Shim for increased Oil Pressure

[Hammerhead]

Ok, the oil pump relief spring shim job is done...for now, it is an experiment after all.
The basics. I pulled the drain plug yesterday afternoon after a short drive at operating temp. Went down to the shop today and started on the job.
Time: 2hrs; drop pan (oil already draining all night), pull cotter pin, cap, dogbone and spring. Took about 15 mins to run to the hardware store for the correct cotter pin, and put all back together.
FYI, My inframe was done 26 months 198Kkm/123Kmi ago, and the gasket stayed stuck to the block and the pan came off just as nice as the valvecover does. Draining the oil overnight made it so that there was very little oil rain.
Key points:
1)you don't have to remove the pump from the engine
2)you do have to remove one pump mounting bolt as the head will not allow the dogbone to come out.
3) cotter pin is 5/32 X 2.25" long. A 2" will work (it's what I used) it just isn't as long, but still bends to lock more than efficient enough (see photo)
4)number of dimes you wish to use.
**edited to add**
5)this assembly holds oil in the galleries and oil system of the motor, it will drop about a quart of oil when you remove it! I highly recommend that you fill the oil filter full of oil if you do this as it takes several seconds to refill the galleries and build pressure. This can be a tense few moments, do not add filling the filter by the pump to the equation.
**end edit**
Tools:
13mm deep well socket to facilitate removal of the studs that hold aux hoses and wires.
Two parts pans are nice, I put bolts in one and studs in the other. I marked the pan where the studs were located to reassemble as was.
3/8 impact to quickly remove pan bolts & studs. I always advise using a ratchet to break them loose by hand to avoid breaking bolts off in the block casting!
Torque wrench to torque the pump bolt and pan bolts/studs on reassembly.
Pliers to remove and then bend the cotter pin locked.
Small hydraulic jack to slowly lower and raise pan back into place.
Something to push on the assembly when installing the cotter pin. I used a long 3/8 extension. It's gonna push back WAY harder then it was in removal! You have been warned.
Optional but highly recommended good practice, anti-seize compound for the bolts
Another recommended option, use a deburring tool to chamfer the opening that the assembly goes into. I found it to be quite an abrupt edge considering you are installing an O-ring (I did not change it as I was unaware it was there and I didn't have one. If somebody knows the size and could post it, that would be much appreciated.)

Caption: Oil pump mounting bolt left loose to demonstrate which one must be removed to perform shimming, and cotter pin is yet to be bent to demonstrate that a 2" long is sufficient.

Background;
I read somewhere before that (I think it was Rawze) used 10 dimes and he was up a little over 50psi, and since I'm not an engineer I just play one at the drag-strip, I just want to boost my pressure a little but not get too high. Unilevers told me a good starting point was 8 dimes. Since I'm naturally cautious when it comes to the equipment I make my living with, I measured 10 dimes with my calipers and then 8 and I decided dropping just 2 wasn't cautious enough for me so I decided on 7. I know it's not much of a difference, but I have played with shimming Harley relief springs so I kind of have the basics of understanding.
I am NOT the oil expert Rawze is. I'm sure he has forgotten more than I will ever learn about oils.
Pre shim, I have used Castrol Hypuron Advanced Formula Semi-synthetic 10W30 for Diesel engines for about a year. The reasons are; 1)Castrol used to sponsor the class I raced in, so 2)When the company I'm leased to switched to this Castrol Semi-synthetic (and they discussed to with cummins prior to the switch) and they get it for the same price as conventional oil, I followed their backing by Cummins and switched. 3)I used to be a believer in using high quality synthetics, rigorous analasys, and extended drains. Now that my motor was about a year from inframe I was looking to go back to that when the whole Castrol thingy happened...So;
Pre-shim;
Castrol Hypuron AF S/S 10W30 my truck would produce about 39-40psi cold start, fresh oil change.
Drop to about 35-36psi at operating temp of 210* and drop to 33-35 when working hard/hot 220+
After about 4K miles it would run 33-35psi at 210* and drop to 31-33 when working hard/hot 220+
Today, after adding 7 dimes of shim;
Castrol Hypron AF S/S 10W30 truck produced 47psi cold, fresh oil change.
I have stayed with the same oil for this change and to "apples to apples" test the $.70 shim as I didn't want to distort my results by switching oil and adding gear lube as well at the same time
Operating temp pressure to be updated when I get back to work, I will be leaving for a load on Sunday or Monday.
Stay tuned...


*Note all temps listed are oil temp, not coolant temp