Discussion and questions related to the course Engine Building Fundamentals
hello friends , i have seen many post about this , but i will comment about my experience
what oil is recommended (5w30,5w50,10w40 ,10w60, 15w50, etc) and any make in special( red line , motul , mobil 1 , etc) for a EJ20 with rod tolerance of 0.038mm(approx).. my car i usually for daily use , and occasional for drag or track use..
in the last build i run 5w50 for a year and half but connecting rod failed. now pretend built with crankshaft in oversize ( 0.25) but is recommended? or if better buy a new crankshaft , i have a nitrated oem crankshaft and manley rods.
and my other question what clarance is recommended to cp pistons (ej20) pison and cilinder wall and piston ring gap to built another ej to 500hp app.
i think use a in 1 ring 0.019"
2 ring 0.021"
oil ring 0.015"
the oil selection and rod oil clearance i would like know opinion for experts to run my car with peace.
My car is practically standar in turbo , inyectors , etc
my car is a sti 1998 ej20 but with short block sti 2005
if were coul guide me i would very grateful
How did the connecting rod fail - did it break or did the bearing fail?
How hot does it get there and do you use an oil cooler?
Usually the oil viscosity the maker recommends is fine for a basically standard engine, which I expect is a 10-30, or 10-40, and I would use a full synthetic. However, some who have experience with that specific engine may suggest a more viscous oil is better.
If your english is up to it (it is MUCH better than my Spanish!), you may find this interesting - http://www.substech.com/dokuwiki/doku.php?id=effect_of_oil_viscosity_on_hydrodynamic_friction_of_engine_bearings
hi friend , the bearing fail , i have a oem oil cooler .
the oil temp in my car round about 90°C in work normal , i have a thermostat of 68°c to reduce de temperrature
regards i reading the article
I've replied to your previous thread about oil viscosity. Brand is very personal and each brand will have its own fans. Personally I use Motul 300V full synthetic but that's not to say it's your only choice.
The piston ring clearances and piston to cylinder wall clearances would be provided by CP. It'd be likely for your application that you'd want a piston to wall clearance of 3.5-4 thou or thereabouts given my experience with CP pistons. The ring gaps would probably be in the region of 0.0045-0.005" per inch of bore.
OK , Andre
i am very grateful for your answer , i clear several doubts .