GDB Inline 4 Cylinder OHV I.C.

[b.lindsey]

Good to see an update Bob. Looks like some of this recent weather has been keeping you busy outside the shop, but happy to see you are finding some shop time as well.

Bill

[90LX_Notch]

Thanks Bill.  Yes, the weather has been keeping us busy. 

I have a couple of other pictures that I need to post.

-Bob

[90LX_Notch]

Block continued-

The water jackets were plunged with a .375 end mill to rough them out.  As above, a .100 ledge was left.  Then a .250 long reach end mill was used to finish the walls.  Next, a .250 ball end mill with a .094 radius was used to finish each pocket.  This created the .094 radius that transitions from the floor to each wall.

-Bob

[90LX_Notch]

Block continued-

The block has 10 holes for the head bolts that have a .099 radius brow around them within the water jacket.  The only way that I could do this was with the rotary table. 

The rotary table was centered to the spindle and my universal fixture plate was then clamped to it.  The setup procedure was as follows: a center was placed in the spindle and lowered into a bolt hole.  The block was then clamped to the fixture plate.  The block was then indicated parallel to the x axis.  A .250 diameter long reach end mill was used.   X was adjusted .240 (.099R+1/2 the endmill diameter + .016) for the first pass.   The endmill was plunged to a depth of .946 and brow was cut.  Next, X was adjusted to .224 for the final pass.

A .250 diameter endmill with a .090 corner radius was next used at a depth of 1.040. X was adjusted to .225 so the endmill would not rub the wall as it cut the .090 radius at the bottom of the water jacket.

What I love about this, is no one will ever see all this work once the top plate is in place with the cylinders pressed in.  I could have left everything with sharp corners; but, that would not have helped me improve my skill level which is what this is all about.

-Bob

[Vixen]

Some nice work there, all done the traditional way by turning the handles. 

Mike

[Dave Otto]

Nice work Bob, enjoyed the update!

Dave

[nj111]

Impressive rotary table work, thank you for these posts. All looks spot on!   Also, love the indicator holder - I shall be copying that idea. Nick

[gbritnell]

Good to see you getting more time on the build. It's coming along great! The block is the most time consuming part of the build.
gbritnell

[michelko]

Unbelievable what can be done with conventional machines 

Regards Michael

[awake]

Wow! That is incredible work. How many hours did it take? Or should that be how many days? (If I were attempting this, I'm certain it would be, how many weeks!)

[Roger B]

Very nicely done    That's a lot of swarf 

[90LX_Notch]

Wow, thank you all for your kind words.

nj111- That holder also slips onto the spindle of the mill to allow indicating without removing a tool.

George- Yes it is.  A lot of planning involved along with all of the machining.  The head will eat a lot of time also.

awake- Each hole took around a half of an hour once I got the process down.  I have over 100 hours into the block.

[90LX_Notch]

Block continued-

I've been deemed an essential employee so progress continues at slow pace.

The lifter pocket on the side of the block was milled using a 3/16 endmill.  The block was clamped to an angle plate for this operation.  Bolts that have been faced on the head were used like jack screws.  They were used with tee-nuts in the mill's tee-slot along with a jam nut to add rigidity to the setup.  The block was then flipped over and the water passage hole was drilled along with the 0-80 mounting holes for the coolant tube.  Next, the location for the crankcase breather was layed out on the 22 degree slope of the block using a spring loaded tap guide as a scribe.

-Bob

[Zephyrin]

incredible skills with the rotary table, for doing this pocket, certainly a lot of concentration while turning the wheels...

[90LX_Notch]

Thank you Zephyrin.  I wouldn't say incredible, just alot of planning with the rotary table.

-Bob