More valve adjusting questions

[Iceni John]

Sorry to keep asking about what is probably a really simple job for the experts here, but for noobies like me I need to learn all I can.   I'm finishing tuning up my Jakes, for which I had to remove them from the heads, and I've also replaced all the fuel crossover tubes' O-rings while I've got the Jakes off.

I adjusted all the passenger-side valves last week (with my nifty new Snap-On tools!) after reinstalling the Jakes, and most of them were close to correct.   I still reset them all to 0.016" cold, and the Jakes to 0.059", and when I started the engine it seemed to idle slightly quieter then before.   Now, when I reinstalled my driver-side Jakes today and checked the valves there, they were all tight, very tight, most about ten or eleven thous.   I reset them all to 16 thou, but I'm curious why one side was so much worse than the other?   What happens if you drive with valves too tight, like some of mine were?

My engine has about 275,000 miles, but I don't think the valve covers have been off for a long time!   How often should valves be checked?   The reason I think the VCs have been on for a long time is because they're a royal PITA to remove!   The passenger-side VC needs the air inlet pipe disconnected and two hoses removed, not too bad, but the driver-side needs a section of exhaust pipe removed and a coolant hose also removed.   The exhaust pipe surprisingly wasn't a problem, but I had to drain out about 5 gallons of coolant to disconnect the hose from the header tank.   What a funkyass setup.   So I don't have to go through this rigmarole again, I've put a Parker 60-series hydraulic hose quick-connect coupling on that hose so it will be a five second job in the future to disconnect it.

I haven't touched the middle rockers' adjustments for the DDEC fuel injectors.   Should I?   If so, what is the clearance for DDEC injectors (I think they're 70s or 75s?), and how do you do it?   Are DDEC injectors less fussy about their rockers' adjustments than MUI injectors, in other words do I need to worry about it at all?   The engine runs well now, so I don't want to possibly muck up something that's OK now.

I'm glad I took the Jakes apart.   The passenger-side solenoid had a twisted middle O-ring, and one of the oil connector tubes was completely broken in two!   That side now works when I apply 12V to the solenoid at idle, and I think I now have a few PSI better oil pressure than before because the oil isn't just squirting out the broken tube.   The driver-side Jakes had one slightly sticking piston, but I polished it with some fine emery cloth on the visibly-scuffed area and it now slides as smoothly as the others.   I hope that after doing all this my Jakes will be better than before!   If nothing else, it's a good learning experience, and it's made me a lot less intimidated of perhaps doing more jobs in the future such as rolling in some new bearings, maybe?   I wouldn't mind however to have a real expert look over my work to double-check I haven't done something stupid, but I'm following the Detroit and Jake manuals to the letter and being as careful as I can.

Thanks, John     

[lostagain]

Removing my valve covers also necessitates disassembling some air intake and exhaust plumbing. But the second time around is easier and faster. You're doing things the way I do: the book in one hand and a wrench in the other. If it runs good, you've done a good job. And I like to go back in and do it again. Especially running the rack: the more you do it, the better feel you get for it, and the better it runs. Once you've done it once or twice, you realize that it is not rocket surgery, and is really not that difficult.

I think one side was tighter than the other because the last guy in there set them that way. You are a better mechanic than he was.

JC

[Bill Gerrie]

Set the valves cold using the go no go procedure in the book. The injectors are something somebody else can chime in for as my  DDEC injectors are set at 1.54 but that was the new setting after the overhaul. Don had me reset them to 1.484 and they are running great but check with a DD dealer if you have to. 

[Iceni John]

Set the valves cold using the go no go procedure in the book. The injectors are something somebody else can chime in for as my  DDEC injectors are set at 1.54 but that was the new setting after the overhaul. Don had me reset them to 1.484 and they are running great but check with a DD dealer if you have to. 

After adjusting each pushrod I checked them with the 15/17 thous Go/NoGo gauge, and they're all spot on.   I was worried that the injectors weren't completely depressed, so I barred the engine back and forwards several times to be sure that each middle rocker was all the way down.   As soon as I get a 3/8" steel elbow for my coolant hose modification I can refill the coolant, then I can start the engine and put 12V to the solenoid to check it works, and check that there's no fuel leaks at the crossover tubes.

I think I'll leave the injectors alone for now.   I've got lots more learning to do before I will feel comfortable adjusting them.   If it ain't broke, don't fix it until it is.

Thanks, John