DIY Main cap cleaning that wont cost lots

General engine questions/issues that aren't specific to the other categories
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DIY Main cap cleaning that wont cost lots

By Benj
- Fri Mar 19, 2010 7:13 am #182238 Ok so if you are like me and building a motor for your car and you shit the bed and forget to take the main caps in cuz they are in a box with the rest of the stuff cuz you tore the motor down 2 years ago... Anyways:

Things you will need:

one 5/16th deep 1/4 inch socket
one 1/4 inch extension
bunch of shop towels
1 can Brake clean
1 sheet of FINE emery cloth
1 scotch bright pad cut into 1//4's
1 ice cream pail
2 different length 7/16th inch bolts
1 nut to fit the 7/16th bolts
2 washers

I think thats it. So mine had some rust and random crap so i wanted to clean then...

one looked like this

Image

Image

anyways it looks like sh.... and something has to be done.

Step 1: take the guide sleeves out. take the 5/16th inch deep socket and start hitting it on a down ward motion on the floor or something hard to make the sleeve pop up and out. for one of the mains you will need that 1/4 inch extension DO NOT LOSE THESE * DO NOT PUT IN A VICE* as this will damage the main cap. once removed it should look like the first pic. sorry no pics of this

Step 2: take that sheet of FINE emery cloth, lat it face down as if it was sitting in the motor and draw a figure 8 with the main until it is clean or you are satisfied with how it looks. sorry no pics of this. But it should look like this.

Image

Step 3: take a 1/4 of the scotch bright pad and put it in the ice cream pail and soak it in brake clean.

Step 4: take the scotch bright pad in one hand and push it into the middle of the main cap and rub back and forth with EVEN PRESSURE as to get even removal. sorry no pics of that. but once that is done to your satisfaction it should look something like this.


Image

Image

Step 5: take the guide sleeves and put them back in. Take the 7/16th inch bolt put a washer on it slide it through the hole, put a washer on the other side and tighten slowly, as to not bur the sleeve, because then it may not go back in the block. Repeat on the other side sorry no pics.

Now that will do one main. Repeat steps 1 to 5 to do the other 4 main caps, and if you are as picky as me the will turn out like this..

Image


and there you go. Good luck, have fun and DONT RUSH :lol:



p.s) :woot: another wrench
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By That One Dude
- Sat Mar 20, 2010 2:59 am #182427 Good stuff.

If I may, a little constructive criticism: I noticed there's a small amount of pitting on a few of the main caps. You'd do well to start polishing out the corrosion with a red Scotchbrite pad until most of the pitting is gone, then switch to a green Scotchbrite pad to give it a good polish.

I have to polish out corrosion, pitting, heat marks, and peening on aircraft wheel bearing races fairly often. I know it's totally different, but a bearing surface is a bearing surface. Needs to be perfectly clean regardless.

That being said, you did a good job cleaning all that corrosion out on the cheap. Keep it up!
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By Benj
- Sat Mar 20, 2010 3:23 am #182433 Lol thax man ya I still have to get that lil bit of pitting out. But till I move they a wrapped up

That One Dude wrote:Good stuff.

If I may, a little constructive criticism: I noticed there's a small amount of pitting on a few of the main caps. You'd do well to start polishing out the corrosion with a red Scotchbrite pad until most of the pitting is gone, then switch to a green Scotchbrite pad to give it a good polish.

I have to polish out corrosion, pitting, heat marks, and peening on aircraft wheel bearing races fairly often. I know it's totally different, but a bearing surface is a bearing surface. Needs to be perfectly clean regardless.

That being said, you did a good job cleaning all that corrosion out on the cheap. Keep it up!
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By That One Dude
- Sun Mar 21, 2010 9:09 pm #182732 Right on. Of course you know to measure the new journal diameters for new bearings, right? I would imagine you probably do, just making sure.
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By Benj
- Mon Mar 22, 2010 3:53 am #182797
That One Dude wrote:Right on. Of course you know to measure the new journal diameters for new bearings, right? I would imagine you probably do, just making sure.


that would only be if you machined these, which all i did was take the rust build up off
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By That One Dude
- Tue Mar 23, 2010 3:44 am #183041 You still take off a small amount of metal. Albeit only a few thousandths at most, but that can be the difference between spinning a bearing, and running at 9K all day in some instances.
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