Hydraulic tappets 2

[123-jn]

I have rebuilt my engine recently and after reading stories about new tappets breaking up and seeing the poor quality of a new one I decided to clean up my old ones (which constantly used to drain down. They cleaned up great and tolerances seemed so much better than the much slacker tolerances on the new one. After being left for 2 weeks upright and bled none had drained in the slightest. So I put them in the engine after bleeding down to start with all are now fully pumped up and I haven't had one bleed down since despite leaving the van for a whole week without starting her. I started with a 1.5 turn preload but one tappet seems to be noisy still, not really noisy just slightly noisy, compared to the rest (like a badly adjusted mini engine rocker). I then reset to zero preload and ran her for a few mins and reset to 1 turn only, the result predictably is the same. I could understand this if I had noticed any discernable difference when putting the tappets back together after cleaning but all were just the same. (same sort of pressure req to bleed etc). Some of my tappet adjust screws are more worn than others where they meet the valve stem I wonder if this could be anything to do with it? I might try a new set just out of pure interest (then cry).

[123-jn]

Just tried to order 4x tappet screws on Brickwerks, I could not believe the postage £7.40 for screws and £4.62 for postage. I paid £10.40 to send a 30kg awning to cheshire . Their parts are top notch and the service is second to none it's such a shame. Royal mail are getting so expensive and if the post man can't carry all the packages I will have a 5 mile drive to fetch it myself from the depot. Shame brickwerks isn't nearer to me!!!

[kevtherev]

If you only adjust them by 0.5 turns the lifter won't compress enough and you'll upset the rocker geometry accelerating valve train wear. In practice what happens when you don't preload the lifter enough is it will take too much time to pressurize and you won't get enough valve lift. This will cause the engine to labor and sound noisy. The noise is often heard coming from the camshaft (center of the engine).

Two turns of the 10mm valve adjusting screw with 1mm threads will preload the lifter ~1.5mm (remember the 1:1.3 rocker ratio). This is about half the distance that the piston inside the lifter can travel. If you use too little preload you will stress the lock ring that holds the lifter together when the lifter socket maks contact with it. If you use too much preload, the plunger may bottom out at first, then as the lifter pumps up to compensate the valve may not close properly and compression, performance and valve life will suffer.
How about 1.5 turns instead of 2? In practice, this seems to be as acceptable as the factory recommendation and a feel good insurance against the ills that other people have experienced over the years following the factory recommendation. In my experience, 1.5 turns of adjustment after the engine has run for many miles remains around 1.5 turns. Sometimes the adjustment is 1/8 of a turn more or less but you will be in the ball park and the engine will continue to run properly thanks to the flexibility of the design. The fact that the setting can exceed the initial adjustment supports the idea that 1.5 turns is better than 2.0 turns.

Taken from ratwell site.
http://www.ratwell.com/technical/HydraulicLifters.html" onclick="window.open(this.href);return false;

[bigherb]

I started with a 1.5 turn preload but one tappet seems to be noisy still, not really noisy just slightly noisy, compared to the rest (like a badly adjusted mini engine rocker). I then reset to zero preload and ran her for a few mins and reset to 1 turn only, the result predictably is the same.

That's because you went the wrong way, you should have screwed it in which would have by coincidence been the factory preset two turn preload. Which does work if you do it right.

[123-jn]

Thanks for the advice chaps, I have now tried the factory preset 2 turns from contact for 100 miles and the 1.5 turns from contact for 100 miles. As mentioned above I also tried 1 turn from contact for a few miles. The result is the same and that is that 7 of the tappets go nice and quiet but 1 on the right bank although it pumps up and stays pumped up for days like the others seems to make a noise. The tapping seems to vary in volume and sound as the tappet turns in it's bore? I need to get my stethoscope out and find out which one it is then I feel a telescopic tube coming with a new tappet. It's soooo annoying. I'll try new adjust screws first but the sound doesnt come from there!!!

[kevtherev]

maybe the check ball is allowing oil past due to a weak return spring

[123-jn]

Is there a way of checking for that?

[kevtherev]

I don't know but there is clearly an issue with the lifter not pumping up fully
What did you clean the lifters with?
Did you dismantle them and clean the varnish out?

[123-jn]

I cleaned the lifters first in parafin to get the gunge off then with thinners to dissolve the varnish. They were spotless and very smooth. I will examine the ones that come out very carefully. I stripped them down to all the little bits and brushed them clean with small nylon and brass brushes. Each went back in its original bore.

[kevtherev]

reads like you did a good job.
I can only suggest old age..PO abuse ...so it might have to be replaced

I have a similar issue but I will live with it for now.

[sarran1955]

Hello,

I cleaned the lifters first in parafin to get the gunge off then with thinners to dissolve the varnish. They were spotless and very smooth. I will examine the ones that come out very carefully. I stripped them down to all the little bits and brushed them clean with small nylon and brass brushes. Each went back in its original bore.

Did you prime them with oil ...

There is a procedure to purge the air....

and keep them upright till the last minute...

Cordialement

[123-jn]

All were primed beautifully but after lying in the engine for 24 hrs they did bleed down but soon pumped up with a few revs after start up and they have stayed pumped up and solid to the push with a hammer handle ever since. One however must be misbehaving when in motion!!!

[kevtherev]

ok well warm the engine up and get them pumped up.
once the tapping starts stop the engine and find the rocker that will move easily ATDC Firing stroke.
That'll be the one that is noisey obviously.
good luck

[123-jn]

Thanks didn't think of it like that.

[123-jn]

well I found one of the culprits cylinder two inlet tappet and set about collapsing the pushrod tube. What alot of oil comes out of that tappet oil gallery!!! I got covered in it!! Now to fit that spring loaded scat pushrod. Here starts the problem, one end should be 20% bigger usually used in the head end to give clearance in performance engines but due to the waterboxers bigger seals the tappet end the tubes should be fitted backwards on these. only problem is that the tubes I have been sent seem to have the same diameter end tube on both ends (20mm OD) this is no good for a waterboxer as this is much smaller than the diameter of the tappet bore so much so that when hot the seal pops inside the bore under the spring pressure and you leave behind you a motorcyclists nightmare. (ask me how I know) I have sent an email to the supplier asking if they have supplied the wrong part . (Big Mouth Spring loaded pushrod tube) Meanwhile I am now van less again) On the positive side it sounded better until ---------- happened. There is still another dodgy tappet in there somewhere that sticks intermittantly I should have changed them all but could not afford it!!