All Small Six Oil pressure/ignorance is bliss

[ActionYobbo]

I built my 200 myself and it’s got 700 miles and another 6 hours running time for tuneup etc. I was just running the idiot light and it went off and stayed off as soon as the engine started. Well I got me some electric gauges and put them in and cold it was showing 30 but as soon as the engine warms up it drops to 10 and sits at 10 or just under. The idiot light in the gauge comes on under 10. So here I was happy driving around with an idiot light and not a care in the world and now I got a gauge and worries of low oil pressure.
I am going to get a mechanical gauge and screw it into the side of the block to get a reading and go from there.

 

[aussie7mains]

Ok, you are probably ok as far as damaging the engine, it did have some oil supply, albeit low pressure. So do check to confirm, the spec is 35-55psi at 2000rpm, hot. If its NOT within that range you need to find out why. Possibly, oil pump is U/S, there is a oil leak internally, for instance a plug has be left out in a gallery. Oil pressure can drop very low at idle, thats OK.

 

[awasson]

How reliable is that electronic gauge and is the oil pressure sender calibrated for the gauge? That seems quite low.

I have the stock but less than precise ford gauge in my 1966 Mustang. My oil pressure cold at startup is a little over half the swing of the gauge and a little under half when it’s cold warm.

One day it completely went to zero at startup but I could hear that oil pressure was still good. It turned out to be the sender unit. It was a year and a half old when it died. Fortunately I bought two so I put the other back in and oil pressure came back to normal.

 

[B RON CO]

Hi, what weight oil are you running? If you want more oil pressure, go with a thicker oil, like 20W-50. A thick additive, like Lucas oil treatment, can also help to raise oil pressure. Did you double check the bearing clearances during the rebuild? Excess clearance will lead to low oil pressure. Good luck

 

[63 Sprint]

I do not recommend running any oil additives.

Open up the link below:
Watch the 2nd video in post #1

https://fordsix.com/threads/oil-oil-additives-fuel-additives.86589/

 

[ActionYobbo]

Hi, what weight oil are you running? If you want more oil pressure, go with a thicker oil, like 20W-50. A thick additive, like Lucas oil treatment, can also help to raise oil pressure. Did you double check the bearing clearances during the rebuild? Excess clearance will lead to low oil pressure. Good luck

Mobil 1 classic 10w30 oil no additives. Did not check any clearances on the rebuild. Just threw it together.

 

[drag-200stang]

What did you replace on this rebuild?

 

[ActionYobbo]

What did you replace on this rebuild?

The motor had under 4000 miles with a blown head gasket when I got it. Guy I got it off pulled it to put a v8 in. It was pulled down and the deck got a 10thou skim and the head only got 1 pass at 2thou. The cylinders were honed and a new set of rings on the old pistons. It got all new bearings same make and part numbers as what was in there. No bottom end machining. New timing set and new distributor.
Basically budget freshen up with some deck work. Internals looked new and fresh. Bearings were replaced only because they were pulled during cleaning the block.

 

[ActionYobbo]

Used a mechanical gauge screwed into the side of the block. 25 to 30 cold idle then 7 to 10 hot idle. 20 to 25 at 2200 hot

 

[aussie7mains]

Used a mechanical gauge screwed into the side of the block. 25 to 30 cold idle then 7 to 10 hot idle. 20 to 25 at 2200 hot

As a guess, wear in the oil pump!

 

[gb500]

Run 20w/50.

 

[aussie7mains]

Run 20w/50.

Will raise the pressure, but not help lubrication. Do you have a Honda GB500, there is a few round here, older guys love em?

 

[63 Sprint]

The Honda GB 500 has ball bearing mains on the crank and needle bearings on the rod end. I can see why higher oil pressure or a higher oil viscosity doesn’t matter much.

 

[ActionYobbo]

As a guess, wear in the oil pump!

Any recommendations on oil pumps? I will put a new pump in it and see if it gets better pressure

 

[B RON CO]

Hi, If I was pulling the pan, I would remove some caps and check the clearance with Plastigauge. Personally, I would try 20W-50 oil and see what happens, like I suggested in post 4. Good luck

 

[aussie7mains]

The Honda GB 500 has ball bearing mains on the crank and needle bearings on the rod end. I can see why higher oil pressure or a higher oil viscosity doesn’t matter much.

Anti friction bearings need no oil pressure, you couldnt get any anyway, too many holes. Plain bearings need a continuos supply of oil fro film thickness and cooling. The film thickness is NOT controlled by oil pressure, so heavier oil doesnt help here.

 

[aussie7mains]

Any recommendations on oil pumps? I will put a new pump in it and see if it gets better pressure

Cant really help here, your in USA, Melling is probably best place to look. Here in Australia they are a bit hard to get for early engines, we have the JP brand for later engines readily available.