[SEL] Bamford EV1 valve timing

[prepair at easynet.co.uk]

Quoting Rob Skinner <rskinner at rustyiron.com>:

> 
> > Any suggestions from Bamford experts or any one else would be 
> > great and
> > should the cam gear timing mark line up with anything ?
> 
> Hi Rod, 
> It's been my experience that the early engine builders didn't have the same
> beliefs regarding valve timing that we have.  And honestly, it's not super
> critical with our slow running engines.  If the exhaust opens at 25 degrees
> rather than 45, the gases still have plently of time to evacuate the
> cylinder.
> After all, you're not building a nitro burning funny car.  In fact, later is
> probably better.
> 
> If it was me, I'd retard everything fifteen degrees and call it good.  Also,
> remember that the rate of piston movement is a sine function.  The closer
> the
> piston is to 0 or 180 degrees after TDC, the closer the velocity of the
> piston
> is to zero.  A few degrees either way isn't going to make a rat's googly.  
> 
> Rob

I haven't got the EV1 timing information, but the later EG series were basically 
the same engine with a batter internal governor mechanism etc. They had a single 
cam, in common with a lot of other engines, and the timing is as follows:

Inlet valve opens 8 degrees BTDC
Inlet valve closes 45 degress ABDC
Exhaust valve opens 45 degrees BBDC
Exhaust valve closes 8 degrees ATDC

The book says that slight adjustments to the valve timing is effected by 
adjusting the tappets! no tappet clearances are given.

The single cam is obviously symmetrical, the valve timing differences being 
obtained by the position of the followers.

HTH

Peter
--
Peter Forbes
prepair at easynet.co.uk
http://www.prepair.co.uk


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