head port work

[Econoline]

Silver sharpy outline of the exhaust gasket holes. I didn't go out all the way to the edge, read it's better if the head side of the ports is a little smaller than the header side of the ports. Seemed good to leave a little meat on there as well. And 4 or 5 hr's was after already doing this to another head then finding a crack 2/3 through getting it ported So I had a little practice already. Btw, Chad, I looked and I used 60 grit rolls on the intakes and 60 then 120 on the exhaust side. And fyi, they were the "premium" 3m rolls, tapered 747D's


And don't get too aggressive, watch out for this, scroll about half way down....

http://vintage-vans.forumotion.com/t36914-started-on-65-truck

 

[wsa111]

To prevent combustion chamber shrouding the intake valve, find a machine shop with a serta valve seat machine & the shop can take the chamber out to close to the headgasket seal while cutting the seats & the bowl below the valve all in one pass.
Then you can mill the head to get the proper cc's.

 

[chad]

Thanks to Seth & Bill.

"…Then...mill the head …"
The machinist did "port averaging" with a machine (I assume it has ) multiple cutters. It musta went down & machined all @ once takin off the 'highs' & missin the 'lows'. He would not CC. I can't aforde to go back to the machine shop. Yrs down the rd, if ever, the '69 "M" head I have will B wrked but I will have more knowledge about all of this and push more for MY wishes (have the knowledge to push back, seek better outcomes, etc).

That Van site is a great 1. They send me birthday wiahes. I see (frm the pic) what happened and cringe.
Took note of yer abrasives,
Again thanks!

 

[Econoline]

My machinist did something like Bill is talking about on the exhaust side, if you look at the finished head the exhaust port area in the chamber has been taken all the way out to near the sealing ring of the gasket.

 

[BCOWANWHEELS]

that's what I have to get done only on the intake and exh . valve areas because of the 1.5 exh. and 1.84 int. valve size. gpnna take it out to where head gasket starts approx. then mirror polish the chambers. I,ll gain cc,s but I can make up for it with custom pistons.

 

[Econoline]

That's a 1.467" 144 intake valve there for the exhaust

 

[chad]

"...Bill is talking about on the exhaust side…"
ok, so that's @ the smaller valve. Looks like something might have been done (similarly) to the intake side, just not as radical (cuz it's an 'arc' on a larger circle? or cuz it's intake?) Is this the "unshrouding the valves"?
Again too late (expensive too) 2 go back to machinest. What if I did that by hand w/my lill burrrrr? No can do cuz of need for accuracy?

Or is 'unshroud' the (in this pic) unseen wrk behind the valve where the embossed area around the stem is greatly reduced (eliminated)?

Thanks as all ways ~

 

[wsa111]

"...Bill is talking about on the exhaust side…"
ok, so that's @ the smaller valve. Looks like something might have been done (similarly) to the intake side, just not as radical (cuz it's an 'arc' on a larger circle? or cuz it's intake?) Is this the "unshrouding the valves"?
Again too late (expensive too) 2 go back to machinest. What if I did that by hand w/my lill burrrrr? No can do cuz of need for accuracy?

Or is 'unshroud' the (in this pic) unseen wrk behind the valve where the embossed area around the stem is greatly reduced (eliminated)?

Thanks as all ways ~

Chad, i was referring to the intake side, but the exhaust side also looks good. Bill