S65 Oil Pump - Changes needed time run extra clearance bearings?

Came across this today. I am unconvinced. Any experts able to comment on this?

https://srd-eng.com/bmw-products/

Cheers,

How odd. We have lots of oil pressure data from the S65 that BE ran for a year... i don't recall oil pressure dropping at high rpms.
If i remember correctly, after 2k rpm the pump provided more oil than the engine could use

$400 for those two small gears. They better be made from titanium and anodized with the blood of unicorns.

I've not seen this before. Interesting. Looks like it's basically an overdrive gear set for the pumps. Overdriving the pumps would cause additional load on the crank, oil pump chains, and drives. Takes HP to run those pumps at 8000rpm. I'm not sold on it, even if you're running thinner oils. Might get a set to test.

Isn't the S65 oil pump variable pressure? If you run more volume/pressure, won't the oil pump just reduce to compensate?

Redd wrote

Isn't the S65 oil pump variable pressure? If you run more volume/pressure, won't the oil pump just reduce to compensate?

Exactly. Based on the data provided by AutoTalent, it seems like the S65 is more than capable of producing acceptable flow while maintaining pressure.

Hopefully deansbimmer will try a set and share the result.

Always something to worry about. Now when we have increased oil clearance in place, the oil pressure will die on us after 5k rpm. Ah well, back to nanny driving...

This is not at all what BE (Autotalen) suggest. Also, whats up with SRD's suggested 60PSI max pressure while BE read 70PSI+?. Quite significant difference, or do I misunderstand something here? Would be really interesting to listen into a discussions between experts here.

https://www.m3post.com/forums/showthread.php?t=1337998

subscribed

http://wiki.rcollins.org/core/index.php/Oil_Flow_-_S65_Oil_Flow_Analysis

tdott wrote

http://wiki.rcollins.org/core/index.php/Oil_Flow_-_S65_Oil_Flow_Analysis

Exactly.

Just bumping this in case there is any new information.

Cheers,

tdott wrote

http://wiki.rcollins.org/core/index.php/Oil_Flow_-_S65_Oil_Flow_Analysis

Holy Data!!!

//steve\\ wrote

Holy Data!!!

A whole lot more than 8 points of data and a cheesy graph trying to sell a product.

tdott wrote

http://wiki.rcollins.org/core/index.php/Oil_Flow_-_S65_Oil_Flow_Analysis

Know this thread is as old as time but...........

Any access to this still? I can't find it online.

Rubin

Probably for the better that they can't be found anymore lol

Redd wrote

Probably for the better that they can't be found anymore lol

Was thinking along the same lines but wasn't sure what happened and didn't want to jump the gun.


I'm curious. Not enough to go out of my way, but enough to read if someone were to post...

IamFODI wrote

Was thinking along the same lines but wasn't sure what happened and didn't want to jump the gun.


I'm curious. Not enough to go out of my way, but enough to read if someone were to post...

Hmm, didn't realize they took the page down, wonder why.

Believe this is similar data posted on the board: https://www.m3post.com/forums/showthread.php?t=1337998

Helmsman wrote

Hmm, didn't realize they took the page down, wonder why.

Believe this is similar data posted on the board: https://www.m3post.com/forums/showthread.php?t=1337998

the whole wiki is down, I think the server was moved or something, probably didn't bother to get it back up yet.
https://srd-eng.com/ website is also down, maybe they went out of business since they haven't sold any of these?
Perhaps RE bought the rights to the product which is why they are pushing it on IG now.

The info is in the thread above tho.

I saw someone on IG, now claiming this is a big issue. IMO it's marketing BS with not enough data to prove any of their claims.

https://www.rogueengineering.com/SRD-S65-Oil-Pump-Sprocket-Set_p_2518.html

This is SRD's engineering brief, I just thought there was something else out there.

I already ordered these and will be part of my rebuild.

We use them in every S65 build that does not have a Dailey Engineering dry sump system. Our most recent experience is that every S65 we see with a spun No. 1 main bearing and/or spun rod bearings has had aftermarket rod bearings installed with larger clearances within 10k miles or so. As BE's analysis candidly admits, the larger clearances do reduce oil pressure by a not immaterial amount, and our view is that the vanos system lacking its own pressurization system periodically exacerbates this phenomenon and increases the deficiency, causing a further drop in oil pressure. Combined with the S65s tight clearances, particularly on the No. 1 main bearing, where the journal expands when the harmonic balance bolts are installed, one winds up with an insufficient oil wedge. Increasing oil pump output by 20% plus with the SRD gears is in our view the best means of addressing the issue prophylactically short of installing a Dailey. And at $400, they are a tad more economically feasible than a Dailey. We are engine dynoing one of our S65 strokers that has the SRD gears installed tomorrow and Tuesday and will report back on the oil pressure analysis. Our clearances all exceed 0022" so it will be interesting to see.

Be well, and go fast.

--Peter

Very interesting 🤔
Does that mean that BE and offset ACL bearings are potentially causing insufficient oil clearance and pressure?

charliev68 wrote

Very interesting 🤔
Does that mean that BE and offset ACL bearings are potentially causing insufficient oil clearance and pressure?

As BE's own analysis showed, the extra clearance provided by its bearings dropped oil pressure 3-5 psi. Add to that the periodic oil pressure suck of vanos, and its periodically a larger pressure drop. Set the bearing clearances (both rod AND main) as we do using the old .001" of clearance per inch of journal, and the pressure drop is even greater. Is this the sole cause of failure? Maybe, maybe not. But it contributes. Larger oil wedge required by wider clearances requires more oil, and that means more pressure.

With the SRD gears on one of our strokers, we are seeing steady 80-90 psi oil pressure, but are still breaking the motor in and haven't done any ramp runs yet. Will report back.

--Peter