Identify this PISTON
Printed From: Unofficial Allis
Category: Allis Chalmers
Forum Name: Farm Equipment
Forum Description: everything about Allis-Chalmers farm equipment
URL: https://www.allischalmers.com/forum/forum_posts.asp?TID=116856
Printed Date: 20 Jul 2025 at 12:20am
Software Version: Web Wiz Forums 11.10 - http://www.webwizforums.com
Topic: Identify this PISTON
Posted By: Macon Rounds
Subject: Identify this PISTON
Date Posted: 30 Dec 2015 at 5:16pm
   This piston was removed from a D15 series I gasoline .... Is it stock ? Is it Propane ? Is it aftermarket high compression ???? I do not have much experiance with rebuilds of D15 engines but have not seen one like this before. Give me your thoughts and knowledge please. ------------- The Allis "D" Series Tractors, Gravely Walk behind Tractors, Cowboy Action Shooting !!!!!!! And Checkmate |
Replies:
Posted By: DrAllis
Date Posted: 30 Dec 2015 at 5:38pm
| Absolutely NOT stock or OEM !! Power Crater bowl only is stock gas or LPG. |
Posted By: Dan73
Date Posted: 30 Dec 2015 at 5:47pm
| Wow are you sure someone isn't messing with you? Looks like an international fire crater pistions do you by any chance have a farmall M there missing a pistion? At any rate I would say it is time to get some new pistions they should have a crater in them with a fairly step sides and a flat bottom not the full bowl like the wd motors had. There is a good thread over in the knowledge base section which shows what the allis chalmers power crater pistions look like. |
Posted By: Don(MO)
Date Posted: 30 Dec 2015 at 6:11pm
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Looks like a M&W piston to me.
------------- 3 WD45's with power steering,G,D15 fork lift,D19, W-Speed Patrol, "A" Gleaner with a 330 corn head,"66" combine,roto-baler, and lots of Snap Coupler implements to make them work for their keep. |
Posted By: Macon Rounds
Date Posted: 30 Dec 2015 at 7:05pm
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If you look at the top left photo it has a MFG name CONFOR MATIC but i have never heard of them. ------------- The Allis "D" Series Tractors, Gravely Walk behind Tractors, Cowboy Action Shooting !!!!!!! And Checkmate |
Posted By: eighty nine
Date Posted: 30 Dec 2015 at 7:08pm
| It has Comfortmatic on the side. Google it. |
Posted By: Macon Rounds
Date Posted: 30 Dec 2015 at 7:10pm
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Well....... i could do that but then look at all the fun we would be missing out on. And the spelling is CONFOR MATIC. ------------- The Allis "D" Series Tractors, Gravely Walk behind Tractors, Cowboy Action Shooting !!!!!!! And Checkmate |
Posted By: eighty nine
Date Posted: 30 Dec 2015 at 7:16pm
Ooops, Thanks for the spell check. 
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Posted By: norm[ind]
Date Posted: 30 Dec 2015 at 7:18pm
| i have heard of them ---took them out of a wd???--we nevr found any others had calls fo them --never fouund out who the supplier was--aftermarket something???? we had onne 20yrs.ago |
Posted By: Dan73
Date Posted: 30 Dec 2015 at 8:00pm
| Well if you do Google it you get one post in here from 2010 when someone asked about them and no one replied and there are a couple of posts from yesterday's tractors where it looks like of you get the number off the piston skirt someone Ober there might be able to set you up with rings. |
Posted By: Brian G. NY
Date Posted: 30 Dec 2015 at 8:17pm
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I have 2 sets of used Conformatic 4-1/8" GE31X "dished" pistons for WD-45 or D-17. I also have a single new Conformatic GE30X flat top piston for a WD. They were from Sfterling Aluminum Products, a fairly well known company from the 40s and 50s.
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Posted By: Macon Rounds
Date Posted: 30 Dec 2015 at 8:36pm
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Yep thats it !!!!! And that's also why i ask question on here ...... You get the real answers with pictures. :-)))) ------------- The Allis "D" Series Tractors, Gravely Walk behind Tractors, Cowboy Action Shooting !!!!!!! And Checkmate |
Posted By: 45 turboa-
Date Posted: 30 Dec 2015 at 9:16pm
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I think tractor supply had conformatic pistons. I know i have overhauled wd's and 45's that had conformatic pistons but they had a dished piston. ------------- turbocharged |
Posted By: Fred in Pa
Date Posted: 31 Dec 2015 at 6:35am
I can get u new pistons like this for the 149 engine . ------------- He who dies with the most toys is, nonetheless ,still dead. If all else fails ,Read all that is PRINTED. |
Posted By: Fred in Pa
Date Posted: 31 Dec 2015 at 7:09am
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I have seen many WD,WC B,C CA engines I have rebuilt with CONFOR MATIC flat pistons in them . ------------- He who dies with the most toys is, nonetheless ,still dead. If all else fails ,Read all that is PRINTED. |
Posted By: Macon Rounds
Date Posted: 31 Dec 2015 at 9:21am
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Hey Fred Do these piston increase compression ??? Thanks in advance. ------------- The Allis "D" Series Tractors, Gravely Walk behind Tractors, Cowboy Action Shooting !!!!!!! And Checkmate |
Posted By: Fred in Pa
Date Posted: 31 Dec 2015 at 10:36am
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Sent u a PM ------------- He who dies with the most toys is, nonetheless ,still dead. If all else fails ,Read all that is PRINTED. |
Posted By: DaveKamp
Date Posted: 31 Dec 2015 at 11:31am
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Since the design has a bump out on the top, it's POSSIBLE that the piston height/displacement could yield a different compression ratio, but more than likely, the engineers didn't go to any extreme measures to increase the CR. The side effect to redesigning piston heads for higher CR, is increased shrouding of the valves, and disturbing the airflow. The internal-combustion secret society realizes that former isn't a really big deal... the piston shrouding valves only occurs when the slug is near TDC, and as the piston continues south, the shrouding moves away, but the complex shape of the top tends to create little pockets of stagnation, so the possible improvements and detractions are likely to cancel out, yielding more of an academic result than actual. So unless there's really well-documented before-after performance change, I'd bet my buck that it was more patent-protected marketing magic than applied science. That being said, one WILL find 'conforming pistons' to be more prevalent in air compressors than internal combustion engines... In larger scale scenarios, I saw the lid off a LeRoi (RoiLine) engine set up to be an engine-compressor 'unit', where the compressor slugs were conformal-fit to improve compressor output. ------------- Ten Amendments, Ten Commandments, and one Golden Rule solve most every problem. Citrus hand-cleaner with Pumice does the rest. |
Posted By: Macon Rounds
Date Posted: 31 Dec 2015 at 12:44pm
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Theory and education is always good ..... ------------- The Allis "D" Series Tractors, Gravely Walk behind Tractors, Cowboy Action Shooting !!!!!!! And Checkmate |
Posted By: Dick L
Date Posted: 31 Dec 2015 at 1:19pm
At top dead center using those pistons on a flush surface head the top ring has got to be way down in the sleeve. Not that it could be a problem but would make a wide ring groove to remove. I had not seen that piston in any of my tear downs.
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Fred in Pa wrote:Posted By: Fred in Pa
Date Posted: 31 Dec 2015 at 1:25pm
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Did u read FLAT PISTON . ? ------------- He who dies with the most toys is, nonetheless ,still dead. If all else fails ,Read all that is PRINTED. |
Posted By: Dick L
Date Posted: 31 Dec 2015 at 1:54pm
An you expect an old man to read with understanding.  Obviously I didn't.  Looking at the picture of the subject piston I wondered. Now I am still wondering.
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