How to determine which springs and retainers to use?

[fairlaniac]

Another area that I don’t know much about but want to understand in this lifetime. How to determine which valve springs to use? I have a 390 short block that was originally in my ’66 Fairlane. I have a 282S cam in it and nothing else too special. I want to drop it in a ’78 F150 that I’m playing with. I have an Edelbrock Performer intake, a finished set of C6AE-R heads, nothing special done to them. Stock valves. A set of OEM adjustable rockers is what I plan to use. I’m just trying to use parts lying around and just have a mild operating 390. With the 282S cam what springs and retainers would I use?  My original kit came with 972-16 springs which are long gone. Between myself and local friends there may be some parts floating around I could use. I’d to know how to determine a range of retainer diameter and a range of springs (rate and diameter) that could be used.

I hope I was somewhat clear?

Thanks!

[blykins]

You pick a spring based off of your head's install height and the camshaft.  The camshaft will dictate spring loads and coil bind clearance. 

Once you have a spring picked, then you choose a retainer and locator that will fit it.  Most manufacturers will list a spring and the associated retainer/locator.

The spring loads can vary for a cam, depending on which head you're using and what displacement the cam is in.  A cam will peak higher with a smaller engine and/or a better performing head.  It will peak lower with a big engine and/or a lower performing head.  The higher the rpms, the more spring load you'll need to handle it. 

For a 390 with C6 heads, factory valve weight, etc., I'd aim for somewhere around 120 lbs seat and 320-330 open.  The exact spring will depend on your install height, which will vary depending on the valve job, etc., but should be somewhere around 1.800-1.850". 

[fairlaniac]

You pick a spring based off of your head's install height and the camshaft.  The camshaft will dictate spring loads and coil bind clearance. 

Once you have a spring picked, then you choose a retainer and locator that will fit it.  Most manufacturers will list a spring and the associated retainer/locator.

The spring loads can vary for a cam, depending on which head you're using and what displacement the cam is in.  A cam will peak higher with a smaller engine and/or a better performing head.  It will peak lower with a big engine and/or a lower performing head.  The higher the rpms, the more spring load you'll need to handle it. 

For a 390 with C6 heads, factory valve weight, etc., I'd aim for somewhere around 120 lbs seat and 320-330 open.  The exact spring will depend on your install height, which will vary depending on the valve job, etc., but should be somewhere around 1.800-1.850".

Thanks Brent!