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Rebushing Rocker Arms

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Stewart

Stewart

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Anyone done this before? Like everything on the 73 they were fairly worn with the worst having 1/32nd inch of vertical play in them. I'm planning on taking them to a machine shop in the morning for a quote for replacing the bushing reaming and drilling the oil holes. If the quote is to high what other options are out there?
 
I am interested to see how this turn out. I have a spare engine that I would like to rebuild, and have on hand ready to go. I am not sure how bad mine are, since they are sitting in a box currently, but it will be interesting to see what people come up with.
 
Hi Stewart, It is pretty unanimous that Rocker Shaft Re builders here on the West Coast can not be beat, most LBC owners are familiar with their excellent service.--Fwiw--Keoke
 
Rockers are not particularly difficult to DIY re-bush ... as long as you have a small lathe and the appropriate measuring eqpt, that is. As I recall, Moss's price for the bushings is like $8 apiece, so the raw material is fairly cheap.
The old bushings can be removed using a hammer and a "suitable drift" (see note). The new ones installed similarly. The oil holes are drilled using a hand electric drill and the appropriate size bits.
The problem comes with sizing the bushings. Typically a machine shop will use a reamer (similar to a highly accurate drill bit) of the appropriate size, .6255-.626". I use an adjustable reamer that can be can be set to the appropriate dimension. I have also bored out a rocker bushing or two on the lathe, but it is really difficult to hold that kind of tolerance with non-professional eqpt (and skills), plus the surface finish is likely to be not as good. So the reamer is definately the way to go.

Lacking a lathe and micrometers, you might be able to save a few bucks by providing the rockers to the machine shop with new bushings installed and the oil holes already drilled. Thus the shop would have one set-up for the x number of rockers to be reamed.

note - the drift tool must be dimensioned such that the nose will fit inside the bushing, then a lip that bears agains the end of the bushing, then another section that will slip inside the hole in the rocker. The rocker bore is conveniently .7485-.7495, a hair less than 3/4", so a hunk of 3/4" round stock won't work without whittling a little off the diameter first.
drift.jpg
 
Would it be cheaper and less time consuming to get newer updated rockers?
 
jlaird said:
https://www.rockerarms.com/MG.htm

These are suspriseingly cheep.
Click to expand...


Same folks Jack, I just forgot they modified their name after moving up north a few years ago. They do great work can supply harden shafts as well.---Keoke-- /bcforum/images/%%GRAEMLIN_URL%%/thumbsup.gif
 
Another option is to rebush your rockers with offset bushings.
I am not sure if these are avaliable for the B series engine but they are for the A series engine through APT. Good news for Midget owners! I just finished rebuilding a street A series 1275 and finished off the engine rebuild with rebuilding my rockers with a hardened shaft and offset 1.3 bushings for a little more lift to go with my Apt 266 cam and a 9.5 compression ratio. Very nice results for an engine that is not too radical for minimal cost. The wear on my old rocker shaft was quit easy to see when it was all a part so I would highly recommend rebuilding the rocker shaft as part of the rebuild process.

Liam
57 mga
59 bugeye
60 bugeye
 
These guys are 25 miles away from me and I didn't know about them. Interesting stuff. I'll have to drive by and check them out.
 
Just replaced the rockers on my 76 with some roller rockers. Talk about a difference! especially in sound and adjustability. Absolutely incredible. Important to remember to use some good assembly lube when doing any way you decide.
I had a rocker that went completely and took the shaft with it. I replaced it with a hardened one from Moss. This has really made a difference.
 
Sadly, the rockers and shaft are often an item that is overlooked during a rebuild. It isn't only the shaft and bushings that wear, but the contact surface of the rocker itself.
I generally replace mine as a matter of course.
Jeff
 
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