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Shaft Roller Rockers Again
Posted by: vairmech ()
Date: January 13, 2023 09:49PM

I wanted to start a new post to show the progress and what it takes to install the roller rockers. Please look at the pictures and the descriptions above each.

This is the image of a stock pushrod and then the stock with the end removed and then the shortened one by .075".

Here are all of the pushrods shortened. They are probably +- .002" by just marking and using my belt sander and checking with my caliper.

This picture shows the finished pushrods with the ends pushed back in.

This is the contact pattern on the valve tip with the shortened pushrods. The stock pushrods were not that far off but since I went to the trouble of checking I just made the pushrods.

Then we get into the things that really matter, fitment. The end rocker shafts have to be shortened and I even angled them so they will clear the aluminum covers. In this first picture you will see the angle I put on the rocker shaft.

This shows the results installed. This is mainly for rocker cover clearance.

This is another view of a different end.

The next thing you need to worry about is the paralellness to the valve stem!

So how do you fix this? With shims.

The one thing I have not addressed is rocker covers. Straight up, the stock cover will not work! In the picture is a Clark's econo cover and it fits on but is not tall enough.

Here are a couple of the rockers fully adjusted. Also note that the ends of the adjusters above the lock nuts are very close to the same, just like it should be when you adjust the nuts on a regular engine.

This is an over view of the entire bank of rockers installed and adjusted.

I will cut the top off the econo cover and make a spacer and then weld it up to make a semi-deep rocker cover. One reason for doing this is I have limited space on the driver's side because of the muffler placement. As it is if I need to remove the driver's side rocker cover I have to remove the headers!

Ken Hand
Handy Car Care
248 613 8586


Re: Shaft Roller Rockers Again
Posted by: v8vair ()
Date: January 14, 2023 02:05PM

The ones that Clark’s sold 20 years ago used individual stands and you shimmed under the stands with a thin washer. Each set of valves had its own stand

1964 Bill Thomas Monza Replica Racer
1964 Spyder Street Car
1998 Honda Prelude Dirt track car
1967 Crown V8 under construction
Mike Levine
Cumming Georgia
North of Atlanta

Re: Shaft Roller Rockers Again
Posted by: vairmech ()
Date: January 14, 2023 07:59PM

In the following images you will see things that you don't normally see inside a rocker cover.

First I had to cut the top off the aluminum rocker cover. It's pretty easy to do with a slitting saw, that keeps the cut straight and smooth.

Here it is with the top cut off.

Here is how close the rocker shafts are even after shortening them.

Even still the cover will only go on one way with the tollerance stackup.

What I will be doing is making a 1/2" spacer and welding it in. The actual added height will be closer to .4" with the saw cut added in. Considering that I only need a minimum of about 1/4" the .4 will give just a little clearance. This spacer will be cut to the shape of the cover and I suspect the final inside will be machined to the inside dimensions. What you see here is just a 1/2" bar set in place to show the height difference.

Ken Hand
Handy Car Care
248 613 8586


Re: Shaft Roller Rockers Again
Posted by: American Mel ()
Date: January 14, 2023 08:04PM

Cool project. thumbs up

WA. state, 1 mile south of the Canadian border, I am not at the end of the world, but you can see it from here.

Re: Shaft Roller Rockers Again
Posted by: CoCoCo ()
Date: January 15, 2023 06:16PM

Yes, very cool indeed!
Is there one single reason for going to this extent? Such as simply wanting stability at a higher rpm maybe?
Or is it for multiple benefits such as in an "all of the above" scenario?

I'm aware of at least some benefits of a shaft mounted rocker, and have actually daydreamed about it for Corvairs as well. So it's very exciting to see someone going through the actual process!
I was not aware that Clark's had one before, so guess I wasn't paying as much attention as I thought.

Did you discuss reasons in another thread somewhere I can read? Either way, I'm following here for sure. Love the great quality pics of the process and progress.



Re: Shaft Roller Rockers Again
Posted by: vairmech ()
Date: January 15, 2023 08:57PM

The main reason is valvetrain stability. You probably have heard of using stud girdles, they do almost the same thing. The stud girdles help stabilize the flexing of the rocker studs. I have broken stock studs.
Also with this particular setup up you get rid of the pushrod guides so you can also use larger 3/8" pushrods if you are that agressive with your cam. I just used HD aftermarket that I shortened for the correct geometry.

Ken Hand
Handy Car Care
248 613 8586


Re: Shaft Roller Rockers Again
Posted by: CoCoCo ()
Date: January 16, 2023 03:05AM

Thanks Ken. Looking forward to hearing more about them as they become available and put into use.

I've often wondered what our friend had done to his engine that let his '63 wind out to almost 9,000 rpm in autocross racing in the late sixties and early seventies.
That kind of rpm was rarely achieved in most engines back then, at least that I knew of. So it was pretty exciting to see and hear it run and to see him do so well against the other fast cars.
I don't remember it ever breaking down either. So whatever he'd done seemed to work.

I should have asked for more details while he and my dad were both still alive.

Thanks again. Sorry for the little segué into the past...


Re: Shaft Roller Rockers Again
Posted by: scottymac ()
Date: January 17, 2023 11:17PM

I've got a set of aluminum SCPerformance (Jeff Ballard?) valve covers that show about 2 1/2" internal clearance. Will that be enough to clear the new rocker arms?

Danville, In.
'65 Corsa coupe basket case
'66 Monza coupe


Re: Shaft Roller Rockers Again
Posted by: vairmech ()
Date: January 18, 2023 07:08AM

That is more than enough clearance to use even with the stud girdles! I think that is what they were made for to begin with.
For me I have a clearance issue, that is why I am going through all of this rocker cover cutting. The tall cover shown will not clear the driver's side muffler. Yes, I have to run a muffler, it's in the rules.

Ken Hand
Handy Car Care
248 613 8586


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