Hot Rods Flathead springs

Building my first Flathead, it’s a merc. It’s stock build nothing special. I ordered a valve kit and came with springs. They seem a bit soft but I don’t think it’s an issue. The original springs that were in this engine are shorter and lifters were not adjustable. I’m putting adjustable lifter in from another BA block I have. The springs from that BA block seem beefier and much longer. In the pic the left spring is from my old BA the middle spring is from this merc engine I’m building and the spring on right is the one from kit. Any idea why the lengths are so different? Both engines appear to have stock cams. Thank for any help.

 

Just wondering if the springs from engines with rotator style valves are different length
than those w/o rotator valves.

 

All three different valves are the same style and length.

 

Valve springs can get shorter as they age and the type of use can collapse them, too. That's why you need to measure the height and match the longest one. Measuring spring pressure at a specific length is important, too. Time consuming process. It's easier to just buy a new set of springs. It seems you are about to do something that could cause disastrous consequences and early engine failure. First, never put used lifters on a cam they weren't on to begin with. The lifters need to go on the same cam lobe they came off, too. No used lifters on a new cam, either. New lifters on a good, smooth used cam is OK. There are two types of spring coils, too. One has coils spaced the same all the way up. The other has several coils that are wound closer together on one end. The tighter windings install with the tight windings facing either up or down but I can't remember which. Age related brain farts, ya know
Either type will work.
To do it right, you should install new valve guides w/seals.

 

Thanks glen. I have all new valve kit. I’ll order up some new adjustable lifters for this build. Save the old ones for the BA

 

Make sure to get good lifters. (Now comes the discussion about which ones are still made well)

 

Yes...springs used in late flatheads with "rotator" type retainers are substantially shorter than earlier versions. Be sure not to mix springs up with the wrong retainers.

 

Easy to remember: the tight windings always go in the direction of the tullip of valve. The reason is the heavier (more m***) end of spring is resting while the light end does the moving - thus creating less force on the valve train.