Oil Pressure Problem 351w

i was thinking of bolting 2 of them together though, a nice v-12????lol

Ryan351w wrote: There have been roller motors for a LONG time in the OEM field. I know in the mustang the roller was introduced in 85. Dodges' in 91. Oil changed in early 2000's

Ryan since it appears you are a student of automotive trivia, you may find it interesting the GM/allison 6.2L diesel was roller for its introductory year of 1982, three years before the mustang 5.0 HO roller cam engine, and even the 350 olds abortion i spoke of went roller half in the latter half of its run in 1980.

Hi,

Thanks very much for the responses... So it sounds like my old pressure is okay, but I'll double check with the mechanical gauge, and keep an eye on it :)

Regards,
Greg

Ryan351w wrote: TRB-That’s exactly the oil I’m referring to. Rotella-T is a diesel oil. And when I buy generic stuff, I make sure they have the same mount of additives.

Ryan,
Glad you stated the Rotella but keep in mind that it's the straight weights that have the ZDDP. I'd hate for someone with a flat tappet engine to be misinformed. The ZDDP has been researched and discussed at length here.

I like Tim run the VR1 in all my engines.

BTW, I am hearing about cam failures on old engines. A couple from flat head Hercules owners who were using what they thought was "good" oil!!!!

Ryan351w wrote: Luckily diesel motors still use flat tappet lifters so those additives are still needed.

Consider checking your sources.

You may have the order backerds, the failing cayalysts and extended gov'ment mandates for emissions warrantees drove the reduced zinc oil blends that neccessatated the roller cams, not the other way around. Automakers didn't just convert their fleets roller to be kewl.

While i agree the oil is better, the diesel oil has much reduced zinc over the last two years, so be wary as this progresses. This is due the same driving forces.
I think you are mistaken about the flat tappet lifters. I can report GM diesels haven't used flat tappets since the 350 olds/diesel abortion almost 30 years ago. Even the old detroit two-strokes are roller.

just a little rule of thumb...10psi per 1,000 rpms.

The better the machining the less pressure needed. I talked to a head guy at Melling and he was telling me that the NASCAR engines run only 70-80psi. Granted these motors come apart every race, regardless of that the motor would take itself apart if there wasn't enough pressure. Remember these motors turn over 9,000!



Another little trick, diesel oil. I run it in everything, 500hp mustang, aurora, boat, diesel truck. The diesel oil is awesome. My buddies dad runs it in his blown 340, in the motor and the blower. It has alot of additives in it that were takin out that protected metal-to-metal contact. It was mainly there for lifters to cam lobes. But when roller lifters and OHC's came on the scene they decided that it wasn't needed anymore. Luckily diesel motors still use flat tappet lifters so those additives are still needed.



Another piece of info-pump placement in the motor packaging itself has no effect of where you will get higher or lower oil pressure. The oil galleys are drilled where they are drilled. They feed the mains and rods then depending on the motor it will pull from the main galleys to feed the lifters/cam/push rods. So running a "jumper" line from the front to back or vise versa is helping a bad spot (low oil pressure) in the motor.

Hi,

I did an oil change (and oil filter) this weekend (the last oil was only 30 hours old). When cold, the oil pressure was around 80psi... and as it warmed up, it dropped to around 55 to 60 psi when cruising. Idle was around 30 (in gear) or 40 (neutral) psi. It stayed like this for around 10 minutes of cruising.

Later the next day, I took a long cruise at say 3000rpm for around 20 minutes... I noticed the oil pressure was a bit lower, around 50 psi.

At idle (neutral) it was 30 psi, but then after idling in neutral for about 2 minutes, it rose to 40 psi. At one point, it was at 50psi after a l0ong time idling.

Could these differences be due to a difference in oil temperature?

I got a mechanical oil pressure gauge, but never got a chance to test it - I'll try next weekend though.

Regards,
Greg

Hi,

Thanks for the feedback.

I do my oil change around every 50 hours. It has been about 40 hours since the last change! Maybe I should just do a oil change again, now - it can't hurt?

I'll definitely test with a mech gauge - just need to find one locally (I'll call some auto shops).

Thanks again,
Greg

Hi Greg no i did not do any of that was always planning on getting another gauge and put it on but were using the boat every second day so have yet to have a chance to do so!

the Lucas seamed to make things abit better to be comfortable running it!!

A little strange that both of us all of a sudden had a problem after letting the oil get a bit low!

Update:

Put a diff version of that Lucas stuff in, it helped a lot, still only getting about 10psi at idle but 40 wile running so will do me out for the rest of the summer i hope!!!

Once again thanks for all the help!

This site has some pictures that you can enlarge to get better views.

Rebuild

If you are thinking of only doing the main and rod bearings without pulling the heads, it can be a bit more difficult.

GottaSki wrote: abolton wrote: Did anyone else see the episode of Horsepower TV where the drilled into the oil passage in the back of the block and ran copper tubing up to the front of the block and tapped into the oil passage? They where said the racers do it all the time on the Ford 351's because of week oil at the front end. Never heard of any weekness with the W oil system. And weak at the front? where the pump is? Similary skeptical.

Im no expert, but I thought I had heard of something along those lines regarding the Ford 460. Maybe thats where the confusion is?

kapla wrote: In the case he decides to put a mech gauge..were should it be plugged? I guess that will need to put the gauge in place of the oil sender?

either tee into the oil pressure switch/sender or remove it and install the gauge start it up and let it get hot no need to go anywhere to see the oil get hot and loose pressure, Driving it is only going to get it hotter quicker and so it takes an extra couple minutes sitting at the dock or on the trailer to find your answer.

In the case he decides to put a mech gauge..were should it be plugged? I guess that will need to put the gauge in place of the oil sender?

1100 isnt that much if the oil was changed regularly, its funny sometimes you tear into a 500 hour engine and it looks like 3000, but try the mechanical guage first then decide which way to go.