Failed vanos test post Beisan

[maupineda]

So i have become fascinated by how this thing works and love the tech chat on it, so here are some photos for those interested in learning about this thing.

Here you see the pump shaft, notice a small oil passage at the bottom, this mates to a reassessed surface on the back of the disc


reassessed surface on the back of the disc, this is about 0.2mm



Below the front of the disc, where typically you re-drill new smaller holes by around 1mm, you can also see the side holes for the pump pistons, this interface is precise, so the pistons once in, create an air tight cylinder



Below you can see the disc and shaft, and the side holes that must align perfectly for the pump to work



pump piston



If you cap the inner side of the hole, and push the piston, it springs back meaning this is sealed interface once the piston is in



ANY tolerance deviation from OE would make the pump to show losses, Raj said his side holes are tighter, well, that can cause the pistons to bind and not create a pumping pulse, there must be a tiny clearance also for lubrication, or the pistons and disc would just wear out. same with the interface to the shaft. this is why I think the best is to stick to your original set as those items have broken-in together. without a CMM dimensional report showing OE vs Beisan it is impossible to say if they are similar, or one is better to the other, I bet engineers spent many hours defining the right tolerances and clearance for the pump to work effectively. so deviating from the OE design may have consequences unless there is testing data that shows improvement in performance without durability impacts.

[Cubieman]

So i have come fascinated by how this thins works and love the tech chat on it, so here are some photos for those interested in learning about this thing.

Here you see the pump shaft, notice a small oil passage at the bottom, this mates to a reassessed surface on the back of the disc


reassessed surface on the back of the disc, this is about 0.2mm



Below the front of the disc, where typically you re-drill new smaller holes by around 1mm, you can also see the side holes for the pump pistons, this interface is precise, so the pistons once in, create an air tight cylinder



Below you can see the disc and shaft, and the side holes that must align perfectly for the pump to work



pump piston



If you cap the inner side of the hole, and push the piston, it springs back meaning this is sealed interface once the piston is in



ANY tolerance deviation from OE would make the pump to show losses, Raj said his side holes are tighter, well, that can cause the pistons to bind and not create a pumping pulse, there must be a tiny clearance also for lubrication, or the pistons and disc would just wear out. same with the interface to the shaft. this is why I think the best is to stick to your original set as those items have broken-in together. without a CMM dimensional report showing OE vs Beisan it is impossible to say if they are similar, or one is better to the other, I bet engineers spent many hours defining the right tolerances and clearance for the pump to work effectively. so deviating from the OE design may have consequences unless there is testing data that shows improvement in performance without durability impacts.

Awesome, thanks you for taking the time to post these images. I wish individual vanos parts could be had, I would buy a new disc (to be re-drilled), pump disc pistons/springs/cups.

I wonder if there would be an effective way to measure the piston holes on the inside of the disc in regards to their postion top to bottom vs OE disc and also diameters vs OE disc.

I also wonder if maybe the OE disc had any kind of tapered/chamfered surfaces where the small "inner hole" turns into the "piston chamber", that may not make sense. Also I suppose it would not be anything but flat in that area as the cup or "nipple" piece must rest flat in there.

Basically wondering if there might be some type of transition in the surface between the small inner hole and where it widens out. I suppose it's just a small hole on the inside and a bigger hole on the other side to allow for the piston. It's just that any deviations to the machine process could have consequences when you consider all the intricacies of fluid dynamics etc. in relation to the function of this vanos system.

I would imagine that Raj had to pressure tested these pumps vs OE before selling them no?

[sapote]

Raj only can check the individual disk, not the whole pump together as the owner has the other parts mating to the disk. IOW, they are matched to each other.

[yhp2009]

I dont know too much about the technical aspects of this discussion... but if the specs and tolerances of the design are as sensitive as you say, i would guess that ANY modifications to the system (ie, redrilled holes means weight differences, larger tabs, etc) will have consequences. And only way to know for certain is to test them which we cant do. Seems like a rabbit hole tbh

[heinzboehmer]

Weight changes and redrilled holes should not affect the pumping mechanism. As far as I understand, oil is pulled into the pistons as those come out of the bores and when those get compressed (the disk is off center so as it spins the pistons get pushed in) high pressure oil is shot out of the pump. Weight will affect moment of inertia, but the disk is solidly coupled to the exhaust cam. So even though holes will (very slightly) decrease the rotational inertia of the engine internals, the speed of the disk is still directly controlled by the cam speed.

The only thing that would affect pumping is what mau has pointed out. Smaller/bigger piston bores and different geometry in the veins that connect the cylinders to the pump output will definitely affect the volume of fluid that can be pumped with each revolution.

[ATB88]

ANY tolerance deviation from OE would make the pump to show losses, Raj said his side holes are tighter, well, that can cause the pistons to bind and not create a pumping pulse, there must be a tiny clearance also for lubrication, or the pistons and disc would just wear out. same with the interface to the shaft. this is why I think the best is to stick to your original set as those items have broken-in together. without a CMM dimensional report showing OE vs Beisan it is impossible to say if they are similar, or one is better to the other, I bet engineers spent many hours defining the right tolerances and clearance for the pump to work effectively. so deviating from the OE design may have consequences unless there is testing data that shows improvement in performance without durability impacts.

Cool teardown and explanation, love this kind of stuff

Although, it seems like nobody has had these kinds of problems using the re-drilled OE disks (which aren't matched to the rest of the components they're being installed with, but are manufactured to OE design and tolerances) that Raj had been supplying up until switching to his proprietary disks. While I appreciate the point that in theory it's best that you keep the parts that have all worn together, in practice it seems like the most important thing is simply OE design and tolerances vs not.

[JeremyJames]

I have had a terrible experience with Beisan in the past. I am still currently dealing with this back from October of 2020. I am not surprised by your experience. Raj is a pure ass too.

[Cubieman]

I have had a terrible experience with Beisan in the past. I am still currently dealing with this back from October of 2020. I am not surprised by your experience. Raj is a pure ass too.

Hmm. What specifically was your issue? That's discouraging to hear as I have always been under the impression that he was fairly reasonable to work with. So far he has responded quickly to my emails, but if I can identify that the non-OE disc is indeed the issue I'll be interested to see if he will simply swap me for a re-drilled unit.

[JeremyJames]

My oil pump disc was not manufactured properly. So he sent me a second one, it was faulty as well. He had to send a 3rd. The pistons were sticking because the OD wasn’t large enough. My daily driver was down for 2 weeks.

He’s been calling me an asshole all day. He’s honestly a prick.

I am happy that some have had a good experience, I however, I had a terrible experience.

[Icecream]

I have had a terrible experience with Beisan in the past. I am still currently dealing with this back from October of 2020. I am not surprised by your experience. Raj is a pure ass too.

I have emailed him a couple times and he responded quickly and was helpful. He probably answers hundreds of emails a month and doesn't charge for his time and has an excellent detailed walk through of the procedures. Sorry you had a bad experience but that is not the norm from what I see.

[sapote]

OP, I'm curious why your stock pump passed the test with great marks: response times in 200ish mili-seconds and you wanted to replace it? My car has 70K miles and I only drilled the new 2 holes smaller for the hub tangs, and Loctite the cam sleeve bolts and that's all.

Re to the new disk cylinder holes, it's tricky that they are precise because a little too larger then pistons lose compression and little too tight then the spring cannot push the piston out during the intake stroke at high rpm (similar to engine valves floating at high rpm) , then it loosing pumping efficiency.

[Cubieman]

My oil pump disc was not manufactured properly. So he sent me a second one, it was faulty as well. He had to send a 3rd. The pistons were sticking because the OD wasn’t large enough. My daily driver was down for 2 weeks.

He’s been calling me an asshole all day. He’s honestly a prick.

I am happy that some have had a good experience, I however, I had a terrible experience.

Did the pistons stick during installation on the bench or was this found out after the vanos was installed that sticking pistons were the cause of your issue?
Did you also have slow vanos response times and/or fail the vanos test?

I am almost wondering if I was told the drive the car "hard" in order to wear down the pistons into their new, tighter fit holes in the new non-OE pump disc.

If that's the case I sure hope it fixes the issue as going back to an OE re-drilled disc with pistons that are worn down from the non-OE disc wouldn't good either.

Always something.

[Cubieman]

OP, I'm curious why your stock pump passed the test with great marks: response times in 200ish seconds and you wanted to replace it? My car has 70K miles and I only drilled the new 2 holes smaller for the hub tangs, and Loctite the cam sleeve bolts and that's all.

Re to the new disk cylinder holes, it's tricky that they are precise because a little too larger then pistons lose compression and little too tight then the spring cannot push the piston out during the intake stroke at high rpm (similar to engine valves floating at high rpm) , then it loosing pumping efficiency.

I had no frame of reference what was good response times when I did that original vanos test.
I simply did a full vanos rebuild because I wanted to take care of the hub tab failure issue and did the rest while I was in there kind of attitude.
Now I'll be in there again and again.

[Tbonem3]

Ya the whole "while you're in there" thing is shit. Easy way to spend unnecessarily and create new problems. Still not bad advice for someone who is paying for labor I suppose. I'm not doing so much of it the second time around.

[Cubieman]

Ya the whole "while you're in there" thing is shit. Easy way to spend unnecessarily and create new problems. Still not bad advice for someone who is paying for labor I suppose. I'm not doing so much of it the second time around.

Yea, finding that out the hard way, just wanted all the Beisan parts and wanted it all at once.
If it's the pump disc that's the issue there is a lot of people that would have similar issues.
An awesome member on here is willing to ship his whole vanos to troubleshoot.