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#1 | |
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Join Date: Dec 2001
Location: Elysburg, Pa
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#2 |
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Location: Northern New Jersey suburbs
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Solid bronze will seize up. I had it happen on my tow vehicle. Exhaust valve got hot pulling a hill and valve started to seize and bent hitting piston. Screw-in bronzewalls or thin wall types never a problem like that. They are softer and more self lubricating. They do wear more easily though. Cast iron guides also can easily seize. I honed thinwalls and screw-ins until the valve would spin free and never had one seize. Nice pictures and work on those heads. Makes me want to go back and do that work as I did for years.
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Rich Biebel S/C 1479 Stock 147R |
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#3 |
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Join Date: Jun 2003
Location: Las Vegas nv
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Solid is for alum heads only - never knew. Liners are ok
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72 cutlass |
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#4 |
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Sold bronze will work in iron heads but they need a little more clearance on the exhaust side.
I have seen many places not use seals also to let a little more oil in there on that side. After I thought about it the guide that seized on my tow vehicle was a screw-in bronze.....Only one to ever do that in my memory... I like the thin walls the best....honed to fit with a Sunnen hand hone....
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Rich Biebel S/C 1479 Stock 147R |
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#5 |
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Join Date: Feb 2012
Location: Colorado Springs Colorado/Thousand Oaks Ca
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Thanks for the nice comments. Lets talk about valve guides and valve jobs. These particular heads utilize bronze knock in guides, the guides are bought with the ID .370 (undersize) the guides are installed which distorts the ID, I then cut a carbon relief slot in the bottom of the exhaust guide with a .450 reamer .125 deep. I use carbide core drills (similiar to a K Line core drill) which I had made, the guide is drilled to .3715 making it strait and round, the guide is then honed to final size with a Sunnen hone with Sunnen hone oil. You now have a perfectly round and strait guide, which allows you to cut a perfect seat. A perfect contact patch on the seat allows you to transfer the heat in the valve to the valve seat.
Rich.....I know you like this stuff, ck out this link http://www.chevelles.com/forums/13-p...-pictures.html Look closely at the valve contact patch (lap lines) |
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#6 |
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" I then cut a carbon relief slot in the bottom of the exhaust guide with a .450 reamer .125 deep."
You lost me on the above operation ? A picture is worth a thousand words. Practically all the head work I did over many years was without the use of a seat and guide machine. Benchtop operations.....hand held drills and tooling. I did buy out a machine shop in the early 1990's and that buy included a Kwik Way 019 S&G machine. I did not use it much. Eventually sold it for a giveaway price. Nice work on the BB heads and I hated replacing the stock guides in them. I would leave them and thin wall line them mostly due to the rediculous way GM factory drilled the guides off center from the seats on some. Also the potential water leak issue passing thru the water jacket. I have taken brand new aluminum heads from the big name manufacturers with nice looking Serdi cut seats so far off the old valve bounce test is a NO bounce and just a thud......LOL Bought a set of Darts for my own engine. Operator who did the VJ on them must have been drunk......had to use my old school stones to fix it.....Not fun but I make it work... Your work is excellent.....
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Rich Biebel S/C 1479 Stock 147R |
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#7 |
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Join Date: Feb 2012
Location: Colorado Springs Colorado/Thousand Oaks Ca
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I finally got the exhaust side of my heads done. Although I'am not sure I have this right, so I have questions. On my BBC builds with conventional camshafts I've always wanted lazy low lift flow then have it come on after .300 lift and take off, this has always worked well for me. On my Buick I gained around 12 CFM @ .200 and 12 CFM @ .300 and about 10 CFM @ .400 and finally 9 CFM @ .466 peak lift, will this help me or hurt me?
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