FP4NC Long Drilling Project (photo intense)

OK, working here on an interesting little project.
Came to me from another shop who is doing the majority of the work, but needed my help with some portion of the job.

Project is to complete an old stock , never machined, engine crankcase.
This is a block modeled after a Ford Model"B" , but done in aluminum.
This engine was done by "Pop Dreyer" in the mid 30's.
Dreyer was a pretty famous fixture around "Indy" for years , a prolific motorcycle side car racer till an accident that almost killed him.
"Pop" later became very active in circle track racing, building cars and engines.
At any rate, i have this block casting.....My primary focus here is to finish the main bearing bores,(line bore) fit bearings (Babbitt) and make the lower end functional.(rear seal, thrust, oil system)

Before i bore the main housings, i want to finish drilling all the oil feed holes for the mains (cross drill) and that means that i need to drill the main oil gallery (length of the block)
Here is the setup: Block placed on the machine table. Note table top has been rotated 90* to give a little extra length.
Head deck (where the block is resting) is surfaced., as is the pan rail, along with locating steps for the main bearing caps and threaded holes for the studs that secure the main caps.

Main bearing bores have been rough machined,by my FP4NC using a ball end mill and profiling the saddle.

First step here is to indicate the pan rail surface. Using the "tilt" of the "Tool Makers Table" the block is adjusted to indicate flat to the "Y" axis.
Because of the position of the block (will become clear later) i needed to extend the reach of my indicator....Here i am using some thick walled 1" tube held in a TG100 collet.
At the end of the tube i have a stepped plug that holds my indicator shank....



Note the piece of thin cardboard visible at the horizontal spindle.....It is set between the end flange of the spindle and the machine casting, then the quill is retracted to pinch the
cardboard, and make the spindle "stiff" to prevent any minor rotation that could affect my indicator readings.....A bit hokey, but it works.



With the pan rail set flat, i need to align the block so that the long axis is parallel with the "Y" .
Here i an using two studs form the mains as locating pins along with a long straight edge (shop built) 36" in length.
Again here i need to extend things in order to be able to do my indication.....
The line of the block is adjusted here by rotating the table....Gotta love that 2038, its just magic for this sort of stuff.

Also note: the accuracy here of the line derived using the main studs is less than perfect (not bad but not perfect) This is not really a problem for the task at hand as
i really just need a repeatable line that i can access from each end of the block....





With the block aligned the next task was to locate the position of the required long axis drilling. The vertical position was set off the pan rail. The horizontal position was set off the
straight edge....

Center drill, and initial pilot drilling......After spot facing the casting to begin so as to reduce drill wander when starting the hole....



More to follow.............................

Cheers Ross

Very nice! Instead of using the straightedge against the studs, why not align the C axis off the machined steps on the sides of the main cap mounts, or the surface near the "equator" (split plane) of the ball-milled saddles? Time for an HBM!

Some figures:
Length of the block overall: 24"
Ming oil gallery length:20.0"
Main gallery ID: 9/16"

I was able to easily source a 9/16" twist drill that was 15" long. Which would require the drilling to be run form both sides of the block in order to get the full length needed.....



Here i use the machine's quill to do the feeding. Because of the depth i need to retract the drill often to clear the chips....
Here is where the FP-NC shines....I use the MPG to do the retraction and and re-position for the next feed....
Little trick here: I retract the tool using the electronic hand wheel....and while i am moving the tool out of the cut, i also retract the quill, ready for the next feed.
But i do not retract the quill all the way....i leave it extended say about 1/2" or so....
When i return the tool into the hole for the next cut i feed in using the MPG till i see the quill move back a bit (handle moves) then i know i am at the beginning of my cut again....no
need to keep track of where you were at the end of the last cut...just bump the quill and start feeding again....





Photo above, reached the length limit for the drill....requiring the block to be rotated 180* to have access to the opposite end of the block.....

Alignment process is repeated...Block set flat to the "Y" and straight .
Location repeated using the same datum points.



Start of the hole from the second end faced before starting the drilling....Completed hole (light through) connected to first drilling smoothly with minimal joggle.
Hole tapped for pipe threads (3/8 NPT)



With the long drilling complete , the cross drillings that feed the mains need to be completed.

More to follow.......

Block is rotated 90*... Rotary table is rotated as well. Block aligned using the same tooling and datum's as used to align for the long drilling.

Cast surface is faced flat and long drilling to the center of the casting run.
Exit of the cross drilling is tapped for 1/8" NPT.



After all the cross drilling is done there needs to be a connecting drilling done from the center of the main saddle to intersect the cross drilling so as to feed the mains, in their center.
Problem is that the cross drilling is not on center to the main saddle.....the casting construction places the cross drilling displaced to the front or rear of the main center line...Its a physical
construction thing....So the connecting drilling must be angled to make the proper intersection at both the center of the main (front to rear) and the cross drilling....
Note the paint park on the long drill to set my needed depth.

Second, the connecting drilling is different for each main....as each are different in width and the displacement off center by the cross drilling varies.
To solve this,each main saddle and cross drilling were drawn in "SurfCam" to derive the proper connecting drill angle.....

A straight down shallow drilling was first run into each main saddle so as to give the angle drilling a foothold to start...
Then the angle drilling run in.....







Final step here was the machining of bores for dowels.
The rough profile cuts of the main housing saddles is clearly visible here.....



Small side note here: The dowel bore are machined using an end mill and circular interpolation, no drilling....leaves a flat bottom bore that i can control the size using cutter comp to get the fit i want...


Cheers Ross

Rich:
Choose the studs because it was easier, and as discussed i was not overly concerned about the exact alignment, just a reliant datum that i could replicate at both ends of the case.
The studs work out nicely as the straight edge fit nicely on top of the cap locating tabs....
Using just two studs , one at each end eliminated any potential arguments that having 5 points of contact along the length of the motor would induce (i did not machine the main cap registers)

Cheers Ross

rklopp said:

Very nice! Instead of using the straightedge against the studs, why not align the C axis off the machined steps on the sides of the main cap mounts, or the surface near the "equator" (split plane) of the ball-milled saddles? Time for an HBM!

Click to expand...

True crankshaft alignment is king... at least that my guess.

And I'm wrong... waited too long to hit respond and Ross comes in with the real info, is fun to speculate though.

To be sure the crank CL is king....
At present the rough profile of the main saddles was done by taking the average center line of the installed, not yet finished cylinder liners.
Giving a pretty good position of the rough saddle machining in specific at each end of the case...
Those bores will become the dial up for the boring bar on the Berco BC4 line boring machine....
Caps installed and the housings finish bored to give .0025" interference with the finished OD of the bronze shells of the main bearings....
Those in turn will be fitted with dowels to each main with "crush"set and the Babbitt bored to clearance for the crank (new) .

Once done, with the thrust finished, oil grooves and spreaders and clearance radii machined.....The crank will be fitted with all bearings...that then will become the truth teller....I will use the crank to align the case
to finish the front cover joint face, the idler bearing bores for the double overhead cam drive and on the opposite end the location for the bell housing register and surface of the rear of the case......

There is no real issue having the long center line of the crank not be perfect to the long center line through the cylinders.(yaw)..Best if it is, but lots of engines running that aren't in perfect line.
There is in fact a big problem if the cylinders are not perpendicular to the crank axis....That is critical and i spend the needed time checking this and making the necessary corrections.

Cheers Ross

I just love your story posts, Ross, please don't stop.
Nicely done, and great photos.

rklopp said:

Time for an HBM!

Click to expand...

I think he just needs a slightly bigger Deckel.

Interesting and well taken photos, thanks for posting, if I win the lottery , one of those green machines(the good green) is going in my shop


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“Little trick here: I retract the tool using the electronic hand wheel....and while i am moving the tool out of the cut, i also retract the quill, ready for the next feed.
But i do not retract the quill all the way....i leave it extended say about 1/2" or so....
When i return the tool into the hole for the next cut i feed in using the MPG till i see the quill move back a bit (handle moves) then i know i am at the beginning of my cut again....no
need to keep track of where you were at the end of the last cut...just bump the quill and start feeding again....”

Ross’ trick is worth repeating and stealing[emoji16]. It would work on a machine with a vertical quill, as long as the quill can be back-driven. That is not the case for the worm-driven quill on my Aciera F5. It does work on the F4 as long as the worm is disengaged. The F4 has both worm and rack quill feed.


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Ross

do you use gun drills with or w/o thru shank coolant for any application?

my concern was long shank twist drill drift

well, its crystal clear now, I absolutely need a Deckel... (the one Mud posted, obviously..) bastards!!

J:
No gun drilling cap. here...No through the spindle coolant sorry to say.
To start this drilling i used a parabolic drill of normal "jobber" length just a bit smaller than the gallery size....
I was worried about drift as well....the long drill was standard geometry twist drill.....was careful to not push the feed .
Cheers Ross