Lining up a Superliner rescue.

[Vladislav]

18 hours ago, Hans Remmers said:

I found a cross reference for your number to the 313gc5168p18 that appears in the 1989 tune up manual.  Calling for injector assembly 736gb259p10, nozzle 114gc39p21 ambac number nbh 770405

Thanks the great! The build sheet for the truck mentioned 736GB259P10 injector assembly but I couldn't find the nozzle #. I suppose that is what you should put in yours if go with Ambac pump. But it seems to me no big difference could be found in injection and combustion if you use nozzles which were supposed for Bosch pump but operated with alternative Ambac unit.

One more question from my side to complete my couriosity. Can't you check the manual for the injector crack pressure and maximum stroke amount for the pump calibration? This info would be enough for me to work out the pump and a set of injectors (I hope).

[Hans Remmers]

8 hours ago, Vladislav said:

Thanks the great! The build sheet for the truck mentioned 736GB259P10 injector assembly but I couldn't find the nozzle #. I suppose that is what you should put in yours if go with Ambac pump. But it seems to me no big difference could be found in injection and combustion if you use nozzles which were supposed for Bosch pump but operated with alternative Ambac unit.

One more question from my side to complete my couriosity. Can't you check the manual for the injector crack pressure and maximum stroke amount for the pump calibration? This info would be enough for me to work out the pump and a set of injectors (I hope).

Crack pressure on the ambac injectors is 4200/+150-0 thats why I don't think I could mix match, bosch is only 3600/+175-0.  I don't know where to look for the other info you're asking for, its not listed in the specs

[Vladislav]

14 hours ago, Hans Remmers said:

Crack pressure on the ambac injectors is 4200/+150-0 thats why I don't think I could mix match, bosch is only 3600/+175-0.  I don't know where to look for the other info you're asking for, its not listed in the specs

Thanks for the figures. They bring some thoughts though. As I figured a plunger is not absolutely tight and does some leak back into the supply gallery. When a cam forces it up to make pressure it sure makes it but a small amount goes away. In dynamic it means the crack pressure gets achieved a bit later than if no leak absolutely. Amount of the leak is dependant to the pressure. So if you set higher numbers in a injector a plunger leaks more and it means the pressure crack gets later. What respectively means you get less actual injection advance.

Taken that to account I would suggest Ambac and Bosch plungers have different tightness so the nozzles set different. And if you change the pump keeping the original injectors it would be wrong. A way may be to correct the pressure. As long as you go to Ambac and its injectors (Ambac nozzles) set higher I think it's possible to set Bosch nozzles to the higher pressure to work with Ambac pump. A nozzle only works better with higher Bars. But if you go from Ambac to Bosch you would need to lower the pressure setting. And that would be bad idea since a injector is supposed to spray under certain load. And if you set lower pressure it could loose spray quality.

[Hans Remmers]

I thought I fixed the Bosch pump issue but its still about the same.  I finally got the barb fitting sealed on the return line after getting the ac compressor bracket out of the way.  I removed the rear cover on the governor assembly where the manifold pressure line attaches and found the diaphragm ripped and the nut had fallen off the shaft allowing that part of the governor to keep the throttle open as the return spring was not longer holding the shaft back.  I made a temporary fix of it and found no improvement.  The engine still gradually rises to about 1800 and won't come back down.

There had to be some driveability concerns nobody admitted to with this when it was parked based on the wear and damage in the governor I've found.

I might check on the price and availability on a reman Robert Bosch tomorrow before going with the ambac conversion.

I got most of the pieces to get the interior back to complete from a junkyard Saturday so I want to get going on that.

[doubleclutchinweasel]

That looks like one of the galvanized cabs, so you should be fortunate there.

There seem to be more good engines and parts out there than there are good cabs any more!

Best of luck to you.

[Vladislav]

Have you found the rack itself moving free? If it's not stuck no stuck plungers are expected to take place. And the revs jump could only be a matter of the governor. Or oil coming into cylinders but it would continue running after shutting off the fuel.

[Hans Remmers]

Finally finished the robert bosch to ambac conversion and got it running right.  The bosch pump did have at least one seized plungers I found after removal.  I didn't feel like dealing with it after finding the aneroid valve was messed up and a rebuilt pump is now nearly $3k.

The ambac swap had plenty of hurdles involved but it seemed to pay off.  The pump I used has been wrapped up in a storage trailer since 2001 and was very reluctant to wake up.  Upon installing I had to open the governor and found the rack stuck in the shutdown position.  I flushed it out and had to rotate the pump many turns before I was able to get fuel discharge from all barrels.  I'm still not entirely confident in the timing as after multiple checks with the pc stand I continued getting inconsistent results.

I finally just decided to see if it would even run and it actually fired very easily after all the trouble leading up to it.  The throttle was giving proper response immediately and it seems to be running out very well.

[doubleclutchinweasel]

13 hours ago, Hans Remmers said:

Finally finished the robert bosch to ambac conversion and got it running right.  The bosch pump did have at least one seized plungers I found after removal.  I didn't feel like dealing with it after finding the aneroid valve was messed up and a rebuilt pump is now nearly $3k.

The ambac swap had plenty of hurdles involved but it seemed to pay off.  The pump I used has been wrapped up in a storage trailer since 2001 and was very reluctant to wake up.  Upon installing I had to open the governor and found the rack stuck in the shutdown position.  I flushed it out and had to rotate the pump many turns before I was able to get fuel discharge from all barrels.  I'm still not entirely confident in the timing as after multiple checks with the pc stand I continued getting inconsistent results.

I finally just decided to see if it would even run and it actually fired very easily after all the trouble leading up to it.  The throttle was giving proper response immediately and it seems to be running out very well.

Awesome.  Glad to hear you got it started.  Keep us informed.

[1958 F.W.D.]

Any more updates??

The Ambosch and BobBobsch thing goes back a ways. My father's Hayward F-Model (300 Maxidyne) had a BobBosch. His Allentown F-Model (300 Plus) had an Ambosch. 

[Hans Remmers]

12 hours ago, 1958 F.W.D. said:

Any more updates??

The Ambosch and BobBobsch thing goes back a ways. My father's Hayward F-Model (300 Maxidyne) had a BobBosch. His Allentown F-Model (300 Plus) had an Ambosch. 

Its running good now so I'm putting rods and mains in it just because it sat so long.  Appears they were done around '97 from the date stamped in the old bearings.  Had typical wear on the front, center and rear mains but not excessive.  Rear thrust washer partially spun on locator pin was the biggest issue I found.  By the weekend I'll get the engine buttoned up and I don't foresee anything else major mechanical necessary.

The pump conversion was an interesting project and I was happy to find all the parts I needed from my donor engine were still in the storage trailer.  The ambac is such a resilient pump and very simple and easy to clean out.  Nothing like the Bosch.

I'm not sure how many engines had the ability to use with either pump.  This block had the 3 ambac mounting holes filled with silicone and hex plugs and the oil drain plugged with a small freeze plug.  The ambac drive hub mounted inside the timing cover through 3 of the 4 bosch pump mounting holes.  I have a 1985 2 valve parts engine with an ambac and it does not have the provision for a robert bosch pump.

I installed the drive hub without removal of the timing cover or cam gear which did require removal of excess material from the aluminum hub and a lot of finesse to get it behind the cam gear.  I didn't find the correct injector lines for the ambac which required me to reshape the existing lines for the time being.  The ambac sits about 6" further back than the bosch.  What I thought were the correct lines are apparently E7 lines which I now realize use metric threads in the head versus the USS coarse E6 threads.

The ambac and bosch throttles operate in opposite directions remedied by shortening and reshaping the linkage rod to the pump and adding another lever on the throttle shaft across the back of the block.  Once I got searching online for linkage pictures I remember now the Superliners used both linkage and cable throttle configurations.  I don't know if this was optional or based on year.

I've also been getting the interior fixed up.  I replaced the stolen left gauge panel and am rounding up my other parts.  I'm trying to find a decent silver grey paint closely matching the original color and make the dash and heater cover match again.

[Vladislav]

9 hours ago, Hans Remmers said:

Its running good now so I'm putting rods and mains in it just because it sat so long.  Appears they were done around '97 from the date stamped in the old bearings.  Had typical wear on the front, center and rear mains but not excessive.  Rear thrust washer partially spun on locator pin was the biggest issue I found.  By the weekend I'll get the engine buttoned up and I don't foresee anything else major mechanical necessary.

The pump conversion was an interesting project and I was happy to find all the parts I needed from my donor engine were still in the storage trailer.  The ambac is such a resilient pump and very simple and easy to clean out.  Nothing like the Bosch.

I'm not sure how many engines had the ability to use with either pump.  This block had the 3 ambac mounting holes filled with silicone and hex plugs and the oil drain plugged with a small freeze plug.  The ambac drive hub mounted inside the timing cover through 3 of the 4 bosch pump mounting holes.  I have a 1985 2 valve parts engine with an ambac and it does not have the provision for a robert bosch pump.

I installed the drive hub without removal of the timing cover or cam gear which did require removal of excess material from the aluminum hub and a lot of finesse to get it behind the cam gear.  I didn't find the correct injector lines for the ambac which required me to reshape the existing lines for the time being.  The ambac sits about 6" further back than the bosch.  What I thought were the correct lines are apparently E7 lines which I now realize use metric threads in the head versus the USS coarse E6 threads.

The ambac and bosch throttles operate in opposite directions remedied by shortening and reshaping the linkage rod to the pump and adding another lever on the throttle shaft across the back of the block.  Once I got searching online for linkage pictures I remember now the Superliners used both linkage and cable throttle configurations.  I don't know if this was optional or based on year.

I've also been getting the interior fixed up.  I replaced the stolen left gauge panel and am rounding up my other parts.  I'm trying to find a decent silver grey paint closely matching the original color and make the dash and heater cover match again.

Sounds like impressive job done and a lot of new experience. Glad you got it fixed.

Also thanks for mentioning all those underwater stones involved.