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Got the Dual oil pressure and real voltage gauge in, No I know what "R" means.. by reamer

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Rembrant

Re: Got the Dual oil pressure and real voltage gauge in, No I know what "R" means.. by reamer

reamer wrote

Right now "R" = 52 psi, will be interesting to see what "N" equals.

Ron,

Is you factory gauge reading from a factory oil pressure sender? Just curious.

I swapped an aftermarket coolant temp sender to a Ford sender this weekend, and now I'm wondering about my oil pressure, which is currently using an aftermarket sender. Currently it reads in the middle of the "M" when driving down the road, and on the "R" at idle.

I seem to recall from the dyno day my oil pressure was running something like 60psi when we first started it, and then around 55-56psi once it was warmed up, but I can't remember what it was at idle.

A proper oil pressure gauge is on my long list of wants...

1994 F150 4x2 Flareside. 5.0 w/MAF, 4R70W, stock.
1984 F150 4X2 Flareside. Mild 302 w/ 5spd. Sold.
1980 F150 4X4 Flareside. 300i6 w/ 5spd. Sold in 2021.
1980 F100 4X2 Flareside. 351w/2bbl w/NP435. Sold in 1995

Danny G

Re: Got the Dual oil pressure and real voltage gauge in, No I know what "R" means.. by reamer

also piggybacking.

I am sure there is a thread on it, but how involved is turning the ammeter to a volt meter?

Is there a step by step someone could link me too?

1986 F-150|Standard Cab|4x2|300Six|C6Transmission w/3.08 rear|Name:TBD
2021 Ranger XLT Super Crew

Gary Lewis

Re: Got the Dual oil pressure and real voltage gauge in, No I know what "R" means.. by reamer

Administrator

Not a step-by-step, but at least a schematic of the way I intend to do it: Documentation/Electrical/3G Conversion and on the Ammeter & Voltmeter tab.

Basically the voltmeter replaces the ammeter so will have battery voltage fed to it at all times via the red/orange wire. But it needs to only work with the key on or it will put a load on the battery. So I plan to use a relay in the dash some place that is pulled in with key-on power and once pulled in supplies a ground to the voltmeter via the yellow/light green wire.

Gary, AKA "Gary fellow": Profile

Dad's: '81 F150 Ranger XLT 4x4: Down for restomod: Full-roller "stroked 351M" w/Trick Flow heads & intake, EEC-V SEFI/E4OD/3.50 gears w/Kevlar clutches
Blue: 2015 F150 Platinum 4x4 SuperCrew wearing Blue Jeans & sporting a 3.5L EB & Max Tow
Big Blue: 1985 F250HD 4x4: 460/ZF5/3.55's, D60 w/Ox locker & 10.25 Sterling/Trutrac, Blue Top & Borgeson, & EEC-V MAF/SEFI

Steve83

Re: Got the Dual oil pressure and real voltage gauge in, No I know what "R" means.. by reamer

Banned User

In reply to this post by Danny G

TheScatch wrote

...turning the ammeter to a volt meter?
Is there a step by step someone could link me too?

This & the NEXT dozen are a step-by-step on an older Ford truck, but the wiring is essentially the same, and it should give you the idea:

This & the NEXT one show a later stock voltmeter in a bullnose cluster:

Rembrant

Re: Got the Dual oil pressure and real voltage gauge in, No I know what "R" means.. by reamer

In reply to this post by reamer

reamer wrote

Took OO-BGUB out today to get it hot and watch the oil pressure drop (as it usually does) the needle usually sits between "N" and "O", at idle, da pressure is 30 psi...

I specifically searched for this thread to find out where my oil pressure was in my 1980. The old 300 purrs like a kitten and runs really well, but the factory oil pressure gauge drops down and the needle covers the "N" when it's hot. It looks quite low on the gauge, but it is technically still within the "Normal" scale. When I start it cold, the needle is straight up in the middle, but it slowly drops down to rest on the "N" as it gets hot. So based on Ron's observations here, I'm guessing that I'm running around 25psi hot? That should be OK for an old 300 with unknow mileage, shouldn't it?

I was reading somewhere a while back that "if the 300 inline six has any oil pressure at all, it has enough" LOL.

I did talk to the previous owner, and he said that when he put the 300 in the truck that it was a very low mileage engine (only had about 40k miles on it). However, I have no idea how it was treated, and when I found it, it had been sitting for probably a decade out in the elements (in the truck, but certainly not prepped for prepared for any kind of long term storage lol).

Gary Lewis

Re: Got the Dual oil pressure and real voltage gauge in, No I know what "R" means.. by reamer

Administrator

Well, yes and no. Or jein if you know German slang. Where the gauge reads is mainly dependent upon the output of the instrument cluster voltage regulator, with each ICVR being different. And many times I've seen the ICVR change its mind mid-drive and all the gauges read differently.

Yes, there is some variability in the gauge itself and the sending unit, but not nearly as much as there seems to be in the ICVR.

So I'm not sure how much pressure you have. But, I think you have enough pressure. Surely over 10 psi, and I've always thought that 10 psi at idle was adequate.

Maybe some day I should spread out on the work table several gauge clusters and using several different ICVRs and senders map what the gauges read at differing pressures?

Gary, AKA "Gary fellow": Profile

Rembrant

Re: Got the Dual oil pressure and real voltage gauge in, No I know what "R" means.. by reamer

Gary Lewis wrote

Well, yes and no. Or jein if you know German slang. Where the gauge reads is mainly dependent upon the output of the instrument cluster voltage regulator, with each ICVR being different. And many times I've seen the ICVR change its mind mid-drive and all the gauges read differently.

Perhaps I'm a little on the optimistic side, but I happen to have a lot of faith in the factory gauges if/when everything is working properly. I've changed the ICVR with a known good one, and nothing changed in my readings, so I'll assume it's OK for the time being (and yes I understand that they may vary a bit).

My temperature in the '80 gauge seems to be pretty accurate, same as in my '84. I have 195* thermostats in both trucks, and when they're up to full operating temp the gauge needles are straight up in the middle, in both trucks. I've checked the engines with an IR gun as well, so they seem to be reading well. I know they have quite a range, but it seems like Ford intended for 195 degrees to be dead center in the gauge?

The oil pressure in my '84 is known as they checked it on the dyno when I had the engine built. It runs past the middle when cold, and almost exactly in the middle when hot, which...if I remember correctly was 50psi or a little higher. The 300 in the '80 on the other hand, I have no idea...BUT, if it's within the normal range on the gauge, and it's not knocking...lol, I'll have to assume that it is OK. Maybe I'll throw some additive in there to thicken it up...

Gary Lewis

Re: Got the Dual oil pressure and real voltage gauge in, No I know what "R" means.. by reamer

Administrator

I, too, have faith in the factory gauges and have gone to great lengths to get them working correctly, including installing a true voltage regulator instead of the ICVR.

Big Blue's gauge points at M when the aftermarket gauge says the pressure is 60 PSI. But, the voltage regulator is set to 5.4v so I'm not sure that it is fair to compare.

Gary, AKA "Gary fellow": Profile

Rembrant

Re: Got the Dual oil pressure and real voltage gauge in, No I know what "R" means.. by reamer

In reply to this post by Rembrant

I might temporarily stick a pressure gauge right on the engine block just so I can see what its actually doing.

Gary Lewis

Re: Got the Dual oil pressure and real voltage gauge in, No I know what "R" means.. by reamer

Administrator

That's the best approach. Then you will know and you can map the actual pressures to the gauge's readout.

Gary, AKA "Gary fellow": Profile