- Thread starter nikos
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Screwdriver
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This might be handy. I found the home made cam grinder quite interesting.
not done it yet
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Most single and twin cylinder diesels have jerk pumps. Nothing unusual.
Morrisman
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Interesting. It didn't show how he milled the lower 'hidden' can profile, or did I miss it?
And was he just freehand grinding the cam profiles, to clean them up, or did he have some profile device to pull the cam in and out while it rotated?
“We’re all doomed”....
All that hard work spoiled by an out of flat stone, shame. And yes, I was expecting a camming action from somewhere, and yes also, he didn’t show the machininge of the hidden lobe - probably used a t slot cutter?
mike os
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Certainly to 1.5 thou
Thederustinator
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If they are diesel pump cams, the grinding is critical, as to much or too litlle fuel at the wrong time will make it run like poo.
Pete.
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I actually like the idea of finishing it on the grinder like that. The profile is set by the CNC machining, then hardened, the grinding done only to give a consistant finish. He might have used a finer stone and some coolant the finish would have been a whole lot better but on the whole it's a good job well done.
8ob
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The problem with cam lift/profile/ramp on an injector pump cam is it's also the timing, symmetry is going to be the all important factor, last thing you want is to run one cylinder with a different timing set up to another. On older multi cylinder Lister/Petter diesels there was a balance bar connecting the individual pumps, it was a relatively easy task getting them balanced using the decompressors to kill off the adj cylinders while going through each pump to maintain a given rpm. Not sure about the OP`s engine.
Bob
Bob
Pete.
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I get that but this engine ran with one lobe worn down maybe 10 thou and the followers worn another 10 or 20 thou each too. A couple of thou variation is not going to be an issue IMO. It would be easy enough to mic the lobe heights and tickle one down to match the other. The profile wouldn't suffer enough to notice.
Screwdriver
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Yeah but it's not an F1 motor. I think there are three or four radii with three or four "landings" for the max/min operation of what is after all a fairly crude mechanical timing controller. Near enough is good enough and if he's skimming a few thou off hardened cam, he's not going to be far off the CNC profile.
My seat of the pants engineering module suggests if you went to the trouble of designing a "follow me" profile you'd be lucky to engineer that within a couple of thou anyway.
My seat of the pants engineering module suggests if you went to the trouble of designing a "follow me" profile you'd be lucky to engineer that within a couple of thou anyway.
zeppelin builder
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check out john renwicks workshop on you tube he shows you how to on a home made camgrinder
ps ive been welding and grinding cams for my vintage 1 cyl engines for years with good results it takes ages with a degree wheel base circle is easy its blending the profile thats hard
ps ive been welding and grinding cams for my vintage 1 cyl engines for years with good results it takes ages with a degree wheel base circle is easy its blending the profile thats hard
Link?
