Injection Timing for Bosch 190's

[driverswanted]

I would like the help of the 6BT people who know the details of advancing injection for larger injectors.



I noticed that my 4bt CPL 767 is to have a stock injection timing at 1. 66mm per my Cummins Injection pumps manual. I put the Bosch 190's in and was told to set the engine to 1. 50mm. That's not right. It even sounds retarded If I want to get my 4BT set up with these 190's shouldn't I be starting from 1. 66 and advancing from there? I have seen 4BT engine dyno charts completed showing the changes to the timing based what appears to be millimeter measurements of advancement at the pump timing mark. The term written on the chart was "Advance (rotate) Pump x. x mm". Should I set my pump bak to 1. 66mm and then start advancing the pump by the stated timing mark ofset in millimeters? If I should use the pump dial indicator method, how much should I be advancing that setting to get the equivelant of these, outside-the-pump timing changes? BTW the chart is showing advancements of 3. 0mm in some cases with dramatic increases in power.

 

[Greenleaf]

retarded If I want to get my 4BT set up with these 190's shouldn't I be starting from 1. 66 and advancing from there?





Should I set my pump bak to 1. 66mm and then start advancing the pump by the stated timing mark ofset in millimeters? If I should use the pump dial indicator method, how much should I be advancing that setting to get the equivelant of these, outside-the-pump timing changes? BTW the chart is showing advancements of 3. 0mm in some cases with dramatic increases in power.

Yes. Start at base time and advance from there. The book is mm of plunger lift. With a dial indicator.



If I was to drive up there. I'd set it till it sounded good. I play it by ear. I see that many of the 4Cylinder engines are set @ 1. 80mm and higher.



There is a method and I don't recall. Outside the pump measure like 1/8th inch was some odd-ball amount of mm plunger lift. I'd have to look it up in my note book. It was something like . 40mm of plunger lift.



OEM of a CPL 1579 is 1. 25mm and the 1/8th inch rotation would set you at 1. 65mm plunger lift. How's that? Sound close?

 

[sdstriper]

Set it with the timing indicator like the book says or even slightly advanced from there, not much though. The book says 1. 40 for my truck and I have been advised to start at 1. 50



What turbo was on a 105hp 4cyl from the factory? Did you put a bigger turbo on? How much HP do you estimate with new injectors?

 

[driverswanted]

Thanks Scott, It's been a while. We still have to hook up. Was in Ashland about three weeks ago but on a rescue mission to get my daughter and her Saab with a blown up turbo. Yeh, I noticed that many guys have the 858 and it starts at 1. 00mm. So that would mean that they are increasing by . 8 and . 4 for your other suggestion. So your numbers suggest that I go to 2. 06 or 2. 46mm.

sdstriper:I started with a H1C and changed to a HY35W. PDR suggested about a 30 hp increase with the 180's in a 4BT. I see the dyno tests on the 4BTswap site are producing turnups ( 2 turns on power, 3. 00mm advancement using outside pump markings and eccentric pin @180-210degrees) close to 160hp@2000RPM and with just standard injectors and the H1C. EGT's were high though at about 1280F. Turning the eccentric pin back to 90 degrees from minimum gave nice EGT's of 1197 F@2100 rpm. The highest dyno run was 183 hp@2400rpm, again everthing being stock parts on a 105hp cpl 858 bolted diectly to the dyno. I gotta dyno mine after I make my changes. I can't imagine my engine cranking out 190+ HP. Wonder what the HY35W and an intercooler will add to that number.