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Autolite 2245- Not the Same

Posted: Wed Feb 01, 2012 2:48 pm
by renovate7
My new spark plugs arrived. They are different from what was in the A2. What was in there was an Autolite AER72S. The new ones are longer and the threaded part that screws into the cylinder head is shorter. Does it matter? Thanks...Tried to up load pic but am getting a message that says the board attachment quota has been reached. Is that for a day, month?

Re: Autolite 2245- Not the Same

Posted: Wed Feb 01, 2012 4:24 pm
by Rickf
The 2245's are the right plug. Not sure what the others are for.

Re: Autolite 2245- Not the Same

Posted: Wed Feb 01, 2012 4:54 pm
by raymond
Not sure about the numbers you listed, but Autolite used to make an AR7, sometimes followed by an S or a C. The 2245 superseded it though.

Raymond

Re: Autolite 2245- Not the Same

Posted: Thu Feb 02, 2012 4:10 am
by renovate7
Thanks. The AER72S is a waterproof/looks almost identical plug. Just the differences I noted.

Re: Autolite 2245- Not the Same

Posted: Fri Feb 03, 2012 8:53 am
by Kurt Lesser
See below.

Kurt

Re: Autolite 2245- Not the Same

Posted: Fri Feb 03, 2012 3:19 pm
by renovate7
I'm finally able to post this pic. Every vendor I see sells the 2245 for the MUTT. The plugs that came out are old and the old numbering system.
IMG_0003 (640x480).jpg
IMG_0003 (640x480).jpg (250.57 KiB) Viewed 5441 times

Re: Autolite 2245- Not the Same

Posted: Sat Feb 04, 2012 7:59 am
by Kurt Lesser
The 2245 is a 14mm plug with a 3/8" reach and a heat range rating of 5. The AER72 is not good substitute, it is the equivalent of an Autolite 2407 which is a higher heat range plug plug with a 1/2" reach. The higher heat range might be good to prevent fowling but it can also lead to run-on when you shut the engine down.

Suitable substitutes are:

Delco WR46
Crown SR6F
Champion 517, ORD02, XMJ17
Motorcraft AR7S

The other problem I see is the longer length outside might not allow the cable to make good contact resulting in lost power or misfiring.

These plug are avallable from multiple sources for around $12 or less, why take unnecessary chances? There listed here for $5.50 ea:

http://www.autopartstomorrow.com/part_n ... spark-plug" onclick="window.open(this.href);return false;

Kurt

Re: Autolite 2245- Not the Same

Posted: Sat Feb 04, 2012 11:55 am
by Rickf
Those old plugs are a hotter plug also, Extended tip means longer path from electrode to shell.

Re: Autolite 2245- Not the Same

Posted: Sat Feb 04, 2012 2:46 pm
by renovate7
I have installed the 2245's, which is the new plug in the picture. The old plugs are the 72s. I was going to keep them as spares but now think I will pitch them. Out with the old, in with the new.

Re: Autolite 2245- Not the Same

Posted: Sat Feb 04, 2012 2:49 pm
by Joe Gopan
Warning, The Ols Champion Number AER-72S was the spark plug for the M-715 OH Cam Tornado Engine, only. It is 1/2 " Reach, the 2245 is 3/8" Reach and is the latest Autolite version for the M-151.

You mentioned the new (2245) Sparkplugs being longer. That is correct, as you are talking about the barrel of the spark plug. The M-715 requires a Water Proof Spark Plug with a shorter barrel as the 6 spark plugs are angled in pairs toward each other and require that shorter barrel in order to have room to install the wires. Installation of Long barrel water Proof Spark Plugs on the M-715 will result in the ends of the barrels almost touching and making it impossible to install the wires.
That is my M-715 story of the day. :wink:

Re: Autolite 2245- Not the Same

Posted: Sat Feb 04, 2012 4:33 pm
by Rickf
I knew I recognized that number from somewhere. The 230, if it ain't leaking it ain't running. :roll:

Re: Autolite 2245- Not the Same

Posted: Sat Feb 15, 2020 9:48 am
by bkvanbek
I just inherited a M38A1 with the waterproof ignition. The ignition was replaced 22 years ago, except for the plugs, and it has sat ever since. So what plugs do I use now?

Re: Autolite 2245- Not the Same

Posted: Sat Feb 15, 2020 3:17 pm
by Rickf
I think the M38A1 uses a 2243 plug but check to be sure. They are a little easier to find then the 2245 but not much. And be prepared to pay upwards of 20.00 a plug.

Re: Autolite 2245- Not the Same

Posted: Sat Feb 15, 2020 6:13 pm
by hambone
This is the best deal I've seen lately.
viewtopic.php?f=12&t=312886

Re: Autolite 2245- Not the Same

Posted: Sun Feb 16, 2020 10:30 am
by Joe Gopan
The 2243 (AR-5S) is a cooler Sparkplug than the 2245 (AR-7S). All four were manufactured by Autolite, the "AR" prefixed one being earlier versions which were OEM in many M-Series including M-38, M-38A1, M-151, etc.