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Re: M21 Engine Rebuild

Posted: Sep 21, 2020 1:09 PM
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.

Re: M21 Engine Rebuild

Posted: Sep 22, 2020 9:02 AM
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.

Re: M21 Engine Rebuild

Posted: Sep 22, 2020 11:39 AM
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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Re: M21 Engine Rebuild

Posted: Sep 27, 2020 4:27 PM
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

Re: M21 Engine Rebuild

Posted: Sep 27, 2020 4:30 PM
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

Re: M21 Engine Rebuild

Posted: Sep 28, 2020 7:47 AM
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.

Re: M21 Engine Rebuild

Posted: Sep 28, 2020 12:56 PM
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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Re: M21 Engine Rebuild

Posted: Sep 29, 2020 9:34 AM
by gadget73
I was just assuming you were Q rather than 007.

Re: M21 Engine Rebuild

Posted: Oct 16, 2020 11:33 AM
by kingoftarmace2004
oh come on! 007 doesn't have hobbies.....