Push hard and live
Join Date: Apr 2007
Location: Carson City, NV
At idle, with warm oil, there is very little oil pressure registered on the gauge. I believe it is OK to have as little as 7psi, which is approximately .5 bar. That is with the oil hot. With cold oil, it should read above half-way on the gauge.
I do not believe the 2300 oil pump will fit the 2000, for at least two reasons, maybe more.
The 2300 oil pump shaft is longer, and has the driven gear screwed directly onto the end. The 2000 pump shaft has a key that fits into a groove in the cross shaft mounted in the front main bearing cover. In my opinion it is a poor design compared to the original 2000. Additionally, there is a different shape to the pump body and upper portion. I doubt the pump could be mounted at all.
If your pressure was very low when cold, I would suspect the pressure release valve in the oil filter assembly. If it becomes stuck, or has even a tiny thing lodged under the sealing face, it will dramatically reduce both the idle and running oil pressure. Of course, it is also possible that your rebuilder left out the pressure valve body entirely.
I have always found it necessary to thoroughly prime the 2000 engine with oil prior to starting. A recently rebuilt 2000 engine will tend to not self-prime.
Carson City, NV
59 102 Touring (first Alfa $500 running)
65 Sprint GT (2nd Alfa, $500 daily driver)
102 Sprint (never did anything with it, but wish I had)
74 Berlina (first new car - now certainly rusted into oblivion)
61 Giulietta Spider G-Prod Race Car (where is it now?)
84 Spider Veloce (rarely drove it, so sold it)
86 Quadrifoglio (Dull car - no more 115s for me)
1971 Montreal "The Full Monty". Fair winds and following seas
59 102 Touring Roadster - restoration complete, enough Alfa for any rational man. Or irrational, for that matter
Two 1946 Stampe SV4C (c/n 294 "Rocinante" - wife's favorite airplane. RIP), and c/n 235 "La Bon Temps Femme" (gone to a new home, but never forgotten)
Zlin 50LA (+9 -6 gees, titanium spar, 1200 lbs, 260HP rumored to now be in Brazil)
1946 Luscombe 8A
Starduster Too (recently spotted at the Nevada City, CA airport - over 20 years and an entire continent separating it from our stewardship in Binghamton, NY)
1955 Cessna 170B (wife taught me to fly tailwheel in this)
64 Mooney M20E ("Rambo". My faithful steed for over 30 years) Nearly 50 years old, and just returned from a trip to Argentina in him
Newest in the fleet
1967 Piper Super Cub on Wipline amphibious floats (a true "all terrain vehicle")
2010 Triumph Thunderbird
You can snap roll an Alfa only one time...