<?php

    $query = new WP_Query(
        array(
            'post_type' => array('project'),
            'meta_query' => array(
                array( 'key' => 'my_meta_key', 'value' => 'query string', 'compare' => 'LIKE' )
            )
        )
    );

    while ( $query->have_posts() ) :
        $query->the_post();
        echo get_the_title();
        // ...
    endwhile;