427 Oil Pressure
 

I have a 1963 427 center oiler and have a question on oil pressure. I have a Melling high volume oil pump, oil cooler and double remote filters. If I run 20W-50 (I'm an old Castrol guy) in the heat of the summer, I get about 90 lbs at idle and can exceed 100 lbs if I slam it. I'm thinking this is excessive and can see what appears to be leaking around the gaskets on the oil filters. I changed to Rotella 15w-40 this summer and reduced the pressure to about 80 lbs at idle but it will still climb to around 90 at high RPM until it gets nice and hot. Is this normal? Should I be concerned with this kind of high oil pressure? :confused:

Tim

Douglas,
I suspect that the spring is either wron or stuck. You should be at 70-80
hot with 40 or so at idle with a hi-volume and 20w50. I always used Valvoline
but that shouldn't make a difference. Unless it is a fresh rebuild and your cleareances are way too tight.
Byron

It is. You might want to try 10/40. You say it idles at 90 but can exceed 100 if you slam it. How high does it go? Do you know? I had a similar "problem" when I installed a HP kit in my Precision Oil Pumps (Melling) pump. It went to 160 psi. You risk bursting oil filters and oil lines at that pressure.

I'm living with my "problem" bu running 5/30 synthetic. When it is hot I get 60 psi at idle and 80-90 at cruising speed. You may or may not want to replace the oil pump.

There have been pictures on this website of distributor drive teeth being worn to nothing trying to drive oil at those pressures..It's a wonder that the distributor drive pin hasn't sheared leaving you beside the road. Doesn't sound like your releif valve in the pump is working at all. I'd be removing the pan and looking at that pump soon. I say way too much presure.

If the pump has been worked on the cup plug that seals the bore for the spring may be inverted causing the spring to be compressed too much therby creating a very high pressure before it bypasses. I am assuming there is a spring in the FE pump (?).

I sent the Melling tech line a question on this and they replied that this is not too excessive an oil pressure and that their recommended pump is a M57 HP (high pressure) and it's cut off is set at 120 lbs. Now I'm really baffled. Maybe George Gessford or Kieth Craft can weigh in.

Tim

I shimmed the pressure relief spring in my Melling HV oil pump to BOOST my oil pressure. Idles at 60 psi (800 rpm) and levels off at 100 psi when the rpms (2000+) come up. Using Valvoline 10-40, no leaks, no bulging filter walls.

I have found that with the Melling M57HV that most of our engines have about 30 to 40 at a hot idle and 70 to 80 at 3000 to 4000 rpms and then levels out. The oil pressure has to do with many things in the engine and the bearing clearance has a lot to do with that. If you have fairly tight clearances, say .002 or tighter this would contribute to this problem. With the tighter clearances it would be best to run a 10W30 oil. If your clearances are .0225 to .0035 and you still have this kind of pressure you may want to look at the relief spring in the pump. I would try the 10W30 oil and if it brings it down to 60 at a hot idle and say 85 or so at higher rpms I would truck on. Good luck with this. Thanks, Keith

I have seen similar with Precision Oil Pumps
 

I installed a Precision Oil Pump blue printed pump in my Craft build Pond aluminum 482 short block. On start up the pressure climbs past 110 psi. As the motor warms up the pressure will drop to around 35 -40 psi and around 90-100 psi under hard acceleration. Cruising at 70 it runs around 75-80 psi. I am running 10-40 wt. non-synthetic oil. I was concerned about pressure when I first got the motor together and running. Spoke to Doug about the pressure of his pumps (personal friend). He stated that it should not be a problem and would come down as the motor warmed up and wore in to a degree. Of course it's aluminum and seams to take longer to warm up and I never jump on it till it is warm. I am confident in both the products I got from Precision and Craft. Picture of Doug helping adjust the valves on the 482.

Thanks to Keith and everyone else for the input. I'm thinking the oil pressure is OK where it is. I'm reluctant to switch to 10w30 now that I'm trying to save on cam wear with the Rotella oil. Proper oil pressure in an FE has always been a mystery to me. Looks like the bottom end in my engine is fine. Maybe a better remote oil filter adapter will stop the trickle down the underside of the filters.

Thanks again

Tim

BTW - If and when this engine needs to be re-worked, I know it's headed to Arkansas!

I have heard that some of the OEM 427 style remote filter mounts that attach to the LH cylinder head are porous and can cause leaks. If this is what you have you may try applying some sort of coating to the inside that will seal the area that the oil is exposed to. That may be all you need to do.

Possibly all the plumbing for the remote oil filters produces lots of back-pressure due to the high volume pump. Are you measuring the pressure before the plumbing, or at engine entrance (after the filters and plumbing)? Very high oil pressure can be a bad thing. If the pressure is caused by all the resistance in the hoses and so forth it could be reduced by going to a 5W-30 synthetic.

Just my $0.02.

Bob

Rick - I've been looking for a billet remote filter mount but all I can find is a single and I'd like to stick with a double filter. I could always try gasket sealer but haven't gone there yet.

Bob - I need to check where the sender is. I'm in California for a week so can't do anything until I get back.

Thanks for the input. $.02 are always welcome.

Tim

curious but I have been told that a guy should have resticters in the heads if running a high volume opil pump ? thoughts?

It's generally wiser to start a new thread when asking a different question such as this; you'll usually get more answers. That being said, this thread answers your question to a point. There are varying points of view on this, as with most things here. FWIW, I have Edelbrock heads with Harland sharp rockers, which have a bushing and not a bearing as the Erson rockers mentioned in the thread. You want a larger hole with bushings (or stock rocker arms) than with bearings. My car is a street cruiser, so I wanted more oil to cool the valve springs. I'm currently running 5/32" holes in the restrictors; this is what I started with, not wanting to have too little oil. It seems about right for me, others will probably gawk at that large of a hole. The oil comes to the heads from a hole in the engine deck, into a hole in the head, which comes at an angle to an undercut bolt which holds down the rocker arm assy. Aftermarket heads are a bit different, but they all have the angled hole which feeds oil up one of the rocker arm stands on either side, from there into the center of the rocker arm shaft to a hole in the bottom of the shaft to each of the rocker arms. Drill and tap the angled hole to 5/16-18. Take a 5/16-18 bolt, drill a hole in the center of the threaded portion, and that is your restrictor. Cut the threads off so they’re about 5/16” long, cut a slot across the top of one side for a screwdriver, deburr everything and install in the heads.
Good Luck and welcome to the club,

Dan