E6 Inj Timing

[Eightball]

New Guy here but old mech. I have a 88 E6 350hp 4valve in Superliner . I swaped engines in it with the same model engine out of another super dog. The old eng had Ambac pump on it , The new eng has the Bosch pump on it that you need a AB lite to time. Ok I used the same head and injector from the old eng. After I got the fuel and rpm set as best I could with about the same manifold psi and pull about the same as the old eng . The trouble is the old eng got around 5.7 mpg the new eng get 5.2 . Have I got lower timing on the bosch pump causing the lower mpg? What does the timing need to be . I pull 88000 all the time so I am pulling between 20 and 28 psi boost EGT 800 to 900 most all the time. Thank for any help from any of you old dog mech

Edited March 6, 2010 by Eightball

[fjh]

New Guy here but old mech. I have a 88 E6 350hp 4valve in Superliner . I swaped engines in it with the same model engine out of another super dog. The old eng had Ambac pump on it , The new eng has the Bosch pump on it that you need a AB lite to time. Ok I used the same head and injector from the old eng. After I got the fuel and rpm set as best I could with about the same manifold psi and pull about the same as the old eng . The trouble is the old eng got around 5.7 mpg the new eng get 5.2 . Have I got lower timing on the bosch pump causing the lower mpg? What does the timing need to be . I pull 88000 all the time so I am pulling between 20 and 28 psi boost EGT 800 to 900 most all the time. Thank for any help from any of you old dog mech

The way I read this is your ambac injectors are still in the heads Correct? Most times the injection pumps are calibrated with the injectors ,so the cracking preasures May be diffrent between the injectors!Having said that I guess you could advance the timing a bit your problem being the ab light or lack there of!

you could try and wing it and set the timing by first putting the engine on the desired timing number on the fly wheel then center the timing tab in the pump where the ab plug goes in the hole by eye But your kind of guessing could be off 1 or 2 degrees!

[Eightball]

The way I read this is your ambac injectors are still in the heads Correct? Most times the injection pumps are calibrated with the injectors ,so the cracking preasures May be diffrent between the injectors!Having said that I guess you could advance the timing a bit your problem being the ab light or lack there of!

you could try and wing it and set the timing by first putting the engine on the desired timing number on the fly wheel then center the timing tab in the pump where the ab plug goes in the hole by eye But your kind of guessing could be off 1 or 2 degrees!

Thank for the reply yes I just swap heads leaving the inj in the heads because I knew they where good , They where replace after I had put the ambac pump on a few year ago . I would have change the pump too, but the guy helping me said it was a differ set up on the gears in the timing cover so I left the Bosch pump on which I knew nothing about. I can get a AB lite I just need to know what kind of timing I can run with out gitting into trouble, I still have the old eng which I could flow time and see what it was set on and set the new eng to that spec. I didnt know there was a differ in the injectors between the Bosch pump and ambac. What is the range of timing on a E6?

[fjh]

Thank for the reply yes I just swap heads leaving the inj in the heads because I knew they where good , They where replace after I had put the ambac pump on a few year ago . I would have change the pump too, but the guy helping me said it was a differ set up on the gears in the timing cover so I left the Bosch pump on which I knew nothing about. I can get a AB lite I just need to know what kind of timing I can run with out gitting into trouble, I still have the old eng which I could flow time and see what it was set on and set the new eng to that spec. I didnt know there was a differ in the injectors between the Bosch pump and ambac. What is the range of timing on a E6?

The rob bosch injectors look diffrent as well the alinment Kog is a ball bearing as apose to a roller bearing looking thing!

Timing Its all over the place depending on year19 -24 degres if I rememeber correctly!What is the year of the engine?

I might be able to find out for ya!

[Eightball]

The rob bosch injectors look diffrent as well the alinment Kog is a ball bearing as apose to a roller bearing looking thing!

Timing Its all over the place depending on year19 -24 degres if I rememeber correctly!What is the year of the engine?

I might be able to find out for ya!

Both are 1988 1800rpm eng. How big a job is it to take the bosch pump off and put the ambac on that eng as far as the gears in the timing cover. That what I want to do in the frist place because I knew I had good inj and a good pump that got good mpg but I got talked out of that by the guy that a old time mack mech that help me . He said I like that bosch pump , he was dead wrong about that. I hate the thing. The bad part is the eng was out of the truck and had never put the oil pan on . I wished a million times I had swap it then.

[fjh]

Both are 1988 1800rpm eng. How big a job is it to take the bosch pump off and put the ambac on that eng as far as the gears in the timing cover. That what I want to do in the frist place because I knew I had good inj and a good pump that got good mpg but I got talked out of that by the guy that a old time mack mech that help me . He said I like that bosch pump , he was dead wrong about that. I hate the thing. The bad part is the eng was out of the truck and had never put the oil pan on . I wished a million times I had swap it then.

First do you have all the fuel lines for the ambac? You would have to swap ALL the rigging over from the ambac engine Pump drive ect and you need to make plugs to go into the holes where the rob pump was!I beleive the gears on the front are the same.there is and oil feed hole that May be pluged off on the robby engine that feeds the ambac pump drive!It Is a fair amount of work!I beleive the turbo drain is diffrent not sure on that I beleive the turbo on the robby will be schwitser and the ambac it will be a Garret! you'd have to check this stuff!Then the trotle linkage and the stop stuff you'll have to fiddle with!

Lots of messing about for little gain.Try tweaking the timing 2 or three deg advance and see if it gains you your .3 or 4. I to like the ambac stuff better but they sort of droped it in the 90's cause robby was cheaper I beleive.The ambac pumps seem to run the engines cleaner for some reason specialy V8s.

[Eightball]

First do you have all the fuel lines for the ambac? You would have to swap ALL the rigging over from the ambac engine Pump drive ect and you need to make plugs to go into the holes where the rob pump was!I beleive the gears on the front are the same.there is and oil feed hole that May be pluged off on the robby engine that feeds the ambac pump drive!It Is a fair amount of work!I beleive the turbo drain is diffrent not sure on that I beleive the turbo on the robby will be schwitser and the ambac it will be a Garret! you'd have to check this stuff!Then the trotle linkage and the stop stuff you'll have to fiddle with!

Lots of messing about for little gain.Try tweaking the timing 2 or three deg advance and see if it gains you your .3 or 4. I to like the ambac stuff better but they sort of droped it in the 90's cause robby was cheaper I beleive.The ambac pumps seem to run the engines cleaner for some reason specialy V8s.

Thamks fjh I have all the old eng setting in the shop with all the line and fitting on it and I use the turbo off the old ambac eng , everthing from the block up is off the ambac eng turbo and all but the fuel line, I will get out and see what what the old ambac eng was timed at because it still on the old eng and has never been moved and then I see what the Bosch is on because it has never been move. and then maybe I can play with the timing some and get the mpg up. I just rebuild the old ambac eng about 500 hrs ago and the 6 main when out so I rebuild the bosch eng before I put it in so I real dont want to build any more eng right now LOL so I will be very careful with the timing . I used to run high or fast as they call it timing on my old cummins and the piston would be cracked around the edge when I would build it but never had one to break or burn . Will too much timing show up on the pyrometer?

[fjh]

. Will too much timing show up on the pyrometer?

Not sure