M21 Engine Rebuild

Finally, a home for all you 524td oil burners out there.
z122643
Posts: 27
Joined: Oct 14, 2014 12:15 PM
Location: Laguna Niguel, CA

Re: M21 Engine Rebuild

Post by z122643 »

gadget73 wrote: Sep 21, 2020 11:54 AM
kingoftarmace2004 wrote: Sep 21, 2020 10:40 AM the cam "sprayer" tube. has holes every cam lobe. it kinda just puts a stream over the lobe as it spins to give it some lubrication. I know you did not ask me, but hey. -Paul
Answers is answers, I'm not picky who they come from. Thanks. Next time I happen to have the cover off mine I'll make sure the holes are clear.
Interesting side note, during the disassembly we noticed that two of the cam lobes were badly scored. Turns out the holes in the "sprinkler" for those lobes were blocked. If you are going to clean the holes use vacuum, do not push the blockage back into the tube, it will just flow to the next hole and block it. You can check if you have a blockage fairly easily by running the engine with the cover off and observing oil flow.
gadget73
Posts: 570
Joined: Nov 22, 2017 11:30 PM
Location: New Jersey

Re: M21 Engine Rebuild

Post by gadget73 »

Thats kind of what I was wondering. I may just pull that tube off and give it a good flush next time things are apart to prevent possible future issues. My cam is in really nice shape and I'd like to keep it that way. I have no idea what the maintenance history is on this thing but everything I've seen so far makes me think it was pretty good.
z122643
Posts: 27
Joined: Oct 14, 2014 12:15 PM
Location: Laguna Niguel, CA

Re: M21 Engine Rebuild

Post by z122643 »

So as I began designing the connecting rod I found something interesting (not unexpected, just interesting). The amount of edge loading at the 6 o'clock position on the pin end was excessive. Just as a sanity check I took a look at the original rod and sure enough excessive edge loading can be observed. There are a couple of design changes I will have to make, ideally I would change the pistons as well but I already have new OEM ones :roll:
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kingoftarmace2004
Posts: 99
Joined: Mar 15, 2018 3:34 PM
Location: Fall River Mills

Re: M21 Engine Rebuild

Post by kingoftarmace2004 »

by the way, what is it that you do for a living that you have access to such very cool tools!? Thanks! -Paul
kingoftarmace2004
Posts: 99
Joined: Mar 15, 2018 3:34 PM
Location: Fall River Mills

Re: M21 Engine Rebuild

Post by kingoftarmace2004 »

also that is the "load side" of the pin. i know round objects should have really no load side but. in theory, just mybe it was engineered or intended to accept all that brute force that the diesel produces. just my two cents -Paul
gadget73
Posts: 570
Joined: Nov 22, 2017 11:30 PM
Location: New Jersey

Re: M21 Engine Rebuild

Post by gadget73 »

There is definitely a direction of stress. The bottom side of the small end gets the abuse compressing things and the stress from the combustion process so it makes perfect sense that it would be the stressed area.
z122643
Posts: 27
Joined: Oct 14, 2014 12:15 PM
Location: Laguna Niguel, CA

Re: M21 Engine Rebuild

Post by z122643 »

kingoftarmace2004 wrote: Sep 27, 2020 4:27 PM by the way, what is it that you do for a living that you have access to such very cool tools!? Thanks! -Paul
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gadget73
Posts: 570
Joined: Nov 22, 2017 11:30 PM
Location: New Jersey

Re: M21 Engine Rebuild

Post by gadget73 »

I was just assuming you were Q rather than 007.
kingoftarmace2004
Posts: 99
Joined: Mar 15, 2018 3:34 PM
Location: Fall River Mills

Re: M21 Engine Rebuild

Post by kingoftarmace2004 »

oh come on! 007 doesn't have hobbies.....
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