Thread: 396+30 oil pressure

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I have a 396 that was built in 1977 y Larson engines in Lincoln Ne. Finally put it into my '29 AA in 1999. Has a Weind (sp) 177 blower. Motor was has forged 7:00 to one (milled from 8 to 1) blower pistons. Had a high presure oil pump. (Motor was to go in '67 Camaro with a 6-71(15 lb boost on street). This motor had all the "goodies" done at the time, shot peened rods, O-ringed block ect.

Put on 32,000 miles with no problem. In summer of 2007 the short story is I put in a standard presure oil pump. Due to gas price, it sat except for a short drive once a week in summer. In Sept of 2008 I started driving it to work as the daily S10 died. That is when I noticed the oil presure would drop from 40 to 30 after motor oil reached 190 degrees or so. Idle went from 20 to 10 psi. Both steady readings on 9 mile back and forth to work.

Had another gear head listen ect. and nothing sounds "wrong" just the low pressure. With the high pressure pump, ran at 60 and idled around 40.

On a recent 30 mile jaunt on I-25 (60+ day) it went from 40 to 35 then to
30 as oil hit the 200 mark and motor warmed to 195.

My question is does anyone know what the speed shops did in '77 when they put the high pressure pump in? I thought it was just added but now I wounder if "speed scrects" were used such as opening the crank oil passage or clearnce.

Think I should put in a new high presure pump? I have a new Morroso high vol-high pres. from sumitt for it.

It is my daily driver and today is -2 at 12:46 am (just got off work a while ago) so it will not be today

Thanks for your thoughts and ideas
Earl

A high pressure pump just has a stronger relief spring in it, it won't help your pressure at low RPM. A high volume pump will keep up to the looser clearances the shop probably built into your engine.
What weight and brand is the oil? Some engines just don't like some brands, try another one.

Originally Posted by R Pope

A high pressure pump just has a stronger relief spring in it, it won't help your pressure at low RPM. A high volume pump will keep up to the looser clearances the shop probably built into your engine.
What weight and brand is the oil? Some engines just don't like some brands, try another one.

yup i would look at oil break down try a race oil 40wt i would say she just big on main and rods clearances that ok for race or something getting the hell beat out of it. i have had some bbc that were a bit low at idle thats ok as long as oil psi builds thru rpm s do not worry about that 10 lbs for every 1000 of rpm you may want to look at your oil for gas you could be out of tune or no choke and small stop and go stuff your going to change out your oil more

oil is 20-50 valoline that has been run at the start until now. I agree on motor may have been set up "loose" just has me ???? on the oil presure drop. (The stock pressure pump is a Melling and this problem has only started with that pump.

Thanks for the input
Earl

Originally Posted by pat mccarthy

yup i would look at oil break down try a race oil 40wt i would say she just big on main and rods clearances that ok for race or something getting the hell beat out of it. i have had some bbc that were a bit low at idle thats ok as long as oil psi builds thru rpm s do not worry about that 10 lbs for every 1000 of rpm you may want to look at your oil for gas you could be out of tune or no choke and small stop and go stuff your going to change out your oil more

Thanks Pat. I forgot that before I had a 30 mile one way drive on I-25 at 75 mph. Now it is 9 miles at 55 mph. I will give the oil change and 40 race oil a try. Before I had one stop light now several and eng temp may not be staying hot enough-long enough to "burn off" the gas the drops at start up. The stock presure pump went in just before I moved.
On the cold day's here you need to pump it a little 2-3 (cool days is one pump) with auto choke. I had also changed from a Holly carb to a Eldbrock which needs no excuess to flood the motor every time it can. I have a new Holly to put back on as soon as it warms up here.

Earl

put the old m77hv back on it if you do not like your oil psi 60 psi is fine with a stock pump when the oil get hot it can and will thin out all bbc i build it nothing to see 65 cold at idle with the m77hv then when at 200 to see that drop to 35 i had one bbc set to kill that engine on the street had 15 hot at idle and 65 max with a m77hv pump that engines was like a timex watch work just fine and took a licking

Originally Posted by OFT

Thanks Pat. I forgot that before I had a 30 mile one way drive on I-25 at 75 mph. Now it is 9 miles at 55 mph. I will give the oil change and 40 race oil a try. Before I had one stop light now several and eng temp may not be staying hot enough-long enough to "burn off" the gas the drops at start up. The stock presure pump went in just before I moved.
On the cold day's here you need to pump it a little 2-3 (cool days is one pump) with auto choke. I had also changed from a Holly carb to a Eldbrock which needs no excuess to flood the motor every time it can. I have a new Holly to put back on as soon as it warms up here.

Earl

the edelbrocks afb are good carbs they will not take hi fuel psi like a holley so if it floods you need to turn down you line psi

I also wouldn't worry too much about some low pressure numbers---could be from the guage pressure line and cold temps not letting full pressure to be read on guage.Why did you change the oil pump?????not low pressure??? Did you check bearings when you had pan off???

like jerry said what do you have for a oil gauge try puting another one like a mechanical if you do not have one now ? i am running a AN 4 line to the back of the my auto meter

Has a SW wings gauge-electric (put in '00) that replaced a SW gague-electric put in in 1979. I had taken the 77HP pump out as in '06 was changing to a stock 454. That motor had issues and I was moving in 3 weeks. Run a 6 qt stock pan and had changed the HP pump for the stock and changed out the pickup. The blower motor was sold and I had to buy it back (at a premium) in order to move.
Divorce can be rough on ya! Any case the 77HP pump was lost by the other owner. Thus I used a new stock pump with a stock pickup for the 6 qt truck pan. The '29 AA sat for a little over 1 year. At 6-7 mpg it was just too high of a cost on gas.

In case your your not sure on the years I've shown, I have owned this trk for right at 40 years. Ya, I'm a grey beard.

The fuel pump is a Carter street, I think-put in 1999. There is no way to turn down pressure as it is fixed. Carb change over was 2006.
I had not checked bearings at that time as the motor was fine when I pulled it out and bought it back two months latter. I'll need to wait to spring when it warms up to change HV/HP pump I have.

I had put stock pump in as cold days the pressure would peg my 80psi gauge.

Thanks for all the help,
Earl

While Pat is the Big Block guy, it seems to me that if the motor was sold and the other dude lost stuff, you may or may not know were you are now. Might be best to get a good game plan and do some work, at least you need to replace that stock pressure pump it would seem.

Edelbrock carbs are very good carbs,. and for me they have always been not just a little better than Hollys but a lot better, easier to tune, better quality,need less to make them perform well, however your milage may vary. Usually they work great right out of the box. Youe carter pump is also good stuff I prefer them as well, but to get the pressure down why not ron a simple in line adjustable pressure regulator if pressure is indeed the problem.

Roland

game plan;
1-change oil per Pat-not worry about the "low" readings
2-get fittings and hose to replace the braided line in now and try pressure reg. Change back to the new holley I have if needed-this may be done anyway to run a drop base air cleaner.
3-Put in the HV/HP oil pump I have and check bearings when it warms up latter this spring. (it is 15 degrees right now and no gargage.)

As for adding stuff keep in mine this is a full fender 1929 AA one ton dually with a full hood that hides the motor. It pull's my 37' 5th wheel RV and a 26' 5th wheel enclosed car trailer. There is no extra space for parts in the eng. bay-LOL (pic in my intro)


Thanks everyone for your help

Earl

Thanks everyone

OFT, This is a little off thread from your orginal problem with your oil pressure problem.

I went and found your post with the picture of your Yellow "AA". Very nice looking truck. But the question I have for you . Do you have any more pic's of this truck? I just bought a 1933 Ford "BB" Ford and I am very curious about your's, and would like to see a few more pic's if you have them.

Roland

Originally Posted by Hombre259

OFT, This is a little off thread from your orginal problem with your oil pressure problem.

I went and found your post with the picture of your Yellow "AA". Very nice looking truck. But the question I have for you . Do you have any more pic's of this truck? I just bought a 1933 Ford "BB" Ford and I am very curious about your's, and would like to see a few more pic's if you have them.

Roland

I have digital of the assembly of yellow one ton. I have film type back to 1970. It has been in 7 different confiqurations. It currently runs the 396 to a TH400 (put that in 1975) with a corp. 14 bolt c and c (cab and chassis) dually rear end. The c and c is 6" narrower than the pickup.
Front axle is a 1932 fat beam offset drilled to take 1958 Chevy 38 (1 1/2 ton) truck spindles too which is a home brew disc break set up plus converting to 9/16 studs from stock 1/2". Rear end runs a Blackbird Customs rear disc setup that allows running the stock 16" Budd steel rim.
Rear springs are the '58 chevy 38 without the overloads. For that I run air ride bags under the frame. The frame was parraled and streched in the rear using another 1929 frame turned backwards to match the stock Chevy taper. Wheel base is 147 1/2" and the cab is set back 6" from stock. She runs a full 8' long bed. Run a stock type firewall.

For more info send me a pm as not sure if this thread area is where this should be.

You will need to get used to general public going ga-ga if you build your BB as a hot rod hauler

Earl

you could try an oil cooler. it raised the pressure on my C10 by 10psi and the pressure wasn't low to start with.

You could also try some Lucas oil stabilizer.