[TazRango]

The 5.2 is a clearance engine.. Meaning you don't smack up the valves when a timing chain breaks.. Something else went horribly wrong there if you have bent up pushrods. It's likely you over-revved and the valves floated. That can easily result in bent pushrods. I take it you didn't notice any busted springs?

 

[TazRango]

The 3.9, 5.2, and 5.9 are interference engines, pushrod and valve damage can occur especially if there is a manual trans behind it. There is nothing in the valvetrain to close the valves if the chain was to break.

Uhh. No they aren't, genius. Only the "point 7" engines are interference. Go back to bed. :jester:

 

[TazRango]

I'm not even going to waste my time explaining it to you, dickhead. Go look it up yourself.

 

[TazRango]

Because you can't.

Don't forget to take your meds.

Ugh. Crawl back under your bridge, troll. Don't come back until you learn the basic workings of an engine.

I appreciate the laugh this morning guys. So what is really going on non interference or not? I have the head off and taking to machine shop today. The pistons do not look like they have any marks. You think I should check those out? and what about the cam shaft? does this not hit the push rods?

The 5.2 is NOT interference unless they have been stroked, decked, and/or have a really high cam/high ratio rockers installed. In stock configuration, the piston does not come all the way to the top of the bore, so there is no way it can smack the valves even when wide open - as evidenced by you not seeing any impact marks. And if the piston HAD hit those valves, it would've bent the valves and broke the stock rockers before it bent the pushrods.

(I'll explain this to you, the troll can watch and maybe learn something :jester

When you rev too high, the springs can't rebound fast enough to keep tension on all of the valvetrain components, and you get slack between the components (cam-lifter-pushrod-rocker-valve). This is called float. When the valves float, the components (which normally all move together in one fluid motion) begin to separate and smack into each other. This in itself can bend the rods and cause other damage. Without tension on them, the pushrods actually start to bounce around in their bores (put a pencil in a paper cup and shake it around), and if the gap gets wide enough, the bottom tip can actually ride up out of its dimple to the edge of the lifter. If it catches the edge, it gets pushed up too far with a lot of force, and it bends. Even if the lifters are able to pump up and compensate quickly enough to keep the pushrod from riding the edge, once the engine slows down they can't deflate quickly enough to keep the pushrod from traveling too far - which has basically the same result.

 

[TazRango]

Time to double up on your meds.

 

[TazRango]

Yeah? Thats funny because I don't see that 'word for word' phrase in my copy of the 1998 FSM. Nor are there ANY steps that refer to installing or removing the arms in any specific order, nor is there any step that involves turning the crankshaft after each cylinder, as there is in the 4.7 (which IS an interference engine) FSM. :jester: You're wrong dude. Give up and slink back under your bridge, lest you embarrass yourself further.

 

[TazRango]

You're just too dense for words. Yes. there is a FANTASTIC reason for that caution. To keep you from bending pushrods due to the lifters being overinflated. Notice it is mentioned AFTER the step telling you to tighten all rocker bolts in no particular order. What did you think it meant?

IT IS NOT AN INTERFERENCE ENGINE. PERIOD. The OP even said there are NO contact marks on the pistons or valves - which if the piston hit the valve with enough force to bend the pushrod there absolutely would be. You're NOT going to win this one, so you might as well go back to your bridge. And you can make alllll the therapy/meds jokes you want, they just make you look even more retarded.

KTHXBYE.

 

[TazRango]

You seem to be the only one who doesn't understand, so guess what that means? :huh:

 

[TazRango]

You appear to ignore the bold caution from the manual I posted, which is a newer version from the 98. :huh:

Will the State of Kansas let you posses weapons?

Yes, as a matter of fact they do. I own several. Thanks for asking.

 

[TazRango]

Yeah, actually they do. I've got a CCW too, so... Yeah.

 

[TazRango]

Wait a minute.. You said you had #4 and #8 dead, but the bent pushrods were in #5 and #7. And you didn't notice the valves were smashed when you took the heads off?? :huh:

If there were no marks on the pistons, then there was no impact. If you told them you broke the chain, it wouldn't surprise me if they 'found' them bent to hike your bill.

 

[TazRango]

Yeah theres something fishy about the whole thing. A not-so-badly-bent pushrod will still work because the lifter will pump up extra to compensate. You just don't want to keep running with a bent pushrod because it'll get worse really fast.

But there's no way to get compression with bent valves. If the stems are bent, they don't seal. If it were me, I'd go after this shitty shop for whatever the valve job and pushrods cost you.

The one between 4 and 8 is 6. Passenger side is (from the front) 2-4-6-8, driver's side (from the front) is 1-3-5-7. I have gone and mapped out the valve order, and there is absolutely no way (even if it were an interference engine) for that combination of valves and rods to have gotten smacked up. The valvetrain is under tension, and there is no reciprocating mass, so when the chain snaps, the cam stops dead. It doesn't keep moving. So considering that 4-8 and 5-7 are sequential in the firing order (1-8-4-3-6-5-7-2), there is no way that both cylinders could have a valve open at the same time. At absolute worst you'd have 4 and 5 OR 7 and 8. But not all 4, because the two pairs are 180 degrees apart in cam rotation. Then there's the fact that there was no damage to the 3-6 and 2-1 valves, which WOULD be in various degrees of open when 4,8,5,or 7 are open. It's all really fishy.