quote:Originally posted by BKL98MK8LSC:
The v-10 has a different crankshaft design from the v-8s. It uses a split throw on the rod journals for even firing(bad idea)and is drilled differently for rod bearing oiling. A fully groved main bearing would provide a 100% increase in oil volume to the rod bearing,but they dont use one.They could do alot better. There are alot of racers using 0-20 and producing over 1000 horse power with the 4 valve v8 without bearing problems. Most would probably like to use heavier oil but pressure to the valve train is not regulated.This will cause the hydraulic cam followers to pump up in the early 4 valve heads and hold the valve open if thick oil is used. That would be bad. Thin oil bleeds off faster and allows this engine to rev to over 9000 rpm,without bearing problems. Later high performance modular 4 valve engines use a miniature hydraulic cam follower with a higher bleed rate that allows heavier oil to be used. They spec 5w-50 in that engine.I dont know if the bearing clearance have changed for the supercharged engines , but all modular ford are a select bearing fit engine,meaning they fit each engine with the exact size bearing required to get the clearances perfect. 5w-40 full synthetic would be my choice for A motorhome with a v-10.
Bk,Thanks for all the Great tech info about the ford v-10 engine.
I agree with the 5w-40 choice(devlac?) in a motorhome,and I doubt Kathy,or anyone else would have ever revved the engine to 9k causing any issues.