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1956 engine tear down

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concrete guy
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1956 engine tear down

#1

Post by concrete guy » Thu Nov 19, 2009 4:09 am

Took the engine out of the 56 FLE a few weeks ago and I am slowly getting to it. Here's what I have found so far.

Right case is not original. It came off a stroker. I haven't split them yet but the right side seems to be from a later model. The decks seem to match up somewhat nicely except the seam on the top of the deck on the rear of the rear cylinder. The right case is around .010" higher on the right side.

The rear piston seems to be traveling at an angle by the looks of the pattern on the piston skirt.

All rod bushings need replaced.

Cam is trashed, Labeled D-H. Hardened surface is worn off and the edges of the lobes seem chipped up.

Cam chest cover bushings for the timer gear and idler geat are worn badly and way off center. All the wear seems to be in only one quadrant of the bushings.

I have an early shovel oil pump and all the gears seem to be in really good shape. It doesn't show any signs of metal going through it.

All the chest gears seem to be in good shape. I pulled the breather gear and it had some shrapnel in it, some metal, some aluminum. One piece is the corner of a small bolt. I can see 3 threads on it. All this material was inside the breather gear. The case bore seems to be in fairly good shape from my untrained eye.

I checked the end play on the main shaft and it does not budge.

Here's my questions so far:

What other things should I be inspecting before I split them?

What's the best way to approach the deck height difference?

Anybody got pics of their rod truing fixture?

I know this is just the begining and there will be plenty more questions to come.

Thanks

Scott



Cotten
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Re: 56 Tear down

#2

Post by Cotten » Thu Nov 19, 2009 3:56 pm

Scott!

You might as well just get her apart, because you know she certainly won't go back anything like she was!

When you go to split the wheels themselves, I suggest an alternative to the conventional BFH method that marrs and distorts them badly.
Two large chisels for wedges on either side of the crankpin will allow light alternating strikes to pop the wheels apart gently.
WHELSPLT.jpg
After your rod re-build, you will want to straighten and align them with a gauge or surface plate. Bending them true is a discussion in itself.
RODGAUGE.jpg
And don't forget to de-magnetize, too!

....Cotten
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concrete guy
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Re: 56 Tear down

#3

Post by concrete guy » Thu Nov 19, 2009 10:29 pm

Thanks for the reply Cotten! She will be coming apart soon. Like your rod fixture :) Is that a mandrel on the big end and do you do your straightening in that fixture? I did get a chance for some pics this morning.
023.jpg
FRONT PISTON
025.jpg
MY SKEWED REAR PISTON
026.jpg
DECK HEIGHT PROBLEM AREA
027.jpg

BREATHER GEAR BORE
032.jpg
Can anyone tell the vintage of this old shovel pump?
034.jpg
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RussW
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Re: 56 Tear down

#4

Post by RussW » Fri Nov 20, 2009 4:52 am

Can't tell for sure from the picture, but could that be an S&S replacement pump from about 20 years ago? Looks just like mine, can't tell if the S&S logos are there, but can see the "R" and "S" designations. If you do notice the S&S markings, let me know and I will get you the numbers for the replacement gaskets to fit that pump (the install instructions say the gaskets are not interchangeable with shovelhead gaskets, even though they are similar.)
oilpump.jpg
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concrete guy
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Re: 56 Tear down

#5

Post by concrete guy » Fri Nov 20, 2009 5:01 am

Yes, it is an S&S and I will take any the info you have.

Thank You!!

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Re: 56 Tear down

#6

Post by RussW » Fri Nov 20, 2009 5:19 am

It was S&S pump kit # 6250, to fit '36-'72 Big Twins. James made the gasket kits exclusively for S&S, part # 6271 rebuild kit includes paper body gasket, paper cover gasket, gear key, and snap ring. Part #6274 included mylar gaskets instead. I don't even know if James makes these kits anymore; if not, contact S&S and find out what gaskets they suggest to use. Send me a PM with your Email, if you would like I will scan the exploded view of this pump with all the S&S part numbers on it and send it to you as a PDF file.

concrete guy
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Re: 56 Tear down

#7

Post by concrete guy » Fri Nov 20, 2009 1:35 pm

Thanks Russ!

Spennebake@aol.com

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Re: 56 Tear down

#8

Post by Cotten » Fri Nov 20, 2009 3:15 pm

Scott!

The gauge is an old AAMCO automotive fixture with the three toes of the expanding mandrel ground smaller for motorcycle crank bores.
At the gudgeon end there is an adjustable platform with faces ground square and perpendicular to the beam. Thus a pin can be placed in the bushing an the rod rotated to where it touches a face, and a feeler gauge then tell you of bend or twist.

My own addition is the dial indicator held with infinite adjustability by a speaker magnet. With a broad 'foot' on the indicator, bend is easily determined by sweeping the pin under it and marking the reading. Then the rod is switched so the other end of the pin sweeps under the indicator, and a difference can be quickly noted.
A rod with no bend will read the same on both sides.

The gauge is an inspection instrument only, as rods are usually straighten'd in a press.

On to your pics, the angular wear on the piston skirt will come out in the wash of the crank overhaul. But the annular groove in the breather gear bore is more of a concern. It leaves one of your passages effectively open continuously.
Welding up the entire groove is un-necessary, and would cause distortions. I found that just a TIG-spot to fill the groove just past the gallery hole is quick, easy to dress, and effective.

Your deck alignment can only be inspected after thorough cleaning, and dressing of the mating surfaces with a machinist's scraper.
You may find weld repairs to blame, or you may find that the cases mate fine if the studs are not pressed in. The fix depends upon the cause.
Your pic is fuzzy (got "macro mode"?), but the primary concern is only the deck itself. There can be pesky leaks below that, of course, so you may consider lapping the cases together just to inspect the contact in that area.

....Cotten

concrete guy
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Re: 56 Tear down

#9

Post by concrete guy » Sat Nov 21, 2009 1:41 am

Thanks Cotten!

I follow your thoughts on just putting a tig spot but it's placement I am still alittle fuzzy on. Can you elaborate?

Not the greatest with cameras but will check the "Macro" option. Well I split the cases this evening. Right side is a 58. I found out that one of the small screws that goes in at an angle on the right side race backed out. Not much damage. I will gets some pics in the morning.

The wheels at first glance look good but I have not broke them down yet. Wheels don't have one hole drilled in them.

The cases were put together with high temp permatex- signs of a quality build.

Bearings and races look good. I have been collectiing new quality parts for awhile now in anticipation of this build. Still need to get a crank pin. Hopefully the wheels look good when I brake them down.

concrete guy
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Re: 56 Tear down

#10

Post by concrete guy » Tue Nov 24, 2009 2:34 am

Was looking at the inside of the left case tonight and I am trying to deterimine if this is a crack or a casting flaw. There is no crack on the surfaced area by the main race and no crack on the register on case joint edge. This line goes all the way across the bottom of the case. On the oustide of the case I can find no signs of a crack. Love to hear your thoughts.
INSIDEOFCASESONPAN003.jpg
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concrete guy
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Re: 56 Tear down

#11

Post by concrete guy » Tue Nov 24, 2009 6:15 am

Cotten wrote: But the annular groove in the breather gear bore is more of a concern. It leaves one of your passages effectively open continuously.
....Cotten
Cotten,

I have been studying the oiling system in more depth. I still need some schooling on the statement above. I am trying to figure out how this small groove will leave one of my passages effectively open contiuously.

Thanks,

Scott

P.S.
The flywheels were drilled, on the inside, never thought to look on the inside edges :oops:

pusher
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Re: 56 Tear down

#12

Post by pusher » Tue Nov 24, 2009 11:14 am

I believe the purpose of the breather gear is to open and close in time with the other gears in the chest to relieve the oil/pressure created from the pistons shooting back into the case

This breather gear (should be made of metal) has a metal screen and rotates in that bore.
Since that nice circular gouge you got there reaches up to the rectangular 'breather' window you have effectively opened a (small) passage in your oiling system.. which I would imagine could be detrimental to the life of the engine

..I think.

concrete guy
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Re: 56 Tear down

#13

Post by concrete guy » Tue Nov 24, 2009 11:44 am

I think I understand the basics of the breather gear. My annular grove is probably a common one. It was created by metal coming out of the bottom end into the crankcase oil scavenging sump and in turn pulled into the breather gear. The breather gear has a small hole (~1/4") called a head drain port. This is one of two places for shrapnel to exit the gear and create a score on the breather gear bore. This is the area that I am having a hard time wrapping my thick head around. This 1/4" hole correlates to no other opening in the bore. The only opening would be the .0015" clearance on each side of the breather gear in the bore. So is it the vacumn that sucks through the gear and is pulling through this annular grove and in turn pulling oil through the outside breather oil trap that is the problem????

Thanks,
Scott

concrete guy
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Re: 56 Tear down

#14

Post by concrete guy » Tue Nov 24, 2009 12:02 pm

martyMusto wrote:Since that nice circular gouge you got there reaches up to the rectangular 'breather' window you have effectively opened a (small) passage in your oiling system.. which I would imagine could be detrimental to the life of the engine

..I think.
The annular groove does not connect to the rectangular window.

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Re: 56 Tear down

#15

Post by Cotten » Tue Nov 24, 2009 4:08 pm

Sorry to get back into this so late...

Please refer to the Service manual for direction of pressures and suctions of the galleries leading to the breather gear.
The gear has holes separate from the window to the cam chest. The timing of the hole to the gallery is critical to the efficiency of the system.

Hard objects have been caught in this rotating shutter, and have been dragged like a cutting tool to make the annular groove of damage. This channel produces the effect of the hole being lined up with the gallery continuously.

My contention is that the entire groove need not be filled.
The groove needs only to be dammed close to the gallery.

Come to think of it, we used two dots of weld, one on either side of the gallery, and finished it with a machinist's scraper and an ADALOX "fuzz brush".

...Cotten

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