MS LIBERTY a Wild Weasel's belly tank

[SPARKY]

ready to drill after lunch.

I have been told the most folks do not drill and tap the block for bell housing bolt that gm did not drill on the LS block---opinions --comments

[SPARKY]

need to get me a good 5/8" drill bit and some 5/8" round stock for the extended pins  then to Hughes for the pump drive kit for the LS to run with out a converter..

[Jack Gifford]

If those 5/8" pins perform the alignment of engine-to-trans, then you'd need the precision of a reamer (and a squaring jig), rather than just a drilled hole.

[SPARKY]

Thanks for the heads up Jack-- back to the drawing board.   I went to great lengths to square up the drill press table but I will research it more.

[fordboy628]

If you have access to a vertical mill, tram it up(square it), and use a reamer to finish the holes.   WAY more accurate than a drill press.

Use a hardened and ground dowel pin for location, press fit in one part, slight (.0005"/.001") clearance in the mating part.

Just my 2 cents
F/B

[SPARKY]

Do have a mill should be tram ---learned a new word---  when I was out buying 5/8 stock  ran into Marty he suggested to use the mill and a 5/8" end mill

[manta22]

Bill;

An end mill will cut a hole that is slightly larger than the diameter of the end mill. You want to drill a hole a few thousandths smaller than 5/8" and use a reamer as others have suggested.

Regards, Neil  Tucson, AZ

[Rex Schimmer]

Basic rule of reaming holes. If you run the reamer into the hole and stop it before you pull it out you will have a press fit hole. If you run the reamer in and out, while turning, you will have a slip fit hole. Works for me.

Rex

[SPARKY]

question  if  the trans and the eng are the ones to be aligned why would I want a press fit in a plate that is to be sandwiched between the to mounting surfaces?  IMNTK

[Jack Gifford]

To answer your question: a slip fit in both pieces doesn't accomplish as precise alignment as a single slip fit (press fit in the other piece).
What is the overall dowelling scheme- two pins to locate block-to-plate and another two for plate-to-trans? Or simply two pins that extend all the way from engine to trans?

[SPARKY]

There are 6 bolts and two locator pins



           o       o

     o                    o

     0                     0

     o                     o


               

[Rex Schimmer]

Sparky,  If the plate is just a spacer they you are right that you probably only need to press fit into the block and simply have a good quality drilled hole for the pin through the plate which should be at max about .005 over size and if you make the bolt holes 1/32 inch over size the plate should be relatively easy to install and all of the bolts should line up. Note that if the locating dowels are pressed into a blind hole in the engine block you would be ahead to have a through hole drilled through them and have the end that sticks out drilled and tapped for a puller. Even though dowel pins are hardened the larger ones are only hard on the outside and if you grind the end a little you can drill them. The hole allows the pin to be driven completely into the hole with out trapping air which will not leak out past the press fit.            Rex

[Stan Back]

Do the best you can.  Drill 'em, mill 'em, ream 'em, whatever.  Don't tighten everything down, and then just tighten everything while it's running and let it self-align.  Works every time (usually).

Stan

[Peter Jack]

Do the best you can.  Drill 'em, mill 'em, ream 'em, whatever.  Don't tighten everything down, and then just tighten everything while it's running and let it self-align.  Works every time (usually).

Stan

Pete

[SPARKY]

And the winner is   SB