Restoration of Sandcast #97

[markb]

I’d like to start putting my cases together soon and realize I’m going to need an oil pump.  The one from E100 is locked up tight.  I’m not sure I’ll even be able to rebuild it.  Besides that one I’ve got two other pumps that came out of sandcast engines and three that came out of diecast engines.  I think I will just tear the sandcast ones apart unless I need parts from the others and hopefully I can end up with at least two good ones.  One of them feels real good and I can hear pumping noises when I turn the gear.  Here’s a pic of the six.  The E100 pump is the one on the lower right.  The top row is diecast pumps and the other two are sandcast pumps. 


Before I started taking them apart I carefully looked them over and made some interesting observations.  There are four different versions that I see.  Rather than clog up this thread I started a thread about oil pump differences here:
http://cb750sandcastonly.com/smf_forum/index.php?topic=1084.0

[markb]

I have the pump bodies separated from the bases on the three sandcast pumps.  None of the screens looked good and since they are available from Yamiya I didn’t bother trying to save them.  I just poked a hole in them and pried them off.  Then I removed the four screws holding the bodies and bases together.  I noticed that they were pan head screws on all three pumps.  The 4/69 parts manual shows hex heads and so does my shop manual.  The later parts manual shows pan head screws.  Has anyone ever seen hex heads?

Next step is to take the bodies apart.  Before I did I noticed what I thought was an odd thing.  On the two later pumps that aren’t froze up I saw there was about a ¼” of axial play on the gear shaft.  Here’s a shot with the gear pushed in.


Here’s a shot with the gear pulled out.  Is this normal?  What keeps the gear from floating around?


I spent about an hour with an impact driver trying to remove the three flat head screws that hold the bodies together.  I had already soaked them and tried heat but they wouldn’t budge.  I finally decided to just drill out the heads.  It took me about five minutes to do all three pumps.  Believe it or not the cover on the E100 pump came off quite easily.  However, just as I expected it’s not good news.  It’s a little milky and corroded inside.  At least the screws stuck out enough that I could remove them.  I turned them all out easy with my fingers.  The flat head was obviously seized on them.


Wiping it off it doesn’t look any better.  I have to quit for now.  Maybe the other two pumps will look better.

[markb]

The two later sandcast pumps are apart and they do look better.  At least one of them has been apart before.  Notice absence of the punch mark on the inner rotor of this one.  I checked and it’s on the inside.


Here is how they’re supposed to be.  Both of these rotors look a little scored.  I have access to a surface grinder and a lathe so I’m planning on grinding the rotors and turning off the ends of the body to bring the side clearance in spec.


This cover looks pretty good and the ones on the other side look good.  I’ll get at least one good pump out of three.  


I’m not sure why but I’m still soaking the E100 pump to see if I can get it apart.  I can’t imagine the rotors are worth saving but I guess I just want to see.

[Steve Swan]

Mark, it's nice to see you're back sharing your project.

[markb]

Thanks, it's good to be back at it.    And if you guys see anything that I'm doing wrong, please let me know.  That's part of the reason I share is so I can get expert feedback.

By the way, about the endplay thing from a couple of posts back.  I checked my three diecast pumps and they were the same so I have concluded it's normal.  I might have to wait until I install one to see what prevents the gear from floating.

[markb]

I got the E100 pump body apart.  It took some soaking and heat but I am pleased that the other side doesn’t look too bad.  I had a couple of surprises when I cleaned up the rotors with some Scotchbrite.  The first one was how nice they cleaned up.  They look better than some of the others.  And unfortunately I didn’t notice this until I had the rotors cleaned but none of them have punch marks!  So I have lost how they were oriented in the body.


I have everything apart on all three pumps except I haven’t been able to get the check valves out of two of them.  Hopefully with more soaking and some heat they will come loose.  I did get the seals out though.  My method is to remove the rubber part and drill a 1/16” diameter hold on each side of the remaining seal housing.  Not through, just enough to get something to hook on.


Then I have an old center punch that I ground a little flat on one side.  I put the shaft in the pump and push the point of the center punch in the hole and taking care not to touch the mating surfaces, I gently lift the body and tap it on the bench so the end of the shaft hits the center punch.  A couple of taps is all it took.  Two of the seals came out without moving to the other side.  The whole process took me less than fifteen minutes.


I cleaned everything up and even the bores on the E100 body look good.  I checked the rotor clearances and all three were in spec.  The gear shaft on E100 is badly pitted and some of the covers have some good gouges but everything else looks pretty good.  If I can get the check valve out of one of the other bases I think I can come up with two decent pumps.

[markb]

Since I got the cases out to plastigage the bearings, I’ve been thinking about putting oil plugs back in it before I forget.  So I finally did the one on the alternator side.


And then I was going to put the front one in and started having an anal attack and wondered if it should be painted or not. I should have just put it in before painting.   Either way I had to plug the whole.  How about it, can anyone tell me if theirs looks painted or not?

[markb]

I'm pretty sure that plug had paint on it.  I'm not much of a painter but I can handle that.  No one else would probably ever know.  But I would.

I'm still trying to get the relief valves out of the two oil pump bases.  And I'm waiting for parts anyway.  So on to other stuff. 

I need a new rotor and starter clutch.  This is the one from E100.  I got the screws out but this thing just isn’t coming apart and probably wouldn’t be usable if I could get it apart.  I’m not going to be able to save every part.


I bought a couple of cheap ones off ebay.  I don’t trust what is inside so I am going to take them apart.  There are some little holes in the starter clutch and the gear so I like to make sure everything is clean.  I don’t bother trying to get the screws out.  They are a common 8x22 flat head.  A drill press makes easy work of them.


Then after you get the starter clutch out the screws usually come out by hand.  One of the rotors would not come apart so I got that one soaking.  The other is all cleaned up and has new springs and rollers and is all put together and ready to put on the crank.  Just waiting for the seal for the gear.

[Marcello Tha]

You give us a lesson in every post.

Marcello

[Wayne]

Mark. I have the front plug out of 576 here on my desk along with my new one. There are no signs of paint at all on the original plug.

[markb]

I went ahead and painted anyway.  I put it in without and where it's recessed it was hard to tell if it was painted or not. Same now that it has some paint on it so I think I leave it that way.  It's such a nitpicky detail I just don't want to think about it anymore. 

[markb]

So it was bugging me that I couldn’t get the one rotor apart.  I was thinking all day about it.  I had plans to machine a ring just slightly bigger than the clutch body and high enough to make room for the clutch to drop out and mount the ring to a plate.  Then in the center of the ring I would mount a rod that the rotor would fit over.  Instead I found a 2’ piece of 5/8” diameter rod and clamped it in a vise.  I had a piece of scrap plate that happened to have a 5/8” diameter hole in it and slipped it on the rod.  Then I stuck three blocks of aluminum, with double-sided tape so they wouldn’t move, with enough clearance to contact the rotor outside of the clutch diameter.  Then I put the rotor on the rod and dropped it a couple of times from about a foot.  Nothing.  So I tried it from two feet.  Three drops and it was apart.  If you’re going to try this I would recommend taking out the pins and springs (I did) because they will pop out.  Total time was about fifteen minutes.  Here’s a picture of my setup.  I was thinking of trying it on the E100 rotor but if it’s that rough on the outside it has to bad on the inside.

[markb]

I’m kind of jumping around here but I want to get the last two oil pumps apart so I can clean everything up and see what I have.  I haven’t been able to get the relief valves out of the bases.  Every couple of days I sprayed some Aero Kroil on them.  Then I would heat up the base with the torch and tap it on the bench and try to pull them out with needle-nose pliers.  They just won’t come out so I made a relief valve extractor.  I started with a piece of ¾” bar stock and bored a 12mm hole to fit on the end of the valve and turned the OD to fit inside the housing.  Then I tapped holes for #6 set screws right on the end.  If you look close you can see where the threads are almost breaking through.


They have to be that close otherwise you can’t get at the set screws when you put it on the end of the valve.  I could have used #4 set screws but they are really small and I wanted to get as much grip on the end of the valve as I could.  I wasn’t worried about marring up this surface because just the spring goes over it.


Then I hooked it onto the end of a slide hammer (dent puller).  I heated the base with the torch until it was really smoking and used the end of the bench to hold it as I gently tapped on it with the slide.  I didn’t want to do it too hard because I didn’t want the set screws to slip. 


I did the newer one first.  About 10 taps and it was out.  Here is the E100 one.  Believe it or not it came out easier.  Now to see if I can save them.

[markb]

I got my seal for the starter gear so I’m ready to put the rotor on the crank.  I’m glad I had some time to think about it.  I had forgotten to stake the screw heads.  I used an old tip from an impact driver set.  Worked great.


I torque the rotor bolt to 60 ft. lbs. according to the specs.  Then I thought about it, that’s probably the torque for the 12mm bolt.  Should I have torque it to the spec for a 10mm bolt (25 in. lbs.)?  I left it for now and dropped it in the cases with new chains.

[markb]

I've been thinking about the rotor bolt torque and I would really like someone to weigh in on this.  The chart I use is out of a Honda manual.  You can check it out but it's not a great image.  It shows a 10mm bolt at 21.7-28.9 ft. lbs. and the rotor bolt at 57.9-65.2 ft. lbs. which I assume is the 12mm variety.  Anyone have an opinion on this?  I’m concerned I might have over-torqued the bolt but I don’t want it coming loose either.