Head milling question

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Reinking
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Head milling question

Post #1 by Reinking » Mon Jul 02, 2018 8:51 pm

Got the head off my 170 at the shop and they have gotten around to checking it out an it is good. Told them I want a 3 angle grind on and new valves valve seals. When we got talking about milling the head I began to question my calculations. Original head gasket has a crush of about .022 and from what I understand the new head gasket has a crush of about .045. It seems at a minimum I need to take .023 off to maintain original compression. Would like to increase horsepower wherever possible and was thinking about taking a little more off to slightly increase compression but how much? Car is going to be a daily driver but would like a little more kick.

What would be the suggestions from those more knowledgable than I?

Thanks

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chad
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Head milling question - valves, ex.port surface, & to increase CR

Post #2 by chad » Tue Jul 03, 2018 8:51 am

don't 4get the back cut on (esp intake) valves (while @ it, no huge additional costs).

To answ ur Q: A standard (no need to do fine mathematics to achieve close tolerances and optimize power, switching pistons, etc) "stop point" many of us here have used is .090. However we add a bit for anomalies in varying heads and as a safety measure so .060 leaves room for error.

Done on head alone reduces combustion chamber sz - increasing CR. My guy hada unitized machine that then went in and equalized all chamber sizes simultaneously. Not something I knew he'd B doing...I asked 4 certain things he would not do & did not get answers to all my Qs on what he would do. Still - mostly happy.

Glad U got the exh manifold. Don't 4get to ck both it & the opposite mating surface for warpage B4 done @ machine shop. W/the pic I saw I'm betting ur head is in need of several passes.

Let me know of any other prt needs - mostly same deal, just pay shipping.
"Big thing is only make one change at a time. Change 2 or more things at a time it becomes difficult to figure which change helped or hurt" turbo2256b » 1/16/2017
Chad - '70 LUEB on '77 frame (i.e. PS, D44, trapezoidal BB 9", 4.11), 250, NV 3550 & DSII to B transplanted, "T" D20/PTO, 2" SL, 1" BL, 4 discs, 33"X15", etc. Seeking: Hydraulic gear motor for Koenig pto. chrlsful@aol.com (413) 259-1749

Reinking
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Re: Head milling question

Post #3 by Reinking » Tue Jul 03, 2018 9:48 am

Thanks Chad. I was think .060 was reasonable for what I am wanting to accomplish but when I mentioned it to the guy on the phone he seem a little surprised. Going to have the shop mill bathe the manifold side of the head and the manifold itself to tru everything up.

Thanks for the manifold, u get the check?

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Re: Head milling question

Post #4 by CZLN6 » Tue Jul 03, 2018 11:30 am

Howdy Reinking:

Another question you should be asking is what octane gas you plan to run. Trans and gearing will also be factors in selection CR. Given what you've told us, I'd suggest a mill cut of .050" to add CR and to compensate for a thicker head gasket. I'll be interested to hear what you end up doing and how it works out.

Adios, David
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http://www.falcon6handbook.com/

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Re: Head milling question

Post #5 by Reinking » Tue Jul 03, 2018 11:42 am

Thanks for the reply. Daily driver currently with a Ford-o-Matic 2 speed, trying to talk my son into going with a 3 speed, not sure about rearend gearing. It’s in a 63 Falcon Convertable.

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chad
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Re: Head milling question

Post #6 by chad » Tue Jul 03, 2018 12:58 pm

"...get the check..."
yes.
The mani is quite true. Ck w/straight edge'n U will C...

The .050 is a good target. It can B machined again in the distant future if U leave more meat than take off too much now.

All the planning should B done B4 prts leave the machine shop. Each component immagined, in place, optimal needs to meet best use. Then machined. David is suggesting further consideration B4 moving onto next sequence in the reassembly.

Have Fun!
"Big thing is only make one change at a time. Change 2 or more things at a time it becomes difficult to figure which change helped or hurt" turbo2256b » 1/16/2017
Chad - '70 LUEB on '77 frame (i.e. PS, D44, trapezoidal BB 9", 4.11), 250, NV 3550 & DSII to B transplanted, "T" D20/PTO, 2" SL, 1" BL, 4 discs, 33"X15", etc. Seeking: Hydraulic gear motor for Koenig pto. chrlsful@aol.com (413) 259-1749

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Re: Head milling question

Post #7 by Reinking » Tue Jul 03, 2018 6:30 pm

Manifold does look good, will only have the exhaust faced on the head. Just waiting for gasket set, thermostat, temp sending unit, head bolts and manifold bolts. Should I get washers foe the head bolts to make sure they don't bottom out?

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chad
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more head milling question

Post #8 by chad » Tue Jul 03, 2018 10:25 pm

all this info should B in "the Handbook". With all the suggestions on it's purchase round here I'm surprised any 1 missed informing U abt this great resource. Do U have it? If so P L E Z referr to it. There is so much in there I think it will bring U ahead of where U may be right now. U should have gotten a copy during ur planning stage Bcuz it seems U may miss out machining & prts pointers after the head leaves the machinist.
Let's hope not, that would B a shame. May B put things on hold 1st?

The Ford Six Cylinder Performance Handbook
"Big thing is only make one change at a time. Change 2 or more things at a time it becomes difficult to figure which change helped or hurt" turbo2256b » 1/16/2017
Chad - '70 LUEB on '77 frame (i.e. PS, D44, trapezoidal BB 9", 4.11), 250, NV 3550 & DSII to B transplanted, "T" D20/PTO, 2" SL, 1" BL, 4 discs, 33"X15", etc. Seeking: Hydraulic gear motor for Koenig pto. chrlsful@aol.com (413) 259-1749

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Re: Head milling question

Post #9 by chero1369 » Wed Jul 04, 2018 9:15 am

I highly recommend using comp cams viton valve seals.#520-16.If you are mechanicly inclined,you can do it yourself by using
C.C. cutter and a slow drill.
I just got so annoyed watching those umbrella seals flopping up and down,doing nothing.

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Re: Head milling question

Post #10 by CZLN6 » Wed Jul 04, 2018 10:48 am

Howdy Back Reinking:

Be sure to add a back cut on the intake valves, as Chad reminded. The back cut should be part of the valve job, while the valves are being faced.

Washers on the head bolts is a good idea. But, be sure to clean the bolt hole bottoms. Also lube the head bolts on install and tighten slowly, in sequence and in stages.

The valve seals chero mentioned are also a good idea. The stock type, umbrella seals are a bit of a frustration.

One question I didn't ask was the elevation at your locale. All things considered, a mill cut of .050" is a conservative and safe cut for performance, mileage and any elevation.

Let us know how it comes out.

Adios, David
co-author of the Falcon Performance Handbook
http://www.falcon6handbook.com/

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chad
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Re: Head milling question

Post #11 by chad » Wed Jul 04, 2018 11:23 am

500 ft, call it Peoria/St Louis, the Ill. River, David
"Big thing is only make one change at a time. Change 2 or more things at a time it becomes difficult to figure which change helped or hurt" turbo2256b » 1/16/2017
Chad - '70 LUEB on '77 frame (i.e. PS, D44, trapezoidal BB 9", 4.11), 250, NV 3550 & DSII to B transplanted, "T" D20/PTO, 2" SL, 1" BL, 4 discs, 33"X15", etc. Seeking: Hydraulic gear motor for Koenig pto. chrlsful@aol.com (413) 259-1749

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Re: Head milling question

Post #12 by rbohm » Wed Jul 04, 2018 1:51 pm

OP the very first thing i would do is measure the combustion chambers you have right now. you dont have to measure all of them just one will do fine for the street. but you need that measurement in CCs. the stock head should be around 53cc as i recall. i would then find a good compression ratio calculator and run the numbers carefully and see where you are at in stock configuration. then start playing with the numbers. lets say you have 53cc chambers, and end up with a compression ratio of 9.5:1, i would say at that point you are done. but lets say your chambers measure out at 60cc, and you end up with a compression ratio of say 8.7:1. then you need to figure out how much you need to remove to get the chambers where you want them. a good machinist can help you there, so rely on them to help you.
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Re: Head milling question

Post #13 by Reinking » Thu Jul 05, 2018 3:19 pm

Thank you all for your help. One last question about the Viton valve seals. I remember reading a thread in the forum where it was suggested to use them only on the intake. Is this the current wisdom with a street engine or should I use them on the exhaust as well?

Thanks again.

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Re: Head milling question

Post #14 by turbo2256b » Fri Jul 13, 2018 10:26 am

its been a while but remember some like there were 2 or 3 170 head combustion chamber CC versions. also versions with smaller and larger valves. Currently on my 250 run the next to smallest chamber 170 heads milled .060 with the old thin head gasket.

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Re: Head milling question

Post #15 by CZLN6 » Sun Jul 15, 2018 1:19 am

Howdy All:

This is likely a new topic, but, Hey Turbo- All 170 heads have chamber volumes ranging from 48 to 52 ccs. The heads that ranged this much were early 170 and 144 heads from 1960 to 1964. There was no predicting what year casting would have which chamber volume. We guessed that the variations were due to poorer casting and or machining control of early production. Later year 170 head castings were more likely to have 52 cc chambers. The last years of the 170s from 1969 - 1972 casting were identical to the 200 castings of those years. They are distinguishable by the 1.75" carb hole. All previous 170 had a 1.5" carb hole.

61 -63 year castings had 1.52" intake valves and 1.266" exhaust valves. 1965 - 1972 170 heads had 1.649" intake valves and 1.38" exhaust valves.

I don't know of any performance advantages of early 170 heads over later D8xx and later castings with larger valves, larger intake tract volume and more consistent castings. However, if Mileage and extremely high compression were the goal, that would be an exception. Turbo- have you ever accurately checked your CR on your 250 engine?

That's my two cents, for what it's worth.

Adios, David
co-author of the Falcon Performance Handbook
http://www.falcon6handbook.com/

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Re: Head milling question

Post #16 by 62Cometman » Mon Jul 16, 2018 5:27 pm

So keeping more or less with the same theme to this thread i did have a question, with a completely stock 170 beside some slight head work and milled .040 what do you think would be maximum valve lift capable before piston to valve contact, im willing to bet since the block hasnt been decked its a lot but i was looking at a camshaft to install in my car and with the new 1.6 ratio rockers id end up with .512 lift over all which to me is a lot but idk if that would make contact. Id hate to spend all that time and energy to swap it and have it be too tall and be stuck with a part i can use
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New/Different head milling questions

Post #17 by chad » Mon Jul 16, 2018 5:40 pm

let's start a new thread devoted entirely to your needs.
I think there's goin ta B an entirely different outcome sought.
"Big thing is only make one change at a time. Change 2 or more things at a time it becomes difficult to figure which change helped or hurt" turbo2256b » 1/16/2017
Chad - '70 LUEB on '77 frame (i.e. PS, D44, trapezoidal BB 9", 4.11), 250, NV 3550 & DSII to B transplanted, "T" D20/PTO, 2" SL, 1" BL, 4 discs, 33"X15", etc. Seeking: Hydraulic gear motor for Koenig pto. chrlsful@aol.com (413) 259-1749

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