454 Oil pressure question

[oconnor marine]

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.

The 454 in my 71 vette is 70-80 psi when cold, 60-70 when driving, 20-30 idling hot. not sure of miles on the engine.

I always heard rule of thumb 10 psi per 1000 rpm. sometimes at 4000rpm on the boat I am around 30 psi when hot.
This is with AMSoil 50 w synthetic. Should I be concerned.

thats fine.
Your motor and most other marine engines have a low pressure / High volume oil pump. Those numbers are perfect. I suggest running a 15W40 delvac or shell rotella.
The vette has a high pressure pump, not the same as what you have in the boat

[c_deezy]

The 330 hp in my Baja runs about 55-60 cold, around 50 after warmed up and about 20-25 when I come off plane and idle after running on plane for awhile (usually 3200-3800 rpm), then as the oil cools down while idling it comes back up after about 30-60 seconds. Mark V engine, 25w40 oil.

[socalstone]

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.

I wouldn't pull the motor over those numbers. I have the same motor in my jetboat. It has slightly higher numbers on all fronts, but could be the gauge. I've seen plenty of performance motors with hot idle numbers similar to yours.

If your still concerned, at least verify the readings before you do anything drastic.

[jw454]

10 psi. per 1000 rpm is a proven fact and pushing more oil pressure than that is just wasting horsepower and promoting spark scatter. A 330 hp. 454 has a standard volume oil pump, which is what it should have and has a rpm range of 4200-4600 rpm. So if you are running within that rpm range at WOT, then your 40 or so lbs is pefectly acceptable. JW.

[redstinger]

Update...Now the best I get is 40lb cold startup, then running down the lake after it is warmed up, about 30lb (regardless of rpm), then when I come off plane down to idle, practically zero-10 range....The other day I went to change the oil, stuck the rubber dipstick probe in there and it wouldn't suck oil out...pulled probe out, it melted shut. oil is really hot. what is causing this. Engine only has about 100 hrs.

[Rockfish71]

Originally Posted by redstinger

Update...Now the best I get is 40lb cold startup, then running down the lake after it is warmed up, about 30lb (regardless of rpm), then when I come off plane down to idle, practically zero-10 range....The other day I went to change the oil, stuck the rubber dipstick probe in there and it wouldn't suck oil out...pulled probe out, it melted shut. oil is really hot. what is causing this. Engine only has about 100 hrs.

You need to check the oil filter bypass valve sounds like you have the 11 lbs valve you need the 30 lbs valve. it is in the block where the filter pad is ond if there is one in the center hole that would be oil going into the engine you need to re move it and leave out.

[Rockfish71]

What generation engine block are you running ?
If you are running a gen 5 or 6 there are two bypass valves installed in the engine block one for the filter bypass and the other one is for the gm factory remote oil cooler witch is up inside the block where the threads for the remote adapter would bolt up to the block remove the one in the middle. where the adapter is and the one offset needs to be changed to a 30 psi or plugged so all the oil will go throught the filter and cooler.
Do a search here on bypass valves
dont run until you get your problem sorted out with the right bypass valve or you will be removing the engines due to you buring them up like a lot of other guys have done. I spent a lot of research on my set up with the right bypass valve install I still have not fired up my engine but for right now I'm only running a filter on the block and will be motioring the oil temp then going from there I hope I can run just a larger filter and no cooler my set up is pretty light 24 foot boat, and make sure you run a good filter like napa wix do not run fram they are junk.


GM (General Motors) 25161284



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25161284 - 1991-2000 & 454 - 502 GM Performance Crate Engines Big Block Chevy Oil Filter Bypass Valve - 30 LB Bypass Pressure Used With Sandwich Adapter For External Oil Cooler Only 25161284


Pace Price Qty
$7.95



Detailed Description
Used on Gen V & VI engines when running an external oil cooler with a sandwich adapter between the block & oil filter. The 30 Lb valve compensates for the restriction caused by running an external cooler. Used in the location adjacent to the oil filter nipple on the oil filter pad. For standard non-sanwich adapter applications use GM # 25013759

25013759 - 1991-2000 (And GM Performance Parts 454 & 502 Engines) Big Block Chevy Oil Cooler / Oil Filter Bypass Valve 25013759
Gen V & Gen VI Engines Use 2 Of These

Pace Price Qty
$6.95



Detailed Description
Gen V & Gen VI Big Block Chevy Engines & All GM Performance Parts 454 & 502 crate engines use two of these bypass valves. Location for oil filter bypass valve is adjacent to oil filter nipple on oil filter mounting pad, Location for second valve (For oil cooler bypass) is above oil filter nipple in block on filter mounting pad. If a cooler is not connected to the oil cooler ports on the oil pan rail, the second valve is not needed. Engines using a sandwich adapter between the block and oil filter to connect a remote oil cooler must use GM # 25161284 oil filter bypass valve (in the location adjacent to oil filter nipple) to compensate for higher system backpressure






Oil by pass valve GenVI

[redstinger]

I never thought of the bypass valve...the guy I bought the boat from had a just enough knowledge to be dangerous and I wouldn't be suprised if when he rebuilt the motor that he put the wrong one in or something.
So with a Mark IV block, do I just have the one valve up in the threads (the middle one)

[getrdunn]

Originally Posted by jw454

10 psi. per 1000 rpm is a proven fact and pushing more oil pressure than that is just wasting horsepower and promoting spark scatter. A 330 hp. 454 has a standard volume oil pump, which is what it should have and has a rpm range of 4200-4600 rpm. So if you are running within that rpm range at WOT, then your 40 or so lbs is pefectly acceptable. JW.

100% correct. I use to worry all the time because I had the same problems before and after engine upgrades. I would always be looking at the pressure and it would concern me. Never ever had a failure. I just got engine temp gauges and monitored them along with the pressure. If it continues to be the same and reliable with said pressures, leave it alone and run it and have fun. Your stock pump is fine. GM has been making them for years. If you do pull the engine just check your clearances between the gears and pump cover. You can always bump up the pressure by reducing the clearance between the gears and your cover to near .0025. You reduce this by sanding (300 grit) your housing on a very flat rigid surface, very little at a time and keep checking. Be sure and check your gears and inside the housing for signs of wear. If there are then replace it with a new hi volume/pressure pump. Even with a new pump it is always a good idea to open it up and check it out as mentioned above.

[carcrash]

Maybe it just needs a bigger oil cooler. Sounds like you are getting hot oil, and hot oil is thin oil, and thin oil is low pressure.