Dear God in Heaven!!!!
I would say absolutely not - what security can you offer that could be enforced? None. Its not clear if your father even had any entitlement , either serious or nebulous, to (a) own or (b) build anything on the land so if he didn't, you don't.
The only advice I would give you is to go get the title sorted. If getting deeds is not an option, I don't think you have any alternative to a personal loan. You will never be able to deal with this property whether by way of sale or mortgage without legal title except perhaps to sell to some eejit who has cash to burn.
mf