Flathead V-8

[Coopertje]

Outstanding work George! Please keep continuing your work of art here, its a great inspiration to me and I am sure to many of us here!

Thanks for efforts and time, regards Jeroen

[gbritnell]

Hi Roger,
The joint is so tight that I think when the head bolts pull it down it won't leak. If it does I will put a very thing layer of a non-hardening sealer on it. I have used this sealer for years while working on motorcycle engines. It's light gray in color and will squeeze out to a very thin layer when clamped.
gbritnell

[gbritnell]

The next part was the front timing cover. This also incorporates a cylindrical tube for the distributor.
I started out by squaring up a piece of aluminum. It was then put in the lathe to cut the recess in the rear. From the lathe it was back to the mill to drill and ream the inside of the distributor tube. As with most of the parts a fixture plate was created for the remaining machining.
The mounting holes were tapped rather than clearance drilled. This would allow the part to be mounted to the fixture plate.
The rotary table was set up and indicated and the part was mounted, indicated and clamped.
I made a step-off chart to create the circular outer shape of the tube and started milling with a ball nosed mill.

You will notice in the picture that there is a knurled ring at the top of the end mill. In most cases I don't like working with collets for several reasons so I use regular R-8 holders. I don't know about you but I have found that the shank diameters of end mills can vary by almost .0005. It doesn't sound like much but when you tighten the end mill with a set screw it can throw it off center thereby altering the cut dimension. I generally leave a .50 R-8 holder in the spindle. I have then made 3 different sized sleeves, one .3754, one .375 and one .3747. This allows me to slip them in and out of the .50 holder and accommodate the different shank sizes.

[gbritnell]

Now using the rotary table I started cutting the outside shape of the cover.

[gbritnell]

I presume the original part was a die cast piece and had stiffening ribs added to it so I'm trying to replicate the cover as closely as possible. The main hub in the center has a large radius on the corner to follow the inner shape and the ribs are tangent to the curved surface and splay out to the outer edges of the cover. To machine these I first roughed the radius, staying away from the ribs and then went back and qualified the thickness of each rib. From there I had a surface to work to much like doing the bellhousing so I could then recut the radial shape and bump up against each rib.

[gbritnell]

With all the shapes cut from the main centerline the part was shifted to the crankshaft hole. The outside shape of the boss was stepped conically and blended into the base of the cover.
The front cover and oil pan will have an O ring seal and for cutting that diameter I needed to make my own cutter. This is the usual drill rod, machined, hardened and honed tool. The cutter was made to the exact size needed so all I had to do was move in to the centerline and the cut was finished.

[gbritnell]

Once again the rotary table was removed and the vise set up. The part was put in the vise with a rod sticking out of the distributor boss. This was used to indicate the part vertical. The hole was then indicated true and using a boring bar turning backwards I cleaned up the outside shape of the boss taking it down till it touched the outer flange of the cover.

[gbritnell]

The final three pictures show the cover mounted on the front of the block.
gbritnell

[gary hart]

Wow!  and double Wow!!

[jschoenly]

Just Awesome!  Keep up the great work.  Love those Flatties!

[gbritnell]

The oil pan, similar to the bellhousing ended up with more chips in the pan than material left on the part. There were no real complex shapes on this piece, not like the bellhousing or timing cover but it still required multiple operations to complete it.

I started with a large rectangular bar of aluminum. This was cut to size, squared and faced leaving my usual .02 per face for cleanup. With the whole inside needing to be hollowed out there was no real easy way given the size and rigidness of my mill so I started out by drilling out as much stock as possible. I started with a pilot drill and increased up to .75 diameter. There are 3 levels in the pan so the depth of the drills was such that I left a good safety margin in the bottom. $46.00 plus $14.00 shipping isn't something you want to do too many times.

[gbritnell]

The next step was to go in with a .50 ball mill and start removing the remaining stock. Once I had the bulk of the material removed I then went around the inside perimeter to set a qualifying dimension.
The pan rail mounting holes were drilled and some tapped for mounting to the fixture plate.

[gbritnell]

From this point some of the cuts would have to be made more than once due to the fact that it would take way too long to calculate each tangent point. The most complex area is around the front of the pan. You have the main side walls which would end up as 2 degrees, the angular walls which tape towards the front and the bottom angular surface which goes from the first depth up to the front seal area.
I started by making a step-off chart and with the inside flange thickness established I stepped down to the front level. I also stepped the large radii on the inside corners.

[gbritnell]

The next area to be roughed out was the cavity around where the oil pump would go.

[gbritnell]

With all the surfaces cut relatively close I tilted the mill head on 2 degrees. I don't often do this as I usually work from my angle table but the pan was too long to fit the angle table so the mill vise was set up longwise (parallel to X) the part clamped and the side walls cut. I marked all the corner fillets with a permanent ink marker so as I was cutting the 2 degree walls I could see when I was at the tangent point.
You can see in this picture that orientation of the vise and part to finish cut the 2 degree walls.