Cylinder head machining

[numancia]

Can somebody provide information about how cylinder heads are machined?
I am above all interested in the machinings and operations required to install the valve guides, valve seats, control cut and so on.
I understand that the way this is done may depend on the OEM considered but is there an usual way to do it?

 

[BrianPetersen]

Big-volume heads go through huge dedicated-purpose multi-station transfer lines. Each station on the transfer line does one specific machining or assembly operation.

 

[numancia]

Thanks.
I am particularly interested in knowing in which order the machinings for the valve guides, valve seats and control cuts are performed.
Any info concerning this point?

 

[00600]

I'm not sure how the OEMs do it, but from an automotive machinist/rebuilder point of view, you square the deck, drill/ream/hone the guides, cut/grind/lap the valve seats, and machine the spring seats.

The OEM has to deal with squaring, drilling, and tapping the acessory mounting bosses, along with drilling and spotfacing the headbolt holes.

I've seen video of purpouse built machining centers that drilled, reamed, tapped and spotfaced several sets (4-8) of heads in one cycle (I'm glad I don't have the job of setting all those tools or re-timing them).

 

[howboycat]

I suggest getting the sunnen engine rebuild book. It will get you the basics. try amazon.com it's about $100.

 

[numancia]

Thank you for this suggestion, cyclecyko. I had a look on Amazon.com. I feel this book describes the machining of small series or prototype cylinder heads and is rather intended for "serious enthusiasts". Am I correct? What I am interested on is rather how big volume cylinder heads are produced and machined. Do you still think that this book is the proper one?

 

[evelrod]

At the risk of being too simplistic...I've worked at a couple GM plants and one Ford plant and, I have seen VIP tours going through. Perhaps, with a little BS*, you might arrange a tour through an engine assembly plant?

Rod

(*)
"If ya can't dazzle 'em with brilliance, baffle 'em with with bull s---"!

 

[Tmoose]

Mostly off topic, but For a while I worked for POPE Corporation, who made precision machine tool spindles. Most customers directly or indirectly were GM, Ford and Chrysler. A big customer was Sometimes Lamb Technicon who made "transfer lines" to machine engine parts. Sometimes They put as many spindles as we could physically stuff together at each station, either individually or in one "block".

http://www.setcousa.com/images/Spindles/cluster_color_125px.jpg

Some spindles would be fitted with complicated tooling that flipped out an insert for a second operation, for instance a rough cut during the forward stroke, then a finish cut on the return stroke, which also has the advantage of ensuring concentricity because a second "set up" was not involved.

Positionally Related features were sometimes done with a (complicated danged) water cooled (for thermal and thus dimensional stability) block spindle. For instance, the main bearing line, cam line, and bell housing dowel holes would sometimes be done with one block spindle, so those features would be (very!) consistently located in every engine.