454 Oil pressure question
 

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.

Whats your oil temp?

couldn't tell ya. But would like to know. Where do you hook up a sender for a gauge?

One of mine runs those numbers....My oil temp is 190-200 crusing @ 3000 and 225+ after a very hard run.

I think the press is to low for shure when hot.

The temp sender you put on the oilfilter ?!

Thats where mine is.

But not shure on a 330.

Also i would run 20/50 straight oil not synt.

Yes, you have a problem. The oil pressure numbers should be more like the Vette"s. Has the pressure been that low since the engines were new or has it been dropping lately?

I've only owned the boat since June so I don't know how long its run this way. Prev owner said engine only has about 100 hrs on it. The boat was overpropped(25p), it was only hitting 4000rpm wot...so maybe he lugged it too much and shortened its life. I ractheted down to a 22p prop to make it a little easier on the motor.

The only way to really know then is to pull the engine and pull it's oil pan. If you ran it easy, you might get a lot more time out of it. However, if you run it hard, you run the risk of sticking a rod out the side of the block. It's a lot cheaper to fix it before something breaks.

Thats what I would say too, I had issues with oiling early in the season with 2 new engines, I have since redone both engines and run 75psi cold, at idle, and now have 45-50 after a good run, oil temps have not went over 200 yet at all, i run valvoline VR1 20-50 .

I have also had people tell me that 50-60 at idle cold is OK and 10-20 idle hot is ok, I was not comfortable with that so I did mone, funny thing is that i have a friend that runs Merc 1075's and he has 52.2 cold and 15-25 hot, that is on a digital readout and all merc controlled.....I would think that is not enough but they are dry sump so maybe it is different, i assume Merc knows and they are 1075HP!!!!

It's a good possibility that the engine was rebuilt with slightly larger clearences and just needs a higher volume oil pump.The Melling hv pump also has the bypass set for higher pressure than a lot of the Merc. original equipment. Unfortunately that means pulling the engine to check.

Thats what i did, I had .003 on mains 1-4 and .0035 on rear with standard pumps, not enough...

Is their a plug on the remote oil filter housing somewhere where the sender goes?

There should be, what type do you have? or you can plumb it by the block adaptor, or in the block itself.

ok I see where the plug is on the remote oil filter housing. easy enough. took the boat out today, cold pressure at 3500 rpm 50 psi. then down to 40 when hot, 10-20psi idle hot.

I'm going to just run it until it dies. Then it gives me a good excuse to go 496 or a new 502 block.

Sorry ,i did not get back sooner. But you found it.
Ithink its a waist of $ if you kill it.
Just rebuilt and beef up a little , can be done in 1 week and alot cheaper then new.

I hear ya, but pulling the motor is not a trivial repair. I've done it several times on my Chris Craft, so not afraid of it, but I think I'll try to get another season out of it, and then if i starting hearing noise or the oil pressure drops down further, then I'll pull it.

so is it better to pull the oil temp reading from the filter, or like my set up has a threaded sender on top of the pan ?

ok just put all new gauges in the boat. 30-40 psi idling cold.40-50 at 3500 rpm cold, but after it heats up, 40 is the max pressure, sometimes its 30 at around 3500-4000 rpm. needle fluctuates a little sometimes when idling. might give a new sender a try since it is 19 yrs old.

Take the sender out and put in a real pressure gauge. If it still reads low put sae 40 and a bottle of lucas in it . I had the same problem with my 2550 at 250 hours . Sold it this summer with 750 hours on it and it's still running fine . Just my .02 :ernaehrung004:

I would definately verify the pressure readings with a mech guage before you pull the engine. Also, you need to run the correct that matches the guage you have installed.

Just a little speed tip.Run the boat with the engine hatch open about 6 inch's . It was good for 3 mph on my 91 , 2550 Chap. :ernaehrung004:

Thanks for the tip...My Stinger is the same way.

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

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.

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.

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.

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.

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



Email this to a friend

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

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)

oil pressure
 

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.

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.

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

Yes it matters which port u use ,,but i could not tell u which is which !
But if u hook them up the wrong way your oil does not run thru the filter correct .:eek:

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

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:eek: 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

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:drink:

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! :eek:
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