351 Log-style manifold
Printed From: CorrectCraftFan.com
Category: Repairs and Maintenance
Forum Name: Boat Maintenance
Forum Discription: Discuss maintenance of your Correct Craft
URL: http://www.CorrectCraftFan.com/forum/forum_posts.asp?TID=25398
Printed Date: November-19-2024 at 6:34am
Topic: 351 Log-style manifold
Posted By: 74Wind
Subject: 351 Log-style manifold
Date Posted: March-29-2012 at 10:29pm
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74 Southwind Thermo-Electron 351. Log-style exhaust manifold cracked. Photos (attached) look worse than it is. Slight leak was improved mid-summer with patch goop, now just occasional drip. Manifold removed today (bolts came out easy)looks fine other than existing patched crack. No visual evidence of any internal jacket leaks (dry soot, no evidence of water leaking into engine). Engine ran great all last year in this condition which would/should/could? indicate no interior crack. Pressure-testing had been suggested but I have neither the skill nor equipment, anyone suggest where I might get this done near Atlanta? Brazing has been suggested but have also heard that improperly done can screw up this obsolete "irreplaceable" part.... This log-style is a dinosaur and I have been unable to source. Anyone parting out an old engine or know where I might find one such as this?  
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Replies:
Posted By: Waterdog
Date Posted: March-29-2012 at 10:51pm
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There are old skool guys that are very good at welding cast iron. Around Atlanta you should find a guy - good luck. Important to pre-heat, weld, post heat. I know a guy that pre-heats fluxs, then silver sodiers, post heats old one of a kind engine blocks. I've driven his 1905 Caddy with a repaired block. Whats that big monthly car catalog with the brown cover? - Hemmings Motor News - you'll find a good guy there. ------------- - waterdog - http://www.correctcraftfan.com/diaries/details.asp?ID=3896&sort=&pagenum=2&yrstart=1978&yrend=1978" rel="nofollow - 78 Ski Tique |
Posted By: 8122pbrainard
Date Posted: March-29-2012 at 10:53pm
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Jeff, What did you use to do the patch? Did you "V" out the crack first? Laurel Lake Skier has been running a epoxy patch for at least 5 years. Pressure testing does not require special equipment. Yo bolt a block off plate on the riser end and hook the hose up to the other. Then you see if water comes out the exhaust side. Brazing can be a permanent fix. A good weld shop will have no problem with doing it. The key is preheating the casting and the prep of the crack. Evidently the person who told you it could damage the manifold had a bad experience. ------------- /diaries/details.asp?ID=1622" rel="nofollow - 54 Atom /diaries/details.asp?ID=2179" rel="nofollow - 77 Tique 64 X55 Dunphy Keep it original, Pete < |
Posted By: 74Wind
Date Posted: March-29-2012 at 11:57pm
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(BTW, the photos are prior to the "patch" job) Didn't "V" it out,thought might make worse..cleaned up sandpaper & small wire brush then few even coats of JB Weld. Still drips a little bit. Now that manifold is off should be able to do a better job. Could touch up, or grind it down and re-do(?). Will also research brazing further. Encouraged to hear of "5 year" patch..but what exactly is and how does one do an epoxy patch? Boat's 90 miles away so can't quite picture the pressure testing process without looking at it. Last fall you'd detailed a more complicated process..I'm a bit lost, is there better detail or a drawing somewhere? Also there's a craigslist Palmer 302 that was suggested, I've no need for an engine but would that manifold apply & fit right up to a 351 without riser/hose modification? Also out of curiosity, my engine had been painted at some point and there is some red that shows thru in spots, the Palmer is red, do you know what the original Thermo-Electron color was? |
Posted By: Waterdog
Date Posted: March-30-2012 at 2:34am
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JB weld is epoxy. If you grind it out and re-apply epoxy try to apply it with in a couple hours so the fresh,clean (acetone wipe) surface dosen't have a chance to oxidize. A good epoxey patch works well. When I bought the ski tique it took about 3 years for me to find out it had a cracked block. Still PO'ed about that "Shock lef holetta" (SP) (polish) ------------- - waterdog - http://www.correctcraftfan.com/diaries/details.asp?ID=3896&sort=&pagenum=2&yrstart=1978&yrend=1978" rel="nofollow - 78 Ski Tique |
Posted By: 8122pbrainard
Date Posted: March-30-2012 at 9:01am
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Jeff, As mentioned, the key to an epoxy job is the prep. It does need to be V'd out and to get to clean metal. If you just put the JB on top of old, it will not stick. ------------- /diaries/details.asp?ID=1622" rel="nofollow - 54 Atom /diaries/details.asp?ID=2179" rel="nofollow - 77 Tique 64 X55 Dunphy Keep it original, Pete < |