Oil pressure jumping around at higher RPM's - add a windage tray?

[Jetmugg]

Excellent information.  I have a couple of spare oil pumps I can pull apart before attempting to ream the bore of the "real" pump. 

I get what you are saying about putting some legs, or "feet" at the end of the pickup tube to keep it from getting smashed against the inside of the pan.  Any ideas about how far from the bottom of the pan the pickup tube should be located?  (I'm thinking about 1/8" or so).

I'll also take one of the pumps apart with an eye towards drilling and tapping for an allen-head set screw (we have plenty of them at work) to allow pressure adjustments to be made.  If the bypass piston bore is close to a standard size, there's a pretty good chance that we will have an appropriate reamer.  (I manage a small manufacturing company with an in-house machine shop).

I'll be busy tonight, but should have some time to work on the pickup tube and oil pump on Wednesday evening.

Steve.

[theman53]

I would keep it up 3/8" to 1/2" or about as big as the hole is in the pickup.

If you take the "freeze plug" out, please drill it for a small cotter pin to go into BEFORE you take it out. That way you know where to put it back to and have some insurance it stays in. It is only held in by the pinched part of the pump and once you take it out it deforms that. Also, if you deform the plug you can open it back up with a press and a socket.

I really think, as I asked before about your oil pan, you were running out of oil to pump. It is always good to over build, but I bet the extra quart of oil will work.

[Jetmugg]

Looking at that little "freeze plug", stamped cup, it is peened in place.  The only way I can see to remove it would be to carefully grind the peened portion of the housing away, which would allow the stamped cup to be removed.

I would love to see a cut-away view of this area, to see if there is a handy place to tap threads for an allen head set screw type arrangement.

To my eye, it doesn't look like there's anything there to D&T a hole into in order to fit a screw.

Southernman - if you could provide a sketch, that would be fantastic.  I just don't have a clear vision of what's behind that plug, other than a spring and a piston.

Steve.

[Jetmugg]

Ok - after taking another look at Southernman's description, I think he is proposing removing the freeze plug, then tapping threads into the large diameter of the housing, which measures 0.738"-0.745" (using a cheap pair of calipers).  That's a little bit too big for a 1/2 NPT pipe plug. 

It's more in the size range of an M20 fastener, which seems mighty large for a short set screw.

Steve.

[theman53]

I thought he was talking bout the other end. If I can find my pics I will send you them. I have taken many of these apart and got them working again no issues.

[theman53]

Got them. This is how I do it.









The cotter pin goes in the hole, any questions

[Jetmugg]

It looks like I'm using the same pump (Schadek)?



Thanks for the pics, Lucas.  I assume you run the drywall screw into the hole in the end of the plug, then pull it out with the vise grips, correct? Cross drilling for the cotter pin is a good idea - thanks for sharing.

At that point, what do you do to the OD of the piston and/or the bore of the lower pump housing?  I'll have to check and see if we have a hone small enough to get into that bore, but I doubt it.  I can polish the OD of the piston to let it slide a little more smoothly if that's an issue.

As to what Southernman was talking about, I don't see a handy way to add a setscrew type of adjustment, apart from making a solid plug for the cap end, then drilling and tapping it.  I don't really think I need to go to that extent with the current setup.

Steve.

[theman53]

Yeah if you don't drill before you pull the plug you don't have a shot at getting it back to where it was. I personally don't cut down the surface of the pump or piston intentionally. I just clean it out and smooth out any burrs. Then I put it back together. If anything I would try to cut the od of the piston out by the "freeze plug" and leave the initial od alone. All of these I have torn down just have a little build up of metal and after that metal eats the pump housing a bit and you clean it out I haven't had an issue. Make sure to take shop air and make the piston function. Try to make it stick, rotate it, and keep doing it. Once you have a feel for it you will see if and where it was getting hung up and make adjustments accordingly.


That pump pictured is the one I run in the mk2 jetta I have. It runs maybe a tick over 50lbs when hot and redline, 15lbs at hot idle. Redline being 6,000rpm and figuring 10 psi for every 1,000 rpm is about right. I have always ran the windage tray and haven't had any issues...but I run better oil, lol

[air-cooled or diesel]

by the way good luck at Bonneville, hope you get hi-rpm oil pressure by then,,

[southernman]

Hey guys, sorry for the delayed response.

I like how theman approached this tweak, and it certainly would be a more conventional approach. Also, the oil pressure numbers appear to be right on the mark.

I'm kind of fortunate that I have access to a full array of machining equipment (Mills, lathes, CNC equipment, etc), so the threaded plug arrangement would be my approach (match the D&T to the hole, then use a lathe to trim and recess the threaded plug to match spring OD), since the cotter pin can 'work' in the hole over time, and you'll end up with a small 'controlled' bleed somewhere down the road. Not a big deal.

The other reason I'd ream the bore is, as theman suggested, rotating the piston around to 'find' high spots means there's been some distortion within the hsg itself. You can keep rotating and sanding until you achieve smooth operation, but setting the pump up on the mill and reaming a couple thousands will accomplish the same thing - but guarantee straightness of the hsg bore.

Either are good solutions, but the reason I prefer the plug is to permit 'tuning' of the spring itself, without working the pin holes each time you change the spring out. Themans solution would work fine on my street driven vehicles providing the pin holes don't wallow and/or pin break (I'd have to rely on his experience with longevity of such mods), and the other is suggested for high rpm/race consideration (i.e. if you wanted to try near 0w/10, 0w oils or similar synthetics, to pull a few more horses out of it, you could use the bypass springs diameter, length, and rates to dial it in).

Good discussion guys and thanks for all the great ideas.

Southernman

[theman53]

The cotter pin is really just insurance when I do it. The pump bore is pinched at the "freeze plug" end and holds it well all by itself. The cotter pin is just there in case while pulling it out and pressing it back in the bore or plug gets distorted. This is the same oil pump out of my last 1.6 build that had 40,000 miles on it and this build has about 7,000 on it. I had some issues by accidentally smashing a wire in the vac pump and it didn't sit right. Long story short I had to pull this pump and clean it again. The cotter pin is fine. If done the way mine is done I would see no issue to run it for a million miles. Especially considering how the stock setup is just held in by the pinched end of the housing.

[Jetmugg]

I've been hectic-busy for a little while, but got the engine put back together over the weekend.  I polished the oil bypass piston using metallurgical polishing equipment, and polished the bore of the bypass section as well as I could without specialized equipment.  The piston moved very smoothly at that point, and I verified movement with an air compressor and rubber nozzle.

I used Theman's cotter pin technique to set the position of the plug, and allow re-installation in the same position relative to the pump body.

The home-spun baffled pan, extended pickup tube, and angled turbo return fitting, and windage tray were all installed using brand new socket-head, integrated washer bolts from McMaster.

I added 4-1/2 quarts of Mobil 1 15-50, and a fresh Bosch 3421 filter before firing it up.  I let it idle and warm up a while before giving her some rpm's. 

I held the rpms between 5500 and 6000 for what seemed like an eternity, with a few short trips on the high side of 6000.  The oil pressure held steady as a rock at about 65 psi, and never bobbled a bit. 

Thanks for all the suggestions.  I feel pretty good about the engine right now, and the real test will be in less than a month.

Steve.

[theman53]

I could be wrong but I don't think that is the correct filter. I think that is the gasser filter, which I have heard has 1/2 the burst rating of the diesel filter and some other stuff I cannot remember, all of which I cannot confirm, but hopefully someone will know and have proof. I use 068115561E it is a mann filter for the ahu and is supposed to have higher burst rating and bypass pressure than even the regular diesel filter. Also, I have always needed 5 quarts for an oil change with the 4 quart pan. The bosch number I got when searching was 72199WS or 72150 for the diesel filters

[srgtlord]

As a side note, in the gasser world bosch oil filters are known to cause the oil light to go on. I personally had this happen. They are in the same quality department as FRAM filters nowadays.

[Jetmugg]

Hmmm - very good information.  I've been using that filter part# since I fired this engine up for the first time.  Between break in, inspection, and having the pan off, I think I've used 3 of them.  It's my fault for not double checking, just relying on the # that the parts counter guy quoted.

One nice feature about that filter is that it's a slightly smaller outside diameter, which helps it clear the center front motor mount.  That's probably not an issue for OEM Volkswagen applications, but I am using a Dodge Omni style front mount.  At one point, I bought what I thought was the correct filter for the application (non-Bosch), but the outside diameter was too large to clear the mount.  The filter would not thread onto the oil cooler adapter due to that interference.

Sounds like I need to do some more research to find a "diesel" oil filter that will work.

This place is a wealth of knowledge!

Steve.