What model engines are used in DW20 tractor / scraper?

What about a chart/list of engines used in various CAT equipment?

THe 6W SNs tractors had the old roots blown D337 engine and starting with the the 67C SNs they used the turbocharged D337F engine a completely new engine from the old original engine in the D337 6W SN.As for engine list & what they,re in there is so many to list so if you know what tractor you want to know the engine it has can be posted for you.

I don't much about the history or serial numbers of the DW-20 and 21, but I ran them for an outfit that I used to work for about 25 years ago. The 20's had turbocharged engines and the 21 had a roots blower. I thought that the 21 was newer than the 20. Shouldn't the 20's have had the blown D337's and the 21 have the turbo'ed 337F?

JC 4T, I listed the DW20s there so the DW20 early was the 6W SN & the same era DW 21s were 8W SNs & both had the roots blown D337 engine. Then the later DW 20 was a 67C SN & the DW 21 was a 69C SN & they both had the D337F. Could have been the one you ran had an earlier engine installed in it for whatever reason, maybe had a blown engine & they got the other one & put in it.Those early scrapers (Ws) came out in 1951 and then the 67C & 69C came out in 1955.Just a little later in the production they made some improvements to both the tractors like after cooling them to up the horsepower & changed the SNs.to 85E 86E 87E & 88Es and some other changes which changed the SNs to these Es.

Thanks SJ. I didn't know that DW-20's and 21's were made at the same time. I thought that 21's came after the 20's. The 20's we had must have been late models because they were after cooled. The old 21 must have been an early one. They were kind of fun to run back then. I don't know if I'd want to spend 10 or 12 hours on one now, though.

I operated DW21's for about 24 years and still admire the design. I saw 3 working in Kingston, Ontario this fall; will try to attach a picture I took. The 86E was the best since more horsepower was always helpful to have. They had an excellent steering system and steered like a Cadilac. The 621 doomed them when speed became something everyone wanted to see. I heard of someone putting a 3406 in one. I still have some D337F parts including a cylinder head and crank. Phil