4020 Injector Nozzle Tip

Hello,

Working on 4020 S/N 263839R with engine block # 47170(no tag on engine)....

When our replacement injectors(aftermarket P/N SDNAR50781) arrived we noticed a significant difference in the length of the nozzles between the old(short tip) & new(long tip) injectors - see attached pictures.

According to the supplier, JD used several nozzle configurations in the pencil type injectors over the years but claims that all pencil type injectors were interchangeable.

Any issues with running these injectors in our engine?


Thanks in advance,

Glen
 

Finally got it figured..........
41851.jpg
41852.jpg
 
The latest Stanadyne pencil injector for the 4020 is part # 20494. There have been several design changes, the old style longer tip is deceiving. Measure from the lower carbon dam seal to the tip end, you will find they are about the same length that way.
 
I would change suppliers.
The earliest pencils had the long tip and a smaller diameter pipe.
That was replaced by a long tipped with a larger pipe but still no chopper as far as
I can remember. I think all the shorter tipped pencils had the chopper even though it
was changed a few times.
Are these injectors new or reman? The outfit I get remans from won't do the long tipped
injectors. Also I have seen those longer tips burn or break off somehow.
 
Thanks for the replies.

Dieseltech: I didn't actually measure the difference in length but my "eye" gauge tells me the tip on the replacement injector would protrude more into the combustion chamber(based on the distance from the upper sealing surface to the nozzle tip)

D-: These are reman units. Can you elaborate on the "larger pipe" & "chopper" you mention in your post.
 
Yeah, the preview mode has a defect in it where the imageURL does a skip and then disappears when you post it. If you'll preview it twice you can see the hop where the URL is there and then it isn't. Only work around I can think of is to preview it, like what you see, preview it again without pictures and then post it. And this describes Classic view, have little experience with modern view.
 
Look in the end of the pipe. If there's nothing there then there is no chopper (filter). Through them away.
Compare them to your originals. The earliest pencils had a pipe smaller than those pictured.
That longer tip does protrude into the piston a little more. Probably why they would burn or break off.
 

Thanks for the info.

I never tried using the classic view but I did manage to get the photos to load using the Upload Photo in the Advanced Posting Tools.
 
(quoted from post at 14:24:06 10/24/16) I would change suppliers. Also I have seen those longer tips burn or break off somehow.

The supplier is taking these injectors back & replacing with new.

I don't want to take a chance especially since they are going to be installed in a fresh engine. I'm installing the Reliance O/H kit with the high comp. hypereutectic piston option & the instructions warn of potential interference issues on 3010/4010 engines equipped with Sicntilla injectors. They recommend installing an additional sealing washer under the injector to obtain sufficient clearance.

I realize our engine configuration is not the same but I'm not up for gambling with the investment.


Thanks again!

Glen
 

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