Posted By |
Discussion Topic:
oil pressure
-- page:
1
2
|
|
46fordnut |
09-12-2010 @ 5:45 AM
|
|
|
Member
Posts: 332
Joined: Oct 2009
|
h*llo again, i just change my oil in my flat 8 . before i did this my pressure would go to 80 when cold and drop down to about 10 when warm. now after the change it goes to 30 when cold the down to about 10 when warm . normal? i used 30 weight oil and a new filter. runs just fine.
|
40guy |
09-12-2010 @ 6:24 AM
|
|
|
Member
Posts: 270
Joined: Oct 2009
|
I'm not sure what the "normal" range is due to the individuality of these cars. That variies from car to car due to guage and sender accuracy. A sudden drop like that may or may not be cause for concern. I too have used straight 30 WT. in my Flathead for 25 years and everytime I change oil the pressure is always the same; 70-80 cold 10-20 warm at idle. I hope something hasn't got over the pump screen. I'm sure others will add to this.
|
37RAGTOPMAN |
09-12-2010 @ 7:29 AM
|
|
|
Senior
Posts: 1958
Joined: Oct 2009
|
is it possible the old oil filter was restricting the flow of oil causing higher pressure,??? how long was it in the engine,? are you using the same brand of oil? I would for testing purposes install a tempory oil pressure gauge and see what the reading are, is you gauge a original and a electric ? also what year car or truck and what engine,???? 50# system or 80# system low oil pressure could be normal, I installed a 80# pump in my 37 and have great oil pressure, and I am using the 50# sender, get back to us.,would like to know how you made out. 37RAGTOPMAN and KEEP on FORDIN,
|
46fordnut |
09-12-2010 @ 7:59 AM
|
|
|
Member
Posts: 332
Joined: Oct 2009
|
2 years on the oil and filter 800 miles. oem electric gauge. 1946 ford super deluxe 24 stud 239 flathead v8 . as far as i know the same engine the car came with. numbers match. yes same brand of oil always. i did find some small old oil chunks in the filter when i changed it this past time. oh ya before i got the car in 05 it did not run or do anything for 18 years! this was not the first oil change i did on it. from what i know the engine has 100,000 miles and never been opened.
|
37RAGTOPMAN |
09-12-2010 @ 8:34 AM
|
|
|
Senior
Posts: 1958
Joined: Oct 2009
|
well you should have have the 80# pump, try a external oil pressure gauge, mechanial type, and see what you get, It might that a piece of the things you found in the oil filter. is in the pressure relief valve ? causing it not to close and build up pressure.? this was there to regulate the oil pressure let hear back from you, 37RAGTOPMAN and KEEP on FORDIN,,,!!!!!!
|
supereal |
09-12-2010 @ 10:02 AM
|
|
|
Senior
Posts: 6819
Joined: Oct 2009
|
That's a long time between oil changes, and finding "chunks" is not a good sign. I'd install a high detergent oil, such as Rotella 10-40, and drain the oil and change the filter after a couple of hundred miles at least a two times. It is a good bet that sitting for 18 years solidified old oil into sludge, producing the chunks. The drop in oil pressure is probably due from the gradual removal of this crud from the oil passages in the engine, particularly the crankshaft. If you are lucky, the engine may survive, as these old flatheads are tough and, often, forgiving. Most will show almost full gauge oil pressure when started cold, and drop to, or near, zero on the gauge when hot and idling. If you hear a rapping sound, shut down immediately, as it is likely a bearing has let loose due to oil starvation.
|
46fordnut |
09-12-2010 @ 4:29 PM
|
|
|
Member
Posts: 332
Joined: Oct 2009
|
the chunks are more like "felt" not large or anything like that. i would say like a soot like is another way to put it. my oil changes are done at least twice a year. only did the 2 year span once. and why use the oil you said ? can you tell me is rotella 10/40 is that the only oil i should use to do this ? what about after i did this what oil should i use? how long do i run the engine with this oil before the change? is there anything bad that can happen by doing this? as far as the gauge mine did go close to zero when warm you are correct there. p.s. i did drain the 18 year old oil out before it ran and put new oil and filter. i always prime my filter when i change the oil.
|
kubes40 |
09-12-2010 @ 6:08 PM
|
|
|
Senior
Posts: 3395
Joined: Oct 2009
|
Hey Super, You know I always respect your advice. You've taught this old dog a few things for certain! I have question for you... I have been taught that when one changes to an 80# oil PUMP he should also go to an 80# sending unit as well as an 80# gauge. If not, how can one expect to get an accurate reading? I know Ford went to an 80# pump sometime directly after WWII. At that time they also went to 80# sending units and 80# dash gauges. This was the time they (Ford) started to stamp 80 or 50 on the sending units to differentiate them from one another. The question remains... an 80# pump with 50# gauges???
|
46fordnut |
09-12-2010 @ 8:41 PM
|
|
|
Member
Posts: 332
Joined: Oct 2009
|
im not sure but someone here used a #80 pump with a #50 sender . they said they have great psi this was on a 1937
|
ford38v8 |
09-12-2010 @ 8:50 PM
|
|
|
Senior
Posts: 2758
Joined: Oct 2009
|
Mike, I think I can answer this question, as they tend to bed down early in Ioway. The pump used in a flathead will still be subject to a pressure relief valve, whether on the pump or in the front of the block. Also, regardless of the pressure or volume produced, only the pairing of sender and gage would be the important issue to attain an accurate reading. Many guys do not know of the point you made regarding the value mark on the sender. I'd suggest that they reread your post to fully understand that senders having no mark at all are all 50 lb senders. We'll see in the morning if I got it right, as I also depend on Bob's expertise.
Alan
|