performed inframe on truck, 3 new heads loaded, replaced cam with used one , had to replace cam bearings due to they glued themselves to old shaft an spun in block, new ones fit back tite in block, timed accessory drive back to cam gear ( figured out how to line up crank gear with cam gear,then turn crank shaft 90 degrees an it lines up accessory gear mark an cam gear together when looking into gear cover inspection hole. set the injectors to 6 in pounds, an intake at .11 an exh at .23, had to drag truck to get it to spin over fast enuff to fire up, (batterys were down) motor started up an seemed to skip some an smoke like crazy, was leaking into cab from flex pipe, noticed rear head was leaking oil out from under it , come to find out we didn't torque the heads down rite. blew the grommets out of the head gaskets,,,, blew water into the cooling system, there wasn't any water in the system, radiator wasn't even in truck yet, water lines off too, ran long enuff to hear it fire up,,,, notice motor tried bogging down the locked down, noticed the front of motor gear cover was extreamly hot, come to find out the cam plate thrust cover in frint cover wasn't shimmed out enuff an was causeing friction, installed few more shims for clearance, started motor back up an it stopped heating up , noticed its still smokeing pretty heavy, so after noticeing that by now all 3 heads were leaking from gaskets blew out, pulled over head off, removed heads, noticed that number one cylinder was wet with fuel an the exhaust hole was staying wet an not dry like the other 5, an piston was very clean an valves were too, kinda like blowinging a head gasket an water getting into it an cleaning it out. but remember there wasn't any water in motor, just ran for few mins didn't over heat either, but when I looked at the 5 other pistons that are burning an that were dry, all the exhaust valves are clean an the pistons are clean, no exhaust sut on them, looks like the valves are barely makeing contact with each other an taps the sut off. im not sure why the valves an pistons are makeing contact , we set the valves at .23 like the tag on motor says. ive been wandering if when I installed the accessory drive gear to cam when the crank was turn 90 degrees did I get my marks off one tooth, ive built few of these motors before new had this issue before, how do I know if I need thicker head gaskets or what may be going on here
Is this a joke? First off, when replacing cam bushings on an 855, they are supposed to be line-bored. Sounds like you need to tear it down and start over.
X-2 I didn't see anything about resetting the injector timing. You just used the old gaskets on the cam followers?
That has me scratching my head. We rebuilt many engines over the last 45 years from little V4 Wisconsins to Cat D399 and 3508's along with several 855, 1150 and 1710 Cummins and a bunch of Detroits from 3-53 to 16V-71's, almost forgot the Mack's! and never had to line bore cam bearings. 99.99 percent of the time we replaced cam bearings on any major rebuild. Unless this is something new as the last 855 I did a major rebuild on was probably ten or more years back. That all being said to install a new cam and not adjust the end play or adjust the cam timing is just asking for problems. Assembling with the same thickness cam follower gaskets is a good starting point, but just a starting point! All bets are off when using a new/used camshaft. The cam/injector timing procedure can be a bit confusing if not done regularly but is very important. To not do it would be like dropping a new distributor in a 350 chevy without even looking to see where the rotor is pointed then wonder why it is running bad and kicking back tearing out the starter drive. Don't want to sound like I'm dumping on the OP but these engines are easy to rebuild but things need to be done correctly and in the proper order. Even a little 3 horse Briggs will not work right if something is not installed correctly, install rod facing the wrong way and it will hit the cam when you turn it over.
Kshansen, I've never overhauled one personally, but my uncle who has put million+ miles on 3 different 855's told me that, so I was/am trusting his info. Either way, this job sounds like a trainwreck. Among other things, if he was indeed getting interference between valves and pistons, I'd be throwing all the push tubes away.
Way back on I believe it was post #17 of the original thread on this engine I felt that this one should have been scrapped. Hate to see more money and time be dumped into it. Sure anything can be fixed and I too hate to give up on an engine or other piece of equipment, but there comes a time when you just need to say "I GIVE UP". With all the trucks running up and down the highways with 855 Cummins under the hood I find it hard to believe that a good used take out engine could not be found and slipped in this truck for less money than it has eaten up this year in parts and labor. Feel bad to be such a downer on this one, feel confident if this was in my garage and I had a open check book for parts I could have this one running like new, but.........
Nine times out of ten if the cam bearings turn or spin in a Cummins block the housing bores need to be machined and oversize O.D. bearings installed. Which they do make but even Cummins would discard a block on core if it was to involve to much machine work. A percentage of Cummins recon engines actually had new blocks. Which also leads to Cummins last ditch effort to save blocks with bad counter bores, by installing counter bore repair sleeves. That was a disaster. Truck Shop