Thursday, January 13, 2011

Flamin' Valve Collets

I've been struggling for the last three shed sessions to compress the valve springs so that I can remove the camshaft and tappets. My little hobbyist quality valve spring compressor just wasn't up to the job, the claw on the end of it thats supposed to go around the valve spring cap just kept bending and twisting off. The problem seemed to be that the collets had frozen into the caps and weren't releasing, meaning that all I was doing was trying to bend the valve stem. A tour around the auto accessory shops showed that I could get a professional compressor for about $200, but it was too big for a little sidevalve engine anyway, so I built my own. A couple of bits of scrap steel welded together and shaped up a bit made the all important claw, then I welded them to a quick action clamp.Its not pretty, but it did the job.
Old faithful clamp, now a valve spring compressor
Every single valve required a huge amount of clamping force (the shaft of the clamp was bending) and a few needed an extra tap with a punch to jar them loose, but eventually they all came free and I could get them out. The poor old clamp is a bit bent now, but there's enough life left in it to do the re-assembly.

 Once again everything looks to be in good shape. The valve seats may need recutting but the camshaft looks to be very good. I reckon it has been redone at some stage. The valves aren't the originals, the inlets are marked BMC, which wasn't formed until after my J was built, the exhausts are Dufour.


  1. Fingers are still crossed for you! Still sounding good!

  2. Wow, you are tackling a big job there. Well done.

  3. Some slyly learnt workshop practice; Kids — don't try this at home, but adults… well, go for it!
    Tired of bending valve spring compressors when attempting removal of those pesky, stuck valve collets?
    Place a small rubber or wooden block on the workbench (even a large socket with a rag covering it) Place the cylinder head on top, with the impediment contacting with the valve head. Find your least favourite Taiwanese socket of a size roughly corresponding to the valve spring retainer and place it over the valve spring retainer. With a knockometer (steel or composition, it doesn't matter) give the bloody thing a semi-decent rap. Short and sharp, just enough to push the retainer down a bit.
    If all is well in the land of bodge, the retainer will drive down, spring back up and leave two neatly-deposited collets sitting under the socket on top of the retainer.
    At the Triumph Motorcycle factory, their motto was: "There's the right way, the wrong way and The Triumph Way."
    This method may sound bogus, but it works a treat and saves time and effort with no damage to anything