Tech Tip: Rocker Box Oil Feed Washers - Copper vs Stato-Seals
So for the past few months you have been rebuilding your motor using the best quality parts and taking your time
Not one step was overlooked or missed as you begin to re-install each component
As you proceed to install your cylinder head and rocker boxes the last step you need to do is to fasten your acorn nuts that retain and seal your rocker oil feed line
Now that everything is installed you start your machine up and it roars back to life. As you begin to high five your buddy’s in excitement you quickly notice an oil leak coming from your rocker feed acorn nuts
Not only do you have an oil leak but it’s a buzz kill, which is not cool!
Today's Tech
Today I would like to cover a new product we stock that will fix all your rocker oil feed leaks and seeps using our new rubber sealing washers
I will also dive into why cooper washers can leak and also how to prevent future leaks using copper or stator-seals
So what does Classic British Spares recommend?
Keep reading to find out
Lets dive in
The purpose of sealing washers
The purpose of using a copper washer or a rubber bonded washer (stato-seal) on your rocker feed lines is to keep oil and debris from entering and exiting
Both copper washers and stato-seal washers can achieve an oil tight seal, however the copper washers can sometimes be a bit "pesky" the first or second go around
Why Cooper washers leak
When using copper washers to seal your rocker oil feed pipe you may experience oil seepage or weeping over time
Other times you may not have any troubles or problems at all
The most overlooked step is annealing copper washers
Often times copper washers are not ready to go "out of the box"
Copper washers need to be annealed every time should you begin to reuse a copper washer
When you are preparing a copper washer (this goes for anything copper) make sure the washer is "cherry red" (from the heat) but without damaging or melting the copper during the process... this is called "annealing"
I like to use water to "quench" the washer when done
Surfaces on both the backside of the acorn nut, oil feed pipe and rocker box surface need to be flat with no obstructions. Remove any burs and address any high or low spots prior to installation
We have also found that some copper washers have an I.D. (inner diameter) that is slightly larger than the shaft, this is to allow the copper washer to fit over the shaft
Excessive gaps around shafts can pave a way to an oil leak, it's best to have a snug fit but without causing obstructions or grief when fitting..
Don’t be afraid to tighten the acorn nuts
Triumph for example, had a torque figure (on early rocker spindles (3/8” x 26)) of 22ftlbs!
I personally think 22lbs is too much (more like 5-8 should be more than enough) but you get my point..
Did I mention your copper washers need to be annealed?
Why stato-seals?
Stato-seals are the perfect combination of simplicity and convenience
Our new rocker oil feed Stato-seals we’ve added to our online parts catalog is aimed to prevent oil leaks and weeps on the rocker oil feed line without the preparation
How stato-seals work
A stato-seal is capable of sealing better than an annealed copper washer due to the fact a stato-seal remains soft and supple while retaining equal pressure around a shaft unlike copper washers which just “slip over” the shaft loosely as we described further above
Stato-seals are very forgiving and will seal just about anything
We have used stato-seals on our builds and in testing and have found that the stato-seal washers seal regardless of the situation or preparation
Pros & Cons
Now that you know how each seal or washer works, lets go over some pros and cons (and my take) on which may give you better results and which part is correct for your application
Copper washer & stato-seal pros & cons
Below is a pros and cons chart comparing both copper washers and stato-seals together, side by side
Yes - Copper | No - Copper | Yes - "Stat-O-Seal" | No - "Stat-O-Seal" | |
Leak Proof | ✔️ | ❌ | ✔️ | |
Affordability | ✔️ | ❌ | ||
Reusable | ✔️ | ✔️ (to a certain degree) | ||
Easy of Installation | ✔️ | ✔️ | ||
Quality | ✔️ | ✔️ |
Which sealing washer is better?
Both copper and stato-seal washers work great - but it depends on your preference
I have personally have had great success with copper washers, I have nothing negative to say about them.. they work with simple preparation
However, I have been told by some of my customers that they have had consistent leaks with copper washers..
For the person that wants a fast and worry free leak, I do recommend going with the new stato washers that we have in-stock should you have the extra money to spare (they are almost double the price)
For the traditional builder, you cant go wrong with copper washers. They work and they are very inexpensive
Specifications
Below is a chart showcasing the full specifications of both copper washers and stato-seal washers side by side
Some manufacturers may have slightly different specifications than what is shown below
Washer Type | I.D. (Inner Diameter) | (Outer Diameter) | Thickness | Fits Shaft |
Copper | .380" | .650" | .040" | 3/8" |
Stat-O-Seal | .370" | .665" | .065" | 3/8" |
Need new washers?
Need a set of stato-seals or copper washer?
We have you covered should you prefer the traditional copper washers or new stato-seal types
Click on the “click here” text below to purchase your washers today
Washer Type | Part Numbers (Triumph & BSA) | Link |
Copper | 70-1335, E1335, 70-0402, E402, 40-0159, 40-159 | Click Here |
Stato-Seal | Works with part numbers above | Click Here |
Both stato-seal and copper washers listed and described above will work with both Triumph and BSA "domed" rocker nuts - some of the original part numbers where.... 70-1435, E1435, 40-0162, 40-162, and other superseded part numbers.
Thanks for reading
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Ride safe - CBS
Brian
How long will the stato-seal rubber hold up when mounted to the head of the bike? The specification for the buna-n rubber in the washer is 220 degrees *F, but the head temperature on the bike can well exceed that. I know that stato-seal washers can also be supplied with a fluoro polymer insert (the red ones) for higher temperature applications. Do you also carry those?
william c harvell
you guys provide a great service here, I,m glad I found your site and services , I love the Classic british bikes , it,s what a bike should look and sound ,perform like, and the free shipping is a a god send to a guy in the middle of nowhere like me here in Mississippi
william c harvell
Tell Peter he needs to replace his o-rings on drive side ,more than likely thats what,s causing his non-feeding side leak
eric roberts
I have a 1973 T100 R. My rocker oil feed bolts (70-3809) are 5/16 dia. My copper washers (82-1880) have a 5/16 ID. Do you have 5/16 ID copper washers or 5/16 ID stato-seal washers ?
Bruce Henderson
Do you have a Stato-seal for the external oil pipe banjo bolts on a Norton Commando head? Thanks, BH