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View Full Version : Engine: Oil breather/fillers: is one better than the other?



Bob Andrews
07-25-2014, 05:24 PM
Changing engines in my 62 Daytona. 259 auto.

The original engine has the tall pipe with and no breathers in the cover. The replacement does not have the fillpipe, has a cap on each cover.

To those with experience, is one set up better than the other in terms of function? It's only a lark, so I'm not that worried about authenticity.

Which do you think I should go with?

Mike Van Veghten
07-25-2014, 07:45 PM
Funny..."only a Lark"....!

By cover...I'm assuming you mean "rocker cover(s)" ? Or is "it" the valley cover you are talking about ?

In any case, the valley cover has some sort of breather, either a road draft tube or a location for a PCV valve/hose nipple. You should also have the breather at the front-center of the engine, this is also a crankcase breather. The way the heads are designed, the heads are not that good of an outlet for a crankcase pressure outlet...so most anything you like, up to no breather is just fine is fine on the rocker covers. As long as the valley and the front breather is in place and working...the rest is up to you.

Mike

Bob Andrews
07-25-2014, 09:15 PM
Yes, I meant rocker covers. Here's a big picture of the two engines together.

http://i12.photobucket.com/albums/a243/bams50/F0A4581F-9968-4BD8-95D4-EF211AC93763_zpsofgsnxkp.jpg (http://s12.photobucket.com/user/bams50/media/F0A4581F-9968-4BD8-95D4-EF211AC93763_zpsofgsnxkp.jpg.html)

One on the left came out. It had the filler tube and road draft tube. The one on the right has no filler tube but has rhe caps on the Rocker Covers. I just wondered if one set up worked better than the other.

As for 'just a Lark' Larks are still my favorite. But value wise, as a group they are not nearly as valuable as say Avantis or Hawks. And if that's okay with me. The bright side is that the difference in value between completely correct and altered isn't much. So that gives me more freedom to change what I want. That's what I meant.

Mike Van Veghten
07-25-2014, 10:55 PM
As noted, the rocker cover breathers aren't as effective as the road draft tube (valley pan) and the filler tube (upper front of the engine). If it is an occasional driver or an around town driver, the rocker cover breathers are fine. If you plan on higher speed freeway drives or any racing, I'd make sure the two "engine" breathers are working.
Otherwise, the built up crankcase pressure fill find the easiest way out it can find, and you may not like the location...!

Mike

Skybolt
07-26-2014, 12:19 AM
The breathers on the valve covers are to let air into the engine and to help the oil flow down to the crankcase. That is why they have the mesh in them to trap dirt etc... and should be serviced occasionally. The filler tube that was at the front and center of the block was supposed to do the same thing on the older engines but crankcase pressure would sometimes blow back up there and bring oil with it. With the proper PCV and newer valve cover breathers working correctly one should have a flow of metered air passing through the caps down through the head drains into the crankcase and out through the PCV valve and up into the carb. That is the theory but it is hard to get it to work as well as it was supposed to. It does do somewhat as it was designed but improvement can be made to make it work better.

Len.

Bob Andrews
07-26-2014, 09:52 AM
Thanks for the good info, guys! I appreciate the time taken to respond.

bezhawk
07-26-2014, 11:01 AM
The breathers on the valve covers are to let air into the engine and to help the oil flow down to the crankcase. That is why they have the mesh in them to trap dirt etc... and should be serviced occasionally. The filler tube that was at the front and center of the block was supposed to do the same thing on the older engines but crankcase pressure would sometimes blow back up there and bring oil with it. With the proper PCV and newer valve cover breathers working correctly one should have a flow of metered air passing through the caps down through the head drains into the crankcase and out through the PCV valve and up into the carb. That is the theory but it is hard to get it to work as well as it was supposed to. It does do somewhat as it was designed but improvement can be made to make it work better.

Len.
What is the best improvements that could be made to make it work the best? I have often wondered how it can work at all (especially on an R2). The PCV valves leave lots to be desired. What have others done to improve crankcase breathing ? What parts did you use?

StudeRich
07-26-2014, 12:57 PM
The R1 and R2 setup IS the "New Improved" System! It is way better with the large breather Tube coming out of the Oil Pan.
It has BOTH the Lower Loc. and speed system AND the Higher Loc. & speed system to the Air Cleaner.

In 1963 it was so good and innovative that a SAE "Paper" was written about it.

I see no problems with it whatsoever.

Both Systems when using proper parts and well maintained, work well for their designed use.

(1) Standard '63-'64 259/289 PCV System for Street use.

(2) R1/R2 High Performance System for Street Plus higher Speed, compression and Power.

StudeRich
07-26-2014, 01:06 PM
Bob; the New improved "Oil Cap" Valve Covers provide for a chance to "clean up" the front of the engine getting rid of that unsightly old fashioned Cadillac/Olds design Oil Filler Pipe, AND the Oil Filter.
The added pluses are you get full filtration of all of the Oil right from the Oil Pump with the Full Flow Filter and better Crankcase breathing.

I see that the early '62 Partial Flow Engine was a Power steering Car Engine.

Reggie
08-09-2014, 05:46 PM
Bob, you better just crate that engine up, send it to Jack in Spokane, and have him go all the way through it. Swap in a 289 crank & new oversize 289 pistons, and bring it up to R1 specs. No sense being a CASO--they aren't making Larks, anymore.

rockinhawk
08-09-2014, 06:31 PM
Rich mentioned the oil filter. I was wondering about that too. Is your new block a Full flow, with the filter on the bottom? If not,you'll need the stand pipe up front to mount the filter on. Unless,of course,you mount it somewhere else.

tim333
08-10-2014, 11:30 PM
I have 57 Commander with the 259. Are there any other breathers besides the oil fill cap with mesh at the front center of the engine?