1. I opened up my package of clevite rod bearings and noticed a big ol thumb print on a couple. I know we try not to touch the bearing surface...what i don't know is the specifics and when to replace bearing.

2. Got block back from machine shop with top-end cam bearings installed- thinking about doing some touch up work that could produce grit and shavings- would like to clean the block better anyway- blow out passages better maybe use detergent too. can I do that with the bearings in or is there something i can do to cover or protect them from dirt etc? or do I make a choice to leave it as is or replace the bearings after I'm done with the block- it has been completely worked over by the machine shop.

thanks

 

Dude, don't sweat it.

#2 Cam bearings are almost always installed by the machine shop......and all good builders (even shade tree mechanics like us) will wire brush and scrub the block afterwards.

Just make sure the bearings are dry right away and coat 'em to prevent any oxidation....you'll be fine.


#1 I can't imagine being worried about a finger print..........but if you're worried, use some cheese clothe or scotch brite to clean it and check your clearances using plati-gauge.

.002-.003" if memory serves me right.

 

I agree, but add that you can wash the block with 'dawn' or your favorite brand, BUT you must make sure that any bare metal is dried completely and oiled after you are done giving the bath. You can also use a white rag to check the cylinder bores for grit & dirt. Oil the rag, and wipe the cylinder wall. If it comes up dark or black, you need to use soap and hot water and wash it down. Again, any surface that is 'brand new to the air' will rust as quick as you can go inside for a cold one and come back out... (exaggerating a little here) and it needs to be oiled for protection.
You can also used compressed air to blow out the oil passages.
tom

 

great...thanks...and, yes, to the plastiguage for sure- I've got a ton of $$ into this thing and won't skimp on any part or procedure- other than doing it myself which is the goal of this whole thing anyway.

I remember some posts where it was said that any type of grit on the bearings is there to stay- can't be cleaned off...but I don't remember the specifics and can't find it again- I'm thinking it could have been someone needing to take a bit of surface off a bearing which may be different.

thanks

 

As far as I can remember- the grit in the bearings was a cam disaster where a lobe(s) was wiped. Grit embedded by a running engine is there to stay.

I have heard regular Tide laundry detergent is what was used for block cleaning. I don't remember why or if other detergents will work as well.

 

ExampleThe machine shop had to drill the block for the retro cam kit- they put in (cheap) cam bearings- lined it up with the lifters per directions and drilled the holes....they then removed the cam bearings and replaced with the clevite 77 that i wanted. They discussed this with me before hand and didn't want to risk getting filings on the cam bearing. The block has been baked twice and is clean...I'm just thinking about doing some valley clean up like discussed. Wonder if I coule coat the bearings with thick grease to protect them or masking tape over them or...something...or nothing.

 

Roger, my $.02...

The grease sounds like a good idea in theory, but, how do you get it off the bearing without wiping it off somehow...with all those nasty, captured metal chips in it? I guess you could keep blasting the bearings off with brake cleaner & try to wash it off without touching the bearings, but I'm guessing that it would be hard to control the run-off. That would make me a little nervous.

My principle would be to keep from ever getting the chips near the bearings in the first place, & to me that means lots of masking paper, tape, patience, & a shop vac afterwards. (In other words, abstinence AND protection. ) I'd tape over the bearing bore sides, too. If ya really want to be ****, tape over the bores, then put another layer of tape sticky side out in an effort to catch strays.

I've used pretty much any powdered laundry detergent, but Tide's the easiest one to tell the better half to get. I try to avoid asking her to do this for at least a day or two after I've used the oven to bake parts & cure coatings.

 

I just love overkill....I'm not going to work on the valley as I'm not at all convinced that it helps- I think the uneven surfaces make pathways easier to find and oil gets where it needs to faster...spreading a liquid over a flat machined surface, imo, will hinder oil flow to the pan. That, of course after much thought and inner debate.

I do want to blow everything out real good and make sure it's as clean as possible- it was baked and cleaned twice and I will figure out a way to keep junk off the cam bearings.

 

LOL..........you talk to 10 different builders, you'll get 10 different answers!!!

I've seen a lot of Chevy builders paint the lifter valley.....I always kinda thought that dumb. To achieve what I thought they were going for I have POLISHED my lifter valleys on the 1/2 dozen or so motors I've built!!!

I'm thinking the smooooth surface will get the oil back to the pan quicker.


Also under the impession a smooth surface will help prevent any cracking???

 

But, but, but -- getting the oil back to the pan quicker gives it less time to cool down on the valley surface. Wouldn't the block, cooled by the cooling system, be a lower temp place than the pan?

I think we are talking about those angels dancing on the heads of pins, now. Mebbe.
tom

 

last thing you'd want to do is get me mixed up with a builder...though I did stay at that holiday inn express place once so i can get to feeling froggy at times. (travelling to S. Cal later this month- so will spend a couple of nights at one- i'll have a whole new build designed by time i get back)

Reasoning: (research design used here is full of confounds)

The reason we don't polish the intake ports is the liquid (gas) can stick to the polished surface. I was thinking that oil is a liquid...so... while I was porting the heads I did an experiement of sorts...I put the polished surface of the head and unpolished (cast surface) at the same angle(s) and applied drops of (light) oil to different dry areas to see how they'd flow- took more liquid to get the flow across the machined surface- it 'stuck' in a way that it didn't with the cast surface where there were like little pathways that were overrun by the liquid and created faster than the polished. The steeper the angle the less it's stick to both-duh-. I think the polished surface would tend to flow thicker oil faster as the rough surface would then have the right surface to stick too. but the grease didn't move at all on either- go figure. Also the uneven, craggy surface of the drain holes in the valley is also better left alone imo- allows the liquid to combine and drip/run faster. imo...IMHO.

so hows that for polishing pin heads for the circus??

 

Wouldn't polishing the valley break the surface tension of the casting, making it more prone to cracking? (Polishing rods?) This also brings up the issue of oil galley restrictor plugs......to keep the oil from pouring down on your rotating assembly. Keep polishing that pin, Roger........

 

I'm on to waxing it now!

 

Kinda lost me on that one..........Rods are polished to RELIEVE stressors and prevent cracking.

http://www.300below.com/site/rodsperformance.html


Connecting rods
Lower-horsepower applications can retain stock connecting rods if a small amount of work is invested in them. The big end of the rod should be resized and the small end bushed so that a full-floating pin can be installed instead of a press-fit pin. This will free up a little horsepower, but more important, it will reduce heat in the pin bore region. By polishing the beams (sides) of the rod, stress risers are removed and the part is strengthened. Aftermarket rod bolts such its those made by ARP need to be installed. The rod bolt is the most critical part of the assembly and absorbs most of the force as the crankshaft rotates.

 

Check out this site...........especially the lifter valley pic about 5/8's down



http://www.sa-motorsports.com/blockdiy/blkdiy.shtm