Oil Plumbing

[cvair4life]

I'm designing hook-ups and plumbing for my remote oil cooler... need some expert opinions on hose ID's

[64powerglide]

Clark's oil cooler adaptor uses 3/8 ID hoses. Page 31 in the online catalog.

[cvair4life]

that is exactly what sparked the question... I had intended to use 8 AN which is 1/2" ID.... but seeing that note in Clarks/Otto made me think.

[bbodie52]

Oil Cooler Basics — Design and importance of Oil Coolers

http://www.enginebasics.com/Engine%20Ba ... asics.html

Engine Oil Cooler hose & fitting size?

http://www.corvetteforum.com/forums/aut ... -size.html

[cvair4life]

Oil Cooler Basics — Design and importance of Oil Coolers

http://www.enginebasics.com/Engine%20Ba ... asics.html

Engine Oil Cooler hose & fitting size?

http://www.corvetteforum.com/forums/aut ... -size.html

Good links and interesting debate on the Vette forum.

Another question - what type of pressure should be expected from the stock oil pump?

How about pressure to expect from the "High Volume" oil pump?

[cvair4life]

TheSamba says -8AN

http://www.thesamba.com/vw/forum/viewto ... n%20false;

[bbodie52]

The oil pressure would be the same with either the stock or high volume oil pump. It is regulated by a spring-loaded plunger (bypass valve) which normally maintains a maximum of 40 psi. However, the oil pressure regulation relies on a bypass path that can be overwhelmed by a combination of a high-volume oil pump and cold engine oil. This has been studied by the Corvair aviation people...

http://flycorvair.net/2013/02/10/though ... temps-etc/

The drill bit is pointing to the pressure regulator bypass hole. It has to be opened up when you install a high volume pump. Otherwise the pressure will be very high until the oil temp is thoroughly warmed up. The enlarged hole allows the bypass to work with cold thick oil. Without enlarging this hole it might take 15 minutes of running on the ground on a 40 F day before the oil settled down to its normal regulated pressure. Before this, an increase in rpm will raise the oil pressure. On very cold start ups you want to watch this, because even with the hole enlarged it is possible to have the oil pressure exceed 80 pounds by carelessly revving the engine to taxi it while the oil is still cold. Give the engine a chance to warm up, don’t be in a rush. Oil pressure spikes are very rough on the drive system running the pump. This is true of almost all engines, not just Corvairs. People don’t talk about ideas like this with the buy-it-in–a-box imported engines because they just wanted to buy something and use it. Since the primary motivation with Corvair builders is to learn while creating, we talk about things. Most people are happy to just have things, people attracted to the Corvair were the ones who took apart the toaster at age 10, because for some of us, we need to know why.

http://corvaircenter.com/phorum/read.php?1,59935,60550

Does it really matter what the displacement of each pump is? Clark's site says the high volume pump puts out approximately 1/3 more volume than the standard pump which puts out more volume than the Corvair engine needs in most cases. You don't need a high volume pump with a deep pan - just an extended pickup tube. Most people today seem to think you don't need a high volume pump with an external oil cooler - reference a recent quote by "UNSAFE". I suspect that the high volume pump was developed to meet "need" that didn't really exist. Many who have installed a high volume pump have gone back to a standard volume pump after tearing up distributor or cam gears...

There is an extensive discussion on this, and reading all of the material at both of the above links may prove to be informative. "UNSAFE" Kevin Willson also makes some comments regarding the high-volume pump, oil coolers, etc. in the above Corvair Center thread that you may find useful.



I wrote some comments about the high volume oil pump and pressure regulation last November...

viewtopic.php?f=80&t=9214&p=61850&hilit ... ber#p61850

[Carputput]

Thank you, this was very helpful and the other reference "Enginebasics" site also. I will keep looking for a relocation kit. Found one on ebay, 8AN lines.
Want to keep my stock cooler for traffic.
Any other recommendations?

[66vairguy]

About the high volume oil pump ---- Years ago a car magazine (Hod Rod I think) did a great article on high volume oil pumps and there proper application. Drag and race engine (often rebuilt after only a short use) sometimes run very large tolerance to reduce friction and this requires a lot of oil volume, BUT THIS IS NOT THE CASE FOR A STREET ENGINE. The article used a stock V8 with both a stock pump and a high volume aftermarket pump. What the found was the oil temperature WAS INCREASED by the high volume oil pump. Why? The pump ALWAYS works with the engine running at a preset pressure. When the pressure by-pass opens to prevent excessive oil pressure (really bad for the bearing) the oil is simply recycled by the pump, but the pump is still pushing at pressure and this "work" converts to heat in THE OIL. The conclusion - unless there is demonstrated need - the stock oil pump always does the job as the engineers intended.

As a side note, a buddy with an old Lincoln got talked into a high volume oil pump (in spite of my warnings) and the extra stress broke the pump drive shaft and his freshly rebuilt engine was ruined. He rebuilt the engine with a stock oil pump and it's been running six years without issue.

Sometimes more is too much.