I just put a 1975 2F into my '74 FJ40. I got the 2F from a junkyard. I replaced the rod bearings, main bearings, and most of the gaskets. It runs great but the oil pressure is lower than my old F. The gauge in my 40 is stock so it reads "L, 1st mark, 2nd mark, H". If I'm driving down the highway the pressure is barely above the 1st mark. Once I come down to idle the pressure drops to 25% of the way from "L" to the "first mark". All pressures are with hot 20W50 oil and the dipstick reading full. Has anyone run an aftermarket gauge to correlate pressure marks? The oil pump seemed ok spec-wise, but there was some scoring on the pump plate. If I need a new pump is there anyone out there who makes a high volume pump at a reasonable price?

The old F guage might not be totally compatible with the 2F sender. I know the temp guage sender is very different between F and 2Fs. Get a mechanical oil meter before you spend the money and work on a new pump, you may be surprised.

I did, in fact, swap in my temp and oil senders from my F. The temp guage seems to work fine though, so now I am a bit confused..

Well, if you swapped both F senders to the 2F motor, and have F guages, they are not the problem. You should still install a mechanical oil guage because it will be more accurate. If your pressure is still low after checking it with a mechanical guage, you should look into getting a new pump.

The OEM oil gauges are notorious liars. As long as anything is showing, it is probably OK. If you worry about it, get a mechanical gauge. With new bearings, it is unlikely to be bad.

As long as you have positive oil pressure you will be fine....I don't have much faith in electrical type gauges, or idiot lights..
Mechanical gauges by far are more accurate....as long as you use a quality gauge..like autometer.... :skull:

I have heard from numerous sources that Auto Meter Makes exceptional quality accurate gauges. I don't as of yet own any yet, but I will replace any of my vintage SW gauges when they fail, or look out of place!
I would Go with an Auto meter oil pressure gauge if didn't have a working oil pressure gauge.
Good Luck
Mike:fj: :jeep2:

my 2F has always been low, i called the dealer and they told me normal for the engine is only 4 PSI at idle. that sounds low to me, but i havent had any probs in 10 yrs.

Find a way to get the actual pressure like was said.

It could be excessive bearing clearance from changing bearings without grinding the journals and going oversize.

Rob

Originally posted by RHINO
my 2F has always been low, i called the dealer and they told me normal for the engine is only 4 PSI at idle. that sounds low to me, but i havent had any probs in 10 yrs.

isnt 4psi toooo low?
i have mechanical cage in my fj60 and its showing 60psi idle and 80 psi high rpm.
or its just my engine going over the limit?

on the autometer subject:

my friend who owns a j**p with a 350 in it runs autometer...they look great and are accurate. I will be putting them in mine when i get the chance and money

Thanks to everyone who has replied. I think this is an interesting topic. Maybe someday this subject would be a nice addition to Woody's tech page.

Jettech, you sound just like that darn little voice ringing in my head as I was torquing the oil pan down. I know your probably dead on. I usually just drowned that voice out with beer.:D

I went to the store this morning and purchased a mechanical gauge. I didn't drop the money for the Autometer (or VDO) gauge so take my following results accordingly. Same conditions as yesterday (20w50 with one quart being Rislone to use as a detergent, about 85 degrees F OAT). The oil pressure on the mechanical gauge would hold steady at no less than 38psi at any speed above 50 mph on a full hot engine. The oil pressure was never less than 13 psi at idle. I'm not jumping up and down, but these seem livable numbers. Since there is a delay built into the factory oil sending system, the two readings differed at anything but a constant rpm. Near as I can tell the "L" is about 4-8 psi. The "first mark" is about 40psi. These values did seem to move around a bit as the temperature (oil viscosity) of the engine changed.

I once read that about 10-11 psi per 1000 rpm is about right (at least for Buicks), so I seem to be in the ballpark. My Haynes doesn't say much on the issue except "oil pressure regulator opening pressure: 50-64 psi at 2400 rpm". My Chiltons says "oil pressure at rpm: 60 psi at 2000 rpm". In short, I think my oil pressure is a bit on the low side probably for what Jettech mentioned, but livable until I can cope with a total rebuild or swap.

The oil pressure on the mechanical gauge would hold steady at no less than 38psi at any speed above 50 mph on a full hot engine. The oil pressure was never less than 13 psi at idle. I'm not jumping up and down, but these seem livable numbers

That sounds fine to me,those are not bad numbers:)

Run it:D

yeah that sounds good to me too, i have never checked my actual pressure, just use the factory guage. its never over half, but i never have nocking sounds or anything, runs like a champ.
yes 4PSI seems quite low to me, but thats what toyota said.
and i have seen 60 PSI expand an oil filter.
so i guess its all a ballpark thing,

I have a mechanical oil pressure guage on my 2F and it shows a constant 60 psi at idle and goes up to 80 psi at freeway speeds. I think the later model 2F engines have a higher pressure oil pump than the earlier ones. Something to think about.