Thematic and ACF example. Uses custom fields, a conditional and set on a hook that is inside the loop.

gistfile1.php

// example of using ACF custom fields, with conditionals
// this has to be set inside the loop, not sure how to place one anywhere yet (haven't needed it)
function childtheme_acf_additions() {
    if (is_single()) { ?>
        <ul class="toggle-specs c-engine">
            <h3 class="expand">Engine Specs <i class="">+</i></h3>
            <div class="panel">
            <?php
            if(get_field('c_engine')) {
                echo '<li><span>Engine:</span> ' . get_field('c_engine') . '</li>';
            }
            if(get_field('c_compression')) {
                echo '<li><span>Compression:</span> ' . get_field('c_compression') . '</li>';
            }
            if(get_field('c_stroke')) {
                echo '<li><span>Stroke:</span> ' . get_field('c_stroke') . ' and <span>Bore</span> ' . get_field('c_bore') .  '</li>';
            }
            if(get_field('c_heads')) {
                echo '<li><span>Heads:</span> ' . get_field('c_heads') . '</li>';
            }
            ?>
            </div>
        </ul> <?php
    }
    else {
        echo '<h3>No Engine Spec Details Available</h3>';
    }
}
add_action('thematic_belowpost', 'childtheme_acf_additions');