Question about inframe on 3406b 7fb 350hp cat engine

the 3 manifolds in question. Square, aftermarket round and factory E round. No doubt that square will flow way better than the other 2. However you gotta remember the manifold is blocked at the outlet by the turbo. It can only flow what the turbo lets out. Not a very technical way to put it but hopefully understandable

 

Maybe this will help:

 

5YG00466 is my serial number. They were all PEEC’s, all 460hp and only produced 1 year 1990.
160-1131 is the piston number. Now this is not a steel top. It will stay together however if you don’t get greedy. I have also used the IPD enhanced durability kit with the 7031 nozzle and a 7FB pump with almost as good a result. To improve upon the 460 bottom end with that 7031 nozzle you’re gonna need to spend a lot of dollars to actually feel it in the seat. I had one built that way with a 4MG pump on it with the static timing at 21, start of advance at 1375 which was maybe a little early but the advance was always lazy and I was compensating to get what I wanted at 1600. Anyway it put 530 to the ground with the pump set 10 percent over. No smoke and 6mpg pulling a welfare wagon. All around one of the better combos I’ve run

 

Absolutely upgrade the cooling jets to 166- #### I can’t remember the last 4 but they are dual jet. always change the spring retainer to the later shorter one. That’s only difference in pumps. If you bore your nozzles ya it will give more fuel but in bigger droplets which burn hotter greater chance hole in piston. Plus I have had a lot it trouble with extrude honing the nozzles, and you got something you can’t run to CAT and get. New nozzles from CAT are 1200 a set no core. They will take yours for a core and a set of OR-3425 will run you 600. Cheap enough it makes honing not worth the risk. Remember you work this truck daily you depend on it. We all are guilty of wanting all we can get but working everyday is a deal too. There is a Service Bulliten about drilling in a very precise location between the back two head bolts putting a fitting in and running a hose down to the oval plate on left rear corner of the block. That needs done it helps bring temps down in rear of block and may help prevent galled pistons on 5&6. Cuz again your asking more out of it which creates heat, pressure etc. cheap horse power usually isn’t good bad useable dependable horsepower ain’t cheap.being so hot you gotta back out of one is no good in my opinion. But a slug is no fun to drive so you gotta find common ground of what you can and can’t live with that’s trial and error

 

166-3650 piston cooling nozzles old age takin its toll