Milling heads
Thread Starter
On The Tree
Joined: Jan 2016
Posts: 136
Likes: 4
Milling heads Hi all,
Considering milling some 853 heads for fun. We have a mill at work and my boss is experienced with it, but hasn't done any engine work. What is the process for putting a head in a mill ? I'm assuming we use something to level it, perhaps a dial indicator. Any tips/suggestions ?
Considering milling some 853 heads for fun. We have a mill at work and my boss is experienced with it, but hasn't done any engine work. What is the process for putting a head in a mill ? I'm assuming we use something to level it, perhaps a dial indicator. Any tips/suggestions ?
Thread Starter
On The Tree
Joined: Jan 2016
Posts: 136
Likes: 4
Perhaps I worded my question poorly. Obviously the head has to be bolted to the table with some standoffs. If the head itself has any twist in it, then how can we know which part of the head to use as a datum when setting up the mill ? Is this even a consideration?
i've tried to do heads on a bridgeport mill, it doesn't work really well. the spindle just wasnt designed to swing 12" of cutter around.
as far as dialing them in, you could do it several ways. cc the chambers and dial the set up to equalize them. you could angle milling for less valve shrouding. im pretty sure most shops just throw it up there on three points and bolt it down and mill it flat enough to seal a headgasket.
as far as dialing them in, you could do it several ways. cc the chambers and dial the set up to equalize them. you could angle milling for less valve shrouding. im pretty sure most shops just throw it up there on three points and bolt it down and mill it flat enough to seal a headgasket.
I've seen some guys that have had success using a knee mill (think bridge port). The biggest thing when doing this is making sure that your head fixture is rock solid and that you have a machine that is in good working order. When swinging such a large cutting tool, it can only exacerbate the problem with a "loose machine".
The dedicated machines used at engine shops are really the way to go. Even if you find an old school guy still using a stone fixture, your probably better off than trying to do the knee mill thing with no experience. If the machine shop has converted to a CBN cutter even better. If not and they still use the stones, just have them slow the machine travel speed down as slow as it will go to get a good finish for mls gaskets. Typically you "dial" about .0025" for each pass (when using stones). Once the head is cleaned up. I'll usually dial a lighter .0015" final and make two passes for an even smoother finish. When I did this for a living I think the machine I was using was a Berco?
The dedicated machines used at engine shops are really the way to go. Even if you find an old school guy still using a stone fixture, your probably better off than trying to do the knee mill thing with no experience. If the machine shop has converted to a CBN cutter even better. If not and they still use the stones, just have them slow the machine travel speed down as slow as it will go to get a good finish for mls gaskets. Typically you "dial" about .0025" for each pass (when using stones). Once the head is cleaned up. I'll usually dial a lighter .0015" final and make two passes for an even smoother finish. When I did this for a living I think the machine I was using was a Berco?
