Could have been worse !!!

[Kevin MacBride]

Last year I did a race at Bishopscourt 'up North' (as we say over here). Originally an old WW2 airfield, it had been used as a racetrack for years, then the military 'took it back', but over the past few years it has reverted back to racetrack again. My first time there, its a very fast track, with long straights and sweeping bends with the odd chicane. A good run for the Aurelia I thought.
However, on the day (weekend) we had torrential rain and biting wind. During practise the car seemed a little off power. I didn't think too much about it as I was more concerned with a leaking roof on my car transporter, an old double cab Transit (which doubled as a bed for the weekend)
Race started ok, I actually was ahead for about half a lap, when a Healey Silverstone went thundering past, Ah, I says to myself, I'll follow him and get used to the track....then the heavens opened...and my wipers failed.....
Not that the wipers would have made much difference, but a good excuse for later. 3rd on the day, happy enough.
Next event was Mondello a few weeks later, and I was about 6/7 seconds a lap slower than usual. A quick check revealed nothing, all plugs were sparking, but the car still felt odd, and there was a distinct 'ping' sound from somewhere. When I got the car home, I did a quick compression test, one cylinder was showing zero. I covered the car up, and left it there.......till today.
And this is what I found.....

[Parisien]

Whatever it is Kevin, it doesn't look good, do fill us in and is it a straightforward fix?

P

[the.cern]

A broken push rod I presume Kevin, what a beast. I presume from what you have written there is no other damage, that is a relief.

I am surprised the compression test showed zero, I would have expected the associated valve to remain closed, or do you think it was high spot to high spot on the two broken parts of the push rod holding the valve open?

Anyway, I hope it will soon be repaired and back on the road and track.

Best wishes,

                Andy

[chriswgawne]

Kevin,
You make it sound like the broken pushrod is the extent of the problem......... and I hope you are correct. Is the head off and does the offending valve open and close fully and smoothly when operated manually?
 I don't understand the complete lack of compression on that cylinder and if it were me, knowing that it was an engine for racing I would take this opportunity to  have a close look at the other pushrods at the very least.
Chris

[the.cern]

Chris, are you on the night shift, or do you, like me, wake in the middle of the night and mull over the days events and tasks for the morning??

                             Andy

[Kevin MacBride]

It's the inlet valve an cylinder three. The little steel cap on the valve had popped off (and was stuck in a pool of oil in a corner of the head). This allowed the valve to stay closed as there was extra clearance between rocker and valve.
The valve will open and close easily by hand, so I assume all is well. All I can do now is replace the pushrod, and see what happens.

[chugga boom]

I am surprised the compression test showed zero, I would have expected the associated valve to remain closed, or do you think it was high spot to high spot on the two broken parts of the push rod holding the valve open?

Just from past experience with a collapsed lifter in a cvh engine, if the valve is shut all the time, gas cannot move in or out of the cylinder to be compressed hense no compression, used to be normal on Vauxhall ohv engines when the rockers snapped and like I said on cvh engines where the hydrolic lifters collapsed, sounds totally illogical but true 

[the.cern]

Thank you James, you live and learn !!!!!

Let us hope that all will be well with a new push rod. If, as Kevin states, the valve moves freely, then there is a real chance of the limited damage shown.

                           Andy

[chriswgawne]

I can't have any secrets Andy can I? I am about 8,000 miles from the UK in a SE direction so an 8 hour time difference.
Sounds like Kevin might be lucky with this one but why did the pushrod break in the first place? This is puzzling me.
Chris

[Kevin MacBride]

The rod seems to be broken just at the oil drain holes, so maybe they developed a crack. I also thought that possibly the adjusting screw may have worked loose, then with more clearance the rod could have 'bounced' and maybe dislodged itself from its position and snapped.
I'm going to chance fitting a new one anyway and see what happens. I have plans to overhaul the engine at some stage. I recently acquired a camshaft from Tim Burrett, which requires modified pistons, which in turn will probably require liners and a whole heap of other parts.
I actually left the cam in the car over the Christmas season, thinking some Lancia loving Elves would surprise me, but alas..no..!

[JohnMillham]

Back in the 1960s when I ran a 3rd. series B20, I had a couple of the push rod ends come loose. Harry supplied new push rods which we left on his Valour stove to warm up for ten minutes before tapping in the ends. I seem to remember that engine overheating was the cause of the problem.
 Regards, John

[Kevin MacBride]

Thanks for the replies, all I can do is wait for a new rod, and see what happens. I swapped over the pushrod, and the valve opens and closes properly, plus all the other tappet clearances were fine, so hopefully its just a freak incident. I was speaking with Peter Harding and he tells me he fits new rods often enough. If fact he'd just fitted the last ones he had in stock when I called.
I know people like to see photos of 'the oily bits', so here's the exposed cylinder head.

[Richard Fridd]

Is that a special exhaust manifold Kevin? Best of luck with the work.

[DavidLaver]

I'd forgotten how the rocker carriers curve.  However I can remember how they wear...  Yours all ok?

Is the heater blanked off?  I'd have thought even racing a bit of warmth up the screen would be handy in such a "lush green land" as you live in.  I also used to make full use of the heated rear screen in mine, and even after new front and rear screen seals and the inside being bone dry.

David

[Kevin MacBride]

I got the manifold from Peter Harding some eight years ago now. As regards the heating (or lack of it), its pure laziness....after I'd restored the bodywork I was in a rush to get the car driving, and I simply never refitted the heater. Every time I'm sitting, strapped into the seat, with a fogged up screen, I'm reminded of the missing heater. And whenever I consider fitting it, I'm usually being handed a paint brush, or a pair of kids, or even a lawnmower......