Regulate oil pressure before or after main gallery?

[jhu]

Hi all, My name is Jon Hroar Ulstad, 40 years from Norway,
Longtime reader first time poster

I have this question that I can't seem to get out of my head. Maybe you have some insight on the topic. I'm racing with Volkswagens ( I know contradiction in terms) and the wellbeing of the oil is essential to have it live.
The case is stock Volkswagen type1 Magnesium, and the normal modified wet sump oil system configuration is as follows oil pump-> oil filter-> oil cooler-> main gallery-> (internal)oil pressure regulator.
A recent fad in the Volkswagen drag racing community has been to block of the internal pressure regulator and run a external before the case, giving: oil pump-> oil filter-> oil pressure regulator-> main gallery.
I would myself like to regulate after the main gallery to make sure a stable oil pressure is present at all time, and in my head I think it might react faster to oil demand changes.
Much like a injection system is set up. In my case it would then be: oil pump-> oil filter-> oil cooler-> main gallery-> external oil pressure regulator.
Any thoughts?

[Circlotron]

If you regulate after the main gallery it would ensure more oil volume passes through the gallery than if you followed "the fad" and regulated before the gallery. This extra flow may be of some advantage in carrying away heat but I can't think of any other benefit.

[Cubic_Cleveland]

I guess it depends how much oil is getting bypassed, and how that's affecting cavitation, aeration, pump life etc. Why have people started this fad? Are there any benefits, or is it monkey see, monkey do?

[Truckedup]

Most auto engines regulate oil pressure in the pump. I believe when auto engines are converted to dry sump for racing they still generally regulate the pressure at the feed pump? Some motorcycles regulate oil pressure at the end of the galley... For your engine it might be best to use what the winners use...

[RL]

I suppose it doesn't really matter, as long as you are measuring the pressure at the end of the main oil gallery.

[cjperformance]

You need to think about potential flow volume of the pump v's oil filter flow capacity and filter bypass pressure differential if a bypass is used. With an 'after filter' regulator you can overload the filter. This can be a simple cure like running a bigger filter or 2 filters in parallel.
If you simply want more adjustability and control, block the stock pressure regulator, fit an adjustable regulator betwen the pump and filter then read pressure from the last point in the main feed circuit.

[Kevin Johnson]

Hi all, My name is Jon Hroar Ulstad, 40 years from Norway,
Longtime reader first time poster

I have this question that I can't seem to get out of my head. Maybe you have some insight on the topic. I'm racing with Volkswagens ( I know contradiction in terms) and the wellbeing of the oil is essential to have it live.
The case is stock Volkswagen type1 Magnesium, and the normal modified wet sump oil system configuration is as follows oil pump-> oil filter-> oil cooler-> main gallery-> (internal)oil pressure regulator.
A recent fad in the Volkswagen drag racing community has been to block of the internal pressure regulator and run a external before the case, giving: oil pump-> oil filter-> oil pressure regulator-> main gallery.
I would myself like to regulate after the main gallery to make sure a stable oil pressure is present at all time, and in my head I think it might react faster to oil demand changes.
Much like a injection system is set up. In my case it would then be: oil pump-> oil filter-> oil cooler-> main gallery-> external oil pressure regulator.
Any thoughts?

Have you read this thread? http://www.thesamba.com/vw/forum/viewto ... sc&start=0

[wyrmrider]

I regulate as far away from the pump as possible
at the end of the gallery on my boats
I put a strong spring in the pump
that way I have full pressure at the end of the gallery

[DaveMcLain]

While it seems to work in most cases I think its wrong to put the pop off at the end of the galley because it only increases the velocity in that passage which is not what you want to do if you want an even distribution of oil flow. The lowest pressure is NOT at the end of the passage after all the leaks as is widely assumed it is at the branch where the velocity is the highest. Velocity increases pressure decreases this is why it would be helpful to have a larger passage early in the flow tract that gets smaller as it goes so that the velocity is more uniform.

[wyrmrider]

good points dave
I ream the main oil galley to reduce velocity
on the output of the regulator I can de-aireate before going back to the pan
perhaps I'll go from 100 # spring in the pump to 80#
using pump as bypass seems to churn up the oil
main feeds are reamed
thanks

[Kevin Johnson]

Hi all, My name is Jon Hroar Ulstad, 40 years from Norway,
Longtime reader first time poster

I have this question that I can't seem to get out of my head. Maybe you have some insight on the topic. I'm racing with Volkswagens ( I know contradiction in terms) and the wellbeing of the oil is essential to have it live.
The case is stock Volkswagen type1 Magnesium, and the normal modified wet sump oil system configuration is as follows oil pump-> oil filter-> oil cooler-> main gallery-> (internal)oil pressure regulator.
A recent fad in the Volkswagen drag racing community has been to block of the internal pressure regulator and run a external before the case, giving: oil pump-> oil filter-> oil pressure regulator-> main gallery.
I would myself like to regulate after the main gallery to make sure a stable oil pressure is present at all time, and in my head I think it might react faster to oil demand changes.
Much like a injection system is set up. In my case it would then be: oil pump-> oil filter-> oil cooler-> main gallery-> external oil pressure regulator.
Any thoughts?

Have you read this thread? http://www.thesamba.com/vw/forum/viewto ... sc&start=0

So the next question is whether you are running a single or dual relief case?

[Walter R. Malik]

Ford Motor Company seemed to do very, VERY well with their racing and marine 427 FE engines which had the oil pressure regulated at both places.

The by-pass valve in the pump was usually set at a pressure about 15% higher than the spring loaded regulator piston at the very end of the main oil gallery. The valve in the pump, (before the oil filter), basically never came into play except for cold starts with cold oil.

[wyrmrider]

Basically I copied what Ford did
I had problems with FE fords without the dual reliefs
I just used 199# in the pump because that spring was easily available
but, for example, the BBM outside pump is easily adjustable
I have modified BBM pumps for hose in and out and used for regulators back in the day

[RL]

Actually porting the oil galleries is far better than worrying about regulator location.

I had an engine that always has bearing distress, even at 125psi, ported the oil galleries from start to finish and the bearing were perfect at only 76psi. This mainly entailed radiusing corners, matching miss-alignments, and porting steps on entrances. If you have flow bench experience visually use those techniques in your head to determine where to do modifications

[wyrmrider]

absolutely necessary- it's flow
and I've found broken drills and passages that were not drilled all the way through
just the pilot
evidently shortened and resharpened too many times or inserted too deep in the gang chuck
broken taps in the bottom of bolt holes and bolt holes not tapped deep enough
you have to check every hole and every thread
a small increase in diameter ups the area considerably
on a similar vein increasing the tranny cooler lines from 3/8 to 1/2 makes a big difference
there is a reason Dodge Diesels use 1/2 inch lines
throw a transdapt adapter and a full flow filter to catch debris in case the converter (clutch) disintegrates
it can save your trans and your expensive cooler -I use coolers with 1/2 in and 1/2 out
cuts backpressure from 45-50 psi to 10-15 and greatly increases flow using the fill the bucket technique
as you may know the cooler circuit lubes the main-shaft and palatinates AND trust washers
just an example- harder to measure inside engine