What do mdf file restore?

We are using sql server 2005.
The disk containing our sql server ldf files crashed so we lost them.
We have all the mdf files though. Can we recover these databases.?
We have tried creating a new database, stopping sql server, replacing the mdf for
the new database with one of the old mdf files, restarting sql server.
We have tried attaching the mdf file without the log file.
We have tried attaching the mdf file with an empty text file that we named to be the same as
the missing log file.
We have tried attaching the mdf file with a log file from another database, appropriately named.
It keeps telling us the database was not shut down cleanly.
The databases that are now unusable were not being updated so the log file should not matter.