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Oil Pump Mods - Max Effort

Even if it doesn't add a single HP or make the motor last one extra mile, the mods you made are top notch in quality and detail.

Almost could be mistaken for a professional motorsports build.

Wow, Thanks for saying so. I love making/modifying stuff for myself, but getting positive feedback is icing on the cake.
 
Thanks, I don't have an Engineering degree to use in order to optimize designs, so I tend to go beyond what seems rational!

I too have looked at that tin lid with the bent tabs and the hole in the center. The melling pump doesn't have that. The pickup is all screen. I can't help to think the tin cover with the hole serves some purpose. I checked mine to the specs and decided to move on. I did buy the stiffer spring and the support ring.

Please post the height of your pump gears from that new pump.
 
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So what's the veredict for us mere mortals? Shim the m181 pressure relief spring?
 
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I didn't even realize this was a problem. I just installed my pump and transfer tube a week ago. I also run the ARP mains. I didn't have any problem installing it. But I just went down and checked. Sure as **** it's touching.

What have others done in this situation? Grind down the stud slightly?

Jordan


The next challenge was dealing with the interference between the stock oil transfer tube and the ARP mainstuds, the main studs really wanted to occupy the some space.
Also I was nervous about the stories of the o-rings popping out...

I figured the best thing was to make a new oil transfer tube that solved those problems(hopefully).

I kinda' did it the hard way, started out drawing the stock oil tube in CAD.
3D printed the stock tube model in SLS nylon, then carved away the problem area.

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After I had some reference models, I increased the tube inner diameter to match the inner oil passage diameters(Block and Pump), and designed new fittings with redundant o-rings to ensure a better seal into the pump and block. Then another SLS print to check fit.

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When I was happy with the new tube and fitting design, I then fabricated the tube and fittings from seamless steel tube and round stock, adding an addition support bracket to ensure that the tube stays in place.
TIG brazing was used for the welding process followed up with a little black oxide coating.
You can see the progression here.

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Overall, I feel good about the new transfer tube.
-Better flow
-Redundant o-rings
-Support bracket to limit movement
-Clears Main Studs

In the future, it would be nice to have the tube mandrel bent and maybe get better at TIG brazing. But I think it should work as intended.
 
Mate, the pick up tube solution is PERFECT. I'm in love. If you won't make another one, I'm fully going to steal the idea and do it myself. Any CAD files you're willing to share gladly accepted. And nice to know now up front that there's a clearance issue as I've got those same studs/nuts/washers on the way for my 16vt build.

I'm not convinced I like your pick up scoop, though. I mean, it's a beautiful thing, for sure, but under G loads that pull the oil toward the blocked side this will actually encourage air to be sucked in rather than oil that would otherwise be available to the pump. If you don't plan on tracking the car it's a non-issue. Me? I love tracks, and kiwi roads that are better than any track bar the nur.

Are you planning to up the capacity of the sump to go with this top-notch pump? I am. :-)
 
What happens if/when the coating flakes off the pump parts? Winds up in the filter I guess/we hope/think?
Probably extends oil pump life well enough...no point buying a new pump anyway.
Do the really need more pressure or more low RPM flow/pressure? Seems to hit 5bar with the stock spring OK?
I wasn't crazy about the IPD spring...

Never really liked the M181 pump for the volvo.
Had better luck just picking later model OE pumps that weren't worn out.

Sell pipe and pickup and just coat a used pump?

It was always a head scratcher for me why if they went to all the trouble to neatly chamfer and bore those holes in pump/block they couldn't be bothered to stick some kind of metal-metal brake line style connection on that stupid transfer pipe instead of those miserable hooptie o-rings.

That solution looks decent too. 2 o-rings that fit tight and a nice brace to hold that stupid pipe in place with stops instead of just 2 rubber square edge soft sealing rings you hope do the job.

Can you get the pan out with the engine in the car with that pickup? Are you going to do some hinged baffles that let oil in, but not out in the sump near the pickup so it doesn't all slosh up the side?
 
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Thanks for the feedback guys,
Positive or negative, it gets me thinking about my choices.
I should say that all this is an ongoing experiment and subject to changes.

So, top down..

-The Intake Scoop design is likely the least valuable item on my pump, it's the result of a bit of thinking and "mental simulation" on oil control in the pan. My observation is that the pickup location is crammed into the front, passenger side corner of the pan. I'm imagining it sucking that corner dry upon hard acceleration, so limiting the ability to pull from the corner and more from the center of the pan would be maybe a bit better, I have a few other designs to try in the future. Also, not sure if the pan can be removed in-car yet..

-The Pan will get a kick-out on the passenger's side to add about a quart or more capacity and put more oil around the pickup. Also adding another baffle and possibly a swinging door.

-Abradable Coating, I had concerns about particles flaking off also, but when it was explained that the coating is just a thicker version of piston skirt coatings and a proven process for oil pumps(aircraft), I felt better about it. We'll see though. Worst case is that it flakes off and ends up in the filter. Because the applied thickness is controlled, it seems a great way to tighten up used pumps as well.

-Relief Spring, I'm probably bucking convention here, but I think the stock spring is fine for my application, I've tried to increase the efficiency of the pump and in turn produce slightly higher line pressures/volume at lower RPM, Why would I care about lower RPM efficiency? I think the load on the bearings is greater at lower RPM's under high-load acceleration, thus I want more pressure/flow, earlier. Plus, if the pump can do this while using less parasitic HP, all the better. Ultimately, the relief spring just limits the peak pressure in the system IMHO.

-Transfer Tube, Lot's of ways to skin this cat, O-ring support rings on stock tube, modify stock tube and/or main stud bolt for clearance. Because I wanted to reduce any possible restriction and turbulent flow, I opted to increase the transfer tube ID, Hard to do that without redesigning the fittings as well. There was room to add a second o-ring.. o-rings are cheap!

-There is no reason why you couldn't do the same type of modifications to the Melling, In fact, the next engine I build will likely use a Melling and similar mods, with more consideration towards cost/value.

-Dry sump system, $$$$. Way more than what I've spent on this overkill wet sump system. Remote wet-sump pump? Hmmm...
 
Your o-ring solution seems a good one.
Your pipe is held in place with a bracket and metal stops with 2 thin (probably Viton?) o-rings that squish down into their grooves flush with a pipe that is constrained by the bracket and stops.
Threading/all metal probably isn't necessary for the life of the o-rings/between engine rebuilds.

One problem I've noticed is that all pipes fit a little different...tooling drift?
Can't be worse than being held in place by two rubber o-rings with a skinny pipe.
But might be a problem/not exactly one size fits all.
 
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