1966 Shovel engine rebuild

[Steve Little]

I am currently building a 66 Shovel engine and dealing with some issues provided by previous engine builders and a few aftermarket parts.
While disassembling the rear rocker box I noticed brown sealant around the o-rings and screws of the rocker arms.

After disassembly of the front rocker cover there was no brown sealant and the front rocker shafts looked different in colour, compared to the rear shafts. On closer inspection, the machining was also different between the two sets of shafts, so I am assuming they came from different origins. I think the dark pair at the back of the picture are original.




The light grey shafts in the foreground of the above picture had the brown sealer on the O-rings and end screws.

[Steve Little]

Let me start this post by saying I haven't played with a Shovel engine for many years.

I purchased a complete James engine gasket kit and the description says “Shovel engines from 1966 thru 1984”.
The kit supplies many O-rings, and quad seals, some of which will be for later Shovel engines, but they don't supply a parts list in the kit.
James... You could be print the parts list on the reverse side of the “How to tighten the primary to engine” sheet you supplied. Just sayin.

My parts manual covers 58-68 and has a description of “O-ring” and part number 11101, for the rocker shaft seal.
My question: did Harley use an O-ring to seal this shaft from 66 until 84?

[ryan]

Let me start this post by saying I haven't played with a Shovel engine for many years.

I purchased a complete James engine gasket kit and the description says “Shovel engines from 1966 thru 1984”.
The kit supplies many O-rings, and quad seals, some of which will be for later Shovel engines, but they don't supply a parts list in the kit.
James... You could be print the parts list on the reverse side of the “How to tighten the primary to engine” sheet you supplied. Just sayin.

My parts manual covers 58-68 and has a description of “O-ring” and part number 11101, for the rocker shaft seal.
My question: did Harley use an O-ring to seal this shaft from 66 until 84?

I have seen two styles of seals on my 1969, 3 rockers had hard plastic Teflon style seals and one rocker had a rubber o-ring. Now my 77 has all o-rings.
I did really understand how the hard Teflon seals even sealed that well.

[Steve Little]

Hi Ryan. Thanks for the info.

If anyone has had problems with a rocker box O-ring that wont seal, the following may be the cause.
After washing and drying all the rocker gear I refitted the old O-rings and screw to each shaft.
Then flipped the shaft upside down and placed the O-ring end into the rocker box's to check the O-ring fit in the rocker box's
The front rocker box shafts had excellent sealing tension. I believe these are the original shafts.

The O-rings of the rear shafts only just sat in the holes under their own weight, but fell through at the slightest touch. No surface tension and no chance of holding oil from dribbling out.



Just for giggles, I tried the front shafts in the rear rocker box and they had an excellent feel and had to be wiggled into the hole. So the problem lay in the aftermarket shafts...Huuuh? Shock horror.

I then took the O-rings off the shafts and measured the gap between the shoulder and screw for the 0-ring gap on each shaft.
Both of the darker coloured shafts (original?) measured 0.079” from the shoulder on the shaft to the face of the screw.
Both of the lighter grey shafts measured 0.089”.
This means that the O-ring has very little side pressure and is not forced up to contact the surface of the holes in the rocker box.



The shoulder on the end of the light grey shafts was 0.010” longer and had very rough machining, compared to the nice machining on the darker shafts. I should have taken a picture before facing them on 240 grit. Ahh well. You can still see the heavy marks under the shiny surface in the picture.
Somehow I had to grind 0.010” of the end of these hardened light grey shafts, and it would not be on 240 grit paper. My lathe is still out of action while I wait for a guy to come and scrape the way$ etc.

Then I remembered my Brierley drill/tool, grinder. This was used to resharpen tooling when I had the frame business. For a home handy man, I have really sharp drills these days.

[Steve Little]

Now. How did Toprock say to do it. Fit the diamond dresser in a chuck and take a few light passes to get the stone faced and clean.



CHECK



Fit rocker shaft to chuck and face off 0.010”

[Steve Little]

Shaft on the right has 0.010" removed. Center shaft not ground yet. Shaft on left is Original.



After looking at all the shafts under my magnified jeweler glasses, I could see that someone had hit the original shafts with a steel hammer and left marks. So I gave them a very light lick with the grinder. Both originals now measure 0.079" and both light grey shafts now measure 0.080"



I then retried all shafts and old O-rings in the holes. All O-rings have excellent holding tension and I believe they will hold oil.

[ryan]

Steve,
That was some very smart thinking, on your part, to grind them that way.
I know you are working in thousandths, but just a quick question, did you turn off your wheel after dressing it? I was taught to dress the wheel every time you turn on a tool grinder after warm up and never shut off the grinder after dressing the wheel or you have to redress the wheel again because of the wheel run out. Just wondering is all.
So, I am really asking if you were ever taught the same way?

Thanks for sharing!

[Steve Little]

Hi Ryan.
Thanks for rolling up your sleeves and getting in there, with me.
Hopefully the information will benefit someone else with leaking Troubleheads.

I didn't know about not turning off the grinding machine, oops! and don't have any training on the machines. I'm a Tradesman in boiler making and structural steel.
The lathe, mill, tool grinder, Fadal CNC mill, and a bunch of other machinist stuff are the remnants of what was left over after selling the frame business.
The guy who bought the business had a limited budget, so I am left with the coolest man cave. If a problem comes up when I'm tinkering with my old tippityfart Harley's I know what I want to achieve, and kind of bumble my way through, with the machines on hand.

While I'm thinking of what is left of Race Frame Engineering..... The guy didn't buy the machining jigs. This never made sense to me, as the jigs are the key to the repeatable accuracy the business was renowned for.
The jigs were made by the tool room machinists who worked here, and are works of art and they are sturdy to withstand the loads of the CNC machine.
Some of the jigs were made for multiple components and some are singles.
If your in the vintage HD frame business (Restoration or manufacture) these jigs would set you apart from the pack and be a leg up in repeatable quality.
p.m me if your interested in buying them and want more info.

Steve

[ryan]

Steve,
I know the comment I made about the wheel dressing was trivial in your situation. As an ex, full time tool and die guy, processes like that stick in my head and sometimes I wonder if other people were taught the same way, is all.
The first tool to come to my mind was the use of a valve grinder and you pulled out a wonderful machine I haven't seen in years, as they were replaced with CNC tool sharpeners.
Your grinder is a great tool to have in a home shop though, I would gladly be proud to have one in my shop.
Thanks again for sharing the malady of the parts and the process to cure the malady.

[Steve Little]

Thanks Ryan.
I appreciate you taking the time to have some input, and give tips garnered from your machining history.

For those that know what is involved, here's some industrial art. 3 jigs from the frame business. There are probably 25 or 30 jigs stacked in the shelves.


Anyone want to guess what the first jig is for.



Ignore the red arrow in the second picture. These pictures are from the machinists files and were used to was a prompt his memory on how to set up.






Cool huh!

[painterdale]

That is cool, Steve! I'd like to see more. Always interesting to see what you've got going on!
Dale

[ryan]

To me, there looks to be 3 different fixtures, not jigs, a jig guides a tool. Now there may be jigs attached to fixtures, for example, a drill hole jig.
With that being said, the pieces being machined do not look familiar to me, but just may after studying them for a bit. Please do not give up the answer, to the puzzle, quite yet.

Thanks

[Steve Little]

OK. While your all going cross eyed trying to work out what the "Fixture" is for, I got on with the next job with this engine.
This picture almost makes it look like you could take the helicoil out and put a new one in. But there are no threads left for the helicoil to screw into so....some rhinoplasti is needed.

[ryan]

Steve,
I agree on the crossed eyed work on figuring them out, I missed where you had already called out the number 3. So I am the goof on that one and I am still at a loss.

In your current case, will you have to machine out your hole and the outer most part of the casting to be able to fill it with weld and remachine your hole? Also if you do have to go that far, will you also check the bore of the exhaust port to see if it needs addressed as well? Will you do the work or farm it out? Have you ever heard the saying, "just get out of your head and do it?" I have that issue quite often, for instance, why set up to machine what the hand can do. Ya get my drift?

[ryan]

OK. While your all going cross eyed trying to work out what the "Fixture" is for, I got on with the next job with this engine.
This picture almost makes it look like you could take the helicoil out and put a new one in. But there are no threads left for the helicoil to screw into so....some rhinoplasti is needed.

Just a mindless thought here because I am almost sure you will not have enough meat for a 1\2" tap. If you do have enough meat for a half inch tap, a steak pocket can be used.