Does anyone know the best way to center the plate/housing before you mill/drill out the holes for the pins.



Can you center off the stock bolt holes???? https://www.nopistons.com/forums/pub...1047683561.gif





Thanks



GregW

you do this on a mill, not a drill press....that should bring your accuraccy up a bit

Aww darn you mean I cant use my dewalt? https://www.nopistons.com/forums/pub...1047683785.gif



I know its done on a mill. You can still drill using a mill. I assume you would use a drill bit for the housings and a off-centerd bit for the plates.



Question still is: What are you guys centering off of. https://www.nopistons.com/forums/pub...1047683561.gif

No... you should drill with a bit 1/32 smaller than the hole size you want. Then you want to finish up with a reemer of the exact size hole you want at 150 rpms to 200 rpms with lots of oil and a slow feed rate.



You can probably centre off the "centre hole" where the Eshaft goes through, do some calcs, and you can then double check it using the "bolt holes"



Don't forget to centre drill first before using a drill bit on it.

Bahhh, thanks for the "advice" but I really am only concerned with centering. Thats ALL I want to know. Read my original post.



So, once again, for those of you who have pinned engines or have pinned an engine yourself. How do you center up the peice.



Thanks



Gregory

if you have a readout on the mill you could use the factory dowel holes to datum from, I dont think that the center plate has a machined hole for the e shaft. Im not sure how you would center the holes as you would want to use the front plate as a reference and these holes are already tapped maybe turn down a bar with a shoulder so you can screw it onto the plate and measure from it

Ahhhhh-ha!



Make a template out of sheet metal using the stock dowel pins to get the same spot on each plate. Ill post some pics when its done!



https://www.nopistons.com/forums/pub...DIR#>/cool.png



GregW

going to be tackling this one also.. want to dowl a s4 na block for lots of boost... can't beat it.... Going to try to mill the plate's like so.... back plate on mill table, then housing then middle plate.. all dowled together and clamped use a valve guide cutter(propersized) they have a cenetered head sized for the stock tension hole size then cut for dowel pin size... (hard to expalin easy to see). then take front plate and 2nd housing with another middle plate dowel together( the first middle plate has already been cutt??) and do the same.... figure I'd use the larger bossed tension structure around the combustion side and 1 across. on intake exhaust side.... there are a couple pics floating around....of this done....

i've never machined dowel pins. BUt I would imagine if you made some sorta jig that utilized the stock bolt holes. Hvae the jig clamped down to the bed real tight, you could just bolt and unbolt the plates and that should ensure the pins line up...

Some people have found better way of strengthening without pinning. It can be repeated on any engine without all the machine work.



Look to the australian forums for some ideas.

However, good luck with this project.