Boomyal
Supreme Mariner
- Joined
- Aug 16, 2003
- Messages
- 12,072
In trying to determine what oil to run in my new/used 5.0 litre roller cam boat motor, I came across this. Initially I want to run dino oil even tho I hope to switch to synts later. I had purchaced a case of Delo 15-40 at Costco but took it back and exchanged it for 5-20w after reading this statement.<br /><br />
I think that I am going to finally change the oil in my 195K mile E150 4.6 liter mod motor. They describe exactly what seems to be happening lately. When I start up, I get a lifter clatter. It has happened for a while but seems to be getting more persistant. I'll drive a couple of blocks and actually shut off the motor and restart it to get the clatter to quit. I thought the lifter was bleeding down at nite but it sounds like that is not the case.<br /><br />I'd say I've had a pretty good run on that oil. About 189K miles since I put it in. Of course I've added to it as it used a quart in 4500 miles and when I change the two filters, but that is one whole lot of time I have not spent sitting at Oil Can Henrys wait to have the oil changed. November 1996 to August 2005.Wrong weight of oil - Hydraulic lifters have an internal operating clearance of approximately .00015 - .00035. This is in the range of 1/10th to 1/20th of the thickness of a human hair. Thick oils (SAE 30 and higher) can cause many problems in hydraulic lifters. Thicker oil slows the bleed-down rate and contributes to lifter pump-up. Old thick oil can cause the plungers to stick and act as if the lifter has collapsed. Thicker oils flow much more slowly through a cold engine, so frequent cold starts result in vastly increased engine component wear. Straight weight oils (even as thick as SAE 50) do not have the film strength of multi-viscosity oils such as 5W-20, 5W-30, and 10W-30, so with the extreme opening rates available to roller cams, straight weight oil films can start to break down. It is this last point (the tremendous film strength of multi viscosity oils as compared to racing oils) that fools many old timers who think that traditional thick, straight weight oils are best for performance applications.<br /><br />Crane R&D strongly recommends the use of multi-viscosity oils in all hydraulic roller lifters. Our tests have consistently shown a 3-5 HP increase throughout the RPM range when compared to straight weight oils. In addition, we have never experienced a component failure due to thin, multi-viscosity. NOTE: exotic fuels (alcohol, nitromethane, etc.) require special lubricants for which most multi-viscosity oils are not qualified.