The 64-year-old, who has previously received three jail sentences for similar offences, was found guilty at Liverpool Crown Court of sex offences against more victims.
During the course of his trial, he was described as a “child molester on an industrial scale” who would not just groom his victims, but also their families.
Victims who had been coached by Bennell as boys told how he had a “power hold” over them as they dreamed of becoming professional footballers.
He was said to have been treated like “God” at Manchester City’s Maine Road ground.
He abused the boys at his homes, where he had arcade games and exotic pets including a puma and a monkey, but also on trips away and in his car while on the way to and from training.
One victim, who he had admitted abusing in 1998, said he knew of four men who had been coached by Bennell, including former Wales manager Gary Speed, who had gone on to take their own lives.
The jury was told there was no evidence to link the deaths to Bennell.
Bennell, who had part of his tongue removed due to cancer, appeared in court via videolink for health reasons and declined to give evidence in his own defence.
But the court heard transcripts of police interviews in which he admitted having a “grooming process” and being attracted to teenage boys, although he denied the new allegations and said his accusers were “jumping on the bandwagon” following publicity.
His barrister, Eleanor Laws QC, described him as being a “sitting target” after being convicted of child sexual abuse in the 1990s and in 2015.
She said: “The defendant is a known target and he coached these boys.
“They know when making allegations, whether truthful or not, that they are making allegations against a convicted paedophile.”