6.4 enhanced long block

[Autoworker]

just finished installing long block 6.4 came all asembled with valve train all i had to do was instale fuel inj and all the acc.blead fuel system cranked over to prime oil in moter long enough /then started ran fine for a bit then started making noise and rough idle koeo p0284 no 8 contribution/p0308 misfire did a balance test and dead no 8 relitive compresion 20 percentremoved valve cover and rocker found bent push rod no 8 exaust valve any ideas why could it be lot rot how long did it sit on the shelf with no 8 exaust valve open position

[Brad Clayton]

No rhyme or reason. Should come apart nice and easy the second time around. And don't forget that quite often 3 times is a charm.

[mchan68]

I vaguely recall common issues specifically with cylinders #5 and #8 being the favourite ones to bend pushtubes upon initial engine startup after a major disassembly (such as heads off) and reassembly, due to not setting the dowel on the crankshaft to the six o'clock position when re-assembling the engine. This of course is referencing 6.0L engines. I know the 6.4L uses a very similar valvetrain layout to the 6.0L. The only intuitive reason I can come up with for setting it up this way is that no pistons are at TDC when the crank is set to that orientation. Hope this helps. Look on the bright side. At least on a 6.4L, you don't need to disturb the cylinder head gasket seal to disassemble the valvetrain like you do on a 6.0L.

[Aaron]

I've never had that issue with a 6.4 or 6.0, and I've never worried about crank position during reassembly.

 

Thing probably sat around for awhile and the valve stuck in the guide LOL.

[Jim Warman]

I've never had that issue with a 6.4 or 6.0, and I've never worried about crank position during reassembly.

 

Thing probably sat around for awhile and the valve stuck in the guide LOL.

+1. We used to have one tech that would ALMOST WITHOUT FAIL bend a push tube when reassembling a 6.0. Neither of us gave a rats ass about where the crank was positioned. He got to the point that he would ask yours truly to install his push tubes for him. I've have never (knock on wood) had a push tube bend on me during assembly on a 6.0 or a 6.4. But I am an anal old fuck and I try not to leave anything to chance.

 

As for needing to ensure no pistons are at TDC when installing push tubes, I am going to opine that some of us are relying a bit too hard on air tools during the reassembly process. I will agree that tightening a rocker arm too fast MAY NOT allow enough time for the lifter to bleed down and cause a concern..... but to have it relate to only one or two cylinders is a tad hard to swallow. Let us remember that you will not have only one piston at TDC at any given time.

[Aaron]

 

I've never had that issue with a 6.4 or 6.0, and I've never worried about crank position during reassembly.Thing probably sat around for awhile and the valve stuck in the guide LOL.

+1. We used to have one tech that would ALMOST WITHOUT FAIL bend a push tube when reassembling a 6.0. Neither of us gave a rats ass about where the crank was positioned. He got to the point that he would ask yours truly to install his push tubes for him. I've have never (knock on wood) had a push tube bend on me during assembly on a 6.0 or a 6.4. But I am an anal old fuck and I try not to leave anything to chance.As for needing to ensure no pistons are at TDC when installing push tubes, I am going to opine that some of us are relying a bit too hard on air tools during the reassembly process. I will agree that tightening a rocker arm too fast MAY NOT allow enough time for the lifter to bleed down and cause a concern..... but to have it relate to only one or two cylinders is a tad hard to swallow. Let us remember that you will not have only one piston at TDC at any given time.

 

I agree with this statement 100%Personally, I would wind all the head bolts down with a speed handle until I felt any kind of resistance. I'd then go over them a couple more times until you could tell the bolt was bottomed out. Then I'd begin torquing to 245 or 210 ft-lbs depending on which ARP lube was being used on the washers.

[Alex Bruene]

I've never had that issue with a 6.4 or 6.0, and I've never worried about crank position during reassembly.

 

Thing probably sat around for awhile and the valve stuck in the guide LOL.

Same here. I've never turned a crank during assembly, and I've never bent a push rod.

[Jeff Clyde]

Same as Alex for me. I have seen many pushrods bent after startup, but were usually from the pushrod not being in the lifter on re-assembly.

[Jim Warman]

Same as Alex for me. I have seen many pushrods bent after startup, but were usually from the pushrod not being in the lifter on re-assembly.

Ladies and gentlemen, we have a BINGO - please do not disturb your cards.

[joshbuys]

I've bent a couple myself....and it's always been when I'm in a hurry and use my air ratchet to run the bolts in, and one of them was with the crank in the 'proper' position....

 

Moral of my story, HAND TOOLS ONLY when reassembling valve trains

[mchan68]

Spinning the engine over by hand a couple revolutions to ensure all valvetrain parts are moving through their proper range of travel before bolting up the valve covers also helps to avoid having to go back in again.

[Jim Warman]

Spinning the engine over by hand a couple revolutions to ensure all valvetrain parts are moving through their proper range of travel before bolting up the valve covers also helps to avoid having to go back in again.

Indeed... one apprentice discovered that a pebble had made its way into a cylinder. If this engine had been started, it could have gotten spendy.

 

Additionally, in the case of todays long timing chains, rolling the engine over allows us to be sure that we didn't have slack in the wrong place.

[mchan68]

Additionally, in the case of todays long timing chains, rolling the engine over allows us to be sure that we didn't have slack in the wrong place.

Getting a little off topic, it ceaselessly amazes me how many guys don't know that these engines DON'T have a timing chain. Believe it or not Jim, someone not too long ago had asked me how often the "timing belt" should be replaced on these engines .

[Jim Warman]

Umm, I realize that Mike - but rolling the motor over a couple of revolutions doesn't only apply to 6.4s.

 

We've spent three decades advising people about the importance of servicing timing belts where applicable - little wonder that some folks ask the question.

 

We also need to remember that we are the mechanics and they aren't - partly because we know (or should) about the internal goings on with these engines.

[Aaron]

Spinning the engine over by hand a couple revolutions to ensure all valvetrain parts are moving through their proper range of travel before bolting up the valve covers also helps to avoid having to go back in again.

This right here, is something I always do, even after running the valve lash on my hot rod, setting the valve lash on a big truck, or reassembling an engine of any type.

 

This adage applies to time also: "Spend a little now, or a lot later."

[Mikill]

I make it a habit of spinning the engine over during assembly of cylinders heads and valve train components.

[jimmy57]

It's odd how fate or karma or whatever it is gets you.

You spin one over with rocker covers off and it's all good. You get in the zone and you're assembling everything like a machine counting all those unused minutes from whooping time guide time badly and forget the safety check and that is the sumbitch that spins over with a dead hole or leaks fuel or.......

 

I wonder if heart docs jumper box your heart after a bypass surgery and check for leaks before they close up your chest with those Snap-On staple pliers?

[Autoworker]

end result replaced push rod no 8 exaust started up all ok did a kick ass road test so far all ok

[mchan68]

end result replaced push rod no 8 exaust started up all ok did a kick ass road test so far all ok

The way all you Quebecers drive, when you say KICK ASS road test I believe it.