no compression

[pjtoledo]

as the valves recessed they would have gradually put more preload on each individual lifter.
from a heavily preloaded lifters perspective there wouldn't be much of a difference.
from the screwed up valve seats perspective problems would be beginning to happen.

 

[rusty ol ranger]

as the valves recessed they would have gradually put more preload on each individual lifter.
from a heavily preloaded lifters perspective there wouldn't be much of a difference.
from the screwed up valve seats perspective problems would be beginning to happen.

Bottom line is no enginr is going to suddenly lose compression on every cylinder

 

[Uncle Gump]

I still think the camshaft sprocket has slipped, no way to tell without removing it.

How does this cause the heads to Crack and suck all the exhaust valves?

 

[pjtoledo]

post #26, bubblegump asks where the lifters bleed off to,,, that's the critical issue

at

Bottom line is no enginr is going to suddenly lose compression on every cylinder

unless all the lifters collapsed at the same time,,, like maybe a blocked oil passage??
exclaimer, just a wild guess scenerio

 

[2011Supercab]

So you think hydraulic lifters bleed all the oil out after you shut the engine off? They don't. If that were true... everytime you started an engine with them it would clatter on start up. Again they don't.

They would bleed off enough that the valve springs would fully close the valves, and at least let it run for a second or 2.

But you could tell me how it would have started if the cam gear actually spun on the cam...

The little nub that holds it in place caught just long enough to run for a few seconds.

 

[rusty ol ranger]

post #26, bubblegump asks where the lifters bleed off to,,, that's the critical issue

at

unless all the lifters collapsed at the same time,,, like maybe a blocked oil passage??
exclaimer, just a wild guess scenerio

I mean i guess anything is possible...but id put the probabilty of that around .2%.

Ive been messing with engines sinve i was 6. Never seen an engine drop compression on every cylinder all at once

 

[Uncle Gump]

They would bleed off enough that the valve springs would fully close the valves, and at least let it run for a second or 2.





The little nub that holds it in place caught just long enough to run for a few seconds.

Ok

 

[1990RangerinSK]

where are you going to put the pushrods in an over head cam engine?

That would be a question for the mechanic who installed them.

 

[1990RangerinSK]

post #26, bubblegump asks where the lifters bleed off to,,, that's the critical issue

at

unless all the lifters collapsed at the same time,,, like maybe a blocked oil passage??
exclaimer, just a wild guess scenerio

Now we might be getting somewhere. The block would have to be in the block. That being the case, replacing heads wouldn't solve the blocked passage in the block, and as soon as you start the engine, kablooey.

 

[ekrampitzjr]

Something bothers me. I suspect we're overlooking something.

Maybe some funny camshaft failure?

Maybe the engine is badly sludged from past poor maintenance and the lifters are starved of oil as a result?

Has anyone looked at the timing chain and sprockets for wear or damage? Still no word about this.

Has someone used anything besides the recommended oil in the lubrication system? I'm referring to engine flushes, aftermarket additives, thickeners such as "Motor Paramedic" (joke), etc. Any chance of a head gasket problem throwing coolant in the oil?

Others have mentioned wrong lifters or pushrods.

Just trying to think of other possibilities...

 

[pjtoledo]

it's late I feel like typing

the oil pressure by itself can't open the valves. it's the camshaft pushing a cavity of oil inside the lifter that opens the valve.
remember, oil doesn't compress so once it's inside the lifter it becomes a "solid" sort of.

rounding things off a bit:

the oil is maybe at 100 psi entering the lifter, the area of the cavity inside the lifter can only be about a third of an inch at best.
so there is only 30-40 pounds of actual pressure pushing up on the pushrod.

up at the spring, seat pressure is maybe 80 pounds. because the rocker has a 1 : 1.5 ratio (rounding things off) there is 120 pounds pushing down on the pushrod.
well, it's not really pushing down, rather it's waiting to resist with that much force.

good thing the cavity of oil doesn't compress because the measly 30-40 pounds of oil pressure is not going to open the valve.

the lifter has to slowly bleed down in order to reach a point of equilibrium, that point is where preload is.
it appears that the lifter is filling while on the base of the cam, and the bleed down is unable to match what the spring pressure is trying to squish out.
that's pushing the lifter past the preload point, holding the valve open.

either that or the damn lifter has no oil in it and the valves aren't opening much at all.

it's 1:23 am, hope this makes some sense.

 

[pjtoledo]

and I'm still trying to figure out how that mechanic managed to install pushrods in an over head cam engine

 

[bubblegump]

According to the timing marks it would be, but is the camshaft sprocket still timed to the camshaft?

Is the keyway still lined up properly on the sprockets? , no way to tell with out removing and inspecting
.View attachment 84667View attachment 84668

we took it apart and looked-they only thing I can think of is that the where ever the lifters bleed to is blocked

 

[bubblegump]

and I'm still trying to figure out how that mechanic managed to install pushrods in an over head cam engine

it is NOT an overhead cam engine-it is a two valve pushrod motor

 

[bubblegump]

it's late I feel like typing

the oil pressure by itself can't open the valves. it's the camshaft pushing a cavity of oil inside the lifter that opens the valve.
remember, oil doesn't compress so once it's inside the lifter it becomes a "solid" sort of.

rounding things off a bit:

the oil is maybe at 100 psi entering the lifter, the area of the cavity inside the lifter can only be about a third of an inch at best.
so there is only 30-40 pounds of actual pressure pushing up on the pushrod.

up at the spring, seat pressure is maybe 80 pounds. because the rocker has a 1 : 1.5 ratio (rounding things off) there is 120 pounds pushing down on the pushrod.
well, it's not really pushing down, rather it's waiting to resist with that much force.

good thing the cavity of oil doesn't compress because the measly 30-40 pounds of oil pressure is not going to open the valve.

the lifter has to slowly bleed down in order to reach a point of equilibrium, that point is where preload is.
it appears that the lifter is filling while on the base of the cam, and the bleed down is unable to match what the spring pressure is trying to squish out.
that's pushing the lifter past the preload point, holding the valve open.

either that or the damn lifter has no oil in it and the valves aren't opening much at all.

it's 1:23 am, hope this makes some sense.

that is what I am thinking but where do they bleed off at?