Timing issue (maybe) 1993 mack E-7

Little background info. We rebuilt it from 350 specs with 16.5 compression to 454 specs with 15.3 positions. 171702 BW turbo and stage 2 injectors (20% more flow than stock) the turbo is huge compared to stock ill post a pic.

The problem is she smokes bad until up to operating temp. I think the timing is too far back still seeing as she dont run hot and rolls coal like nobody's business. Pulling the steep hills on I 88 (belden hill) the temp never got over 180 and pulling the 5 mi hill coming out of bean town same thing temp never got above 180.

The only electronic thing is the fuel pump. Its a Bosch p7100 (same as 12V Cummins) except electronically controlled. Static timing for a 400 is 10.5 degrees. The way mack changes the timing is threw the econovance which is controlled by oil pressure. Depending on the model/yr it either has a 10 degree or +20 degree econovance. Not sure what we have.

So if we have a static +10 it means it only will go to 20 deg of advance and could be running too far re-tarted with the mods we have done.



So would you guys say its safe that the timing is still too far back and needs to be advanced more. Also we have a blixxton tuner which is pretty much a resistor that fools the rack to open all the way

 

The turbo is the s475 that the 12.7 guys love. Were seeing 38-42 psi compared to 28 with the stock windmill

Even not running totally 100% right it pulls like a bear. We left my uncles 500 12.7 in the dust and he was 20k lighter than us. Seat of the pants dyno says 525-575. I'm gonna get flack for this but it out pulls a stock 500 5ek that another friend runs. We have 3.91 lo-pro 22.5 and 13 dbl over

 

Here's what the pump looks like

 

@wore out @AModelCat any words of wisdom?

 

The pump off the 400 is the same and between shifts its lets out a black trail as long as the wagon and going up hill it lets out a steady stream. We've ready countless pdf files and cant determine if we have the 10 or 20 degree econovance. If we only have the 10 its only getting 20 degree of timing under load.

Tomorrow were gonna advance it up to 15-17 and run a load with it. Rochester diesel and Antrim both know how to get those E-7s to run and they say the stock pump is fine. Still being able to roal coal should be proof, right?

The other thing I was thinking is that the ecu is still mapped for a 350 16.5 compression static timed @ 7.5 but my dad doesn't think its the problem, I do. What gets me is it only does it when cold.

If we can't figure it out soon were taking it down to Antrim and if they cant turn the pump up or wont were going full mechanical.

How far you advance your b mod?

 

I told him from the start that the 350 file and the ignition mapping with that is the problem. He's not used to computers.He's grew up around E-6s and big cams, even had a 6-71.

New delivery valve on the pump and new supply pump. The local pump shop won't do performance only build the pump to OEM specs. Do you know anyone good with Bosch P pumps?

We dont even have 2500 mi on it since the 1st run so maybe it just needs broken in still? I'm going to re-torque the heads and run the over head tomorrow and were gonna advance it up to around 17 or so and see what it does.

Thanks wore. Just not a lot of info out there about tuning the E-7.

The only difference between the 350 and 400 is 400 has 15.3 pistons but has same pump and injectors. Some books say 350-400 have same turbo other sources say they dont so I'm stumped. Local mack is worthless.

 

What year? That's not the issue we have. Does it have the p pump hanging off the passenger side of the block or is it an etech with unit pumps. Totally diff animals