From time to time I have the "overhead ran" on my Detroit 60 Series. Should I do this on my 6.9's and 7.3's?? What is this?? I'm assuming that it is adjusting the valve clearances, but is there more?? Where can I find the specs for an '88 and '89 7.3??

 

These engines have hydraulic lifters, and as such don't need any valve adjustment.
I've never heard the term "overhead ran"

 

the reason your not familar with the turm run a overhead is you have never own a BIG diesel before. Did you not see 60 series detroit. And yes big diesels have hydrologic lifters also. Are you saying you never adjust the valves on anything with hydraulic lifters? The turm run the overhead has been around about as long as there were diesels. Run the overhead includes couple other things also such as timming. But since there is no distributor you might have never knew a diesel has to be timed same as a gasoline engine even with a electronic ignition. So the gentlemen you sounded like from your response he was green about diesels in fact running a overhead on any diesel is something old truckdrivers do to maintain there equipment properly. If you have never done it before its something that keeps equipment running in peak performance & longer life. You probably have never herd of tuning your truck for high altitude settings either have you? Im not referring to a chip or tunner? Thats another thing us old guys that have been around diesels a long time and know how to achieve longer life greater performance and proper maintenance. You would be amazed how setting up a diesel for thin air ( high altitude) will improve everything performance fuel milage life of the engine.On a cat if you do rods & mains alone at 200- 300,000 you can get a easy million out of it before a inframe is needed. That old truckdriver asking about the overhead could probly teach many people on this site & others more than you think. Lets face it we put close to a quarter million or more miles on a diesel easy year after year ive had years ive run allmost half million a year. You can run that many miles in a year with a slouchy assed under powered big truck nor setting around in shops because you havent maintained it properly for running hard. Unless they came out with something in the past day or 2 in diesel tech. Ive been trucking and a owner operator 42 accident free years. Do yourself a favor run the overhead on your truck get it set for high altitude. You might just end up with a truck that didnt run this good day 1. I wont go into massaging your pump and tweeking it. Thats another days story like a marine application cam in a diesel.

 

another trucker here with over 5 million miles driven on all different engines, and never heard of "running the overhead"
i have run most of them. mack inline 6 and V8, detroit 2 stroke and 4 stroke, cummins inline 6 and V8, cat inline 6 and V8, volvo, international inline 6 and V8, scania inline 6 and V8

 

264, these engines don’t need any overhead ran. I have never heard that term either, ask them what they do when you take it in next time. If you don’t have any valve train ticks or taps or racket, have a healthy and relatively young fuel system, that’s about it. If it runs good leave it be lol

 

I don't need to ask, I've done it. I bring a cyl up to TDC then adjust the intake clearance on a different cyl and the exhaust on another cyl. Rotate the engine to the next at TDC and follow a chart on which intake and exhaust to adjust. When all 6 are done I do it again adjusting the Jake Brake. This usually needs to be done every 100K or so in my Detroit. It will gradually go out of spec, then it has a noticeable drop in power and fuel mileage. I know it is time to do it again then. If you don't monitor fuel mileage closely (with pen and paper- not your dash reading) or drive the same truck regularly, you may not ever know anything is wrong. Due to me having my Western Star for 20+ years and 1.7 million on it - I'm kinda familiar with it.

 

Gotcha 264, the way I read it it was like you weren’t sure about it. I didn’t realize you did it yourself, I apologize. Shops around me just call it a valve set, our ag equipment gets done at X amount of hours.

IDIs have hydraulic lifters so there’s no adjustment. Parts get replaced when they wear out, I’m at 500km and still good, I don’t know the average lifespan of these parts. Like everything else, it depends on maintenance.

 

i have 496,000 miles on my 88 7.3 never been apart and i would not hesitate to take it cross country this afternoon.
and here wee call that a valve lash adjustment.
and on top of that, the IDI does not have adjustable valves.