Continued...
Speedy Spares did indeed have cylinder head gaskets for the 1592cc engine, in fact they had four! I purchased two and set off home again more than ever convinced that the tappets were the problem. This was easily checked by simply slackening off all the tappets and re-testing the compressions. All of them came back to normal around 180psi (normal that is for the low compression head I now have). What a relief - I did not have to change the head gasket after all!
Moral: Don't jump to conclusions!
Many years ago I was going on leave from my ship and the Chief Engineer was doing my end-of-voyage performance appraisal. One of the questions he had to answer was "In an engine room emergency, can Andy make decisions quickly?" He answered: "Yes. Sometimes too quickly". That answer still haunts me 55 years later!
I had set the tappets wrongly, not just in the wrong order but to the wrong clearances! After all these years of doing it!
Get it right, Owler!
First step.. Assume you are going to set the tappets on Cylinder #1. Make sure the valves on Cyl #1 are fully closed before you start. This happens when Cyl #1 is at "Top Dead Centre" on the firing stroke. Because the engine has four cylinders when Cyl #1 is ready to fire its "partner" cylinder (Cyl #4 on a Bagheera) will have just finished its exhaust stroke and be just starting its inlet stroke. You can see this easily as you turn the engine by looking at the valves on the partner cylinder. When the exhaust has closed and the inlet just starts to move - that is Top Dead Centre for Cyl #1. Set the valves as described below and then rotate the engine by one revolution and do the valves on Cyl #4 (the valves on Cyl #1 will then be changing over from Exhaust to Inlet). Repeat the process for Cyl #2 and Cyl #3.
Except that I had become confused in my haste to get the job done quickly and been looking at the wrong partner cylinder!
Second step.. Adjust the valve clearances according to the manual. 0.25mm for the inlet valve and 0.30mm for the exhaust valve. The traditional way is to use feeler gauges of the right thickness but I have always found this a fiddely and time consuming task. There is so little space around a Bagheera rocker box! You really need three hands, one for the locking nut spanner, one for the feelers and a third for the Tappet adjusting screw!
Some years ago I discovered the Gunson "Clik-Adjust".
http://www.frost.co.uk/images/datasheets/M560_datasheet.pdfIt is a very clever tool - I wish I had invented it - but the principle is simple..
There is a lever that carries a 12mm socket to fit the tappet lock nut and a central knob with a slot to fit the tappet screw head. The central knob has a "clicker" that operates 30 times for one revolution of the tappet screw. If you know the pitch of the tappet screw thread (Bagheeras have an M7 screw and 1.0mm/rev) you can work out the number of clicks you need for the inlet and exhaust valves. Inlet valve = 0.25mm or 7.5 clicks, exhaust = 0.30mm or 10 clicks.
It works like this...
- Fit the Clik-adjust onto the tappet (make sure the valve is fully closed first, see above)
- Loosen the lock nut by about 1/4 turn
- Tighten the tappet screw until a loud CLICK is heard from the central knob (this takes up all the existing clearance and any wear in the pushrods or rockers)
- Slacken off the tappet screw by the right number of clicks (I use 8 clicks for the inlet valve and 10 for the exhaust valve)
- Tighten the lock nut.
- Job done!
But I had done this simple task wrong as well! And I had been doing it wrong for years! I had been setting the inlet valve to 5 clicks and the exhaust to 7 clicks. I must have made the mistake when I first followed the Gunson instructions for calculating the number of clicks (if you do not know the pitch of the adjusting screw). My Grey Bagheera had very quiet tappets and I was very proud of that. I now know the clearances were too small!
So a combination of two errors made me set the tappets badly and my old problem of jumping to conclusions gave me a panic attack 24 hours before setting off for Prescott!
But that wasn’t the end of the story! We normally tow our trailer to Prescott behind our 9m 1994 Winnebago motorhome as seven* of us go for the whole weekend and stay in the camping field for three nights. (*Me, Charlie my wife, and five cats). About 1500 on Friday we were all loaded up ready to go, cats in their boxes strapped down on the bed, food and liquids for seven for four days and three nights, spares, tools, manuals and kitty-litter trays and I went to start Winnie to reverse onto Baggy Joe’s trailer to couple up. But Winnie would not start! The starter motor was operating very slowly and making grinding noises! At 2200 that evening we gave up and changed the plan! In the end we used our smaller motorhome and left home very early on Sunday, leaving the cats behind! So my apologies to those who hoped to see Baggy Joe at the Matra stand on the Saturday. We did try our best!
Footnote: Two weeks later and Winnie’s starting problem is still not fixed. The battery cables have been checked, re-terminated and tested. The twin batteries, less than 12 months old, have been charged again, and the starter motor just received back from a check-up with nothing found wrong except some signs of overheating on the armature. Tomorrow we will put all back together and start to look at the engine and automatic gearbox for clues. You can’t push-start a 6.5 tonne RV with a 6.5litre V8 turbo diesel. Starters need to be reliable!
Andy