hjh (1/24/2019)
Reading Ted`s 57 Fairlane 292 rebuild in Y Block Magazine ,Ted mentioned stretching the main caps for a better fit in the block. I have had many different [,including 2 air craft ] engines apart and never heard of stretching main caps. Ted or some one help me here on how that is done , or is it like resizing pistons ? You learn something new every day. Thanks Harry Hutten
The loose caps have a memory for staying loose so they do want to resort back to the ‘collapsed’ value and remain loose if doing anything short of heating them up and getting serious with them. Prior to align honing the block with ‘loose’ main caps, here’s what is done to get those caps tight once again in their block registers. With the caps in a vise so there is an outward pressure being applied that temporarily expands the width of the cap, heat is applied with a rosebud torch. Once the cap cools, it is measured for width and compared to the width (register) in the block where it resides. If the cap is 0.002-0.003” wider than the block register, then all is good. If the cap still falls short, it’s reheated again in the same manner until the aforementioned press fit values are attained. This is a lengthy process and many times if one cap is loose, you’ll also find several others if not all that are also loose. Each cap must be individually worked on.