?? Log ready for Machinist?

[LameHoof65]

Called a couple of local machinist's both said they could do a mill, 3 angle valve job put the Valves, Seals, and Springs in for about $120.00. Sounds real good to me, but then I have never had this done before. I am thinking about leaving the stock valves in the head and changing out the springs, retainers and going to the chrome moly pushrods. I am looking at putting a dual pattern high lift cam in as well and this leads me to my question/s. Do I need to invest in a roller rocker and/or something that would give me higher lift or can I keep my standard rocker. This is not the head I am trying to fab for the fi, but the one I plan to use with the Holley 500/2300 setup. I want performance but this is only an interim upgrade so I don't want to over do it $$$ wise. I haven't CC'd this head yet and I don't really know it's quality...One of the machinists stated that he would mag flux & completely clean the head before starting the rebuild. I would like to put it at about 9.5 to 10:1 on the compression but no more. And finally, because I am not planning on reving over 6000 any time soon do you all think this setup will hold up?? I know in the Fordsix handbook Ak apparently used the original springs with T/C'd engines with about a .030 shim and he could get it to withstand a 6000 rev... I am not sure which cam but something around 268/270 duration I am not sure about the lift either... but I want it to pull strong through about 1500 to 5000. Help me out---I am in over my head here.

 

[Hot 6t Falcon]

Darwin,

Even if the water is over your head, you seem to be swimming just fine. You have a GOOD plan.

All of the things you're about to do are tried and true. The stock valves and rockers are just fine. If you can find a set of junk yard adjustable rockers from a 144 use them (you'll need the pushrod too).

Hydraulic lifters will limit you, and everyone else too, to about 5500-6000 rpm. They will pump up and hold the valves open. They are a good limiting factor so you don't over rev. EVERYBODY that has hydraulic lifters - whether in a stock 289 or the wildest 351 ever created has the same limitation with hydraulic lifters. They are a good thing.

Have the machinist back cut the intake valves too. I don't recommend backkcutting the exhaust valves in a street engine that you expect to be reliable and live a long life. For racing, or a 5000 mile motor, cut the exhaust too. Read the post in the high tech section about porting and backcutting.

Here's one more spot you can get really intimate with the cylinder head. When the head is disassembled, cleaned, and checked for cracks, stick you finger in the intake valve hole as far as you can and feel around for flashing. When the two halves of the head are cast together there can be a 1/4 lip of flashing way up in there. Obviously a 1/4 inch obstruction in the port is NOT good for flow, grind it out of there.

CC it after it has been cleaned. Before it is milled. Then figure abut 2.3 cc for every .010 milled. Use the compression calulator on my web site (in my signature) to figure in changes. the calculator is fun to play with once you get the hang of it. I say to stay between 9.0 and 9.3 (maybe 9.5 tops) compression otherwise you'll be fighting pinging and using up very expensive premium gas and octane additives.

That cam will do you fine. The two barrel will let it breathe.

Good Luck,