Allis Chalmers I600 - Proper spark plug

[CamR]

Hello looking for advice on a proper spark plug make and number for my Allis Chalmers I600.
 

[JMS/.MN]

I600 is based on the D17 tractor, so whatever that engine calls for. I don"t have my book handy.
 

[thebigyellowtruck]

Napa auto has many different plugs for the d17. here is a link to them.
D17 spark plugs at NAPA

 

[DiyDave]

I don't want to start a fight, so I will ask a question. Isn't the I60/600 based on the D-15, with the 160 cubic engine? If so, AC fire ring 45's are what we always usedta use. You can get them in several heat ranges.
 

[Bob Bancroft]

I had kind of thought the I400 was based on the D15, and the I600 was based on the D17.
C H Wendels AC book page 336 shows pictures of both. According to the spec's. and pictures, the I400 was based on the D10/12, and the I600 was based on the D15.
I suppose it depends on fuel, climate, etc., but Champion spark plugs have never been friendly in these engines. We also always used AC 45's. Now I use Autolite. The hotter ones seem to work fine. 295 comes to mind, but that's by memory.
 

[CamR]

Thanks very much for all of your assistance and input. I am really not sure of the engine size. There is a stamped number on the block that reads
160-159845B.
Could those first three digits mean 160 cubic inch? At first I thought those 3 digits indicated from I600 engine.
 

[Bob Bancroft]

Yes- 160 cu. in., as in the late D15, known as D15 series II.