question on L76 valve rockers

[BarryK]

since I have the top of my '65 L76 motor open including the valve covers off, I was studying the motor to learn more about how it works and how things go together.
I noticed that on my rockers that some of them are very tight and have no movement side-to side if you push against them but others are very loose and kinda wiggle easily if you push against them.
I had the valves checked and adjusted back in the summer by the JohnZ cold method so was wondering if this looseness on some of the rockers is normal or not.
At first I was thinking that maybe the differences were that because some were intake and some are exhaust valve rockers therefore the adjustments would be different, but there is no pattern on which ones are loose and which ones are tight.
Any insight would be appreciated.
Thanks!

 

[BarryK]

never mind all, I got my answer

 

[Kid_Again]

Hmmmmm. Well, the degree of "looseness" is set by where the tappet sits on the cam so it varies.

Let's start with the basics. How do you know which cam you have?

I have an aftermarket solid lifter cam in the sb so I go through each firing position and adjust each valve according to the cam card. For a hydraulic lifter cam I use the procedure found in the shop manual where I set the crank on #1 TDC, adjust the respective valves and then go to #6TDC and set the lash on the rest.

 

[BarryK]

I don't know 100% what cam i have in there but suspect it is the stock 30-30 cam from the idle and powerband characteristics.

a couple of people answered me on the other forum and explained as you did that the tightness and looseness of the various rockers are because that some of the valves or lifters are up on the cam's ramp where others are not.

i'm not trying to adjust the valves, I just noticed as I was looking at the motor that some of the rockers were loose, others tight, and just didn't understand why. Now I do. It's always nice to learn someting new and understand a little more how these motors work. As i'm just learning pretty much everything is new to me which is why I have to ask so many "basic" or "newbie" type questions.

 

[Kid_Again]

Well, good luck and don't worry about it until it becomes a problem. When I bought my sb, it was advertised as a correct 365hp engine. Sure as hell sounded like a solid lifter engine. Yeah right. When I tore it down, it had solid lifters riding on the original 350 hp hydraulic cam. So much for being "correct".

 

[tigernut]

Barry,
You might check out the following site. It provides a good basic explanation of what is going on in your engine.

There also is a nifty animated diagram of an engine working (with valves opening and closing):

http://auto.howstuffworks.com/engine1.htm


Doug

 

[BarryK]

cool, I'll check it out Doug

 

[BarryK]

Well, good luck and don't worry about it until it becomes a problem. When I bought my sb, it was advertised as a correct 365hp engine. Sure as hell sounded like a solid lifter engine. Yeah right. When I tore it down, it had solid lifters riding on the original 350 hp hydraulic cam. So much for being "correct".

gee, that must have run just wonderfully!