Shimming the pressure relief spring on a B6T oil pump

[Rick the Quick]

I have my B6T oil pump apart for inspection. It looks like new inside and passes all clearance checks. The only problem I can see is the relief spring free length. Tech Capri calls for 1.791" free length. I measure 1.776". Any downside to me shimming it with a washer to tighten things up? That's my plan unless someone tells me why I shouldn't.

[ryanprins13]

Can you tell me how/where your measuring it? 15 thou isnt a lot.
I put a 60 thou shim in my b3 oil pump which brought the dump pressure up to 60psi but i never measured anything beforehand. Oil pressure dump was 50psi before the shim. Was this engine running before? If so did you have an oil pressure gauge on it? If so what pressure did it dump at?

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[bravekozak]

What is your current oil pressure in psi at idle and at 3500 rpm?

[Rick the Quick]

Can you tell me how/where your measuring it? 15 thou isnt a lot.
I put a 60 thou shim in my b3 oil pump which brought the dump pressure up to 60psi but i never measured anything beforehand. Oil pressure dump was 50psi before the shim. Was this engine running before? If so did you have an oil pressure gauge on it? If so what pressure did it dump at?

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I'm measuring it with a digital caliper. Where am I measuring it? Here in the kitchen......LOL. Oh I am measuring the total free length. I would send a picture if I could. I pm mailed a guy on the Forum for help with pictures......Oh that was you. The B6T engine came in a '91 Capri. I drove it 1400 miles from Chicago with no problems. I changed oil and filter before leaving Chicago. When I arrived her in New Mexico the oil was still clean and still at the full mark. No smoke blue or white or any other color. Lousy oil pressure which I assumed to be a bad gauge, sender or connections. I realize I should have checked the pressure with a manual gauge before pulling the engine but the reality is a spur of the moment at 9 pm had the engine out at midnight. If I remember correctly it never read over 20 psi. Hot, cold, idle or wide open. I will be inspecting the rod, main clearances and the oil pump while the engine is out and obviously going to use a manual gauge and a light when it goes in the '93 body.

[Rick the Quick]

What is your current oil pressure in psi at idle and at 3500 rpm?

Hello Kozak, like I explained to Ryan, I don't believe it ever showed over 20 PSI. And if I recollect I had an XR2 about 10 years ago that did the same thing. I got it from a guy that needed to get home from Oklahoma City (500 miles +). He got it for $500 because it had very low oil pressure. He sold it to me cheap and I dumped it after realizing it was full of electrical glitches and it rattled (the body not the engine) and the power windows were always acting up etc. The other reason I dumped it was the fact I had a very nice charcoal gray 88 Festiva. I didn't know about the Forum back then and didn't have a clue the Capri engine would fit in the Festiva. The whole point being the Capri electrical system does not impress me and I am guessing both cars had factory oil pressure gauges that were not accurate. Now do I shim the spring or buy a replacement from Mazda and shim it also?

[Rick the Quick]

Lots of information on the Mazda sites. Clubprotege, miataturbo, tec.

[ryanprins13]

I'm measuring it with a digital caliper. Where am I measuring it? Here in the kitchen......LOL. Oh I am measuring the total free length. I would send a picture if I could. I pm mailed a guy on the Forum for help with pictures......Oh that was you. The B6T engine came in a '91 Capri. I drove it 1400 miles from Chicago with no problems. I changed oil and filter before leaving Chicago. When I arrived her in New Mexico the oil was still clean and still at the full mark. No smoke blue or white or any other color. Lousy oil pressure which I assumed to be a bad gauge, sender or connections. I realize I should have checked the pressure with a manual gauge before pulling the engine but the reality is a spur of the moment at 9 pm had the engine out at midnight. If I remember correctly it never read over 20 psi. Hot, cold, idle or wide open. I will be inspecting the rod, main clearances and the oil pump while the engine is out and obviously going to use a manual gauge and a light when it goes in the '93 body.

I got home around midnight last night and quickly asked you that so hopefully someone else could give you a good answer soon since i dont really know much about this. I will reply to your message in a bit.
Your measuring its length out of the pump without compressing it 15 thou with the jaw side of the calipers not the extendy end?

I seem to recall people talking about the capri oil pressure gauges not being accurite but i am not sure.

. Now do I shim the spring or buy a replacement from Mazda and shim it also?

Can you buy just the spring? Do you have another engine or oil pump with the same spring?

I will just give you the information i got from Ryal Greenwood (dragonhealer) on shimming a B3 oil pump. Its what i did and it bumped the dump pressure up 10psi. I had to take mine apart anyway to clean since the bore was gummed up and the plunger valve thing was sticking. Im not saying you should do it or its needed or anything, just here is the info:

"With the oil pan off, remove the split pin retaining the regulator; spring seat, spring, valve plunger.
Measure plunger bore diameter(11.94mm/
0.47in), fit 1.5 - 1.6mm (0.059-0.063in)
hard steel washer that fits diameter fairly closely, and re-assemble. HAS to be hard. 30C rockwell minimum.
Don't. Be tempted to shim at the retainer end, lost an engine that way, washer has to go inside the plunger, where the spring goes

1.6mm washer will raise set pressure apx 10psi.
Min. Allowable hot pressure 47psi, hot idle 15psi."

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[ryanprins13]

As i mentioned in my message to you- how does this imgur photo look? Is it too big?


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[Rick the Quick]

Thanks Ryan, I did at one time have an oil pump question and Ryal did mention shimming. I didn't write down the details or save the post because I thought I could easily find it in the archives. Boy was I wrong....LOL. The imgur photo is of perfect size. I'm sitting in front of a 21" monitor. If I was using my phone it could be too large. I can't imagine using a phone to access the forum if I had access to a computer with a full size monitor.

[ryanprins13]

Thanks Ryan, I did at one time have an oil pump question and Ryal did mention shimming. I didn't write down the details or save the post because I thought I could easily find it in the archives. Boy was I wrong....LOL. The imgur photo is of perfect size. I'm sitting in front of a 21" monitor. If I was using my phone it could be too large. I can't imagine using a phone to access the forum if I had access to a computer with a full size monitor.

Haha, yes, things get lost here easily. I started a list of links i find myself frequently searching for on my phone.
Ok, cool. Maybe it has to do with it being a different forum, glad it works here.
The stuff on your phone gets bigger if you hold it closer to your face....
But the home computer is too slow, no data and all my photos are on my phone. So the phone becomes the choice.
Oh, i have heard windows 8 and 10 are app based, perhaps they have an app for tapatalk you can download? It would be worth it for you if they did. I recently upgraded my xp to windows 7 so im not sure what the newer computers are like.


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