Defective rocker arm shaft photo

[Tinster]

My new rocker arm shaft arrived today . HooRah!!!
(double mailed to save the $60. seller shipping charge)

Here's a photo side by side of old and new shafts at
rockers No. 11 and No. 12. Clearly the rocker shaft that
I removed was defective when it left the point of manufacture.
The missing oil groove explains dry rocker No. 12 and low oil
pressure that resulted in dry Rocker No. 1.

I can't wait to put everything back together and see how things
are supposed to operate. PS: Paul- both shaft ends
are threaded to accept hex socket, tapered end bolts.

regards,

dale(Tinster)

 

[tdskip]

Wow Dale - that is interesting. Thanks for the photo. I'm eager to hear how the works.

 

[martx-5]

I would venture to say that there <span style="font-weight: bold">was</span> an oil flat (groove) on the original shaft, but that the wear on it was enough to wipe out any remnant of it. If you look at the groove on the left side of the original shaft, that is almost gone also. I doubt there there was a defect in the original shaft. That's just what I observe and is my opinion.

 

[Tinster]

Could very well be Art. My micrometer claims a groove
was never cut there. But heck!! What do I know about
auto engine stuff?? LOL

I'm just happy I have a new shaft with 12 identical
oil grooves cut into it.

Thanks for your thoughts,

dale(Tinster)

 

[Brosky]

Dale,

It looks to me as though it was there. If you look at the pictures and the shape of the slots that come into the groove, there is a definite difference from what I see. I think that it just got worn away. I'd bet that the rockers that originally fit over that area will be very sloppy on your new shaft.

 

[Tinster]

Hi Paul,

I cleaning each piece with my usual attention to detail.
I am 600 and 1500 wet paper polishing all contact surfaces.
Mother's to shine up the Alum pedestals.

The pedestals require a but of lube to get them in place.
The rocker arms slide down the dry shaft and have no
side to side wobble.

I switched out No12 for another rocker arm and it made no difference. The rocker arms feel tight but do not bind at
all when I rotate them around the new shaft. I can spin them
a little if I push them hard enough.

Please better define sloppy so I know what to feel for.

thanks for the input,

dale(Tinster)

 

[14dna]

Dale;
I think he means if there is any sideways movement at all, then the rocker should be replaced.
My concern would be the rocker that is #12

Dave

P.S. You are doing a great job :banana:

 

[DrEntropy]

Ummm... a (I ~KNOW~ you have one) dial indicator MacGyver'd to measure side-to-side ("twist" on th' shaft) movement at the adjuster end of the rocker (all must obviously be well secured) ON the shaft may show the difference. Without I.D. micrometers you can't measure the bore on both sides of each rocker with any accuracy but I'd bet there's a difference side-to-side...

Don't pick nits for anything other than curiosity. It'll run well with th' new shaft and again: "It'll OUTLIVE ALL OF US!!"

Reassemble it and DRIVE some more! :wink:

 

[Tinster]

Ummm... a (I ~KNOW~ you have one) dial indicator MacGyver'd to measure side-to-side ("twist" on th' shaft) movement at the adjuster end of the rocker (all must obviously be well secured) ON the shaft may show the difference. Without I.D. micrometers you can't measure the bore on both sides of each rocker with any accuracy but I'd bet there's a difference side-to-side...

Don't pick nits for anything other than curiosity. It'll run well with th' new shaft and again: "It'll OUTLIVE ALL OF US!!"

Reassemble it and DRIVE some more! :wink:

<span style="color: #CC0000">Doc: I have an I.D. micrometer.
On 4 rockers that I measured at 90* cross diameter
I got .568" to .569" I.D., including No 12.

Side to side I got the same small variations.
.568" to .569" I.D.

thanks for the input,

dale</span>

 

[DrEntropy]

You're golden if th' shaft-to-bushing clearances are inside tolerances then!!! :thumbsup:

 

[70herald]

Ummm... a (I ~KNOW~ you have one) dial indicator MacGyver'd to measure side-to-side ("twist" on th' shaft) movement at the adjuster end of the rocker (all must obviously be well secured) ON the shaft may show the difference. Without I.D. micrometers you can't measure the bore on both sides of each rocker with any accuracy but I'd bet there's a difference side-to-side...

Don't pick nits for anything other than curiosity. It'll run well with th' new shaft and again: "It'll OUTLIVE ALL OF US!!"

Reassemble it and DRIVE some more! :wink:

<span style="color: #CC0000">Doc: I have an I.D. micrometer.
On 4 rockers that I measured at 90* cross diameter
I got .568" to .569" I.D., including No 12.

Side to side I got the same small variations.
.568" to .569" I.D.

thanks for the input,

dale</span>

This is exactly why the rockers are made out of a harder material than the shaft. If there is wear (and there is ALWAYS wear) it is the relatively cheap shaft which takes the abuse, and not the more expensive rockers.

I found the exact same thing on the herald engine shaft totally worn out, and the rockers ID in good condition.

Dale waiting to see a new update of you zooming around PR in the TR.

 

[Tinster]

Thanks Yisrael,

This was a curiosity thread to begin with.
I could detect no wear on the rocker arms visually,
by feel or with a micrometer. I kinda figured the shaft
must be harder steel.

The car ran fine except I had two dry rocker arms.
I'll put things back together and see what I see.
Also a kind member is gifting me a few almost new
rocker arms.

I too am looking forward to zooming around the island.
Hopefully in a few weeks the temps will have fallen
into the driving range. Heat indexes have been hovering
around 100* for the past few weeks. Way too hot for October.

best regards,

dale

 

[Brosky]

Looks like the questions were all answered while I was hard at work all day.

Good luck Dale!