Few of those old engines had what you would call radical timing, either cylinder intake / exhaust ports or rotary intake so they will usually run OK when converted to glo RC operation. Most conversions I have seen or done over the years disappoint the user from a performance and durability standpoint as they tend to wear out or break quickly. Still good fun to play with and an important part of modeling. I always enjoy the rare sight of an old airplane design flying with an old engine. But I also enjoy watching a newly built, doped finish plane flying with modern electric power because it never gets gooped up with glo fuel residue and can stay pristine for years.