Allis WD45 M&W pistons
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Category: Allis Chalmers
Forum Name: Farm Equipment
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URL: https://www.allischalmers.com/forum/forum_posts.asp?TID=21447
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Topic: Allis WD45 M&W pistons
Posted By: chris5
Subject: Allis WD45 M&W pistons
Date Posted: 27 Nov 2010 at 8:20pm
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recently tore apart my Allis WD45 and found I have 1/8 over M&W pistons. Have a few questions, Turns out I have a 4" stroke, is there a reason for this with these pistons? The crank also has a part #2265?69?(forget the last 2 digits off hand) that doesn't match any others. Does anyone have any idea what the compression ratio is with these pistons and how about the compression ratio of the flat top high compression through ytmag? Seeing i am rebuilding it I want the most HP I can get within a reasonable budget and am debating buying new pistons and selling these or going with the M&W but also not sure if I could use the 4.5 crank if I get one. What would they be valued at in good condition if I were to sell them? Thanks for everyone who helps, sorry this is a lot of questions. |
Replies:
Posted By: Chalmersbob
Date Posted: 27 Nov 2010 at 9:26pm
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You are sure it's a WD45 and not a WD?
Bob
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Posted By: wi50
Date Posted: 27 Nov 2010 at 10:15pm
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Measure the height of the piston, from the wrist pin center to the top, I think the M&W's are 3". Assumeing that you have the WD pistons being you have the 4" stroke crank.
Simply putting in the 4.5" stroke crank would make to much compression, with the tall piston, but some machine work to the pistons in the lathe and you could get it down to a reasonable comp ratio, and a higher ratio than any combination of parts you can buy. I like the M&W pistons for this reason compared to other aftermarket pistons.
I've gotten free take out M&W pistons and sleves, and I've bought some in the past. I don't know what a fair value is to them if you were going to sell them. My feeling is that by the time I buy rings, find new O-rings and buy the other parts to overhaul the engine, I can just as well buy a new kit, putting the value of take out parts fairley minimal, unless one wants them for some custom project.
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Posted By: chris5
Date Posted: 28 Nov 2010 at 7:36am
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So as far as torque an HP would I be better off with the 4" crank and M&W's or better off with the 4.5" crank and new flat top high compression pistons? Thanks again, Chris |
Posted By: DrAllis
Date Posted: 28 Nov 2010 at 7:49am
| What is the p/n on those M&W pistons?? SP-46 ???(for a 4 inch crank) or SP-48??( for 4 1/2 inch crank) |
Posted By: wi50
Date Posted: 28 Nov 2010 at 8:24am
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you're better of with a new kit and the 4.5" stroke crank.
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Posted By: mlpankey
Date Posted: 28 Nov 2010 at 8:28am
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i think your part number begining with 226 means you have a four and a half stroked crank. is it possible you missed a 1/4 inch in measuring? ------------- people if they don't already know it you can't tell them. quote yogi berra |
Posted By: chris5
Date Posted: 28 Nov 2010 at 8:54am
| The piston part # is AP48 and crank # is 226569, checked this AM. |
Posted By: Larry(OH)
Date Posted: 28 Nov 2010 at 8:57am
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cant remember what the WD M&W part number is, but the 45 crank and the WD pistons will hit the valves..( i have a nice model for valve reliefs) I think you need to take off about .300 from the top to clear everything. ------------- '40 WC puller,'50 WD puller,'50 M puller '65 770 Ollie *ALLIS EXPRESS contact* I can explain it to you, BUT I cannot understand it for you!! |
Posted By: chris5
Date Posted: 28 Nov 2010 at 9:44am
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I put the crank back in along with a piston/rod and measured it that way and am only coming up with 4". So I am assuming it will be fine to use the 4.5" crank with the AP48 pistons. Still unsure if I should go with the new flat top pistons or the M&W for the most HP. Any guidance there would be apprecieated. |
Posted By: wi50
Date Posted: 28 Nov 2010 at 9:47am
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I'm 90% sure the AP-48 part number is the WD45 or 4.5" stroke and the AP-46 is for the WD. I've got both but have to look to be sure.
There's quite a bit of wrist pin offset in the M&W pistons if you measure.
Depending on what you are doing, new parts or old parts, Hastings has rings listed for the M&W application. Also the o-rings on the M&W sleves are thinner than other aftermarket sleves I've seen. I don't know if new ones are available or if they are the same as some aftermarket or AGCO supplied o-ring kits are. I have a set of M&W sleves here that I need to find o-rings for sometime in order to use but I have not checked to see.
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Posted By: jjwo
Date Posted: 28 Nov 2010 at 11:13am
| We had a WD with M&W's and it would pull anything as good as our 45's and slightly faster because of the gearing. Fuel consumption was the same. I've heard they do not help a 45 like they will a WD. |
Posted By: Dave (Mid-MI)
Date Posted: 28 Nov 2010 at 12:04pm
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Here is some info from an M & W brochure that I found on e-bay a few years ago:
Tractor Piston Piston Displacement Observed Compression
Model Set No. Diameter (Cu. In.) Belt H.P. Ratio
M&W Std. M&W Std. M&W Std. M&W Std.
WC SP-46 4-1/8 4 214 201 40.6 29.9 7.2 5.5
WD SP-46 4-1/8 4 214 201 43.2 34.6 7.2 5.8
WD45 SP-48 4-1/8 4 240 226 49.7 43.2 7.3 6.5
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Posted By: David Maddux
Date Posted: 28 Nov 2010 at 12:12pm
| I was wondering what the going price would be for a good set of M&W's. I have a set, that I have been trying to decide what to do with. Dave. |
Posted By: DrAllis
Date Posted: 28 Nov 2010 at 2:50pm
| If you truly have a 4 inch stroke now, and go the 4 1/2 inch stroke using the same sleeves, you'll likely damage the pistons and break the top ring from hitting the old "ring edge" in the sleeve. |
Posted By: mlpankey
Date Posted: 28 Nov 2010 at 3:33pm
------------- people if they don't already know it you can't tell them. quote yogi berra |
DrAllis wrote:Posted By: DrAllis
Date Posted: 28 Nov 2010 at 3:48pm
| I have not....but, that doesn't mean much....I always dealt with 4 1/2" (or more) cranks. |
Posted By: mlpankey
Date Posted: 28 Nov 2010 at 3:53pm
------------- people if they don't already know it you can't tell them. quote yogi berra |
Posted By: wi50
Date Posted: 28 Nov 2010 at 10:43pm
New sleves can be had for about $60 each, I don't know what a new set of rings are for the M&W pistons but would guess $60-100. Add gasket set, berrings, etc and I can buy a complete new kit for less than patching something togather.
I have bought M&W pistons alone for $25 each for a project, but it was a custom project and I wanted them, I got another set free, or traded favors which sometimes costs way to much. I don't know what they are "worth", you can alwayse put a price on them and see what someone will offer.
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Posted By: Steve M C/IL
Date Posted: 28 Nov 2010 at 11:46pm
| I have 1980 vintage M&W pistons out of my 45 right now.They are marked SP48.I have a new set of Power Seal(own rights to M&W) pistons marked AP48 to put in.They really look alot alike but,bowl in new ones hold 90cc and old ones hold 83cc. With Daves chart and my math(questionable) the new stuff is only 6.7 to one not 7.3. I believe Dr Allis is correct when he says the best you can do for a 45 or 17 is to put 170(8:1) sleeve kits in. |
Posted By: Rick
Date Posted: 29 Nov 2010 at 8:25am
| For what it's worth,the part number 226569 is a 4.5" stroke WD45 crank. I've sold several in the past 10 years with that number. And...all of the cranks that had the 4.5" stroke,started with 226XXX...all of them. Rick |
Posted By: skipwelte
Date Posted: 29 Nov 2010 at 11:18am
| The 4" crank for a WC or WD starts with U, the 4.5 for the 45 starts with 226. You have a 4 1/2 stroke WD 45 crank. Ive tried to measure the stroke with a tape and never came up with the correct stroke either. |
Posted By: mlpankey
Date Posted: 29 Nov 2010 at 1:55pm
------------- people if they don't already know it you can't tell them. quote yogi berra |