New V8 Tappets - is this correct?.

#1
Hi All,

I had a friend call round today who is rebuilding a Range Rover 3.9 engine.
He bought a set of 16 new tappets from eBay, from a seller claiming they were OE parts manufactured by Delphi. They came in a plain white cardboard box, and there are no identification markings at all on the box or tappets. I always believed that the OE tappets were manufactured in the USA, right through the life of the Rover V8.

Now, when I have bought OE manufactured tappets in the past, they have come individually packed in bags to keep debris out. These were just relying on the box.
He took two tappets out the box and placed them cam face end down on my worktop. He then pressed the push-rod end of one tappet into the body against the spring with a biro. It went in about 8mm. He then pressed the other one in, and it went solid after about 4mm. Several in the box are like this.

He was asking me if I think these are OK to use in his 'new' engine.
My first reaction is NO, but I must confess I have never done this particular 'test' myself, and would be interested what others on here think.....
 
#2
The tappets I bought for my P6 some years ago from S&G Walker were in small polythene bags with a Rover label on each one and they certainly didn't jam after testing the spring on a few of them.

I certainbly wouldn't install any jammed tappets into my engine.
 
#3
I put a new set in my engine from S & G Walker in 1998, they were individually packaged, I dont remember any
manufacturers markings on tappets or packaging. I charged each tappet with a pressure oil can (containing clean
new engine oil) checked that it held its charge and did not leak back through the aperture when depression tried.
To my mind that is the true test for a hydraulic tappet, certainly not pushing it in with a biro without the tappet
being charged with oil first !(I assume this was done when dry)

If the piston goes in more than 10 thou (IIRC) after being charged with oil, that is a defect and that tappet should not be used.
I am relying on 40 yr old memory now,so I may be awry in the above measurement, but am sure somebody on here will
know ?
 
#4
MJP6B said:
....certainly not pushing it in with a biro without the tappet
being charged with oil first !(I assume this was done when dry)
Quite so, he was just demonstrating an observation to me, rather than conducting any actual test.
It was done dry, but I would not expect some of the tappets to behave in this way myself. They did not actually stick, just would not depress as far as the others.
Is it possible the ones that would not depress as far have some charge of oil already inside them perhaps?.
 
#5
It could well be, as you say, that some may have a part charge of oil within them, but from a reputable manufacturer
it is far more likely that they are all in the same condition. With the tappets
being supplied "loose in a box", and from your observations they do not all seem to be in the same
condition of charge/internal machining, I would be concerned and suspicious if I was fitting them to a rebuilt engine.

It is after all quite a lot of work to exchange them for good ones, if some prove faulty, once you have rebuilt the engine
and found them to be wanting.

In fact I will go so far as to say that if I was the buyer I would reject the lot (if I could), get a refund, and
buy either a sealed set or individually sealed items.
 
#6
ERF wrote,
He then pressed the push-rod end of one tappet into the body against the spring with a biro. It went in about 8mm. He then pressed the other one in, and it went solid after about 4mm. Several in the box are like this.
Mine were Crane [99284-16] hydraulic tappets and were in a plain white cardboard box and had similar compression differences but when i removed the top retaining spring and checked internals it was a matter of the amount/charge of preservative oil inside which prevented full depression. those with less oil charge depressed further and after tipping out the oil of those that didnt depress much they then depressed fully when assembled. It may be a case to remove the partial oil charge from them all and check again to eliminate machining defects/concerns then reassemble.
Scott
 
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