454 Oil pressure question - Page 4

Monkeyron · 05-30-2009, 11:10 PM

OK,
I came here with a Similar Problem. Had a 90 454 Mag that was installed in a 2001 Hawaiian 24 ft. The Motor rotted apart from poor Maintenance in Salt water. Replaced motor with a fresh rebuilt short Block done locally. I had them build it for a Boat and Balanced. Installed a Hipo Melling pump.
Fired it up at 40 lbs cold and idle. Stays at 40 warm then drops to 25-30 at 2-4000 rpm. Cools down and back to 40 at idle or 4000 rpm?
Pulled sending unit and tested with Air Compressor at various pressures. They Match the Gauge pressure. The Oil filter Block mount has 2 port above it. 1-is an 1/8" NPT the 2nd is a 1/4" NPT that is more center with the Filter base. Dose it matter which port is used?
I'm using 10-30 Synthetic. 2 hours on the Motor.
Not sure about the Bypass valve for the Cooler/Remote filter installed?
Not sure what Gen the Block is. How would I find out?
Any Ideas?
Ron

Monkeyron · 05-30-2009, 11:57 PM

Well the Lines are right. What I was not sure was the Oil Sender Ports. The 1/8" NPT was left of center and the 1/4" NPT was center with the Filter Mount base. Both are about 2" above the Filter base mount..
Now for the Filter, it is not the Mercury Filter. It's a short Bosch. Plugging in a Manual gauge in the Morning in to the 1/4" to see if?
Ron

Audiofn · 05-31-2009, 05:29 AM

Ron I think you may want to go to a thicker oil. I run 20-50 in mine. Have you guys both checked to make sure that you have the correct amount of oil in the motors? You could be over full and airating your oil as well. My 420hp 454's are currently idling at about 500 rpm and I some times freek when I look at the oil preasure forgetting how low they idle. If I bump them up to about 800rpm they are at 10-15psi when warm.

Monkeyron · 05-31-2009, 10:25 AM

Quote:

Originally Posted by Audiofn

Ron I think you may want to go to a thicker oil. I run 20-50 in mine. Have you guys both checked to make sure that you have the correct amount of oil in the motors? You could be over full and airating your oil as well. My 420hp 454's are currently idling at about 500 rpm and I some times freek when I look at the oil preasure forgetting how low they idle. If I bump them up to about 800rpm they are at 10-15psi when warm.

When I first Poured the Oil in, I had 7 Quarts in. Fired it up, timed it, checked all the leaks

Pulled the stick and its full. From what I can tell it looks like the Mercuiser 8 Qrt pan. It had a Windage tray and I had to get a Milidon deep Pickup. Here in the Driveway it will show 40 lbs at all RPMs. I then took it to the Lake for a Shakedown. It did the exact same thing as the Old Motor did. Warmed up and then the Pressure dropped to 25 lbs at 3-4000 rpms. I'm using 10-30w Tech 100% Synthetic oil from Wallyworld as I know it's good stuff.
I ran my Sandcar for 3 miles in the Dunes@ 5-7000 rpms with no Oil! No damages. So I was sold for sure! I will also pick the Builder's Brain along with the Other OffShore Racers I know here.
Ron

Monkeyron · 05-31-2009, 09:41 PM

Well I finally feel better now!
I installed the Manual Gauge on the Motor in the 3/8" npt port. I also removed the Mobile 1 Filter and took Smitty's suggestion and installed the K & N HP-3002 Filter. Fired it up and there is was! 50 lbs cold. Warmed it up and it hit 60 lbs @ 4000. Idled @ 40 lbs and 140 degrees water temp. Will take it to the lake in a couple of days for another Shake down.
Thanks Guys,
Ron

redstinger · 06-01-2009, 10:30 AM

now I run between 10-20 psi at 3200 rpm, engine hot.

Monkeyron · 06-01-2009, 11:22 AM

Quote:

Originally Posted by redstinger

now I run between 10-20 psi at 3200 rpm, engine hot.

Now that 10-20 lbs at cruising would just make me worry that I may not make it back and ruin my day!

Change your filter to the K & N HP-3002 and see how that works out fer ya.
How many hours on the motor? Remote Filter?
Ron

wilstruck · 06-02-2009, 03:23 PM

Quote:

Originally Posted by redstinger

330 hp 454 is about 40 idling when cold, then runs up to about 50-60 psi on takeoff, then after warms up 30-40 when cruising. when hot idling 10-20. about 100 hrs on engine.

I purchased a boat at the end of last season (Baja w/ 496 mag)had it out a few times with same readings. First time out this season had same readings but alarm sounding after hitting a little mud. Oil temps dropped to 0 at idle and 20-30 at 3000 rpm, engine temp stayed at 160. Pulled boat out of water brought home hooked up to ears and oil back to 40 psi cold. 20-30 psi at idle when engine reaches operating temp of160. Whats the average oil reading for a 454 or 496?

Need to get it out again after flushing engine and see if alarm continues to sound. Should I be worried of these oil readings?

Will

redstinger · 06-02-2009, 03:42 PM

Yes, remote filter. Only about 150 hrs on the motor. My top end has dropped from 48 mph down to about 40 mph...maybe I am losing compression?? The previous owner had the boat way overpropped, 25 pitch. Maybe running 100 hrs with that prop hurt the motor...if you drove your truck uphill in 5th gear for 100 hrs the motor probably would be compromised.

redstinger · 06-06-2009, 09:18 PM

was able to get a mech gauge on it. same readings as the electric....30-40 psi cold, about 10-15 idle, warm oil 20 psi at fast idle...didn't even bother getting it hot.

no noise, engine runs good...top end is down about 5mph from last season though.