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b230 oil pump shimming, for higher pressure on 16v.


300+ Club
Jan 24, 2009
I've never taken one apart before. What am I looking to do? replace the spring or shim it?

I could ask for pictures, if anyone has any information or method to contribute on taking apart and re-assembling, I would appreciate. (I don't wanna break it)
The 16V pump would be greater oil volume not so much more pressure. The oil pump as used with the 16v penta engines should give you an idea of what to use. It might be the same as a B230 pump. I don't know what they did if anything for the 16V head in the penta engines but the block is a B230 type block.
Nice... I'll nab one because it's so cheap.

What are the advantages over the stock auto pumps?
The 1987 Penta AQ171C 2.5L motor with the 16V penta head I bought had hydraulic lifters. It also had that 3340 volvo oil pump. Being a C version it had rear thrust on the crankshaft also. The 8v penta heads have solid lifters, same as the cars heads have. That little puck thing you have to swap out to adjust the valve clearances is on top of the solid lifter bucket. I'm talking about the volvo redblock penta 4 banger boat motors. Remember volvo puts penta on other motors like ford and chevy..
If your runnning hydraulic lifers, I also suggest running an external feed line like the ford guys do.
If your runnning hydraulic lifers, I also suggest running an external feed line like the ford guys do.

Ken and I were discussing this clever move you did this morning. I'll be doing that. are there more picture details in your thread?
summitracing sells higher volume options of our pumps(mellings i think). I used to shim oil pumps from toyotas . Looks likie the volvo ones have some type of schrader valve doo hickey up top that can be played with.
I detailed the install in my old build thread, not to many pages from the end. And that little shrader valve lookin thing does not control pressure, its a air bleed that allows the pump to get a prime, the oil keeps it cloosed during operation.

The melling 181 and volvo pumps have the same gear depth.

Run the early pusrod b2x motor high pressure from ipd, its like 8 bucks.
sten parner sells a hicapa pump... works just fine in my 16v with b230bottom... pressure as it should also in higher rpms...
Test oil pump original pressure by adding a drill and pressure gauge and some oil, record.

If you remove the bottom of the pump you will see the spring in there that bleeds off excessive pressure. Shim that sping or add a stiffer one, then bench test using a drill and a oil pressure gauge. Record changes. But remember oil pressure is a direct result of how tight or loose your bearings/ engine are as well.
Kris Weldy

Typically you would want t use washers for shims, i just added a nut to clarify where you would want to shim the pump, My nut shim would not work due to the huge diameter of the nut, but you get the idea. Loosen the 4 , 5mm allen bolts...

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There's data in the link I posted. I didn't add washers, springs may very, but I welded on a oilpressure guage fitting and tested volvo pump, melling pump with different springs.
Volvo introduced their 'higher' volume in-pan oil pump with the B23FT motor. Supposedly, all B230FTs and B230Fs also use that oil pump PN 1346144.

I have opened up a number of B230F motors and found that the oil pumps were NOT the 1346144 pump. But, all of the B230FT motors that I have opened up [from '85 to '98] DID have the higher volume 144 pump.

The 'standard' volume oil pumps have gears that are just under 1in tall.....~0.994in.

the 1346144 pump has gears that are about 1 and 3/16in tall........~1.182in.

There are some things that you can and probably should do to an oil pump if you want to optimise the flow......besides the usual thing of checking the clearances between the gears and the housing. When I prep a 144 pump, I do some porting/smoothing/blending inside the housing; as well as doing some things to make sure the clearances are on the snug side if at all possible.

[procedures for checking clearances are in the engine reconditioning green manuals.]

The AQ171C [basically a B230F block with a stroker crank and a 16V head] uses the same in-pan oil pump as a B230F. I've only opened up one AQ171, and I don't remember if it had a 144 pump or not.

Be that as that may be, the more important thing is to make sure that the oil flow...in VOLUME....is adequate. There are three places in a B230 block where there are restrictions that can impede volume flow. I put up a gallery on pbase illustrating those locations, and what I did to correct the deficiencies.

I checked to see if StenParner offers a high volume oil pump. They only offer their version of the 1346144 pump.

Back when Mellings came out with the M181, it was supposed to be a replacement for the 144 pump.....meaning that it is a 'higher' volume pump, in comparison to the B21F/FT and B23E/F oil pump.

The 144 oil pump was listed by Volvo as having approximately 15% more flow than the pumps using the 1in tall gears.

Re oiling to the 16V head on the B230 block: The B234F [and the AQ171/AQ251] all use the same HG as does the B230 motors. Meaning that the oiling to the head follows the same flow path from the block to the head past the second head bolt on the lower side....right above the oil filter boss.

There are likely a few things that you can do to make sure that there is an adequate flow volume path for the oil once it reaches the head. I'm reasonably confident that you can figure that out.

Whether you believe me or not, taking care of the in-block oil gallery restrictions does make a difference in how much volume actually flows. AND, it also results in higher line pressures.

....admittedly, the viscosity of oil used and the bearing clearances are going to have quite an influence on just what line pressures you will see. The thinner the oil and the greater the bearing clearances, the lower the line pressure you will see.

One area of restriction that no one has ever brought up is the restrictions in the oil cooler sandwiches and the angled extension housing used to relocate the oil filter/cooler sandwich further back along the block's side.

Porting the Wahler sandwich appropriately, and the extension housing appropriately, is worth 2-3 PSI line pressure at idle. BTDT

The oiling ports on the Redblock blow a$$. There mixed sizes, and not even milled in on center. A person could get in there and port it, but man that would be tough to do a proper job. And I also worried about blowing the orings off the feed tube. All of that got me to feed the pump external through the oil pan and directly to the oilfilter adapter and cooler setup remotely. I didnt seem to have anymore oilin troubles after that even with Hydraulic lifters.