1956 Rocker Arm Nuts

[Alexander C.]

Re: 1956 Rocker Arm Nuts

I'll take pictures the next valve adjustment I do.

My engine has only 24K miles on it so most things were fine. Everything met the standards you suggest and were reused.

[Clem Z.]

Re: 1956 Rocker Arm Nuts

I'll take pictures the next valve adjustment I do.

My engine has only 24K miles on it so most things were fine. Everything met the standards you suggest and were reused.

you can use "PAL" nuts to help lock the adjustment nuts. these were use to "lock" the nut used on connecting rod nuts for years. http://webcache.googleusercontent.co...www.google.com

[Joe L.]

Re: 1956 Rocker Arm Nuts

All------


Attached are photos of NOS examples of the GM #3837180 rocker ball and GM #3837181 rocker ball nut. I believe these were the original parts used for 1955-56 Corvettes.

[Clem Z.]

Re: 1956 Rocker Arm Nuts

All------


Attached are photos of NOS examples of the GM #3837180 rocker ball and GM #3837181 rocker ball nut. I believe these were the original parts used for 1955-56 Corvettes.

i wonder if the poster was using the nuts up side down with the taper on the top of the nuts fitting into the taper on top of the ball.

[Joe L.]

Re: 1956 Rocker Arm Nuts

i wonder if the poster was using the nuts up side down with the taper on the top of the nuts fitting into the taper on top of the ball.

clem------


As incredible as it sounds, I think that these rocker balls and nuts were actually designed to be installed so that the taper of the nut installed downward. Here's how I came to that conclusion:

1) The taper and relief machined into the top of the rocker balls is more than just a chamfer. It looks to be as if it's an actual taper. As such, it would seem to me that it must have been done for a purpose;

2) The taper on the nut seems to fit perfectly into the taper on the rocker ball;

3) Most conclusive is this: the distorted thread portion of the nut is on the flat end of the nut. I believe this would make it impossible to start the nut from that end. If so, the nut would have to be started from the tapered end and this would obviously mean the taper must be oriented downward, interfacing the taper on the rocker ball.

Now the question is why this would have been done and for that I have no answer.

[Clem Z.]

Re: 1956 Rocker Arm Nuts

clem------


As incredible as it sounds, I think that these rocker balls and nuts were actually designed to be installed so that the taper of the nut installed downward. Here's how I came to that conclusion:

1) The taper and relief machined into the top of the rocker balls is more than just a chamfer. It looks to be as if it's an actual taper. As such, it would seem to me that it must have been done for a purpose;

2) The taper on the nut seems to fit perfectly into the taper on the rocker ball;

3) Most conclusive is this: the distorted thread portion of the nut is on the flat end of the nut. I believe this would make it impossible to start the nut from that end. If so, the nut would have to be started from the tapered end and this would obviously mean the taper must be oriented downward, interfacing the taper on the rocker ball.

Now the question is why this would have been done and for that I have no answer.

i owned a new 1955 power pac chevy and i don't remember that,but that was a long long time ago. i also have some old 50s chevy shop manuals i will check. seems like that would cut down on the amount of contact area between the nut and ball to hold the adjustment.

[Jim L.]

Re: 1956 Rocker Arm Nuts

Well, Joe, you've certainly explained the apparent disconnect evident in my post #13 above. I've never seen rocker balls and nuts like that.
Jim

[Alexander C.]

Re: 1956 Rocker Arm Nuts

All------


Attached are photos of NOS examples of the GM #3837180 rocker ball and GM #3837181 rocker ball nut. I believe these were the original parts used for 1955-56 Corvettes.

While I agree those are the exact rocker balls that I have, those are not the same original nuts.

I just drove my '56 6hrs round trip to LA and back Saturday and have not had a chance to remove the valve covers yet. Perhaps tonight and I'll post pictures of my rocker nuts...

Here is a picture I found on eBay. Mine look similar to these however mine also have an additional taper on the bottom of them that these in the picture do not, it is that taper which fits into the top of the rocker ball. When I rebuilt my engine a few weeks ago, I went by my local machine shop to get 3 or 4 as they were gone and replaced with the newer version. He had a couple old Chevy heads (exactly like mine, same powerpack casting shape on the ends even) and they also had these nuts. He said they were original heads that hes had for about 40 years on a shelf. Seems like quite a coincidence. They were quite rusty but cleaned up great after overnight in CLR.

[Edward M.]

Re: 1956 Rocker Arm Nuts

Ed;

Hope the Tornados stayed away from you. Saw on the news this morning - really looks bad. Our thoughts and prayers are with all the folks in those areas. The last weekend storms in MO showed a number of old classic cars that were in garages that were hit too, i.e. 67 Chevelle, 53 Studebaker. Ouch!

Stu Fox

OK, we just got power back. Lost power last Wednesday. Had to head into the tornado shelter 5 times last Wednesday.

We were lucky, my family and I are fine, and we have no damage to our property. We just lost our big trees.

Many in this area were not so fortunate.

One poor classic car guy in the subdivision where my inlaws live wasn't so lucky. He lost his mid 60s Buick Riveira in a Tornado in 1995. He replaced it with a 66 Impala. The 66 Impala was badly damaged in the tornados last Wednesday. Car owner is fine, the rest is just stuff.