Oil pressure question

[chas427fe]

I have a 428 FE, CJ block that has been bored and stroked to 460. Until this year, it had 53 lbs of pressure at 3000 rpm which is my normal cruiseing speed.
Last year at the beginning of winter, I changed the oil. I have used Pennsoil 10w40 since it was new. (Builder recommended this ) The only thing different was I used a Ford racing filter this time. After 500 miles of this, I went back to the Moroso filter that I hade been using and no change. I sent an oil sample to Blackstone labs and their comment was it looked like new oil with no metal in it.

1000 rpm = 15 lbs
2000 rpm = 30 lbs
3000 rpm = 43 lbs
6000 rpm = 60 lbs

It has a Melling 57 high volume oil pump
Comp cam with hydraulic roller lifters
7000-8000 miles on the engine

Any thoughts why my pressure would drop 10 lbs? Thanks for any and all comments. Chas

[Wbulk]

When something happens with oil pressure that is odd, I always hook up my trusty cheap mechanical gauge to verify pressure. Could be electrical.

[RICK LAKE]

chas427fe Chas 10#'s is alot if this is just an oil swap and filter. When you first start the car does the needle pin to 60 psi+? Is the problem with the oil pressure only after the motor is hot and been running for a while? I have 2 thoughts on your problem, bad gauge or problem in the motor.. Wb has the easiest idea, get a good mechanical gauge and retest the motor. If the pressure matches the gauge in the car, you have motor problem.
I would start with the rocker arm studs or bolts and make sure they are all still at 35 ft. of torque. If this is good I am pull the oil pan. Do you have an old filters from the motor? If you do, cut one open and look for metal partials in the pleets. If the answer is yes, time to pull apart the motor and check for damage. If not, I would look at the oil pump and pressure nipple in the puymp to be seated. It is easy for it to get stuck a little open and bleed pressure off the system. You might or might not see any thing. A cheap way would be to replace the oil pump with a blue printed one. I would go to Doug and buy a blue printed one with a 70-80# spring upgrade.
I don't want to get into a oil pressure issue on the forum. IMO and 14 years of racing an FE based motor, SBC numbers are not enough. 10# at idle might be OK IF it's a 427 crossdrilled crankshaft. It is IMO way short on any FE motor. You have 10# at the gauge which means you have a dribble at the rockers and maybe 2-5 psi at the rear rods. When you pull the pan check #4,#8 rods for play and rod bearing clearance. These rods get the oil last. Check the rest if you have the time with plastic gauge. Make sure all bolts or nuts are at spec, If not you have a problem starting. You also might want to look at a oil suppliment like Lucas. It has a clinging additive to help dry starts. Even better is adding a 2-3 quart accusump as a per oiler for the motor. Been using one for 8 years. It's nice to have 30-40 psi of pressure before cranking the motor. 80% of wear and tear on a motor is done at startup. Hard spirited driving could have cause low oil pressures and you might have not seen the gauge drop to almost "0" around a high speed turn and pull a little "g". The other thing is overfill the oil system 1 quart because of the HV oil pump. It pulls 28% more oil than a stock pump. It is possible that you may have sucked the oil pan dry because of the slow returns on the motor. Try gauge first and hope for the best. If no change add more info. Rick L.

[chas427fe]

Thanks for the replies.
I have an Autometer mechanical gauge in the car. It is 3 years old so I would not discount that as a possiblity.
Rick, the oil pressure does go beyond 60 at start up. I will get a second gauge to verify that item and then move to the rocker arms, which are Erson rollers. I do not have an old oil filter but I did get a clean lab test from Blackstone. If this does not solve the problem, I will have to get it into the shop. Can't work under the car anymore because of vertigo.

[STL Mark]

Ask your builder about 20w50 oil. It may be a simple as - your oil is too thin.

[Michael C Henry]

It sounds to me like you have pressurized oil escaping some where in the system. I ended up switching my 428 block to threaded plugs to ensure that the soft plugs didn't get pushed out of place. I've seen one of the rockerstands break and let oil pressure drop to a point where the original engine owner let a friend of mine buy the engine for little or nothing, my friend found the broken rockerstand problem replaced the stand and used the engine for years later. I've also heard of the releif valve in the oilpump getting stuck in the releiving position. A leak almost any where in the system could cause your simptoms. Gasket sump to pump. gasket pump mount to block, any of the gallery plugs. Did you do anything with the front center gallery at the front ? Originally a 428 had a soft plug with a bent cotter pin. It can be replaced with a 1/4" pipe plug with a small hole to quickly evacuate the air in system at start up. A small hole will let a lot of air out but less oil. That is what I currently have in my sideoiler now, but it would be more necesary in a top center oiler like a 428.

[RICK LAKE]

chas427fe Chas if the needle is pined at startup and you are not blowing the filter off the motor I would think the oil pressure relief spring and nipple are working ok. Auto meter gauges are very good over many years. Have a set in the bird for over 15 years, never hd a problem or thinking the calibration are off.
Let's try 1 thing before you take the car to a mechanic. Change the oil to 15W-40 rotella oil and see what the pressures are after a drive. This oil will not hurt any thing. I have been using it for 10+ years due to the zinc and other additives removed from the oil. I also add additives of EOS and Lucas to all my motors. Change the oil and filter, add 1 extra quart of oil to the system and drive it like you normally do. record the pressures and get back to us. DON'T have the motor idling for any more that 10-15 seconds. If you have to idle increase the rpms to 1,000. There is a 10-30 psi drop in pressure from the oil pump to the rockers. Clearances have alot to do with this and oil pressures. You may get lucky and the motor will respond. Drive it the rest of the summer and in your winter( if you have one ) Have the motor pulled and gone through, at least the bottom end and camshaft bearings. Rick L.

[chas427fe]

I will order a new filter and change the oil to the thicker blend and see what happens. I will keep you posted. Chas

[chas427fe]

Changed the oil tonight using Rotella 15W40 with 1 qt. of the Lucas additive. The results are better but not where it was.
Water temp = 95.
1000rpm = 21 psi
2000rpm = 40 psi
3000rpm = 48 psi

Talked to the builder and suggested changing the oil pump that it might be wearing out.

[RICK LAKE]

chas427fe Chas the numbers are better because of a thicker new oil. With the 15w-40 and lucas oil suppliment you are running about a 20w-50 heavy race oil. If you are only going for a couple more drives this year, I would think it is OK to do. No beating on the car just cruising. 10#'s is better than nothing but I think that the bottom end is hurting a little. IMO it's better to quit early and pull the motor for a going over. I think you will find that most guys break there motors cruising and doing nothing wrong. Problem is, if you break a rod and put it through the sid of the block, you are looking at bumbers for repair unless you have spare bullets laying around. I have no luck, so the worst case would be splitting the block in half East coast is getting hit this weekend, maybe monday will be a good day for us. Good luck. Rick L.

[chas427fe]

Thanks Rick for all you help. I will keep an eye on it and see about pulling this winter. Chas

[chas427fe]

Rick thanks for all your suggestions. I will have to wait for winter to work on it and see how it goes. Chas