Reply With Quoteour 460 runs 70 lbs cold and after a hard run the oil temp goes up to around 240 and the pressure drops to around 20-30lbs . hot oil=low pressure. i bet the oil pressure comes up after the oil cools down. mine has be like that since day one.
out on the lake yesterday and oil pressure dropped 20 lbs , and oil temp went up to 240 deg. normally run 70 lbs and 190 deg. oil temp . whats up ? spun baering ?
our 460 runs 70 lbs cold and after a hard run the oil temp goes up to around 240 and the pressure drops to around 20-30lbs . hot oil=low pressure. i bet the oil pressure comes up after the oil cools down. mine has be like that since day one.
Any knocking or other unusual noises? Pull the filter and cut it open, check the element pleats for bearing material [copper] If there is copper in the filter you have a bearing going south.
My oil runs up to 300 if I'm on it hard for any duration, does that mean I have something wrong !?!?!? Oil gets hot, 240 aint shit. There isnt anything that can make oil run hotter except no water in the block. If its a jet, it will run hot, get an oil cooler.
We are not operating our passenger car engines at 2000-3000 rpm. Instead, we are modifying them to be used in high performance boats and are subjecting them to 4000-5000+ rpm heavy load conditions. And so oil temps can shoot through the roof.
This is one of the reasons I am such an advocate of synthetic lubricants. They have higher film strengths and maintain their viscosity over a wider temperature range--both hot and cold temps. Just be sure to stick with ester based synthetic lubricants.
But I digress...this post is a concern over oil temperature. I have seen oil temperature gages show alarmingly high readings after nailing it for a sustained period of time in a boat. Temp shoots up fast. I don't currently have an oil temp gage in my boat. But after what I saw on that gage, I am not surprised how much my pressure drops in my new engine (with a petroleum based oil for break-in). On a recent tuning day at Camp Far West, I started out with about 42 psi at idle. After some long sustained high rpm passes, my oil pressure dropped accross the board and was now at 21 psi at idle. I was concerned at first. Then I just figured I already wasted the oil that was in it. But the next day out (with cold oil), I had my old oil pressure readings back for most of the afternoon while putting around.
Anybody here: just tap a temp gage into your oil pressure line and you'll see what I'm talking about.
Passenger car engines use maybe--what--50 hp while cruising down the freeway. There is minimal load. By way of compararison, imagine driving around in a pumped V8 with a 5000 stall speed converter--floored all the time.
Fomoco, I don't know why your oil pressure was diferent that day.....any noises? Was your water temp higher too? Were you hard on your engine that day? How many hours on your oil? How much oil does your motor hold? Have you checked your oil level?
Oil does a lot of things besides lubricate. It acts as a seal; it is a corrosion inhibitor; it is a cleaning agent; it is a cooling agent (i.e.absorbs heat), etc. So use a good oil.
LO
What first got my att. was that I was loosing rpm , the first few times out I was able to turn 5500 rpms . then yesterday I lost 200 rpm , no big deal right ? also noticed oil temp and press . difference . so I change the oil and filter , all ten quarts . back to the lake hoping for the best , now I can only turn 4100 rpms at best , and motor sounds poor ? temp up , pressure low . not good . I realy hope you guys are right , cause I don't want to tear this motor down . too much precaution taken to not have this problem i.e. forged pistons , shot peened rods , balanced , and 10 quaurt oil pan with windage tray . read $$$
FOMOCO76:
What first got my att. was that I was loosing rpm , the first few times out I was able to turn 5500 rpms . then yesterday I lost 200 rpm , no big deal right ? also noticed oil temp and press . difference . so I change the oil and filter , all ten quarts . back to the lake hoping for the best , now I can only turn 4100 rpms at best , and motor sounds poor ? temp up , pressure low . not good . I realy hope you guys are right , cause I don't want to tear this motor down . too much precaution taken to not have this problem i.e. forged pistons , shot peened rods , balanced , and 10 quaurt oil pan with windage tray . read $$$ Been there done that, did you cut the filter open?? if your clearances are too tight say good nite to the rods.
Ooooh boy....
Look at the filter internals....first thing. If you find anything suspicious, flip the motor and unbutton the pan and look under the caps.
Go see if, by chance, your distributor housing is loose and is slowly retarding...
Does your pump turn freely?
LO
For the next motor .What would be good clearance's for a 460 in a jet boat running 5-6000 rpms . because I have a cheeter nos kit hooked up that I haven't tried yet .
[QUOTE]Originally posted by FOMOCO76:
For the next motor .What would be good clearance's for a 460 in a jet boat running 5-6000 rpms . because I have a cheeter nos kit hooked up that I haven't tried yet . [/QUOTE IMO run .0025" on the rods and .0035" on the mains. Side clearance the rods for more than .020" Piston clearance: follow the mfg's recommendation as well as ring end gaps as different conditions and pistons require different gaps such as hypereutectic pistons need up to .032" end gap on the top ring.
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