271 fuel pump
Printed From: Unofficial Allis
Category: Allis Chalmers
Forum Name: Construction and other equipment
Forum Description: everything else with orange (or yellow) paint
URL: https://www.allischalmers.com/forum/forum_posts.asp?TID=176775
Printed Date: 07 Jun 2024 at 7:09am
Software Version: Web Wiz Forums 11.10 - http://www.webwizforums.com
Topic: 271 fuel pump
Posted By: WaltDevore
Subject: 271 fuel pump
Date Posted: 14 Dec 2020 at 9:40pm
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Well Gentlemen, the saga continues. I received an universal fuel pump rebuild kit for my HD5G and of course it's not the right one. More than that, my parts book the covers all serial numbers does not show this kind of pump. So a new pump is on order. I think the side spring plunger mechanism is the problem and don't know if the one in the kit would work. I don't want to open it and lose the ability to return it. The parts guy thinks this is a very old original pump. It looks too simple, how can it pump? The double gear is not there. Any suggestions? Here are the pictures:   |
Replies:
Posted By: Coke-in-MN
Date Posted: 14 Dec 2020 at 11:56pm
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Call it a Wankel engine and you will understand - the rotor is off center on the shaft and travels a elliptical circle inside housing thus creating cavitation and displacement as it travels , it creates pressure as it displaces fuel and discharges it out side port . while the opposite side of eccentric creates a vacuum to draw fuel in . Now just like a gear pump the clearance of rotor to casting of body has to be next to 0 or leakage will just bypass the full eccentric . Might have to face both sides by lapping and then see if a thinner or thicker gasket is needed to get proper clearance of rotor to case clearance . ------------- Faith isn't a jump in the dark. It is a walk in the light. Faith is not guessing; it is knowing something. "Challenges are what make life interesting; overcoming them is what makes life meaningful." |
Posted By: WaltDevore
Date Posted: 15 Dec 2020 at 12:01am
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Thanks for that. Interesting it didn't make the Parts Book. I guess the non heroic thing to do is be happy I can put an "updated" pump on. Must be a good reason it became obsolete |
Posted By: SteveM C/IL
Date Posted: 15 Dec 2020 at 8:18am
| The gear pump is definitely more positive pressure. I assume you do have fuel getting to the pump? As I remember, you are to leave outlet injector lines loose and crank with racks closed until fuel purges air from injectors. It's all in the manual. |
Posted By: WaltDevore
Date Posted: 15 Dec 2020 at 10:12am
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Thanks for reminding me. |