Farm Equipment - D17 Series II spark plug confirmation

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D17 Series II spark plug confirmation

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=200999
Printed Date: 17 May 2024 at 8:50pm
Software Version: Web Wiz Forums 11.10 - http://www.webwizforums.com

Topic: D17 Series II spark plug confirmation

Posted By: EPALLIS
Subject: D17 Series II spark plug confirmation
Date Posted: 21 Apr 2024 at 9:09pm

Hi: Just need a confirmation that I'm treating this 60-year-old A-C girl correctly. On a D17 Series II, the original owner's manual says to use AC Delco 45XL spark plugs. I understand these are no longer made. I then went to the cross-reference conversion chart, and it said today that I should be using Autolight 405 in the Allis Chalmers D17 Series II. Does that sound correct? Thanks in advance for any assistance. Appreciate it!

Replies:

Posted By: DrAllis
Date Posted: 21 Apr 2024 at 9:45pm

R-45 XL or R-45 XLS

Posted By: Don Jr NY
Date Posted: 22 Apr 2024 at 4:40am

Our "unofficial" series II is a 1961 and uses the long reach plugs. Ours has Champion RN11YC in it. I thought only the series I used the short reach plugs like the AC 45's but I'm not sure of the serial number break between the two. Don Jr.

Posted By: DrAllis
Date Posted: 22 Apr 2024 at 6:17am

I believe the chassis s/n was 24001 and up had the long reach spark plugs. One has to be careful because over the years engines and cylinder heads have been swapped out. The newer cylinder head always has a casting plug on the front and rear of the cylinder head face that takes a 7/16" wrench to install/remove it. The older short plug heads are smooth with no core casting plugs located there.

Posted By: EPALLIS
Date Posted: 22 Apr 2024 at 9:01pm

Got it. Thanks Doc. My serial number is #36121. If you have time I'm curious to what the "S" stands for in the 45XLS? Thanks again!

Posted By: DrAllis
Date Posted: 22 Apr 2024 at 10:11pm

The electrode is a little deeper into the combustion chamber.

Posted By: SteveM C/IL
Date Posted: 22 Apr 2024 at 10:13pm

Isn't it "extended tip" ? The porcelin and electrode stick out more than regular plugs.