I'm running the CB performance dry sump pump and am attempting to get a bit more pressure at hot idle. I'm considering addressing two potential issues:
Primary Concern: I used Loctite 518 AND the gasket between the cover and the pressure side of the pump. 518 is a gasket replacement and NOT a gasket enhancer. Anybody care to guess if I managed to increase the cover to gear clearance a bit by using 518 and the gasket on the front cover?
Secondary Concern: The last 3 feet of my supply line necks down from -12AN to a T and then -10AN. Not likely in my mind to cause a hot idle issue (cold idle is 40PSI), but thought I'd mention it.
Idle pressure is almost exactly 10PSI at 185F and 1000RPM. I'm using Brad Penn 20w-50. BTW - both motors appear to have water vapor coming out of the breathers with Brad Penn. I've heard others having this "issue" too. Is it an issue? I'm considering trying Jake's "Snake Oil"...
Try joe Gibbs racing oil.
Opinions on DT50 vs. Snake Oil (Raby's Brand)?
My "Snake Oil" became DT50 last year.
As for the 518, it shouldn't be used with a gasket, often if it is it will compromise the gasket due to its density.
Yeah... I'm half tempted to pull the fan shroud and replace the gasket/518 combo with just a gasket. Then again I have a set of Finch heads from Len waiting to go on (to replace my 2L heads) that is awfully tempting!
i dont think i used a gasket at all. just the 518. i did open the passages of the pump and radiused all of the 90 degree turns. is your oil light flickering at idle?
If I drop it much below 1000RPM with the dual pole VDO (which is set higher than stock) it will flicker or come on.
I radiused all the turns and paid special attention to the outlets as they seemed especially small. I spent some time porting and measuring this pump. A good bit more than a "cleanup" though...
What are your pressures at idle?
at 800 rpm on the blistering hot days, 230 degree oil temps im at 6 to 8 psi, running 5-30wt amzoil. no flicker with the stock sending unit. but i dont even sweat it. no load at idle.
Seems to me that a ported blueprinted oil pump would flow more, but may end up doing it at a lower oil pressure.
Have you looked at the relief valve and blueprinted that?
There was a good thread here about getting the seat smoother and making that valve do its job better...
Rich
I installed one of the Headflow Masters oil control valves out of curiosity and it made little difference at idle. I have a Weltmeister high pressure setup on the secondary relief still.
have you looked at the thread about the seating area of those valves?
Its rough and when honed and trued up, can and does increase oil pressure.
Something to look at if and when you remove the engine for heads and other work.
Rich
Are you talking the secondary relief valve? The one in the side of the case?
http://www.914world.com/bbs2/index.php?showtopic=210207&hl=relief++valve++honing
Yeah... That's the one that got entirely replaced by Adrian's widget:
http://www.headflowmasters.com/vw-oil-pressure-valve-body.html#.UlxkHGRgZRc
that might be cool, but if the seat sucks, then a new piston will still let pressure move past.
The seat is in the case.
Rich
It's not a new piston. It's an insert that replaces the piston and seat (press fit) and then uses a ball to act as the piston. Take a look a that link I sent in the previous post. It should by pass the "bad seat" problem entirely.
cool, but you still have an issue IMHO of low oil pressure.
Is there anyway for you to increase the oil pressure with a different pump?
Did your oil pressure get worse over time, or has this been since day one of the rebuild?
What is the capacity of your system?
If its small enough, go buy the other types of oil suggested, see if that helps.
rich
Day 1. But I've never run an oil pressure gauge before this build. All the normal things were done to this case to help guarantee good pressure.
The only thing I can really do pump wise is to address the issues at the top of the thread. The is the CB Dry Sump setup, so going back to a wet sump isn't really palatable. Above idle is all good so far. Technically even idle is passable, I'd just like to see more pressure there. Again, pressure is off the chart when "cold".
Forgot to say capacity is about 11 qts.
Accusump might help, depending upon how you configure it.
It may be worthwhile to try out Jakes oil...
He made mention of this in another low oil pressure thread...changing from BP to Gibbs...
Not sure, maybe the heated oils have different viscosities...which kinda sucks considering the ratings are there for a reason...
He has done some research on the oils...its what...50 bucks...
Worth a try I guess.
rich
Shit... DT50 is $10.99 a quart! It's like $140 an oil change! I read something about "additive clash" going from Brad Penn to DT50 too, so I've written the company to check it out.
Do you recall how tall the gears are in your pump?
Rich
I think it's a 21/pressure, 26/scavenge
you can get up to 30mm to fit in there.
Keep in mind, higher oil pressure will mean higher oil temps.
For your motor, at your elevation, doing what you do with the car...you need to find the sweet spot....
Not to low on pressure, yet not so high that your temps are hard to regulate.
Take a look at the Melling pumps for the type4.
I believe they have 30mm gears.
rich
Thanks Rich, but I really need a dry sump pump with the G's this car is making. I lost the last set of rod bearings with a 27mm pump, tuna can, and a 1/2 quart over. I might yank the pump cover if it starts to scare me.
I'll let everyone know what I hear from Joe Gibbs/Driven about the DT50 and Brad Penn perceived compatibility issue.
There must be a 30 mm dry sump pump...I know I had three huge ones on that race car, still have stow left, bot shadeck.
The pumps I have are not designed for the stock cooling, so that is a problem.
Yeah... BugPack is affordable, but won't work with stock cooling. Thorsten Pieper will fit but is $400 plus shipping from Germany (assuming he is still making them). And the AutoCraft is $600 and needs different plumbing (the BugPack may need that too).
How close to the shroud is your existing pump?
We are talking about 5 mm at most difference...
Maybe take a look at the CB performance dry sump covers with the 30mm melting.
Hmm, let me see what I have left, not sure it will fit but it may give up an idea or two.
I have a treuhaft pump, looks like it's about 2 inches out of the case.
The motor had a 911 cooling shroud, so space was not as much of an issue.
You could measure the clearance you have now from the cover to the shroud.
Clay on the lid, bolt the shroud back down.
Remove and measure the clay.
The shroud could be shimmed out about 5mm and still work as designed.
You could make a shim plate of 5mm to go between the cover and the pump body
Then get taller gears.
I just touched on that this process was done, so it can work easy enough.
Rich
Thanks for the feedback Jake. Interesting that I thought it was an accepted practice by most big builders to completely disable the secondary. It's will cost me about a $0.50 crush washer for me to try putting the stock secondary back in. Can't imagine it would help at idle, but I may benefit elsewhere.
Some of you know I'm starting to work with a regulated voltage supply to test this theory (which I hope to install soon). This just came to me from VDO:
=======
Aaron,
The gauges are rated for 16 volts and yes, a fluctuation in voltage will affect the accuracy of the gauge.
They are designed to receive a constant voltage of around 14 volts. A fluctuation of 12 to 14 would throw off the reading by about 5 to 10 psi.
Best regards,
Technical Support Team
Business Unit CVAM
Continental
Division Interior
6755 Snowdrift Road
Allentown, PA 18106
USA
Another possibility with the VDO being inaccurate is poor/shifting grounds.
You can isolate the VDO from the car chassis and then run a dedicated ground from the sensor to the gauge.
A regulated power supply is very simple.
You can actually install one component like a LM7812 that will output 12.0V as long as the input is ~12.8 or higher.
I put a mechanical oil pressure gauge in with the VDO and they give the same answer, but I dont have a lot of time on the system.
I would also like to see a detailed diagram of your oil setup. I know it was discussed over in the paddock, but I never did get a good diagram. Although I did start working on some new http://www.914world.com/bbs2/index.php?showtopic=217063&hl=visio that you commented on and even pulled out a spare case so I can inspect it.
I am still installing the front dual oil coolers. For right now I will just use a filter sandwich plate, but want to do a sump upgrade after that.
This widget will take as low as 8V and regulate it up to a whopping 46V if necessary. I've only tested it with a few different voltages and it stayed right were a put it. I'm outputting 14V exactly via my Fluke.
It's pretty darn inexpensive too!
I should mention all of the voltages I tested with were *below* 13V.
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