The need to breathe

[joescoolcustoms]

Over the years, the miles covered, I have noticed a few tell-tell signs of a breathing system not up to capacity of the engine. If you see some of these conditions, you may need to either up the capacity of the breathing system, or consider refurbishing your rings sealing condition.

Obvious, but some people have missed the clue, (me), engine coated in a oil mist and the back of the vehicle covered in a oil mist.

The guy behind you saying you just dumped all kinds of oil on his Monoque Manx when you got out of the throttle when getting off the interstate after a 2 1/2 hour run at high speed.

To a lessor extent.... (but usually come in groupings of these)

Oil mist around your breather box.

valve cover on the 3/4 side consistently loosing oil past several gaskets changes

Oil mist around rear crank pulley (if not sand sealed)

Oil consistently leaking from weep hole in bellhousing/engine case split

Distributor leaking oil.

Fuel Pump base leaking oil.

Pushrod tubes developing oil leaks.

Cylinder bases developing oil leaks.


Successful Crankcase venting can be a Black Art on bigger inch engines.
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Bad News Racing 2018 NORRA 1000 3rd in Class
Best Day Ever Racing 2022 NORRA 1000 2nd in Class and first All Female team to complete the race

Everyone is gifted. Some just do not open the package.

Looks like it was painted with a live chicken,polished with a brick and buffed with a pine cone

[Busted Knuckle Garage]

I see the last post to this thread was about 2 years ago. Does anyone have any new ideas on the breather systems? I have a new 2165 engine with a fancy breather box mounted where the oil filler tube goes. It is clearly not working. There is oil vapor everywhere like Joe described in his last post above. I admit I am a newby but this ain't brain surgery.

Thanks for all you're constructive comments.
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Frank

[vwracerdave]

Nothing new has been developed the last 40 years. A breather system is still a breather system. You will get a lot more info if you search around in the Performance engine thread.
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2017 Street Comp Champion - Thunder Valley Raceway Park - Noble, OK
2010 Sportsman ET Champion - Mid-America Dragway - Arkansas City, KS
1997 Sportsman ET Champion - Thunder Valley Raceway Park - Noble ,OK
Featured in Dec. 2001 HOT VW's Magazine page 63

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[Busted Knuckle Garage]

Well Dave I took you're advice and searched the forum. You owe me a bottle of Tylenol. But after it is all said and all read you are correct. Nothing new in 40 years. Thanks for the tip.
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Frank

[joescoolcustoms]

I now have a lot more miles on my 2165 engine with 4 cross continent trips, a Baja race, and lots of miles traveling to buggy events. A little over 70,000 miles on it, in the same buggy, so testing is consistent.

On hard runs on the interstate, under harsh load, for an hour +, at 80 mph, the way I had it set up with the 3/4 VC non-vented but with oil return on bottom to the sump, the engine would still mist oil. Not bad, but any oil lost means I was not properly handling the situation. At that point, I had 55,000 + miles on the engine/transaxle/chassis, I had lost interest in finding a cure, just drive it at that point and add a quart every 2000 miles.

When I decided to race Baja, I was scared of that 3/4 VC oil return being a issue so low, getting ripped off. So I removed it, capped the sump, replaced the VC with a new unit without any venting or oil management. Just go on blind faith and take two cases of oil with me across the US and for the race.

Huh! The engine does not mist oil now unless I am running hard around 4000 rpm for extended periods, (90 + mph). And then it is only a fine mist, not dumping.

If you look at Page 1 of this thread, my system now is just the right side breathing. The left side VC is closed and the top tank plugged on the left bottom. The rest is just as the photo.

Some data for consistency. The transaxle is a 4.12 R/P with a 0.82 4th gear and 29 inch tall rear tires. So when traveling, the engine runs 2750 rpm @ 70 mph. The oil temp returning into the engine is a fairly stable 195 to 210* F. Head temp ranges from 375 to 400*F on # 3 plug located sensor. Type 181 fan shroud with no bottom thermo flaps, and Type III cool tins under the cylinders. External thermo controlled fan cooled cooler and oil filter. Stock Dog House cooler in place with Hoover bit and foam wrapped to prevent leaking cooling air. Small valve heads, (041) and small carbs (dual 36 Dells). FK7 cam with 1.4 rockers. Single high rev valve springs. 010 cast iron distributor with protronics pickup. Nothing really exotic except crank, rods and pistons.
_________________
Bad News Racing 2018 NORRA 1000 3rd in Class
Best Day Ever Racing 2022 NORRA 1000 2nd in Class and first All Female team to complete the race

Everyone is gifted. Some just do not open the package.

Looks like it was painted with a live chicken,polished with a brick and buffed with a pine cone