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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=130849
Printed Date: 30 Jun 2024 at 11:31am
Software Version: Web Wiz Forums 11.10 - http://www.webwizforums.com
Topic: next question
Posted By: darrel in ND
Subject: next question
Date Posted: 03 Nov 2016 at 4:39pm
| This one is for the 2 stroke Detroit experts. 3-71 out of my AD3. The previous owner said he was running the machine, and it backfired, then after that, it smoked heavily and had no power. Been racking my brain (and there ain't much there) trying to figure out what could have went wrong. After I was all loaded up at this previous owners place today, and about ready to drive away, he tells me just a minute. I have one more thing for you. He came back with a NOS blower seal kit for this engine. I asked him if he had got it because he thought that that was what was wrong with the engine and he said no. He had just got that seal kit because it was on ebay, it was cheap, it was for this engine, and thought that if he ever needed it, he'd have it. But after I left his place, I started to think that maybe, it's possible, that giving the symptoms of the engine that he did, maybe the blower seals are all that is wrong. Does that theory add up at all. I mean, I really don't know what a 2 stroke Detroit does when blower seals go out, so I am just guessing or wishful thinking. Any thoughts. ..? Thanks Darrel |
Replies:
Posted By: DMiller
Date Posted: 03 Nov 2016 at 7:45pm
| To me sounds as if the emergency shut down flapper came loose and is choking air flow off. Pull the intake and look down the throat of the blower. |
Posted By: JohnCO
Date Posted: 03 Nov 2016 at 8:39pm
|
Or could the supercharger shaft broke? ------------- "If at first you don't succeed, get a bigger hammer" Allis Express participant |
Posted By: SteveM C/IL
Date Posted: 03 Nov 2016 at 8:57pm
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only thing that happens with bad seals is sucking some oil.Wouldn't have much effect on how it ran.Sorry.if you put seals in you NEED a book.Have to pull and install drive gears together as they are helical cut and the rotors are spiral too.There are clearance demensions for rotor lobes which are set by shim behind one gear.Matters whether rt hand or left how clearance is set.Look in intake side at the end plate(may need a mirror?)and see if it all oily.I doubt the seals are a problem. Some engines don't have an emergency shut off. Grader I ran did not.Was a 54.If flapper does close in one they smoke BIG TIME with no power.Can't comprehend one back firing either.Miss maybe but back fire?Check out everthing from blower hsg outward for some blockage. As a side note.....if you lay one on it's side,it will run away on crankcase oil with the fuel shut off! The emergency brake can kill it.LOL! (leave it in gear) |
Posted By: DanWi
Date Posted: 03 Nov 2016 at 9:34pm
| Isn't that a motor under the right circumstance they can run backward? |
Posted By: LeonR2013
Date Posted: 03 Nov 2016 at 9:39pm
| Shameless sez, it's that time of year. Maybe it has the flu. LOL |
Posted By: Eric B
Date Posted: 03 Nov 2016 at 11:07pm
Yes they can run backwards...likely to happen if you power out to a near stall. They run without oil pressure...smoke coming out of the air cleaner. What is being described can also be from a damaged piston, I had that happen. With a 3-71 if you have one out of three partially down...it would be very noticeable on the power. If you pull the air box covers off and turn over the engine manually you can see the piston tops. ------------- Currently- WD,WC,3WF's,2 D14's B. Previously- I 600,TL745,200,FL9,FR12,H3,816 LBH. Earth has no sorrow that Heaven cannot heal! |
DanWi wrote:Posted By: shameless (ne)
Date Posted: 04 Nov 2016 at 10:16pm
| when I turn over the old lady.....oooops....I mean the loving wife, I can see the tops!!! wait...what was the question? |
Posted By: Coke-in-MN
Date Posted: 07 Nov 2016 at 4:41pm
|
blower seals and oil consumption and erratic running if to much oil is sucked into engine . seems you would notice oil coming out of breather hole on lower blower housing also . detroits are fairly basic but the idea of 2 stroke throws everyone off - motor launches aboard carrier I was on used Detroit engines - they kept a old P coat handy to plug the air intake IF they started running away . ------------- 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: SteveM C/IL
Date Posted: 07 Nov 2016 at 9:31pm
| I had my detroits run backward several times...always a stall kill situation.Found out a 3406B Cat would run backward too. |
Posted By: JC-WI
Date Posted: 08 Nov 2016 at 1:53am
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As far as I know, the allis engines had the kill flap on the intake side of the blower, and if flapped, it will die... Seen truck 6-71 engines have the flap between the blower and the engine., once tripped, they were manual reset. But a backfire first?? I would think more in a cam... or the governor linkage maybe. Weep holes in the air box could be plugged to not allow oil to escape. My HD15 had oil imn the airbox and when dozing, and point the nose up or down, it would reallt take offand had to grab the kill knob several times... and an hour of play would make ye look like a well oiled black man. ------------- He who says there is no evil has already deceived himself The truth is the truth, sugar coated or not. Trawler II says, "Remember that." |
Posted By: Ian Beale
Date Posted: 08 Nov 2016 at 3:23am
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Shameless "
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