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Oil Pressure Problem

RootesRooter

Donation Time
Scotty - Well, like you said, you've been paying more attention to the temp gauge until recently. Fresh results from Hartmandm's tests are needed to see if you've got a sticking PRV.
 

spmdr

Diamond Level Sponsor
I have issues with the video as well.

First off, the oil PRL is not a magic SOURCE of oil pressure.

If the PRL is closed, adding pressure to the PRL will not add engine oil pressure.

The main reason for the PRL is to bleed of excess oil pressure.


My main problem with the video is the suggestion that the PRL be set at IDLE.

WRONG!


The PRV has at least two functions.

1) bleed off excess oil pressure.

2) bleed off excess Volume of COLD oil.

You have to be careful with the PRV that you don't reduce it's volume flow with cold oil.


I have had issues with PRV sticking Open AND sticking Closed!

I'm tempted to try a Ball in place of the Piston.

DW
 
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Tim R

Silver Level Sponsor
DW,
Your comments are interesting, as you say the PRV is there to prevent excessive pressure, splitting filters causing leaks etc etc.

It is true that adding pressure to a closed PRV won't increase oil pressure BUT increasing the spring pressure so that higher oil pressure is required for it to lift and release does.

I'm not sure why setting the pressure at idle is wrong? If you increase pressure at idle it stays proportionally increased as revs rise all the way through the range. I claim no specialist expertise on this but this modification has been done on numerous cars over a very long period without any issues that I am aware of.

Your idea of a ball could be an ideal solution and if you were to produce some you would undoubtedly find customers.

When your PRV stuck in the closed position, did it cause you any damage? (I've read of people having oil filters burst)

Best Wishes,

Tim R
 

Scotty

Silver Level Sponsor
So as it turns out, I don't have a stuck anything. What I have is a carb problem. Here's the deal:

I took the advice given and adjusted the Weber 32/36 from SS back to stock spec. Bang! The oil pressure went back up to 40 on a cold start and stayed there. I noticed that if I lean the Weber too much, my Temp Gauge rises like mad and I will overheat if it let it, so my issue is this damn Weber that either runs rich but likes that or starves and starts to get too hot. What am I doing wrong here? I've read the paperwork on how to tune this thing and I simply can't figure it out.

And yes, the 1725 fires up from stone cold and sits at 40 on the Oil Pressure Gauge. I'll drive it when my hand is better and see what the gauge does and answer a few more questions.
 
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spmdr

Diamond Level Sponsor
This is why NOT to set the oil pressure with the PRV at Idle.

At idle, the oil pump is turning at a slow speed, half the speed of the crank shaft.

The oil pump is a positive displacement pump, at slow speeds, low volume.

If you adjust the pressure at idle, chances are you will raising the pressure

only by reducing the VOLUME the PRV will flow.


What you should do AFTER adjusting the PRV, is remove it and verify the piston

MOVES all the way open.

IF the piston movement is limited by the spring being too far compressed (coil bind),

You NEED to replace the spring with a stiffer one that lets the piston move all the way open.


Regarding the PRV sticking closed, I recently noticed it on the Weekend Racer when I

was at high RPM in 3rd gear, the oil gauge was near 100 psi !!

It was at Fontana at the end of a race. I immediately dropped the throttle and clutched it at the same time.

No problems found and I have not had that problem since.
 
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RootesRooter

Donation Time
I've had my oil psi noticeably drop once while the temperature was almost pegged due to running up Pikes Peak on a very hot day. But I'm not sure if running too lean with the engine in normal temperature range could cause the kind of drop you experienced. Very odd circumstances. Looking forward to reading your test results!

Regardless, I hope you didn't run it long or at high speeds while it was badly starving. Piston melt-down is a frequent consequence.
 
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Scotty

Silver Level Sponsor
Sorry this took awhile. I took it on a long drive.

Series V with the brass oil pressure relief valve?

What oil pressure are you seeing just after starting when the engine is cold?

40-45

What oil pressure are you seeing shortly after starting when the engine drops to the usual idle speed (at or less than 1k rpms)?

Stays at 40 when warmed up and at rest and drops and stays at 25 after driving it for a mile, mile and a half.

What oil pressure are you seeing when the engine is normal temperature (85C) at idle?

Will lower to 25 and fluctuate between 25 and 30 after driving and then parking and let idle.

What oil pressure are you seeing when the engine is normal temperature at 2k rpms or greater?

So far it’s stayed at 25. It wasn’t a long trip, 2 miles total. Temp stayed at 190. Running 15-40 in her if that makes any difference with straight 30W in the all synchro trans.

Mike
 

husky drvr

Platinum Level Sponsor
Sorry this took awhile. I took it on a long drive.

Scotty,

A question - you have a sIV with a 1725 - are you running an oil cooler?

If you have a cooler, you can ignore the rest of my ramblings.

The sV with 1725 came standard with an oil cooler. You realize that Rootes wouldn't have installed an oil cooler system if they thought it was unnecessary. The larger bearings and additional main bearings needed a larger capacity oil pump which in turn circulates the oil at a higher flow rate. The Alpine's oil sump is well shrouded from air flow. The faster oil circulation, additional heat generated in the bearings, and lack of cooling air flow around the oil sump seemingly caused a heat shedding issue that wasn't a problem with the three main engines.

One other point is an ICE uses the oil as a coolant, as well the the radiator and liquid coolant. As an experiment, next time you drive your Alpine long enough to get it thoroughly warm, use your infrared thermometer to check the oil temp on the lower side of the oil filter. As a guess, I think you'll find the oil temp is 200*F, maybe some higher. If you think about it, if the operating oil temp is that high, then the engine will be trying to shed heat from the oil through the liquid coolant and radiator. Alpine radiators aren't well known to be able to over cool the engine, extra heat wont help.

Anything you can do to increase the volume of oil in the system (tall truck oil filter - maybe) and the amount of air flow around the oil sump (small air dam positioned to direct air up around the oil sump) will probably help your hot oil pressure issue. Ideally, an oil cooler system would be best.

Have fun,
 

alpine_64

Donation Time
Scotty,
sV with 1725 came standard with an oil cooler. You realize that Rootes wouldn't have installed an oil cooler system if they thought it was unnecessary.

This brings up a topic we discussed years ago. I think when @RootesRacer (iirc) adapted a ford oil to water cooler base.
Jarrid had done some research into oil temps and implication for the psi and degradation.. Iirc " the 1725 really hammers the oil"

What is interesting is they fitted the coolers to the alloy head " series" alpine 1725 .. The fastback alpine alloy head used an allpy sump instead.. Yet the alloy head 1725 in scepters, gazelle and similar saloon cars didnt have coolers or alloy sumps..

Always found that strange. Maybe tbey edpectes the sporty models to get driven harder?
 

Scotty

Silver Level Sponsor
@husky drvr - I don’t have an Oil Cooler installed but anything that will help it run cooler and efficient I’m all for. How do I go about this and where/how should I install it? She’s my daily driver so stock in this case means nothing to me.
 

Scotty

Silver Level Sponsor
This brings up a topic we discussed years ago. I think when @RootesRacer (iirc) adapted a ford oil to water cooler base.
Jarrid had done some research into oil temps and implication for the psi and degradation.. Iirc " the 1725 really hammers the oil"

What is interesting is they fitted the coolers to the alloy head " series" alpine 1725 .. The fastback alpine alloy head used an allpy sump instead.. Yet the alloy head 1725 in scepters, gazelle and similar saloon cars didnt have coolers or alloy sumps..

Always found that strange. Maybe tbey edpectes the sporty models to get driven harder?

That is strange and doesn’t make sense. I’d want every way possible to keep it cool regardless the styling of the car, but you figure a family out there somewhere took a Gazelle for a family trip or something.
 

Barry

Diamond Level Sponsor
This brings up a topic we discussed years ago. I think when @RootesRacer (iirc) adapted a ford oil to water cooler base.
Jarrid had done some research into oil temps and implication for the psi and degradation.. Iirc " the 1725 really hammers the oil"

What is interesting is they fitted the coolers to the alloy head " series" alpine 1725 .. The fastback alpine alloy head used an allpy sump instead.. Yet the alloy head 1725 in scepters, gazelle and similar saloon cars didnt have coolers or alloy sumps..

Always found that strange. Maybe tbey edpectes the sporty models to get driven harder?




The S-V Alpine 1725 was rated at 97 BHP versus 91 BHP for the Rapier, Sceptre and Vogue. Perhaps the combination of the extra 6 HP and the "brisker" driving style for the Alpine was the straw that broke the Camel's back with respect to oil temperature and required the air-to-oil cooler.

I am a fan of water-to-oil coolers because the oil quickly heats up to a desirable temp. and the maximum oil temp. is typically well controlled. The potential "gotcha" is the additional thermal load on the radiator.
 

RootesRooter

Donation Time
I wonder if the Sceptre, Gazelle etc had a milder cam than the Alpine GT/Rapier, therefore fewer HP and less heat. I've got an old magazine article on the fastbacks somewhere that said Rootes/Chrysler designed the fastback body thinking an oil cooler wouldn't be needed, but when testing showed otherwise, there was no place to mount a cooler, so they went with the aluminum pan. The fastback 1725 was rated at a few less HP that the Series V, probably because of the narrower intake ports. Maybe they thought that would be enough to keep overheating under control?


This brings up a topic we discussed years ago. I think when @RootesRacer (iirc) adapted a ford oil to water cooler base.
Jarrid had done some research into oil temps and implication for the psi and degradation.. Iirc " the 1725 really hammers the oil"

What is interesting is they fitted the coolers to the alloy head " series" alpine 1725 .. The fastback alpine alloy head used an allpy sump instead.. Yet the alloy head 1725 in scepters, gazelle and similar saloon cars didnt have coolers or alloy sumps..

Always found that strange. Maybe tbey edpectes the sporty models to get driven harder?
 

Tim R

Silver Level Sponsor
We run a thermostatically controlled oil cooler on our Alpine. It opens only when the oil is hot. Tim R


 

Tim R

Silver Level Sponsor
As it shows in the video there is no wiring, it is simply a thermostat that is part of the under oil filter take off. When under 80* no oil gets cooled, when over 80* oil flows to the cooler.
Tim R
 

Tom H

Platinum Level Sponsor
Tim, I have a couple questions about the thermostatically controlled oil cooler. I assume that on a 1725 one can easily remover the original oil copper adapter that is under the filter attachment and simply remount the original filter mount directly onto the block. Is that true? If so that means:
1) Scotty, the original poster, should be able to find and install the original factory oil cooler adapter (and then find an original cooler and find a way to mount it.)

2) Also, it means one could remove the original cooler adapter on a 1725 engine (as noted above) and instead install the new thermostatically controlled one on top of the filter mount and maybe connect the original cooler hose to the new adapter. Do you know if the original hose connectors will mate to the threads of the new adapter?

Thanks, Tom
 

Scotty

Silver Level Sponsor
Tim, I have a couple questions about the thermostatically controlled oil cooler. I assume that on a 1725 one can easily remover the original oil copper adapter that is under the filter attachment and simply remount the original filter mount directly onto the block. Is that true? If so that means:
1) Scotty, the original poster, should be able to find and install the original factory oil cooler adapter (and then find an original cooler and find a way to mount it.)

2) Also, it means one could remove the original cooler adapter on a 1725 engine (as noted above) and instead install the new thermostatically controlled one on top of the filter mount and maybe connect the original cooler hose to the new adapter. Do you know if the original hose connectors will mate to the threads of the new adapter?

Thanks, Tom

On this, I’m more concerned about performance than originality since mine is a driver. If I can walk into a parts store and walk out with what I need and it works as well or better than OEM, I’m ok with it. I have a feeling this might be a pain to assemble the parts and the money I spend on original could be spent on something better and more reliable. I just need to know what I can use.
 

husky drvr

Platinum Level Sponsor
Tim, I have a couple questions about the thermostatically controlled oil cooler. I assume that on a 1725 one can easily remover the original oil cooler adapter that is under the filter attachment and simply remount the original filter mount directly onto the block. Is that true? Yes the cooler adapter is easily removable.

If so that means:
1) Scotty, the original poster, should be able to find and install the original factory oil cooler adapter (and then find an original cooler and find a way to mount it.) Yes, that might be the simplest.

2) Also, it means one could remove the original cooler adapter on a 1725 engine (as noted above) and instead install the new thermostatically controlled one on top of the filter mount and maybe connect the original cooler hose to the new adapter. If the new adapter is ordered with the matching fittings, several types are offered. Do you know if the original hose connectors will mate to the threads of the new adapter?

Thanks, Tom

Tom,

Here is a link to a US supplier of the same parts as Tim used (I think). I'm not convinced the "thermostatically" controlled unit is any better, or even functionally different, from the O/E cooler adapter's method of pressure differential control of oil flow through the cooler. At least not by examining the very minimal information I could find online. A phone conversation might be more informative.

EDIT#2: I did find a small tidbit of information about the MOCAL thermostatic cooler adapter while checking out one of the online catalogues. The thermostatic cooler base does have a "waxstat" thermally operated method of operation, not a pressure differential like the O/E cooler adapter. Considering modern lower viscosity multi-viscosity oils in use today, the thermostat is probably a better choice.

The one thing to be aware of is a warning about using a cooler matrix (too small) that allows the oil to overheat to around 270*F in your usage. The waxstat can be permanently damaged at that temp level. The good thing is the waxstat can be replaced.


https://irp-cdn.multiscreensite.com/e112be6e/files/uploaded/thermo21.pdf

http://www.batinc.net/mocal.htm

Edit: Adding link for UK company that Tim used.

https://www.thinkauto.com/index.html
 
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