First a little catch up.

My son has a D2 (previous owner slipped sleeve, gave to my son for $0, spent $2,800 rebuilding it with flanged sleeves) that has leaked since the rebuild at the back where the engine meets the bell housing. About a quart every 250-500 miles. Oil level would drop to bottom of dipstick, then stop. 5,000 miles so far on rebuild.

Started a whole thread on this because for sure it was the crucifix seals, and I was worried about reusing the main bearing after dropping the cap to replace the cruxes.

We dropped the pan was expecting bad crucifix seals or worse a leaking RMS, but looks like it was just countersunk nibs at the bottom of the crucifix (we shaved them before final torquing -- bad move as torquing pulled the cruxes below the mating surface). There was no oil at all on the back of the engine above the sump mating surface and the sump seal was super oily across the back when we pulled it off. Filled the bottom of crucifixes with lots of hylomar, fitted a new sump gasket, now at 200 miles and not a drop so far -- fingers crossed.

What worried me when we had the pan off was there was some "gelatinous" crud at the bottom of the oil sump after only 5,000 miles on a clean rebuild (otherwise everything inside looked great -- there was even still a lot of fresh cross-hatch on the cylinder sleeves). My brother thought the gunk felt like excess sealant, but to me it felt like wet cardboard.

And yes, we used a basic Fram PH-16. I am guessing that is where the gunk in the sump came from. Have always used the orange Frams on everything but my '73 911 (great marketing as I bought into the brand) for nearly 35 years now, but never again.

So I am upgrading the filter this week when my son gets back from school for spring break.

I have read many of the threads here on filters (including "end all") and have decided on the M1-301 as a good compromise (bigger than the 204 but not as big as the monster purolator/Mann propane tanks). However, I can't seem to confirm anywhere what the bypass pressure is for this filter.

Can anyone confirm what it is? Is it the same as the M1-204? I want to stay as close to the 8-11psi range per the OEM specs.

Thanks.

BTW, since we are on the topic of filters, has anyone done any research on the filter as a potential heat exchanger for the engine? My 73 911 has a HUGE oil filter (I only us Mahle filters -- the engine runs 13 quarts and is as much oil cooled as air cooled) and there are some finned heat exchangers folks make that you can wrap around the filter to dissipate even more heat. Has anyone seen or thought about something similar for the D2?

BTW2, you have to love the Germans: in my longnose 911, the gauge front and center is the tach, with the next most prominent gauge being the oil pressure AND temp and then the separate one for oil level -- three gauges for oil alone. The speedometer is off to the side by the clock. No idiot lights on this baby.

 

Reread thread or quicker to do a web search.
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Mobil 1 - Oil Filter
Line: MOB | Part # M1-301
Manufacturer's Defect Warranty
UPC: 52948093903
4 Inch Spin-on
Style: Canister
Outside Diameter (In): 3.650 Inch
Thread Size: 3/4-16 Inch
Height (In): 5.370 Inch
Anti-Drainback Valve Included: Yes
Outside Diameter (mm): 93mm
Additional Details
Burst Pressure (psi): 550 psi
Bypass Valve Pressure (psi): 8 To 11 psi
Flow Rate (gpm): 24.3 gpm
Gasket Inside Diameter (In): 2.420 Inch
Gasket Outside Diameter (In): 2.810 Inch
Gasket Thickness (In): 0.390 Inch
Gaskets Included: Yes
Inside Diameter (In): 3.650 Inch
Filter Media: Cellulose/Synthetic Blend
Removal Nut Included: No

 

Thanks for the replies. Good to know.

I couldn't find anything on the web about the M1-301 (can you tell me on what site you found those specs), so I went and bought 2 WIX 51515s at O'Reilly's, which has bypass specs in the same range as genuine.

After I go thru the two WIXes, I may give the 301 a try.

 

Older 87-91 RRC's used to use the larger M301/PH8A size filters (you can look in the oil filter books as a cross reference). Then LR started using the smaller PH16 style filters. I've always used the M301/PH8A size (even on my 05 Jeep Wranglers). Basically same specs with more filter media.

 

Why when Mobil makes simple specs/information difficult to find?
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