You Guys With Hydraulic Heads...Is this Normal?

[rs899]

I was about to slap a rebuilt injection pump on, took off the valve cover and noticed that all of my cam lobes look like they have been hitting the lifters very hard and heating the hardened surface of the cam.  I don't recall the cam looking like this when I put in in about 5k miles ago ( but I am old and can't remember stuff well anymore).




http://s577.photobucket.com/albums/ss212/rs899/?action=view&current=IMG_0428.jpg
http://s577.photobucket.com/albums/ss212/rs899/?action=view&current=IMG_0433.jpg


Is this normal or is SOMETHING going on?  The cam and lifters have some number of miles on them ( not sure how many, got them from Tyler)

Should I buy some new lifters?  Or forget about it?


This has been my first exposure to hydraulic heads - never saw anything like this on my mechanical heads.

Rick

[honda_is_the_best]

my cam/lifters out of an engine with over 300k miles looked better than those. what does the face of the lifter look like? is that the leading or following edge of the cam? looks to be the following edge.. so it really doesnt make sense as to why the back side is the one with the wear.. maybe the rest of the cam is clean now, and that back side is not. just my thoughts..

[rs899]

It's the following edge.  I haven't removed the cam yet, but from what I can see of the tops of the lifters, nothing unusual there.

Edit:  It's both sides of all lobes- the area around the tip looks OK.

[rs899]

I had a nightmare about this last night....

C'mon, what do you think, hydro experts- speak up don't be shy...are your cams prettier?


Remember ( I suppose you don't) I rescued this Jetta from the scrapper when the PO screwed up the timing.  They rebuilt the head...several of the valves looked new.  I wonder if they(stupidly) used (longer) mechanical valves- all of the pistons were hit by the old valves, but 2 of them were not hit that hard.

The cam and lifters that went with the head (when it was damaged) were left in the leaky trunk and rusted in the humid Florida summer.  I bought a cam and a set of lifters from Tyler from a head someone had broken an injector boss off of.  I don't recall anything looking amiss when I got those, but that head probably had 100K miles (or 162km , being from Tyler)

Here was the story and pix of the carnage from last year:
http://www.vwdiesel.net/forum/index.php?topic=21204.0


Ideas?

[Quantum TD]

I see in your photos, your head was damaged. Is that the same head that's giving you these problems? If so, you might consider checking the lifter bores (the tubes where the lifters sit) and replacing your lifters. If you had valve impact, the lifters can mushroom into the bores when they are pushed up against an immovable object (your camshaft). That can cause tension in the movement of the lifters.

[Dakotakid]

VW had camshafts with poor surface hardening in the mid 80's. I believe they were produced in Mex. My friend was a VOA technician at the local dealer and he stated that the service dept. parking lot was full of bad cam cars back then. VW would not replace the camshafts. Instead, they had the dealers remove the cams and send them in and they were reground and put back in the cars. The turn-around time was often several weeks and the customers were angry. Darrell (friend) stated that the cams he was told to put back in the cars looked horrible.

Out of all the hydro cams I have ran across, I have only used one. I threw the others away. I installed solids in the hydro heads and have never had a problem.

About 16 months ago, I felt rich and purchased a rebuilt hydro head from the "Jack in Ohio" guy. The camshaft he sent me in that head looked like a dinosaur infant had used it for teething......I sent it right back to him in the "core" head. I installed a solid cam and life is good.

[rs899]

I don't think its an issue with the bores because only #1 cyl was really trashed and needed extensive work.  And this problem seems to be on most if not all lobes.  I am leaning towards replacing all the lifters and using a mechanical cam ( if that works, and there have been a few reports that it does), or maybe just using a mechanical cam anyway with these lifters since I have a few mechanical cams to sacrifice.

Edit:  These lifters are used and are the mates to the cam ( from a different non-trashed engine), although they are not in the same positions they were on the cam in its first installation.

What's a good way to test a lifter?

[rs899]

A little more data, the wear is on every lobe, front and back, but I don't see any at the tip.  I guess the term is spalling- excessive pressure and heat discoloring the surface.  It doesn't feel any different, just looks different at this point anyway.

[honda_is_the_best]

I had a nightmare about this last night....

C'mon, what do you think, hydro experts- speak up don't be shy...are your cams prettier?


Remember ( I suppose you don't) I rescued this Jetta from the scrapper when the PO screwed up the timing.  They rebuilt the head...several of the valves looked new.  I wonder if they(stupidly) used (longer) mechanical valves- all of the pistons were hit by the old valves, but 2 of them were not hit that hard.

Here was the story and pix of the carnage from last year:
http://www.vwdiesel.net/forum/index.php?topic=21204.0


Ideas?

im pretty sure there is no possible way to use hydro lifters on solid length valves.. i think the valves are QUITE A BIT longer with solids..

[rs899]

I think they are something like 9.5mm longer- is that enough that the hydraulic lifter can (almost) handle?

I also wonder if the valve springs have been replaced with something else stiffer.  They just seemed extra squeeky compared with the other 1.6 I have.

I seem to have plenty of oil/pressure up there.

I really don't know what to do at this point.  I could pull the head and use a 11mm mechanical that I have, but I really don't want to go there.  I really think the issue has to do with the lifters, valves or springs not being right.  I have another hydraulic head, but it's really worn out.  I think I will pull the cam off, compare the lifters and take a spring from #1.

I am open to ideas...scratching my head.  I wish I had stripped this head before I put it on, but it's on there now and holding compression just fine.  I got the thing from a machine shop...not  that that matters...

[honda_is_the_best]

yea, if the mech valves are almost a full centimeter longer, theres no possible way someone put mech valves under hydro lifters and made the engine run. it just wouldnt work. the valves would always be open.

[smutts]

the valves would always be open.

Till the pistons persuaded them otherwise.

But looking at the photo's, agreed, well odd. If no nasty noises, I would be tempted to keep my fingers crossed and ignore it.

As for ugly cams, I haven't dared look at the red GTD since the other half drove it 20 miles with NO OIL WHATSOEVER in it. "Oh I wondered what that annoying buzzer and red light meant." ARRGH!  
It started first time the other day! But the noise of four knocking big ends, rumbling mains, wrecked camshaft, not good. How do I post a sound recording for your enjoyment?
End of threadjack!

[rs899]

If it's not springs, lifters or valves ( and I am kinda ruling out the cam because I'm sure it must have been fine when I got it and it had been well burned in), another possibility might be that the machine shop lapped the valves/seats so much that they extend past the point where the lifter can handle it.  There's probably a spec in the Bentley, but I don't know if I will be able to measure that without taking the head off....

[honda_is_the_best]

i think bentley spec  measures the valves from the deck of the head. and usually when they are lapped too much, the heads of the valves are shaved to get a correct valve height.

[smutts]

Just a thought from my Peugeot TUD5 diesel, it has solid lifters. Just to be odd, the exhaust valves never change, the intakes close up to zero & less clearance. ("They all do that Sir." WTF???) Result being the car would be a bugger to start on a really cold day, fine once engine warmed up. But this was due to bugger all compression with a cold engine as the intakes were held slightly open. Alloy head expands more than the steel intake valves, so valves close when warm. SO.............
If there was no valve clearance, the car might be a bugger to start cold.