Only 80 ft#'s? Somebudy pop in. Seems low to me even if ARP said thats what it takes. Sorry just had to question this.

Chet

 

it seems that the 7.3 with its 1/2" head bolts took 110 ft-lbs, and thats the spec chiltons shows for all diesels in their 87-93 category, but i'm calling it a book error because of the change in bolt size. i reviewed IDIdieseljohn's thread from his head gasket job, and he mentioned putting his to 80.

but now i have a new problem. i just put in the pushrods and rockers, and found that my valves hit my pistons when the rockers are screwed down.
so do they make shorter pushrods to compensate for having the block and head milled down?

i'm going to review the recent thread here about someone else having the same issue on his build

 

ok, i've done a little more playing around on my piston-valve contact issue here, and i found that adding a washer of 0.040 under the rocker arm gives me enough clearance to rotate the engine with a stack of feeler gages between the rocker arm and the valve tip. the biggest i've tried so far was 0.095 of feeler gages and no contact while rotating the engine. i tried 0.115 and it cleared on the exhaust but touched on the intake. so it looks like i just need to pick up some more washers at 0.040 thick to shim my rockers up, and i'll be golden. any thoughts on this plan?
my only other options would be thicker head gaskets or shorter pushrods, neither of which seem to be available from any source i can contact after closing time on a friday night.

 

Wait this doesn't make any sense.

.040 under the rocker will loosen the clearences likely to the point that the lifters are all the way up. But then .095 between the valve and the rocker will push the valve down more making any clearance problems worse. I don't know the rocker ratio but they look like big block rockers which I think are 1.7 so .040 times 1.7 = .068 So by putting in the .040 shim and then adding .095 your actually adding .027 of "lift" to the valve.

This of course is all negated by the hydraulic lifters pumping up and removing all the clearance created by the shim.

 

the feeler gage shims i spoke of there were STRICTLY for testing how much space i had between piston and valve, i hope i was clear on that.
chiltons says the rockers are a 1.59 ratio, i'll call it 1.6 for easy math.
for your math there, 040 under the base of the rocker translates to 040 + (040 * 1.6) which totals 0.104". thats 040 at the pushrod side, and the rest on the valve side. this is consistent with my experimental findings, that i had a very small interference on the cylinder i first tested

i was just back there studying things a bit more, and found that a number of lifters aren't collapsing at all, and when i spun the rockers down with my cordless drill, i hadn't noticed that i was opening valves on nearly all of them, except the three whose lifters were able to bleed down properly.
so i changed my test. this time i tightened each rocker with the valves closed, until it just got snug, so any slack in the lifter was taken up, but the valve was still closed. then i ran through with my 095 feeler gage stack, loosened the rocker a half turn, tightened it to exactly where it was, and rotated the engine. this time, a few cylinders felt like they might have barely touched as the piston approached the top, but would likely be fine if i were to step down my feeler gage stack to 090.

all that being said, i'll be replacing the lifters, as their inability to bleed down suggests they're totally stuck. i even sprayed them with pb blaster and tapped on em a little, with no sign of freeing up. so new lifters it is, as this latest test suggests they were the whole problem in themselves

 

EDIT 1.6 * .040 is .064 not .106

The lifters may not be bad, they SHOULD take a while to bleed down and need pressure to do it. So if you tighten everything up in stock form and leave it for a while (maybe hours) they should then be "bled down" into place. IF you tighten it all down, wait a while, then turn it over and it still doesn't clear then you have a problem. One of 2 issues, either the lifters are stuck up or the surfacing took off enough material that the lifters are at the bottom of there adjustment. At which point you would need shorter push rods which yes you can get.

To tell which it is VERY unlikely that they would all stick, but they would all be at the bottom of there stroke. So are the valves that are closed even height? Is just a couple hitting/high/low or all? etc.

 

Do you have a dial plunger guage that you can use to measure lift? Do you know how much lift you should have? And at what point?

I say measure the lift, and see what you got at both total lift and when impacting the piston. The lift will always be the lift, and the distance from valve seat to piston will always be what it is.

 

i don't have a dial indicator yet, but could buy one on sunday if necessary.
but this latest round of testing seems to suggest that i'll be ok once i have lifters that can collapse.

but sure, i'll leave all the lifters under stress overnight and see what happens. when i first put them back in, one on the left bank was free, and 3 or 4 on the right bank. all the others were stuck, and still are. i'll see where they are in the morning, and i'll go from there

 

well, i just got out there a few minutes ago and spun the engine over. all the lifters had bled down and now i can spin the engine freely. so i'll verify that my valves are closed and that i have resonalble clearance between valve and piston, but i think we're starting to look good.

 

update:
allowing the lifters to bleed down solved all the valve issues. after i verified that i had clearance (not precisely measured), i then forced every lifter to fully collapse, such that i could freely wiggle the rocker arm. so all the lifters can collapse eventually, but they take awhile to do it. they're all together in stock form now.

i've got the engine all ready to go in, hoist attached and everything. i added a few more pics to the album linked to earlier.

the concerns on sliding it in there now are that
1) the hoist rig lost 3000#, so it sits higher and might require the van be raised a bit more to clear the hoist boom against the body. the requirement here is that the boom be closer to level.
2) the engine is heavier now with the heads on than it was when i pulled it out. and my hoist is only rated for 500# with the boom fully extended, 1000 with it collapsed. hopefully i won't be far enough over its rating to have any issues.
this also raises concerns about the strength of the hitch on the hoist rig - with the hoist boom 2/3 extended, i could see some flex both in the hitch reciever and as viewed from the hoist itself, between loaded and unloaded. not just moving the leaf springs around, but apparently flexing the hitch receiver itself. so before i start extending the boom, i'll have a bottle jack under the end of the hitch to support against any abnormal forces.
3) i don't have anything other than a hammer to force the boom to extend on my hoist, so that might be a bit of a slow process to slide it in. or on second thought, i could have a ratchet strap pulling straight back and up, going out the back doors and to some kind of anchor - that might make it easier to slide the boom down. of course, i'll keep one holding it up too, so i don't overextend my boom accidentally.

overall, every problem i can see here has a clear solution, so i'll have it in place either on sunday or monday, depending what time i get home on sunday and if i choose to work on it then.

i can't wait to hear this thing run!!

 

Just be carefull Josh! Don't put yourself in the position to get hurt during anytime for reinstall. It will come back to bit you. Good luck, and I hope it all works out.

Chet

 

don't worry, i'll be safe. just airing out the concerns i do have, in part cause it helps me think, and it may help someone on a future overhaul who reads my thread.
with the extra supports for my hoist as described in my last post, i'll be plenty safe, and of course i won't be putting myself under the engine until its securely on its mounts.

 

i got the engine in today. everything went pretty smoothly. now i just have to put all the rest of the stuff onto it, and hopefully i'll be able to fire it up monday night, or possibly tuesday

 

phew,what a time of it.you've got 'er on the run now brother.keep at it.good luck.

 

i've almost got her ready to fire up. heres the current view https://www.dropbox.com/s/wu0ya2565g...2000.52.59.jpg so tomorrow i get to put on the radiator and batteries, turn the key, and see what happens.

i really can't wait! 3 weeks of downtime has been tough, and its almost there