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southpw Member
Joined: Jun 15, 2014 Posts: 268 Location: Cambridge, Ontario, Canada
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Posted: Mon Sep 12, 2016 5:55 pm Post subject: Cylinder Head facing |
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Good evening guys. I am having a real hard time removing all the gasket material on my head. When I think I have it all removed by using gasket remover and scraper, I let it sit, which then lets it dry completely and I see there is more material left and not a smooth surface. I have gone through 1 and a half spray cans of the gasket remover product.
So Im thinking of getting head faced but unsure how many times the head has already been faced. Is there a spec as to how shallow the bowl can get? I measure the depth at .460" currently.
Brad
_________________ 1952 M38 project
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4x4M38 Member
Joined: May 30, 2014 Posts: 3447 Location: Texas Hill Country
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southpw Member
Joined: Jun 15, 2014 Posts: 268 Location: Cambridge, Ontario, Canada
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Posted: Mon Sep 12, 2016 6:48 pm Post subject: |
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Hi Brian. Those rust areas seems to be where the gasket remains. The other areas(where the dotted areas are) are the amooth areas but look like the gasket surface.
I would feel better if I could just resurface it without any issues. Unsure what original head thickness was and what the min thickness allowance is.
Brad _________________ 1952 M38 project
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OKCM38CDN Member
Joined: Feb 17, 2012 Posts: 530 Location: Del City, OK
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Posted: Mon Sep 12, 2016 8:04 pm Post subject: |
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Have you thought about using a BRASS wire brush on a grinder... brass should not hurt the head but take off the extra gunk... _________________ Hal, KB1ZQ
TSGT, USAF (Ret)
1952 M-38 CDN CAR 52-31313
1952 M-100 Strick #104
1951 Willys Wagon (For Sale)
1954 Willys M38A1 201001205
Tornado Alley
Del City, OK |
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4x4M38 Member
Joined: May 30, 2014 Posts: 3447 Location: Texas Hill Country
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4x4M38 Member
Joined: May 30, 2014 Posts: 3447 Location: Texas Hill Country
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wesk Site Administrator
Joined: Apr 04, 2005 Posts: 16260 Location: Wisconsin
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mbullism Member
Joined: Jul 14, 2015 Posts: 36
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Posted: Tue Sep 13, 2016 5:23 am Post subject: |
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I have seen discussions on head thickness vs compression ratio. Fairly certain it was measured from top of the rib to mating surface.
Will try and find a link-
ETA: this is not what I was thinking of, but see item #4
http://www.classicmilitaryautomotive.com/tag/l-134/
(it sure sounds like a lot... just passing it on) |
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wesk Site Administrator
Joined: Apr 04, 2005 Posts: 16260 Location: Wisconsin
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Posted: Tue Sep 13, 2016 9:23 am Post subject: |
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As I said above, Part 2 / Par 4 of that link restates what I said, Over shaving of the head can result in too high a compression and valve interference. Also the info posted there is only what they assume to be original approximate factory head thickness as we do not have any factory published data available. I can hardly imagine that removing nearly a 1/4" from a 1/2" head could be considered an option. Also the head helps remove heat from the engine so the more meat you remove from the head the faster it will get hot and the less heat it will wick away from the engine.
My advice remains the same, take the head to your auto machinist and see what they have to say. _________________ Wes K
45 MB, 51 M38, 54 M37, 66 M101A1, 60 CJ5, 76 DJ5D, 47Bantam T3-C & 5? M100
Mjeeps photo album: http://www.willysmjeeps.com/v2/modules.php?set_albumName=Wes-Knettle&op=modload&name=gallery&file=index&include=view_album.php |
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southpw Member
Joined: Jun 15, 2014 Posts: 268 Location: Cambridge, Ontario, Canada
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Posted: Tue Sep 13, 2016 10:08 am Post subject: |
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Will do. Thanks for all the advice and info
Brad _________________ 1952 M38 project
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mbullism Member
Joined: Jul 14, 2015 Posts: 36
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Posted: Tue Sep 13, 2016 1:15 pm Post subject: |
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Took me a while to track this down... lol- work gets in the way:
Quote: | The standard 6.48:1 head dome volume was about 90.5 cc. It’s important to know if your head has already been milled (for reasons I outline later) before you have it milled. You can tell by measuring the thickness of the head from the mating surface to one of the machined head stud bosses on the corner of the head. A standard head will be around 2.1406 inches (plus or minus a few thousanths). If you want to go for the 7:1, then you want the total thickness of the head to be around 2.109 in., which should not be exceeded unless you know what you are doing. (Jim Allen) |
The quote above pulled from the links below, and the 2A page link has interesting photos comparing a 6.48 head with a supersonic head and an industrial low compression head.
http://www.thecj2apage.com/forums/going-supersonic-texas-version_topic27294.html
http://g503.com/forums/viewtopic.php?f=10&t=123939#p717838
YMMV...
Last edited by mbullism on Wed Sep 14, 2016 6:54 am; edited 1 time in total |
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southpw Member
Joined: Jun 15, 2014 Posts: 268 Location: Cambridge, Ontario, Canada
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Posted: Tue Sep 13, 2016 3:19 pm Post subject: |
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Thanks for that info. My head thickness measures 2.095" so I may be best to just keep working this material off and not face it again. _________________ 1952 M38 project
Brad |
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4x4M38 Member
Joined: May 30, 2014 Posts: 3447 Location: Texas Hill Country
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mbullism Member
Joined: Jul 14, 2015 Posts: 36
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Posted: Tue Sep 13, 2016 7:30 pm Post subject: |
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I'm not saying don't take it to a machine shop, only that you get as much info as possible to make an informed(?) decision is all...
On another note, x2 on the brass wire brush, just watch out for the gold colored wire wheels that are actually stiff steel. A magnet wont lie- |
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