Monty

Today I was fine tuning my pump on the 92. Since the 90 model feed truck was right by it. I decided to pull the diapraghm off of both. After I got the 4 cap diapraghm off, I noticed that the 90 models eccentric cone was tapered alot more(allowing farther pin travel) than my 92's. The 90 models eccentric also showed a different stamped part number than the 92. The 90 models was a 75 while the 92's was a 70H. This can be found on the bottom of the eccentric cone. So, I switched the 90 models 75 into the 92 and took it for a ride. You could definately tell a difference. In fact, instead of boost stopping at the 32-33 mark, she went right on up to the 35 mark. Quickness of the truck off of acceleration was definately noticed between the two. So, if you havent already, check your eccentric number, and, if you can find a donor on a non intercooled to compare. The 90 model is a 3/4 4wd Automatic with a CPL of 0807 and the 92 is CPL # 1351.

Old Smoky

Good observation! <br><br>Mine doesn't have any numbers on it. It looks like a custom machined unit. ??? <br><br>My original one was a 70S.<br><br>Mike<br>

Monty

70S? Hmm.. Wonder why so many choices. Could it be that the automatics got a deeper cone to aid in quicker spoolup? I didnt get the caliper out or anything, but I could definately tell a big difference in the two.

Alec

Funny -- I asked someone who supposedly could order all parts Bosch if there were different eccentrics available for the our pumps. They said no. <br><br>Monty -- can you measure the the two pins and check to see if the two AFC springs are the same? I will try to pull my pin and check the number and post its dimensions . . .of course, with my to do list, it could be months before I get there . . .<br><br>Smoky, what dimensions did you finally go with on your custom part?<br><br>Thanks for the info Monty!

Monty

I will see what I can do. I did notice that the spring was a green and black color while the spring on my truck was an all silver spring, no color. I did push them down at the same time with my hands and they both seemed to have the same tension though. But, you never can tell. When I first got the truck, I let a retired Cummins engineer play with it, so he may have switched out springs.

I will see what I can do tommorrow.

Jbolt001

Mine is a 70H. Ist the taper steeper or just offset more?<br><br>Jay

Monty

The 75 (90 model) had a deeper look to it all the way up the eccentric.

Jim Shulmister

Do i understand this correctly?<br> The cone tapers down to a smaller diameter at the southbound end. As the boost pressure at the diaphram above the cone increases, the cone is forced downwards, increasing the metered amount of fuel supplied to the engine &quot;richening&quot; to compensate for the higher amount of air supplied by the turbo.<br> This in mind, the cone in the 90' as described in the first post here, must have a greater pitch than the original from the 92'? The increased fuel would cause the higher boost reading he is getting.<br> Makes sense, but how do we find out how to get them thar cones??<br> -RATCHET-

Monty

Yessir, your explanation is correct. Where to get them, that is another story. I guess you could always switch them out when another 1st genner isnt looking. <br><br>FWIW...Bosch should be able to get one if you give them the number that I posted.

Old Smoky

asilitch,<br>I finished drawing up another design Sunday. This one is NOT liner. It has a compounding radius (does that make sense?) that is larger at the bottom and smoothly steps down to the top. It is now on AutoCAD, and will be machined on a CNC. I would post a picture but haven't got that figured out on this site yet. The final unit should be quite &quot;tunable.&quot; I am trying to make everyone happy here. The idea is that it can be set mild for no/low smoke, and wild for high low-end torque and fast turbo spool up. It will be hardened to something like 50 on the Rockwell scale (cant remember right now), unlike the DD pin. : <br><br>Seems to be a few of options for the different years and models.<br><br>

Monty

Jbolt, I havent had a chance to take any measurements of the two yet. Any of you guys running the non intercooled trucks care to take a peak at your eccentric and tell me what you find? Im curious to see how many different eccentric versions are out there.

Redleg

Your more than welcome to come take a look for yourself. While your at it, show me how to set timing, and turn up the fuel. <br><br>Learning fast, but I'm sure you'll have an answer before I'm of any use (eagerly waiting for results).<br><br>Don

jleonard

I will check mine on my early 91 and let you know.

I just checked mine....it is a 75
Jay

jughead

[quote author=OkieBroncRider link=board=9;threadid=10514;start=0#101108 date=1044490793]<br>Jbolt, I havent had a chance to take any measurements of the two yet. Any of you guys running the non intercooled trucks care to take a peak at your eccentric and tell me what you find? Im curious to see how many different eccentric versions are out there.<br>[/quote] been a long time since i had mine out. i think it had the #45 on it. when i get time will check it again.

Lil Dog

This all explains how my 89 &quot;seemed&quot; alot faster off the line than my 93 even without any governor adjustments. I never thought that the eccentrics would be different in cone taper angle... I should have swapped them before I sold it... :'(

I have a pic of the cone on my 89, just at and angle shot.. Not much use but I attached it anyway..

J-eh