DIY Oil pump shimming and porting.

[91_CB7_Sedan]

Taken from Cervan from d-series.org I'm not responsible for your own doing, actions, and/or mishaps. DO AT YOUR OWN RISK!!!

Shimming the oil pump:

First off, i allways inspect the oil pump before i do any modifications If the oil pump is bad, its not worth doing all that work to find that out in the end. Sorry for the crappy pics guys.

So first you take off the Philips headed bolts that hold down the rotor cover.Im using my impact driver to remove them, its the BEST! 35 dollars ive ever spent.


After that you measure the rotors per honda spec. this one was on the tighter side of spec and everything looked good.




Next you remove the hex head bolt on top of the oil pump next to the pickup tube inlet. this is where the pressure bleed off valve is when the pressure gets to a certain point, this piston lifts and limits the ammount of pressure that is produced. Be carefull when removing this, the spring is quite strong.


Next you want to get your shim, with an ID of .30 and OD that matches the diameter of the piston (i didnt measure sorry). I found a washer that the OD was correct, but the ID was too small, and the thickness was .048. The thickness of the shim you are looking for is to be between .025 - .035 thousanths, that will give you an oil pressure of about 80-100 psi at 7000 rpm's (this is even more important on turbo and high rpm engines).

I got the washer out of a harbor freight multi pack thats under 5 dollars its under the caliper in the picture.


Next i bored out the ID of the washer with my die grinder. Then since its so small i couldnt use a grinder and hold it, because then it wouldnt be flat. So i took the end of one of my screwdrivers that im going to return to sears and ground the washer down on my concrete floor. Slowly it took metal off until i got down to my desired thickness. (As seen in the second picture, the differences between the way they come and the finished product).



Before you reinstall make sure the shim sits flat and level on the bolt, then clean the piston and the passage out, then coat everything in engine oil. (If your going to be porting as well, leave this out for now, it will need to be cleaned).




And thats it!

[91_CB7_Sedan]

Oilpump porting:

If you allready shimmed the oil pump, then your ready to port it, take the rotors out and set them aside. Next take the hex plug out on the bottom of the pump.


Now to port i used a carbide bit that was 25$ at tacoma screw, i also bought some cheap ass HF ones but this takes the cake on durability. Be carefull though, if you have never ported before with a carbide bit, it can easily take huge chunks out of alluminum. here is the bit i used.


Next you will want to enlarge the opening on the output passage, you can go larger but i found this to be perfect for what im looking for.


Then i enlarged the pickup passage a little bit, since the pickup tube itself isnt nearly as large as the gasket, i didnt see any reason to enlarge it that far.


And finally the inside port, this one is tricky and you have to be carefull you dont want to knick any of the surfaces that the rotors ride on. I took a fair amount out of here I found that if you lubricate where your grinding it doesnt jump as much and helps the bit last longer.


Thats it on the porting, be sure to clean everything very very well! I used a degreaser cleaned the inside and passages out, then washed it with water twice, and then blew it out with compressed air to make sure that no shavings were left behind. After that, reinstall the rotors with oil on the top and bottoms of them to lubricate them. put the cover back on, and install the pressure valve and the hex bolt on the bottom. And your done! congrats you just ported and shimmed your oil pump.

Front seal replacement:

I replaced the front seal while i was doing this so i thought i minds well show you how to do that too, I drove the old seal out with a screwdriver and a hammer. To install it i put the new seal in level as far as i can into the hole, and then put your 32mm axel nut socket over the seal, (It fits perfectly) then i drove it down evenly with a rubber mallet. Easy as that.

[91_CB7_Sedan]

Maybe sticky worthy so the turbo guys won't have to go hunting it down?

EDIT: Wasn't sure if I should post here (B/c it's beneficial to the turbo guys) or in the DIY Forum...

If it needs to be moved, I apologize.

[ashb82]

why do u need to do this. i rev my f22 to 8k should i have this done.

[91_CB7_Sedan]

why do u need to do this. i rev my f22 to 8k should i have this done.

Are you running an upgraded oil system?

[ashb82]

what is a upgraded oil system. bone stock oil system with balance shafts removal kit

[91_CB7_Sedan]

what is a upgraded oil system. bone stock oil system with balance shafts removal kit

Is your oil pressure significant enough at 8000rpms? Doing this only increases your oil pressure. Most built engine's that have upgraded fuel, and internals, and electronics, need an upgraded oil system to help lube the parts at faster than stock speeds. Doing this helps out the turbo guys I know b/c the loss of oil pressure due to the feed/return oil lines coming to/from the compressor housing, Shimming/porting the oil pump helps correct that loss in oil psi.

If your asking if this procedure is something that has to be done in order to rev that high safely, the answer is no.

[ashb82]

i have 90psi @ wot goes to 100psi but the falls to 90 psi and i have 20 psi @ idle

[SOHC-FTW]

i have 90psi @ wot goes to 100psi but the falls to 90 psi and i have 20 psi @ idle

Thats awsome then this DYI is not for you.

[ashb82]

good i was getting worried that i left something out in my build