14-10-2019, 08:08 PM
It might be worth checking your compression ratio; the trouble with 80-odd year old cylinder heads is they may have been skimmed a few times. For a daily runner about 6:1 is a sensible limit, much more than that and it will not only get noisier but the bottom end may start to feel the strain. The downside of a lower ratio is merely lack of performance!