i just got my b18c1 rebuilt and was wondering what oil you guys suggest. i have been running castrol synthetic for years and doing oil changes every 2500 miles. dont know if i should change to a different oil or stick with it. and also how often do you guys change your oil?

 

use dino oil 10-30 or just 30w for the first 500-700 miles, drain and change the filter. add 10-30 dino, drive 1500 miles and you can switch to synthetic anytime here after. you just want to make sure the rings seat.

 

Changing synthetic oil every 2500 miles is a complete waste of time and money and creates way more used oil that has to disposed of. I would go at least 5K miles if I were using synthetic.

Amsoil has a 0w30 oil that can be used in vehicles that call for 5w or 10w30, with a claimed 15K mile/1-year drain interval. I'm thinking of trying it out in my B18C1 with 275K miles on it.

As for what oil after an engine re-build, the suggestions at the end of this post look pretty good to me:

https://honda-tech.com/forums/all-motor-naturally-aspirated-44/how-build-%22reliable%22-lsvtec-b20vtec-1676914/

Oil changing schedule:
Startup - 30w non detergent, change after warm up
after 20 miles - your favorite non-syn
after 100 miles - your favorite non-syn
after 500 miles - your favorite non-syn
after 1000 miles - your favorite non-syn/synthetic (it is now safe to run synthetic)

 

so just follow that schedule and i should be good?