I was wondering if anyone has tested VTC with air- especially after a rebuild. First, it was helpful that I tested because I found a problem with one that I rebuilt a few weeks ago. Good. But what I have found on the two that I rebuilt is that they do move easily when pressure is applied but they don't pop back on their own. They have to be tapped- or smacked on a block of wood- to pop back. Is this normal?

I can see how it might be: in the same way that bad VTCs clatter from the cam opening valves, I wonder if when pressure is removed that the vibrations from actuating the valves don't "shake" them loose and then pop back with the spring pressure.

I'm also theorizing that the friction of both ends of the spring is a contributing factor since both of its contact surfaces are turing in opposite directions. I found that filing the sharp edges of the new spring helped significantly when compressing the spring by hand against the middle piece and trying to turn it.

Thoughts?

 

It's a shame this thread is 7-8 years too late for real input from all the old-school VE guys :/

I wish I had some input but I've never had to rebuild any VTCs yet. My blue VE has brand new VTCs and my black VE has 170k and never a peep out of the original VTCs (which is surprising, considering the original owners didn't seem to take very good care of it)

How exactly have you been testing them with air?

 

I plug the cam end with something that will seal it- in this case it was the "nipple" end of a suction cup- and find a way to keep it from popping out- like hold it in or set it down on a hard surface. The oil feed hole is on the bolt end, so use a blow tool with a rubber end that seals and blow. My friend at his shop has a pressure regulator, so I dialed down to 40-60 lbs and blew. I don't think a short blip of tank pressure (100, 125+) will hurt a properly assembled/intact unit, but safety says use caution if you use higher pressure- or really any I guess. (About safety: I've heard stories like... about the gun on the top of the tank that "didn't sound right" to the gunner. So the Sergeant gets up there and fires the thing to see what's up and it blows apart on him and takes his leg off or worse. So you never know when...)

If you have made your marks, you can see how much it moved- and you can feel it move because the cap turns with the shaft the opposite direction of the body- if you didn't know.- and that's where you probably have it in your hand while you hold it down. If it doesn't move... ummm... there's a problem. What I found is that one of the internal seals was missing on one I reassembled and it didn't work. Duh. Not sure how I missed that.

 

I put new ones in my 5sp because I went full out on it (new chains, new sprockets, guides, tensioners) Might have been excessive, but it turned out beneficial when the front VTC in my automatic dropped cap pieces into the chain, broke the chain and chewed up the idler gear- or whatever it's called. Shortened the the 500 mile trip that day by about 280 miles. So I'm reusing all of the stuff from the other car in the auto that was near pristine. (with new tensioners, some new guides) Between the two cars I had two rebuildable VTCs- or so I thought. Doh. Broken internal gear on one, missing seal on the other. The other two: one came apart in my hand when I took it off- unmarked- and with a broken middle gear anyway, and the other was ground down in the front by a spinning cap. TMI??

Is your black one a late '93 or '94? They might have remedied the issue by then. Or, how do you *know* they are original??

 

I'm pretty rusty as it has been quite a few years since I played with them but I don't really see them moving too easily with air. I wouldn't expect it to snap back too easily.

Sorry, I don't really remember anymore. I remember them being fun to take apart and figure out how they work though . Also they don't slide (advance/retard) terribly smooth, at least mine didn't, but mine still had small milling marks on the splines.

Good times, and good luck with the reinstall

 

40 or 60 PSI is the same whether it's oil or air, right?

 

well I imagine the air will escape much easier/faster but yeah

 

My black one is a '92. I have no proof they are original, but based on the obviously poor maintenance history and neglect of the engine over the years I just don't find it plausible that the owner had the VTC's replaced over the years - unless it was very very early on in the car's life, and if that was the case I would think the poor maintenance history after that would have crapped the VTC's out by now. I also see no evidence that the timing covers have ever been touched/removed.

Nonetheless, either way, I'm happy to have two completely clack-free VEs

*edit* I'll probably jinx myself now, though. I've had my black one all dismantled for months now for a complete-car overhaul and with my luck it'll probably start clacking when I get it all back together

 

I said it before but didn't jinx myself (thank the man upstairs). Complete overhaul? You change your mind? I thought you were doing a semi overhaul. And it started with fixing the power steering pump. lol

 

Maybe there is enough gunk between the splines it isn't clacking



But if it runs good you can't ask for much more