12-12-2018, 04:13 PM
Yep, the engine has a HC head fitted.
Another significant factor on performance is ignition timing. Bear in mind the engine will never consume less than 95RON fuel now and in the 20's/30's it was perhaps 60RON.
The spec for ignition advance is static timing set to points opening at TDC for the HC 3brg engine; and the distributor provides a whopping 8degrees of advance....so what's considered safe/optimised ignition timing for this engine based on modern fuel usage? I've heard mention of over advancement leading to crank failures - which isn't something I want to happen (again!).
A Bosch 009 - which I understand has been a fairly standard mod in the recent past - has about 24degrees of advance available (but no vac advance function either).
Another significant factor on performance is ignition timing. Bear in mind the engine will never consume less than 95RON fuel now and in the 20's/30's it was perhaps 60RON.
The spec for ignition advance is static timing set to points opening at TDC for the HC 3brg engine; and the distributor provides a whopping 8degrees of advance....so what's considered safe/optimised ignition timing for this engine based on modern fuel usage? I've heard mention of over advancement leading to crank failures - which isn't something I want to happen (again!).
A Bosch 009 - which I understand has been a fairly standard mod in the recent past - has about 24degrees of advance available (but no vac advance function either).