3406B Advice

@wore out

 

Check your water pump for Gods sake.

IPD durability kit, 7W7031 nozzles STOCK timing I will stress again STOCK. The 7FB is already starting at 21 and isn’t gonna perform the best due to too much timing on those pistons below 1500. same turbo leave the screws alone

 

For what it's worth I rebuilt one with the IPD steel top piston kit (durability) recently and couldn't be happier with it so far. I haven't put enough miles on it to vouch for durabilty though.

 

I'll leave that to @wore out , but on my 4MG I had to change oilers to Emodel double squirters and shim the relief on the oil pump. You may want to change to the higher volume oil pump instead of shimming. When you get the kit the numbers will be available for the different oilers and oil pump. We can give them to you here as well if you have any problems.

 

Those are not marine nozzles. They are industrial. You bump that timing you’re gonna burn it up. Very simple. You bump your fuel you’re gonna burn it up I can’t be more clear. The 7FB has way more meat between the top ring land and top of piston with an extremely narrow bowl that’s how they stand the timing they do. The pistons you’re going to use come out of a 3408 HUEI engine. They match nothing but closely resemble the later wide shallow bowl crowns.

This makes me sound like an ### and i don’t care. You can listen to the don’t know come here from sickem crowd……or do it and be reliable.

No where in any CAT or fuel data literature can I or anyone else find where one nozzle flows more than another. The only differences are pop pressures and spray angle that’s it. The extra fuel comes from rack travel. The shallow wide bowl works best with around 14 degrees base timing then advance from there. I run a 5KJ pump which has the exact curve of a 4MG but allows me to run higher pop nozzles verses the 4MG. Pullers can advance a 7FB on these pistons because they are wide ### open and overhauling every off season. You want reliable but being honest you have the wrong set up. Put it back factory pistons nozzles with a good turbo and call it a day

when it comes to timing whether it’s 7FB or 4ZR industrial and all in between some where about 30 to 31 all in at 1900 to 2grand is all you want. So a 7FB static is ar 21 starts advance at 1500rpm and advances to 30. An early 3ZJ will be for example 11.5 with the start of advance at 1260 all in at 28 or 9 at 1800. So can you see why advancing a hair on a 3ZJ is ok….but a 7FB you run outta room quick.
Marine engines are rated at 2100 industrial are rated at 1800 so which is better in honesty for a truck?

A B will never be a hot rod it will not produce the torque at 550 that an E will. You want an E buy one.

 

You'll probably have pitted landings where the grommets sit in/on the top of the block under the head. The block will probably need counterbored as well.

 

I don't pull ours hard below 1500. On a long pull I try to stay above 1600.