You won't believe what I figured out! Easy Cam Polish!
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- Опубліковано 5 вер 2024
- I found out one of my cams had some scoring on it! So I show you how to address the issue in this video! This is for a Subaru cam shaft but the concept can be used on ANY cam!
Another trick that is often used for polishing crankshaft journals is to wrap the sandpaper around entirely and use a shoelace wrapped a few times around it to move the sandpaper back and forth. This way you keep constant 360° pressure and dont create any out of round issues. Simple but I'm told it works well.
On my 2006 Renault Megane 1.5 DCI , POS, bought for peanuts 1 month ago with 299 000 kms,holed piston and all, the cam is so scored that the (upper, of course) aluminum cap is so worn, that it even has sharp edges protruding out to the sides, its aluminum has beed extruded,displaced to the sides; when i sand down and half-polish the cam journals it will become undersized;
On top of that,the Alu. cap will have an oversized bore, so, i will mic. both cam and bore,and sand down the cap to around .001 to .002 clearance ;
Won't be 100% round any more but i have done them like that for many years, works well
Doing like this for a while now. Didn't knew it was a think 😂. Done it many times as long as you keep it even and doesn't go beyond. Then it's good to go
I first thought about using diamond lapping compound but then I remembered about non - embedding lapping compounds . So I’m gunna find some of that instead & then put some on the cam bearing surfaces & lightly torque it down & begin to lap away the problem areas that are possibly causing the cam to bind .
I'd totally try it honestly. In hindsight I probably would have gone up to 5k grit
You had me at "side quest"
This is a great thing to do. I did mine on an old lathe I got ripped off on from Craigslist. It was good enough for this process though! Haven't put up a video on it yet. I got to the Aluminum with a Dremel extension and buff wheels.
a lathe is the PERFECT way to do it! This video is the broke boy version
nice way to help save some money. But, frankly, if I saw a cam with that kind of wear on a journal (much less a lobe) I would be replacing he camshaft and lifters. That is not meant to be offensive to say your approach is not viable. I just don't feel it is worth having an excessive clearance with a non-machined surface. My two cents...
the lifters in these motors have a cap over them. i would send it off for a regrind if the lobe was messed up. since these ride in an oil jacket as long as they are smooth and not gouging out the aluminum journal it sits in they are fine. But I completely understand what you are saying. Many other motor types I defiantly wouldn't suggest it. Motor has 45k on it making some descent power since this video ;D
Not the proper way to polish cams or cranks, that will miss shape the cam. Must wrap sand paper all the way around, secure loosely with electrical tape then wrap a shoe lace around 2 or 3 times and pull back and forth, that way there is constant pressure all the way around the cam and it will stay round
Car has 50k on the motor since then bud.
What if the lobe is gouged?
If it gouged too far id not suggest this. This was very light. Caught my fingernail but not deep.
Nice tip. Did you do any polishing to the journals and bearings?
I just took the rough edges off the journals. There aren't really bearings. And the journals are aluminum so the gouging shouldn't bother the steel cams was my thinking.
Damn, if this is rough to the touch & mine is not, as in if you touch the journals it’s smooth but has visible scores, then I think I’m good?
I'd polish them lightly and send it
now do the journals
I actually did do them just to take down any gouging. Motor has like 40k on it still running strong.
Mate that camshaft is Toast. Scrap it.
been running for 60k miles now... mate
Definitely not the proper way to polish any kind of cans of drinks you do it that way you're going to get them out of round
Sept they have like 50k on them since...