Oil psi 454

[Xpresso]

I have 7.4 454 with oil pressure problem. Starts up and always runs 150-160 degrees. Oil psi at 45. When I start cruising at 3300 rpm the oil psi drops down to 0 after ten minutes. Temp is good , no engine noise, and runs perfect. I changed the sending unit , new home run to gauge , new gauge , k n oil filter , 15/40 rottela oil with one quart Lucas. Changed the oil bypass valve. Funny thing as soon as you let off the throttle oil pressure goes back up to 45 psi. Engine has 75 hours on it with all new everything. I can run it at 3800 rpms for a full trip 1.5 hours and engine does not miss a beat. I pulled the filter multiple times and cut open with no filings. Filter clean.

 

[Scott Danforth]

Install a mechanical gauge to verify. If your oil pressure is really dropping, your going to be pulling the motor

 

[Xpresso]

Someone mentioned oil foaming ???

 

[alldodge]

Engine has 75 hours on it with all new everything.

Agree, mechanical gauge

Was this a stock rebuild, or were things changed as in the oil pump and bearings?
Where is the sender located on the block?
Are you using the original remote oil filter housing and lines?

 

[kenny nunez]

Another problem along with foaming could be a vortex forming around the pickup screen.

 

[Scott Danforth]

Another problem along with foaming could be a vortex forming around the pickup screen.

only if the sump is not full

I believe that Smokey Yunick disproved a vortex could be done on a proper filled sump with even the highest volume oil pump available. at the same time he disproved the ability to suck all the oil out of a sump with a high volume oil pump. I remember seeing the high speed pics about 30 years ago

oil foaming/frothing would come from having too much oil in the sump and the rod journals slapping the oil surface.


however its all speculation until we get proof from a mechanical gauge screwed into the oil galley. most likely is somewhere omong the $2 sender connected to the $3 gauge by the $0.30 wire that the boat builders put in the boat.

 

[kenny nunez]

Smokey was one of the sharpest people on the racing scene and I can respect that. I understand that the strip of metal covering the hole in the pickup is to break a vortex. One of my friends with 20’ Cigarette 454 experienced the vortex problem after a rebuild. They changed the pickup and the problem went away.

 

[ottawamerc]

I have the exact same issue with my 454, I'm going with a shitty gauge and sender cause mine like yours runs flawlessly