Smoking engine

[GK5268]

Gary, just out of interest what radius were your cam followers ground to (old vs new)?

I got these off Tony Betts, I think the radius is as described in the William's Austin Seven Specials book, so, would be 3/4" (from standard of 3/8"), the tappet guides were cut down to suit, took about 20 minutes to remove, cut & re-fit each one!

I only ask because my 'received wisdom' is that standard cam follower radius generally gives better bottom-end torque. Though it's possible the general improvement in performance through flattening the radii offsets this?

My experience on my engine is that it has made an improvement, hill climbing is much easier and the engine seems to rev much freer and it can be made to tick over very slowly. The flatter profile does not change the valve timing, the valves just open & close quicker, so they are open longer allowing a better charge of fuel and better evacuation, I am pleased with the result and has made my car much more enjoyable to drive up hills and in traffic.