When I rebuilt my FE 390 I replaced the intake with a Performer RPM. Because the new intake does not have the exhaust cross over, I discarded the lifter valley tray. This was also after doing some research and discovering the lifter valley tray was intended to keep
oil from splashing on the underside of the original intake and burning/crystalizing into chunks.
Now the issue - I have replaced my intake gaskets four times. I have read every post on the proper method for cleaning and prep and have followed them to the letter, yet I am still getting leaks at the rear of the intake. I am not using the end gaskets, I am making them out of RTV silicone (have also tried two different types of RTV). The engine is tilted down in the rear, thus allowing
oil to naturally flow in that direction. A theory I want to throw out is with the
oil on the underneath side of the intake could it possibly be preventing the RTV silicone from sealing properly? Even after I let it cure for at least 24 hours as per the directions. I have never had a leak at the front, however it is higher than the rear.
Lastly, assuming I get the RTV silicone to seal to both surfaces, would constant exposure to the engine oil (i.e. oil on the underside of the intake flowing to the rear of the engine and over the end gasket) lead to the end gasket coming "unstuck"? Do I need to put a lifter valley tray back in hoping this will keep oil from splashing on the underside of the intake and flowing to the rear over the gasket?
As I said, just a theory. However, I certainly appreciate any suggestions you guys can send my way. I understand FEs like to mark their territory, but it seems mine is being way too "territorial"!
Thanks!
Rick