Thursday, March 5, 2015

Volvo 940 Homemade Valve Spring Compressor

Normally removing the valves from an ohc engine is very simple, you just compress the springs using a spring compressor you can rent at any auto parts store. They grab onto the outside of the spring and you screw down a plunger. Here is a picture of one:
Unfortunately these will not work on a 8v redblock engine because the valve springs are recessed into the head and you can't grab onto the outside of them.  There are two other common types of valve spring compressors you can buy, one that looks like a giant c-clamp and another one that attaches to one of the studs on top of the engine and uses that as leverage to press on the valve spring. Both of these would have worked on my engine but they weren't available for rent and cost around $100-$200 locally. Since they are a very simple design I thought I'd build my own. This is the style I modeled it after:
It consists of a raised bar which bolts to the valve cover studs. From this bar there is a lever which compresses the valves, and it can slide back and forth to easily move from one valve to the next.


Here's what it looks like:

 
It's mostly made of steel scraps. The only part I bought was the wheel which provides a nice smooth action when compressing the springs.



The part that actually presses on the valves is an oxygen sensor socket (the cutout gives you access to the valve keeper) with a couple adapters on top to get it to be the right length.

To use it all you do is position it over the valve, press down, and remove the keepers using a magnet-on-a-stick.