Shrapnel in Exhaust Valve Inspection Cap?

[greg brillus]

I've got the whole ET100/1 mod down to an art form now, and can carry out the whole mod with tops of the rockers nicely polished quite quickly, simple and clever design, should have been like that from the factory I suppose. I do it to all engines regardless now.

 

[Rob H]

Update. Still not been able to remove the rocker bearing, will try the slide hammer approach in the next day or two.

Took of the timing cover to check for any lose metal, none to be found. Checked the rear cylinder cam and followers to see if metal going down the tube has caused damage, possibly slight mark on one side of the exhaust cam and follower. It was noted that the tips of both cams appear to be pitted slightly, don't think to do witht he current problem but interested to hear any views on condition if ok to use as is or need attention

 

[Rob H]

oops, some duplicate pictures, sorry


Now removed.

 

[timetraveller]

Do you know the origin of the cams and followers? The pitting is not normal and looks as though either there has been some seizing (just about impossible I would have thought) or they have been welded up with voids in the weld. Those pictures of the followers show really bad scoring which indicates to me that something hard has been going through that cam/follower interface. I have seen many worn out cams and followers but not that amount of detailed scoring. Normally the whole of the cam nose or the follower have smooth wear, right until one is down through the hardening. You say that there does not seem to be debris in the bottom of the timing cover. Have you scraped out the oil in the little pockets at the bottom with a finger? I would expect to find small but sharp particles from those photographs.

 

[clevtrev]

OK removed the tappet adjuster and push rod. Checked the rocker, seems to move smoothly with no up/down or sideways play on the bearing!

removed the locking rocker feed bolt but bearing seems well stuck in the tunnel, any tips to remove?

Put the feed bolt back in, with a screw in the top. sharp tap with a hammer, remove and try again. The bush could be pulled into a groove in the tunnel.

 

[roy the mechanic]

Judging by the pictures the followers have been "reclaimed" with stellite welding. By the blackness of the pivots either a long time ago, or insufficient oil changes! . Sorry, but it looks like time to raid the piggy bank.

 

[chankly bore]

Followers appear to have been "re-surfaced'' on a very coarse grinding wheel. Use them in a necklace!

 

[sidmadrid]

Original followers have an oil hole on the non pivot end?

 

[Rob H]

Unfortunately, don't know the origin of the cams and followers. I would guess that some of the scoring has been caused by some metal finding its way between the two. I checked the oil pockets a the bottom of the crankcase and nothing to be found, was suprised also. Went back again to double check and found the metal in the corner recess at the top front corner of the cover above the opening for the ATD. Don't understand how it would end up there, seems an odd place to collect.
Any comment on the cams are they no good also?

 

[greg brillus]

Rob with all the rebuilds I do, if that was one of my engines I would replace the cams and followers. People used to build up and reface followers years ago mostly because new parts were unobtainable, but that is not an issue now, only the cost of the parts may hurt a bit. The pitting on the cam lobes is not a good thing either. I am actually rebuilding my Rapide at this moment too, so I know how you might feel when it comes to having to spend chunks of money, having had to unexpectedly replace all the gears in my gearbox as the dogs look quite worn, it never jumped out of gear but I couldn't convince myself to put all the original gears back in.............there's always something unexpected that needs attention when you delve into these things. Good luck.........Greg.