D17 power crater pistons
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=8765
Printed Date: 19 Jan 2025 at 3:59pm
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Topic: D17 power crater pistons
Posted By: TomMN
Subject: D17 power crater pistons
Date Posted: 28 Feb 2010 at 11:09am
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I'm wondering about the difference in the shape of the power crater on different engine kits. MikeB (SD) posted a nice chart of several different compression heights a while back which I saved for reference. I have two D17 engines here one is a 1958 series one, the other is a 1964 series three. Here is the series one - could be original:  Here is the series three - some overhaul kit I think:  What shape are the craters on new kits today and is one better than the other? My engines are both stuck and sitting with PB Blaster waiting for warmer weather. I'm curious as to what compression height pistons are in them. Thanks. Tom |
Replies:
Posted By: DanD
Date Posted: 28 Feb 2010 at 12:49pm
| Looks to me like the pistons in the second engine are aftermarket 4.25" pistons. Looks like the sleeve is thinner in the second picture. The pistons in the first engine look like original AC design. |
Posted By: mlpankey
Date Posted: 28 Feb 2010 at 2:09pm
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are any of the pistons in the pics at tdc it looks as if 2@ 3 might be. still along ways away from zero deck height . i cant see why anybody would want that over a flat top. jmho ------------- people if they don't already know it you can't tell them. quote yogi berra |
Posted By: TomMN
Date Posted: 28 Feb 2010 at 3:46pm
| No none of these are at tdc. I went out and measured the bores and the top picture is 4" and the bottom is 4 1/8". I don't plan on doing any pulling with the industrial D17 so I am thinking of trying on making the engine close to original, but of course price of engine kits will make a difference too. With so many different pistons that Allis used in the 226 I don't want to end up with only the compression of a WD45. |
Posted By: Dans 7080
Date Posted: 28 Feb 2010 at 3:54pm
| I put a set of high compression 4" pistons in my D-17. I got the kit from the local agco dealer. If i remember right it took the compression ratio from 7.50 to 1 to 8.25 to 1. |
Posted By: mlpankey
Date Posted: 28 Feb 2010 at 4:45pm
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if you arent gonna use any of those sleeves i sure would like to have them if you dont crack them removing them. those 4.125 would be good to bore 4.188 and the four inch i could use my 4 1/8 pistons that have alot of runs on them and have shrank a bit undersize ------------- people if they don't already know it you can't tell them. quote yogi berra |