Around 1990 I bought a 1974 Trident that required me to do a fair bit of work to some of the cycle parts plus rebuild the top end. At that time I made a number of special tools of my own and bought just about the entire set of factory service tools from someone in town.
I never had to open up the bottom end so two pieces of plastic in the set I bought that a BSA manual calls 60-2211 and -2212, "Crankcase baffle plate (front)" and "...(rear)" have been sitting unused at the bottom of the 'Trident' drawer in my toolbox ever since. When looking for something else this afternoon I came across them, which reminded me that I have no idea what they are used for. What are they used for?
Thanks for pointing this out. My search for "baffle plate" didn't turn that up.
Originally Posted by DMadigan
Use crankcase baffles 60-2211 and 60-2212 to hold the outer piston skirts at the case mouth.
Although they might work for this (although, aren't they really too weak to support the pistons against the force of the cylinders?), I'm still unclear on why they are called "baffle plates" instead of, say, "piston support plates."
You Learn Something New Every Day; 36 years with at least one triple and I never knew there were special tools for keeping the pistons up when you put the block on. I suspect BSA were beginning to catch on to the Japanese habit of 'What Can We Make From The Scrap Bin And Get The Punters To Pay A Fortune For?'.
And, unlike my preferred bits of wood, they don't even hold the pistons 'stepped' ...
Aha! Again, a picture is worth 1000 words. Thank you very much. But, what manual is that picture from? I don't remember having seen it in my Trident shop manual.
Two more questions: 1) do they really make installing the cylinders easier than using blocks of wood? It's been 20 years since I did this on my Trident and either it wasn't that hard with blocks of wood, or it was so painful that I've blotted the details out of my memory (or, there just isn't much memory left...)
And 2), why would they be called "baffle plates" / "crankcase baffles"? Seriously, none of the dictionary definitions of 'baffle' account for the name of these pieces of plastic ("confuse," "create bewilderment," "frustrate," "deflect sound" ...). Is it because they deflect dropped wrist pin retaining clips from landing in the bottom of the crankcase? Of course, I'm using an American dictionary -- do English dictionaries have something that makes sense of this?
When the center "piston ring slipper" comes off the piston it can be lost in the bottom end. It is a nuisance to retrieve. The "Baffle" deflects the piston ring slipper from falling into the depths of the crankcase. A confounded nuisance.
It also supports the two outer pistons and prevents them from getting damaged by the adjacent cylinder studs as you juggle the center piston into the cylinder. My memory isn't clear, but I don't think these were offered by TriCor on the East Coast.
The "Baffle" deflects the piston ring slipper from falling into the depths of the crankcase.
So, it really is a baffle:
baff.le -v.t. ...6) an artificial obstruction for checking or deflecting the flow of sounds, light, gasses, etc.
Where by "etc." I can now see the dictionary meant "nuts, bolts, rings, ..."
Thanks, Dave and John ... I've always stuffed the open crankcase with rags or paper towels to catch anything that drops off, and stop the rods and pistons banging against crankcase parts. Thus far, since my first 'block off' rebuild - when I'd bolted the block back on and suddenly remembered, "Tch, ..." (or words to that effect), "... I've forgotten to take the insulating tape off the rods" ... - I haven't forgotten to remove everything unnecessary from the crankcase ...