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Preliminary machine shop results are in on my cylinder heads...some concern
Machine shop doing a preliminary on my heads. Took apart the first one right there in front of me. Used an air C.
Results so far: All valve guides will have to be replaced on 5 cylinders. All springs will have to be replaced all five cylinders they are too old being in there since 1968. Next he siad they will test the valves using called "magniflux" (I think that's what he said) (The shop specializes in high performance racing engines, land and sea) Thanks (The sixth one, is a replacement new/rebuilt head)
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1969 911 E Coupe "Little Bull" "Horse" "H." Heart, "G." Gears, and "P" the Porsche Last edited by H.G.P.; 11-27-2004 at 08:21 AM.. |
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11-27-2004, 08:13 AM
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Magnaflux is a process that will reveal cracks and imperfections. It is used extensively in the aviation industry.
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1984 Targa |
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11-27-2004, 08:21 AM
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my guess is the valves will fail the stem taper test, (worn out stems cause slop in the new guides) and have to be replaced anyway. i've never heard of magnafluxing valves. i mean it could be done, but why?
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https://www.instagram.com/johnwalker8704 8009 103rd pl ne Marysville Wa 98270 206 637 4071 Last edited by john walker's workshop; 11-27-2004 at 09:03 AM.. |
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11-27-2004, 08:38 AM
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Agree with John, have never heard of magnafluxing valves. I work in the aircraft industry and have spent thousands of hours working with a magnaflux machine.
Valves just do not crack that often and when they do its known immediately, like what happened with your one cylinder. If there are any questions about the integrity of the valves, replace them! On an overhaul most of the exhaust valves are replaced anyway, its just good insurance as they are under a lot of stress. The intakes wear less and if they are within limits they usually can be reused. Which shop is saying that the valves need to be magnafluxed? Joe A
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2021 Subaru Legacy, 2002 Dodge Ram 2500 Cummins (the workhorse), 1992 Jaguar XJ S-3 V-12 VDP (one of only 100 examples made), 1969 Jaguar XJ (been in the family since new), 1985 911 Targa backdated to 1973 RS specs with a 3.6 shoehorned in the back, 1959 Austin Healey Sprite (former SCCA H-Prod), 1995 BMW R1100RSL, 1971 & '72 BMW R75/5 "Toaster," Ural Tourist w/sidecar, 1949 Aeronca Sedan / QB Last edited by Joeaksa; 11-27-2004 at 08:48 AM.. |
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11-27-2004, 08:45 AM
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It would not be unusual to have the heads magnafluxed, and perhaps that's what the shop intended to say. I agree that going through the effort on valves themselves seems like an odd thing to do.
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11-27-2004, 10:08 AM
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I'd just replace the valves anyway. Especially exhuast. Very doubtful they will be within spec. Is this a shop experienced with Porsche heads? There are little things to redoing these right that a shop without Porsche knowledge could mess up. Just a thought. These are not everyday heads...
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GruppeB #935 84 Carrera Targa B.A.S.T.A.R.D. (for sale) 82 SC RSR Project (on ebay) 95 Dodge Ram 2500 03 Toyota 4runner |
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11-27-2004, 01:33 PM
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Quote:
Steel parts are magnafluxed, aluminum heads can be examined using dye-penetrate (DIY). During a magnaflux examination the steel part is magnatized, aluminum is non-ferrous.
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Clifton Brown https://www.mancalamarketing.com |
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11-27-2004, 02:20 PM
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