Bob Shores Pacifier

[Dreeves]

Got to love corian for fixtures. I use it all the time.  I have a friend who does tops with it and get cut offs.  Great job on the engine.

Dave

[stevehuckss396]

Got to love corian for fixtures. I use it all the time.  I have a friend who does tops with it and get cut offs.  Great job on the engine.

Dave

I use it for everything. My pal Jimmy gets cuts from a local cabinet shop. I use it for fixtures, engine display bases, and I have even built entire engines out of it. I also have enough white to make 2000 spark plug insulators.

These were gifts to the guy who gives us the cuts.

[stevehuckss396]

Hello Race fans!

Had the day off work today. Boss felt it was unsafe to work with the snowy weather. Wish he would have told me before I made the 60 mile round trip.



Drilled a few holes to day!




Then made some pockets for some bearings.




Then the part was rotated to the other side. The screw holes were counterbored. When the part was profiled
I had setup for conventional milling instead of climb so I will have some hand work to do to make this part pretty.




These bearings are 1/8 X 1/4. They slip in and out, not pressed in.

[stevehuckss396]

Next part went better.


Turned a piece of al-you-mini-um down to the correct diameter.




Tipped the piece up in the mill and found center.





Drilled some more holes. The hole on the right is about an inch deep as it goes thru the entire part.




More holes and then the pockets for the other bearings and a pocket for an o-ring seal.





The part was cut from the stock and faced to the proper dimension. The paper keeps me from getting jaw
marks in the finished surface.




Before I finished the nose I milled a small flat on the side. Easier to hold right now.





The hole was drilled thru the top portion of the piece. I then stuck an endmill thru to create a flat spot
before continuing with the drilled hole.





The part was then inserted into the 4 jaw and was setup on the thru hole. The nose was completed
and another bearing pocket machined into the piece.




The #0-80 holes were tapped and the 2 parts joined.

[stevehuckss396]

I made this little gear holder when I built the Peewee. Later I used it for the Demon and now I have it for this project.
The screw is just snugged as the fit of the gear in the holder is nice and snug.




Two gears are cut from the stock, faced to size, drilled, and reamed.




The shafts were cut from drill rod. The gears are pressed onto the shafts. Then bearings are pressed onto the
short shaft and the rear bearing is pressed onto the long shaft. The front of the long shaft is polished with
some 320 grit paper so the front bearing slips on.





The bearing is pressed into the nose of the body and the shafts are inserted. The drawing calls for aluminum
fittings but I had some drill rod handy so they are steel. The pulley was made from steel also.






Water Pump, she is done!




The shaft looked a little short. Turns out I made the pulley .020 wider than the drawing so the shaft is right
where it should be. I have to take it apart to put the o-ring in it so I'll fix the pulley at that time.

[stevehuckss396]

The Bob Shores version of this pump just has reamed bores for the shafts to ride in. They don't last very long even if the shafts are hardened drill blanks and the body is bronze. I redesigned the pump to use bearings and also added the o-ring to seal the thru shaft. I made a similar design for the Demon and no leaks so I thought it would be best to do it here. While it is an updated pump it still looks exactly like the shores design. Nobody will be able to tell if you build it in brass.

[b.lindsey]

Moving right along Steve!!  Any idea when the replacement castings will be poured? The water pump looks fantastic!!

Bill

[stevehuckss396]

Moving right along Steve!!  Any idea when the replacement castings will be poured? The water pump looks fantastic!!

Bill

No I dont. I have a fair idea that things will work out OK so i'm going to press on and when they get here I will be light years ahead. If they don't i'll have a pile of parts for sale.

[Brian Rupnow]

Steve--I haven't commented in very many of your threads, because I am in awe of what you do. I think you are a very talented fellow, and it shows up in the complexity and beauty of the machinery you build. I will follow this build, because it is interesting and I always learn something from your posts.----Brian

[stevehuckss396]

Steve--I haven't commented in very many of your threads, because I am in awe of what you do. I think you are a very talented fellow, and it shows up in the complexity and beauty of the machinery you build. I will follow this build, because it is interesting and I always learn something from your posts.----Brian

Thanks Brian! I appreciate the kind words. Hope I can live up to them on this one.

[Don1966]

Oh! I like that Steve you always make it look so simple.

Don

[stevehuckss396]

Well this one is a dumb move. If it works out good I'll be way a head and if not, full day in the toilet.


2 Blocks squared and to size. They were supposed to be 3.649 so I rounded to 3.650. I will do the same on the block . . . hopefully.




I was taught to drill hole pattern from the mating surfaces so the bottom of the part is facing up. The hole pattern is spot drilled because these need to be accurate. Then the holes drilled.




The depth of the holes for the valve cage were measured from the deck surface so I figured it best to put them in now. Again spot drill, drill, and ream.




Then with a ¾ inch end mill I but the combustion chambers in with a very slow plunge.




The bottom being complete the part was rotated to the top and the counter bores completed.




Again the part rotated to the exhaust surface. The holes to bolt the exhaust are drilled. I also plunge an end mill into the part where the exhaust port will be. It really doesn't do much other than serve as an alignment tool to get the port drilled in the correct spot.




The intake side is done the same way.




Now here's the good part. Set the part up at the correct angle. With an end mill around the size of the drill size, mill a flat spot in the center of the pre-made port. With the naked eye you can center up get within a few thou of where you need to be. If you have never done this try it. Makes locating the port real easy.






The holes are drilled for mounting the rocker tower.




The sparkplug holes are not to bad. I located the holes by finding the front edge of the head and coming over to center. A line was scribed where the edge of the end mill needed to be and I moved over to it carefully until I felt I was in the correct spot and plunged to the correct depth. The holes were spotted and drilled. I rarely do this but I used the spindle to align the tap and threaded the holes. This is one of those times where it is worth the extra effort. The base of the plug needs to seal against the surface of the head so alignment is critical.




The only thing left was to run an end mill across the top of the head to create some ribs. I went to the trouble because If Bob would have made a match plate for the heads I believe he would have added the feature.






I didn't cover the rocker towers. They are just basic milling of some ¼ inch stock with a few holes.

[stevehuckss396]

I tried a few different things to day and this one seemed the easiest. So here goes. Pictures are real bad. The camera could not decide what to focus on so it focused on nothing.



5/16 drill rod chucked and I left about 3/8 inch longer stem than needed. I wanted to eliminate most of the taper so I center drilled it.




Then the stem was turned down to between .126 and .125. It was nice with the center as the taper was only .0003 in over an inch. Then with some 320 sand paper the stem was polished to .1245 to .1240. This takes a little time but if care is used you can get the entire length of the stem well within the standard I set for myself, but not always. Just for reference I didn't count but I think I pitched about 5 of them. There was one that had a .1239 spot that I kept because it was up by the head and that part of the stem is in the valve cage.

Then I measured from the back of the head to the top of the stem and put a small groove to mark it. Then moved over to cut the groove for the retaining clip.





Once all 8 were done I put a larger cutoff tool in and cut a chamfer at the top and parted them off leaving the finished stem.





The part was then rotated and inserted into a collet. The head was cut to diameter, the head was faced, and the angle cut in that order. The thickness of the head was measured again from the back of the head so I am less than .005 off on my length. I'll take 8 of those please!




Some folks think i'm nuts but thats it. I install them and game over. I don't lapp them and here's why. I have a super nice finish on my valve cages. The finish on the valve angles is real nice also. If everything is machined well and all diameters are concentric, they will seal. I believe!, but have no scientific data to back it up, that most people who lapp there valves make them worse because they ruin the nice finish by using too course a compound.

Here's how I test them. I put them in the head and try to start the engine. If it starts and runs well after a few days of tuning, they are sealed. If I have a problem and need to take a look at the heads I will order some 2500 grit compound and try to polish the seats to a mirror finish. I have seen other builders try compound from the auto parts and it makes them worse.

Drop them in and try them before you try to fix something that may not be wrong.

Just saying.

Recognize the shaft anybody. . . . . . anybody . . . .










Heres whats left!

[b.lindsey]

Looks like a productive and successful day in the shop to me Steve!!  Nice work!!

Bill

[stevehuckss396]

Looks like I have monday and tuesday off so I might get the heads done by the end of next week.