Here is a pic of the block. Someone has polished the complete block inside? What´s the sense of this?

Regards, Günther

 

Reduce casting flash and improve oil drain back.

 

Helps with oil drainback.

Another old school method was painting with Glyptal which was kind of epoxy paint used in electrical motors. Made a smooth surface to help oil drainback.

 

Someone did a nice job.

 

Do the glyptal if it bugs you
Polished screened every surface possible on a Dart little M yrs ago all it did was **** off the guy cleaning it and make a mess lol

If you think about it once the engine has been started and oil run down it only comes so fast dont think it makes a difference one way or the other.
last engine did nothing excpet the oil return hols, chamfer it a bit.

 

No, really you would be surprised the amount of sand from the casting process that is still in the nooks and crannies of the block. I found a couple pockets of sand about 1/8" deep on the underside of my 454 block I just built. There's a lot of crap just waiting to come loose and tear things up. It does help drainback a little, but I've seen 1st hand what just a little bit of dirt does to pistons and bearings. I polish mine top and bottom.

 

That can help with cooling as well as oil drain back , Thats because u have no slag that can become hot spots anymore making the entire area dissipate the heat more evenly

 

On a street motor it is a complete waste of time and effort. Oil drain back is never a problem on a street driven engine.

 

I look at it a lot like flow through an intake port. A very thin layer clings to the surface which lets the rest breeze on by. Without laminar flow, turbulence is introduced which actually slows everything down.

 

Its to create surface tension, cracks start along parting lines and uneven spots in castings I do all my work that way at least for the last 40 years. Hears a rod polished and shot peened.

 

It will look great when you turn it into art.https://www.bing.com/images/search?q...M=IGRE:thumbs:

 

Pop Chevy is 100% correct. I do it even on high performance street engines..

 

I think it is more important to pay attention to oil control overall.......
A lot of people run high volume pumps......which do exactly what their name implies.....pump a lot of volume. But where does 95% of this oil end up? Under the valve covers......
On a true racing application (road course/oval track) I like to enlarge the cylinder head drainback holes and chamfer them.......get the oil out of the head first.....a HV pump will suck the pan dry because all of the oil is still under the valve covers.......
Premium standard volume pumps control the oil going up......relieving the holes in the head help it get back......simple.
As for polishing the valley? A waste IMHO. Looks nice though.

Jebby

 

The only time I've seen a high volume pump cause a problem is when someone ran at high r.p.m with a low oil level.
I also open the oil drain back holes and enlarge passages depending on the aplication. I have an 8 qt pan that I absolutely do not need on my 79,but I use it because I like having it.
polishing the lifter valley is the way I was taught and it's never caused a problem. A waste of time? I can't go with that, any extra time you spend in an engine the more things you will catch. A few years ago I built a street strip 302 ford for a friend's daughter. While polishing the lifter valley I found 2 cracks nobody would have ever seen them without a Magnaflux inspection. Any extra attention you can spend checking things the better you can prevent a failure.doing the same thing everytime the better.just like I use a torque wrench, each bolt gets 2 clicks, not 1 not 3 but 2 because I know everything will always be the same.
I don't build engines for a living like some of you, but nobody ever came back and said an engine ever came apart because I overlooked something.
I was taught by the guys that wrote the book on building race engines, it worked for them it always worked for me. You can't get an engine too clean (ask my ex wife about washing pistons and rods in the dishwasher) and you can't spend too much time inspecting

 

IMHO any hi-perf build should have all casting flash removed, sharp edges deburred/chamfered and oil passages messaged. However, I'll stick with coating the valley with Glyptal over polishing it.

In any event, given that hard cornering thru long sweepers while keeping the revs within optimum range can uncover the oil pickup (BTDT), anything that promotes oil return to the sump is definitely worth consideration where such circumstances are anticipated.

My $.02





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Not a darn thing wrong with glyptal, it's good stuff. I've seen it survive hot tanking and everything else. You can't chisel that stuff off if the surface is prepared properly.

 

Since it is already deburred/smoothed on the inside of the block, go ahead and put Glyptal paint on it. This keeps the imbedded carbon particles and any casting sand from getting into the oil. A normal cast iron block will put LOTS of carbon particulate in the circulating oil. This causes the oil to darken very quickly and puts more work on the oil filter. Sealing the internal surfaces will eliminate that issue and keep oil cleaner, longer.