There are very good journals where you can publish your research works Among them some are free of cost and some of them demand publishing charge.Generally,
Elsevier and Springer journals are very good journals with high impact factor for publishing your research work.But my personal preference goes for Springer .These two journals demand some money for publication. But again these two are very good journals for mechanical engineering.
Both this publishing companies has several journals on specific topics .Such as Applied Thermal engineering journal is publshed by Elsevier to cover all the research works in Thermal Engineering,Springer has a journal named "Journal of Mechanical Science and Technology " which is a renound journal in mechanical engineering.
So, in journal site you have to search according to your research topic.
There are other journals too such as IOSR-JMCE,IJMMME,Emerland ,Beggle House ,Hindawi Publishing corporation etc. But my personal preference goes to springer.
It should be said that megazines in the research community refer to professional publications, but not research publications. For research, the right media are journals.
If you take a look at which journals the top researchers in your research field publish then these must be reputable journals.
If you tell me your specific research areas, I may recommend a few good ones to you. Mechanical Engineering is just too broad to get very helpful answers.
IMechE Journal of Automobile Engineering, and International Journal of Vehicle Design publish all Automobile Eng topics.
Journal of Aircraft and AIAA Journal are well know in Aerospace Eng.
You can google to find their website addresses. Paper submission is now done mostly online.
There are more prestigious journals that publish focused research topics, instead of disciplines. For example, I published a paper on vibration of atomising discs for power production in the prestigious Proceedings of the Royal Society of London, instead of a less prestigious IMechE Jounral of Mechancial Engineerign Science.