• Hi Guest!
    You can help ensure that British Car Forum (BCF) continues to provide a great place to engage in the British car hobby! If you find BCF a beneficial community, please consider supporting our efforts with a subscription.
    There are some perks with a member upgrade!
    **Upgrade Now**
    (PS: Subscribers don't see this gawd-aweful banner
Tips
Tips

Tappet Noise

Share this page

G

gonzo

Jedi Warrior
Gold
Country flag
Offline
Over the last few years my AH 3000 BJ7 has developed noisy tappets. Valve adjustments by 13-1 rule to spec still results in valve train clatter at idle Engine runs smooth, no overheating with 55psi oil pressure at speed and 25 to 30 psi at idle when hot. Just those noisy tappets, particularly for valves #7, 8 and #9 using a stethoscope. Valve cover off shows good oil lubrication throughout valve train. Oil seeping through holes; no geysers. Rockers are good. Dismantled valve assembly, removed pushrods and lifters (tappets). On inspection, the condition of both pushrods and tappets is disconcerting.

Pushrods show ball seat wear with corresponding wear patterns on tappet cups. Some of the tappets cups appear to be worn through or wearing through and have what appears to be pin holes. The cam facing side of the tappets are clean with normal wear pattern for a 50K mile rebuilt engine (trying to upload pics). So, a few questions:

Can tappets and pushrods be renewed without replacing camshaft? And if so, are the usual suppliers suggested for these parts (The worn ones are Moss items from 1990s).
On replacement, should the flat tappet engine break-in procedure be followed? 2000RPM for 20 min.s with ZDDP additives etc.
All suggestions are encouraged and welcomed. Thanks, GONZO
 

Attachments

  • 20160306_130742.jpg
    20160306_130742.jpg
    20.4 KB · Views: 218
  • 20160306_130849.jpg
    20160306_130849.jpg
    18.8 KB · Views: 194
Gonz What shape are rocker bushings and rocker shaft in ? Were some valves too tight ? Tappet on the right has some wear. Should be a slight crown but not visible by eye. You can see it was spinning which is good. If you can see that cam lobes are good you can put new tappets in and break it in again. Put moly lube or break-in lube on all parts. Good luck :tennis:
 
The six cylinder engine is very quiet when it's in good condition and the rocker shaft has to be very worn to be noisy, whereas cams and followers get quite noisy if they're worn. If either is worn you'll have to replace both as I've just done and you can just about do it with the engine in the car.

Having just been through all this with an engine imported from the States, I've just bought followers from Piper Cams Ltd and had them reprofile the camshaft. The ones I bought from an official UK outlet were poor quality and 3 thou undersize, so I sent them back. Therefore I'd find an American company who reprofile Camshafts and have them supply the followers to be sure of quality.

At least Healey engines are simple, very robust and easy to work on. My son is doing a Rolls Silver Wraith one at the moment and it's about ten times as much work and faff to get together. Even the head has 39 studs, the vibration damper is a nightmare and it's hours of work just to fit all the oil cups to the crank.
 
If you have accelerated wear on the tappets or cam lobes then adjusting the valves would quiet the valve train temporarily, if the noise stays constant more than likely its the end of the rocker arm to valve stem contact that is worn , dished or not profiled properly.
 
The rocker arm assembly was rebuilt and shows no signs of wear in the bushes or on shaft. All rockers move freely with no play; however, the rocker arm to valve stem show some wear but still retain their rounded profiles - no flat spots, dished or rough edges. I'll take some pics later. The prospect of replacing the cam after just having the front-end of the engine apart to replace the timing gear tensioner and seals, is not something I look forward to doing again anytime soon. And I'd probably pull the engine to get at these bits.

Root cause for the worn tappets could be attributed to their initial poor quality and my insistence to Top Dead Center valve adjustments in the early years after the engine rebuilt. Any other words of encouragement are appreciated. GONZO
 
Good question: for many years now I've been using Castrol GTX 20 W 50 and for the past 10 years, ZDDP zinc additive.
 
gonzo said:
Good question: for many years now I've been using Castrol GTX 20 W 50 and for the past 10 years, ZDDP zinc additive.
Click to expand...
ive read that the zddp additive to your oil isn't as good as oil having it already formulated in it. I've had tapping noise to two of my engines that turned out to be broken piston rings that ended up on top of the piston along with some piston particles. On my last engine I used a stethoscope and the sound was loud on #1 piston area but it was #6 piston that was bad. I hope this is not the case with your engine. You might see if you can borrow a bore sight tool to get a look at the piston tops. Your lifters look good. Check rocker arm surfaces that hit the tops of the valves for a groove. These can be also fixed.
 
Back
Top