I finally finished the 86 Rebuilt 6.9 swap to my 87; power/gas mileage is terrible.
The 86' donor truck was standard cab, manual transmission, non-turbo. I could tow a car hauler at 55 no problem & plenty of power (for me) going uphill; maintained 55 empty no trouble.
I put the motor in my 87' F350, crew cab, 4x4, w/ auto trans (C6).
I've driven it a little over 2,000 miles and average about 10 mpg, terrible yes, but what is worse I can't tow anything of significant weight more than 30-35 mph up a grade; I'm getting passed by everyone. Even empty I'm lucky to maintain to 40 up a hill.
My 87' truck is heavier than the 86' donor truck but I can't believe the lack of performance.
Was that the factory, out the door performance, of this rig configured like mine, how did they sell them?
Could I have possibly missed something on the swap that is robbing power? Manual to Auto Transmission swap - IP, Timing, etc.
I would like to figure this problem out before I go to the expense of having someone install my ATS Turbo off my previous motor.
I know I should install the turbo & my problems will be solved, but there has to be something wrong w/ the non-turbo set-up. I cannot believe this is the best I can do w/ a non-turbo 6.9 - As always, any ideas would be appreciated.
Thanks,
Del
The 86' donor truck was standard cab, manual transmission, non-turbo. I could tow a car hauler at 55 no problem & plenty of power (for me) going uphill; maintained 55 empty no trouble.
I put the motor in my 87' F350, crew cab, 4x4, w/ auto trans (C6).
I've driven it a little over 2,000 miles and average about 10 mpg, terrible yes, but what is worse I can't tow anything of significant weight more than 30-35 mph up a grade; I'm getting passed by everyone. Even empty I'm lucky to maintain to 40 up a hill.
My 87' truck is heavier than the 86' donor truck but I can't believe the lack of performance.
Was that the factory, out the door performance, of this rig configured like mine, how did they sell them?
Could I have possibly missed something on the swap that is robbing power? Manual to Auto Transmission swap - IP, Timing, etc.
I would like to figure this problem out before I go to the expense of having someone install my ATS Turbo off my previous motor.
I know I should install the turbo & my problems will be solved, but there has to be something wrong w/ the non-turbo set-up. I cannot believe this is the best I can do w/ a non-turbo 6.9 - As always, any ideas would be appreciated.
Thanks,
Del