what does this mean?
Thread Starter
Heel & Toe
Joined: Jul 2007
Posts: 15
Likes: 0
From: pittsburgh pennsylvania
what does this mean?
what does it mean if heads get a "five angle valve job" or three or whatever...? what does this mean? also.. what does it mean to have the heads "milled"? thanks,
matt
matt
Melting Slicks
Joined: Oct 2005
Posts: 3,178
Likes: 5
From: Daleville Indiana
St. Jude Donor '08
Milling of a head refers to machining the flat surface of the head to make it flat and to move the combustion chambers closer to the piston top for more compression. The three angle valve job is when the valve seat is cut from the stock 45-70 degree to a 30-45-60 cut. I don't know about the five but I would think the valve seat is smoothed more.
http://www.chevyhiperformance.com/te...les/index.html
http://www.chevyhiperformance.com/te...les/index.html
Le Mans Master
Joined: Oct 2004
Posts: 5,841
Likes: 19
From: CLT, North Carolina
5 angles is a sales ploy to sell you two more than you need or what the heads will want anyway. 45 (LT1/LT4) is the stock valve seat angle. Top cut it with a 30 to establish seat diameter. Bottom cut it with a 60 to narrow seat to the desired width. Stick with the 60.
