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Tech Area => General Buick Tech => Topic started by: Forzfed on July 02 2018, 03:00:09 PM

Title: Oil Pressure?
Post by: Forzfed on July 02 2018, 03:00:09 PM
I know it is like beating a dead horse.  I finally got the 4.1 running and put a new Delco cover on it that I had sitting around for ever.  My oil pressure cold is around 60 if not a bit shy.  I'm thinking since I will probably be revving the engine close to 6500 rpm I might need some more oil pressure going by the 10 psi/1000 rpm rule.  What do you guys think?
Title: Re: Oil Pressure?
Post by: Scoobum on July 02 2018, 03:05:20 PM
Think mine's about 35 psi hot with my foot on the brake and in D. I buzz it to 5800 at the shift points. I haven't had any issues. Don't ask me what it is at 5800...cuz I ain't got time to look...lol!
Title: Re: Oil Pressure?
Post by: Steve Wood on July 02 2018, 03:52:18 PM
Sounds good to me
Title: Re: Oil Pressure?
Post by: Forzfed on July 02 2018, 04:11:52 PM
I'm sitting at 25psi hot at idle.  This is a stock ported cover not a high volume.  But I would like to rev it to 8k! :P
Title: Re: Oil Pressure?
Post by: earlbrown on July 02 2018, 04:39:44 PM
I'm thinking since I will probably be revving the engine close to 6500 rpm I might need some more oil pressure going by the 10 psi/1000 rpm rule.  What do you guys think?


I think oil technology has come just a little ways since the 10PSI/1000rpm rule was invented.

but if you just have to jack up the pressure, start adding 6mm washers under the 1" nut on the relief valve.
Title: Re: Oil Pressure?
Post by: Forzfed on July 02 2018, 05:31:28 PM
I'm fine with that Earl I do not want to run crazy pressure! :cheers:
Title: Re: Oil Pressure?
Post by: daveismissing on July 02 2018, 07:24:30 PM
I thought near zero hot idle pressure was a Buick requirement?
Title: Re: Oil Pressure?
Post by: Steve Wood on July 02 2018, 07:25:58 PM
Conley always told me that a Buick was good if it had 7 psi of pressure at hot idle...
Title: Re: Oil Pressure?
Post by: good2win22 on July 02 2018, 10:40:56 PM
I know one fella who put a fitting in the back of the lifter gallery, ran a line and notched the tranny bell housing.  He has his oil pressure sending unit mounted to that line. Says it's the end of the line for the oil plumbing. He has 10-12 psi, hot idle on Joe Gibbs 10w40(xp7). I don't remember if he had the big pump gears or not
Title: Re: Oil Pressure?
Post by: earlbrown on July 02 2018, 11:05:43 PM
You can mke the gears a foot tall and it won't matter.     Once the gears are spinning it's the relief spring that sets the pressure at the block.
Title: Re: Oil Pressure?
Post by: Forzfed on September 07 2018, 02:04:21 PM
So, get this!  I put an oil cooler on the car last weekend.  Broke it in with out one.  Didn't want to take a chance of metal filings from the old one going into my new motor.  I didn't realize the new cooler is twice as big as the old one!  And with the weather getting a little cooler now I can't get below 45 psi at idle.  Recommendation s?  I'm switching over to synthetic next year.  This race oil I'm running is too thick!
Title: Re: Oil Pressure?
Post by: Steve Wood on September 07 2018, 02:11:26 PM
better switch to a lighter weight oil now....gonna be snapping the cam sensor gear pin and wearing out the front cam bearing fast, imo
Title: Re: Oil Pressure?
Post by: Forzfed on September 07 2018, 02:17:49 PM
Yeah, I was kind of thinking that too. :(
Title: Re: Oil Pressure?
Post by: Forzfed on September 07 2018, 02:28:32 PM
With the cooler the oil worked out to $100.  Oh, well I guess it will be clean.  What do you guys think for viscosity?  I was thinking 10w40 in Synthetic should be good?
Title: Re: Oil Pressure?
Post by: earlbrown on September 07 2018, 03:32:13 PM
Go as thin as you can on the second number for your exact engine to maintain the pressure you need at WOT.

On the first number go as low as you can get (and it'll still be too thick).
Title: Re: Oil Pressure?
Post by: Steve Wood on September 07 2018, 04:31:35 PM
You did  not tell us what you currently have in it...I am guessing 5-30 might be what you need
Title: Re: Oil Pressure?
Post by: Forzfed on September 07 2018, 05:47:31 PM
I currently have Pennzoil 25w50,  I was thinking later maybe 10w30 synthetic .
Title: Re: Oil Pressure?
Post by: Steve Wood on September 07 2018, 07:52:16 PM
Why not now? First, don't give me bs about break in on conventional oil and second, the engine was broken in during the first few minutes of driving. I will be nice and not ask you what in the world you were smoking when you bought 25-50 oil. Earl can ask that...

Title: Re: Oil Pressure?
Post by: good2win22 on September 07 2018, 08:08:12 PM
I use joe gibbs 10-30.  23-25 hot idle and just a touch over 60 at 6000 rpm.  The pressure seems to remain pretty consistent above 3000 rpm.  Nice thing about relief valves....
Title: Re: Oil Pressure?
Post by: gusszgs on September 07 2018, 10:16:49 PM
Why not now? First, don't give me bs about break in on conventional oil and second, the engine was broken in during the first few minutes of driving. I will be nice and not ask you what in the world you were smoking when you bought 25-50 oil. Earl can ask that...


 :icon_lol: :icon_lol:  agreed


All I've run is 5/30 on the stock unopened 200k motor, have yet to even have an oil PSI gauge on it. Just the idiot light for the idiot owner  :D
Title: Re: Oil Pressure?
Post by: Forzfed on September 08 2018, 11:39:32 AM
Why not now?
That came out wrong. I meant to say I was thinking instead of 10w40 to put in 10w30.  I bought the Pennzoil because it was half the price of Joe Gibbs.  My intention was always to switch to synthetic once the rings sealed.
I want to hit the drag strip at the end of the month and I am definitely not going to run with that kind of oil pressure!
Title: Re: Oil Pressure?
Post by: Steve Wood on September 08 2018, 11:50:38 AM
Modern rings seal almost instantly so it's important to drive the car ASAP and put some load on them to prevent future oil consumption
Title: Re: Oil Pressure?
Post by: Forzfed on September 08 2018, 02:44:40 PM
Steve, I agree with you but unfortunately it is the machining practices here that are the down fall.  It took some good miles before the smoke stopped blowing out of the tail pipes.  It was very faint but it was still there.
When I had the engine  machined in Texas at the shop that Conley's got to do their stuff it was amazing!  Top notch work.  Even the machinist here were impressed!
Title: Re: Oil Pressure?
Post by: Steve Wood on September 08 2018, 04:59:56 PM
Damn... Guess they didn't hone it right





Title: Re: Oil Pressure?
Post by: earlbrown on September 08 2018, 05:25:19 PM
If you installed moly rings and it took actual time to stop smoking due to ''seating'' of the rings...



....you no longer have moly rings.


When I hone for moly rings, I want the cylinders to look like a mirror.
Title: Re: Oil Pressure?
Post by: Forzfed on September 08 2018, 05:50:16 PM
Damn Earl, why couldn't you live closer? :)
Title: Re: Oil Pressure?
Post by: TexasT on September 08 2018, 06:13:01 PM
G&G up in Tomball?
Title: Re: Oil Pressure?
Post by: earlbrown on September 08 2018, 07:04:47 PM
Damn Earl, why couldn't you live closer? :)


You could actually do it yourself when you get the block back from hackin...   er..  ''honing''.    Wrap some fine wet/dry around one of those drill powered 3 stone hones and start polishing.   If you really get antsy, jizz some semichrome polish on the sandpaper and shine it up.
Title: Re: Oil Pressure?
Post by: Forzfed on September 10 2018, 04:28:49 PM
I changed my oil today.  I am now running 5w30 Royal Purple with 25 psi warm and 75psi at high rpms.  This motor revs mids 6's easy.
Title: Re: Oil Pressure?
Post by: earlbrown on September 10 2018, 09:02:10 PM
Sounds like the next change needs to be 0W-20.
Title: Re: Oil Pressure?
Post by: Forzfed on September 10 2018, 10:30:44 PM
For this time of season probably but it should be fine for summer.
Title: Re: Oil Pressure?
Post by: Steve Wood on September 11 2018, 09:51:07 AM
The pressure is more reasonable.  My only negative comment is that I have seldom seen anything good reported about Royal Purple outside of their own advertising.
Title: Re: Oil Pressure?
Post by: Forzfed on September 11 2018, 10:17:02 AM
My buddy ran it in his Stage II.  I have another buddy that runs mobil 10w30 in his little 2 liter 4 cyl that runs 146 mph in the 1/4.
Title: Re: Oil Pressure?
Post by: Steve Wood on September 11 2018, 10:25:33 AM
That makes for good ads but not necessarily low wear and long life

My own experience with it consisted of one case.  I noticed that after a couple of thousand miles, on a hot day, the oil pressure was dropping.  Went back to Valvoline Racing Oil and the pressure was steady no matter how hot the day and no matter how many miles.

Mobil1 consistently has done well thru out the years.
Title: Re: Oil Pressure?
Post by: Forzfed on September 11 2018, 12:01:02 PM
Interesting!  I guess I will have to see how it does.  It was cheap enough, worked out to $6.50/quart your price.
Title: Re: Oil Pressure?
Post by: Steve Wood on September 11 2018, 01:44:24 PM
It's a lot hotter here.

But, when I read the wear rating on 540rat's list, I decided that it was simply not a very good oil.
Title: Re: Oil Pressure?
Post by: Top Speed on September 12 2018, 11:24:24 AM
Steve, I came to the same conclusion as well. 
Title: Re: Oil Pressure?
Post by: Steve Wood on September 14 2018, 09:39:35 AM
Many are proud of how much oil pressure their engine is making.  I wonder how much of this oil pressure is causing the bypass valve in the filter to blow open and circulate unfiltered oil thru the engine even after the oil has warmed up?

The low end number on the oil rating will have quite a bit to do with that as well.  If the oil is a 15-50, it will be far more likely to cause the bypass valve to pop open than a 0-50 would.

The quality of the oil filter, and its size, will affect this as well.  Of course, a filter with very tiny passages in the filter media will be more prone to trigger the bypass valve as well.  It really does not matter how well your filter filters if the oil is all going thru the bypass when the oil is cold.  Quality of oil filters vary and some actually tell you what the bypass valve is rated at pressure-wise.  The Fram filters are generally pretty sorry in construction, but the Fram Racing filters were made pretty well.  I have always found the Baldwin filters to be good as well.  Both have higher than normal rated bypass valves.  Wix filters usually get a high rating and they make the Napa filters as well.  Do your research.

Excessive oil pressure does more than pop open the bypass valve.  It causes wear on the front cam bearing which leads to drop in oil flow and it adds strain to the oil pump drive and cam sensor gear.  High oil pressure is not always the same as having high volume thru the engine.  Pressure is created by resistance to flow.  Just like on a turbo.

Oil pressure at idle is not a critical number.  There is very little load on the mechanical bits of an engine at idle.  Lawrence Conley told me once that a Buick with 7 psi at idle was fine as long as it had good pressure under power.  60 psi at wide open throttle on top end is fine.  75 psi is overkill on a 6000 rpm engine and not only leads to increased wear, it also creates excess power consumption that is not going to the rear tires.

Oils have improved a lot over the the past 30 years.  Do your research and don't believe ads.  Believe research and testing.
Title: Re: Oil Pressure?
Post by: larrym on September 14 2018, 01:25:05 PM
I usually use any good brand name oil that is on sale, I typically run a weight that gives me a heat soaked pressure that is around 20 psi. Think my last change was Castrol GTX  10/30. It never stays in there long plus a WIX filter
Title: Re: Oil Pressure?
Post by: Scoobum on September 22 2018, 09:51:27 PM
Oil-15w40 diesel
Filter-Wix
Approximately 500 passes on the bearing from my engine on the right
Oil pump mods courtesy of JB Racing out of Montreal Quebec Canada

Bearing...https://www.youtube.com/watch?v=cp7owFIjaa4 (https://www.youtube.com/watch?v=cp7owFIjaa4)
Oil Filter-...https://www.youtube.com/watch?v=1OUPGI-rD38 (https://www.youtube.com/watch?v=1OUPGI-rD38)
Title: Re: Oil Pressure?
Post by: Tim Hensley on September 23 2018, 03:26:18 AM
That filter dose clear the SLIC

Title: Re: Oil Pressure?
Post by: Steve Wood on September 23 2018, 04:30:55 PM
I put Mobil1 5-30 extended life in my riding mower the other day
Title: Re: Oil Pressure?
Post by: earlbrown on September 24 2018, 10:56:29 PM
I put Mobil1 5-30 extended life in my riding mower the other day

I do that too.  Not one single thing I own has dino oil in it.   The extra fuel mileage more that pays for the extra initial cost.

And the mower bogs less with full synthetic.
Title: Re: Oil Pressure?
Post by: TexasT on September 25 2018, 07:30:32 AM
If your mower is bogging you might need more power. Or cut more often.
Title: Re: Oil Pressure?
Post by: Steve Wood on September 25 2018, 09:56:36 AM
I put Mobil1 5-30 extended life in my riding mower the other day

I do that too.  Not one single thing I own has dino oil in it.   The extra fuel mileage more that pays for the extra initial cost.

And the mower bogs less with full synthetic.

I noticed mine acted like it had a bit more power and it starts easier
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