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MBL intake manifold water jacket cracks

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jwoldeboat
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MBL intake manifold water jacket cracks

Post by jwoldeboat » Wed Sep 26, 2012 8:44 am

Have several hair line cracks that have appeared on the front side of the round water jacket section of the intake manifold,no water is leaking or seeping from the cracks. Looking for any ideas or thoughts on how to fix,welding ?? replaceing ?? Any feed back on this problem and how to fix will be greatly appreciated. Thanks !!! JW

farupp
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Post by farupp » Wed Sep 26, 2012 10:08 am

JW, mine rusted out from the inside. The exterior cracks were the first signs of a problem. I didn't try to fix it. I replaced it as I had a spare. When I looked at it from inside it seems that a repair wouldn't have been possible.

Frank
Frank Rupp
1959 22-foot Sea Skiff Ranger
283 Flywheel Forward engine

jim g
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Post by jim g » Wed Sep 26, 2012 3:04 pm

Whats you see cracking is an exhaust chamber. Its cracking because of the cast iron rusting and expanding outwards. Don't worry about it intill you see or smell exhaust gas coming from it.

jwoldeboat
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mbl intake manifold cracks

Post by jwoldeboat » Wed Sep 26, 2012 7:05 pm

jim g thanks for the info, when i put the boat in last June I noticed a very small one inch hair line crack in the intake manifold and I only used the boat a couple of times when my grandkids were here. I took the boat out just before the Fourth of July as I do not use it on the lake in July or August as the lake gets like the North Sea with all the crazy summer boaters. Boat goes back in the lake after Labor day when all the crazy nut cases go home and boating is now fun and enjoyable again. When I first put the boat in last week I noticed that the small one inch harline crack had now grown to several larger hairline cracks which is the reason for my posting. Last weekend the lake was dead calm at last and I had a chance to run the boat for a couple of hours and gave it a good run at some really good speeds but noticed farly strong cockpit fumes that I did not notice back in June .I thought the fumes might be coming from the oil blow by tube in front of the carb but everything there was clean. Never thought that the fumes could be coming from the hairline cracks in the intake manifold so thanks again for the info and I am now off to search for a replacement intake manifold as I think the current one is beyond repair

jim g
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Post by jim g » Thu Sep 27, 2012 4:41 pm

If the cracks are small you can fill them with cold epoxy by permatex. If the fumes have an oily smell it will be from the crankcase vent. It doesn't always leave a mess. Also check your exhaust elbow real good if its a cast iron one. They get eaten away from the inside and can crack or get a small hole in them. Especially on the underside. If your getting a strong exhaust gas smell in the boat the elbow would be the first suspect then the exhaust pipe packing then the intake.

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