Author Topic: Not ADVISABLE to ADJUST THE PRESSURE RELIEF VALVE IN YOUR Q or U  (Read 5173 times)

Old Man

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Re: Not ADVISABLE to ADJUST THE PRESSURE RELIEF VALVE IN YOUR Q or U
« Reply #15 on: August 19, 2014, 04:39:36 PM »
Interesting. Reading between the lines it seems Chrysler had the gauge hooked up to the wrong side of the pump. The later 6s run oil pressure at the same number as the road speed,30 mph/30psi,40mph/40psi,50mph/50psi etc. At first start up they will run 60 psi on cold (room temperature) engines at 50 mph. They idle at 20 psi. I use SAE 40 any manufacturer. I buy by price. They all have to meet the same ASI ratings up here or they can't be sold. Not at retail anyways. We seem to have fewer problems up here in Canada maybe because we have a smaller market and the word gets around fast if there's any problem with any product. Chet,I add a slip coefficient additive called Prolong,have for many years. I had a knock in one of my 6s for 2 or 3 years that I finally got around to and it was on a big end of a rod. I found no damage whatsoever and I just changed the bearing shells and that fixed the knock. I believe that the Prolong saved the day. I highly recommend you use something like it if you're going to muck around with your oil pressure especially on the a slung babbitt motor. I have a friend who has a 1953 Chev truck and says the 5 psi that it runs is the normal oil pressure and he has no worries,so he says. He has had the truck for several years. Maybe we worry too much about our Plymouths. And they have better metals in the block etc. than the off brands. Also Chet you can't compress a liquid. You can only compress a gas. This is why brakes work the way they do. The brake fluid works as a solid when pushed against but goes back to a liquid when the pushing stops. (Pumps ,such as on firertrucks, are pushing the water out at exactly the same rate as they are moving it through the vanes of the impeller. There is no compression. What you see coming out the firefighter's hoses is what is moving through the pump. )           

chetbrz

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Re: Not ADVISABLE to ADJUST THE PRESSURE RELIEF VALVE IN YOUR Q or U
« Reply #16 on: August 20, 2014, 07:51:50 PM »
... Chet,I add a slip coefficient additive called Prolong,have for many years. I had a knock in one of my 6s for 2 or 3 years that I finally got around to and it was on a big end of a rod. I found no damage whatsoever and I just changed the bearing shells and that fixed the knock. I believe that the Prolong saved the day. I highly recommend you use something like it if you're going to muck around with your oil pressure especially on the a slung babbitt motor. I have a friend who has a 1953 Chev truck and says the 5 psi that it runs is the normal oil pressure and he has no worries,so he says. He has had the truck for several years. Maybe we worry too much about our Plymouths. And they have better metals in the block etc. than the off brands. Also Chet you can't compress a liquid. You can only compress a gas. This is why brakes work the way they do. The brake fluid works as a solid when pushed against but goes back to a liquid when the pushing stops. (Pumps ,such as on firertrucks, are pushing the water out at exactly the same rate as they are moving it through the vanes of the impeller. There is no compression. What you see coming out the firefighter's hoses is what is moving through the pump. )         

Thanks for the info on the Prolong I will be addressing the motor sometime next year.  I haven't driven the 29 in awhile.  As far as liquids under pressure go., I do understand the physics.  What prompted your statement ?

Chet...   
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