 degree speed advance for 12 at the crank. It should have HEAVY SMOKE with no turbo if pump is set up like it's claimed.

 

[tom upton]

Pump has a 6 degree speed advance for 12 at the crank. It should have HEAVY SMOKE with no turbo if pump is set up like it's claimed.

So I should align the marks in pump window with flywheel at 12 degrees BTDC?

 

[Dieseltech]

So I should align the marks in pump window with flywheel at 12 degrees BTDC?

I'd start with what the service book calls for. 12 degrees BTDC sounds too far advanced as pump is timed for END OF INJECTION.

 

[tom upton]

I'd start with what the service book calls for. 12 degrees BTDC sounds too far advanced as pump is timed for END OF INJECTION.

Thanks very much. Yesterday I set back to 8 and it seems to run better, but hard to tell without hooking to the sled. The book I have just says to set flywheel on FP mark , but not the original flywheel so all I have is TDC. I guess I need to look for old flywheel in my mess of parts and see how many degrees FP is from TDC for my starting point. By memory direct injection specs call for 2 to 4 depending on model. Am I correct that indirect pump should be advanced farther than direct due to precombustion chamber/ energy cell thing going on? Anyway thanks for your help. I will let you know how it pulls as we have another pull coming up this Saturday.

 

[tom upton]

I'd start with what the service book calls for. 12 degrees BTDC sounds too far advanced as pump is timed for END OF INJECTION.

Thanks very much. Yesterday I set back to 8 and it seems to run better, but hard to tell without hooking to the sled. The book I have just says to set flywheel on FP mark , but not the original flywheel so all I have is TDC. I guess I need to look for old flywheel in my mess of parts and see how many degrees FP is from TDC for my starting point. By memory direct injection specs call for 2 to 4 depending on model. Am I correct that indirect pump should be advanced farther than direct due to precombustion chamber/ energy cell thing going on? Anyway thanks for your help. I will let you know how it pulls as we have another pull coming up this Saturday.