[Custom455]

I need opinion on oil pressure.
When the car starts I have 15 to 20 pounds on start up. As the car runs down the highway I have about 10 to 5 pounds more then the rpm, 3000 rpm 40 psi. After driving a good distance, and the car is up to temp at idle I only have 5 to 6 psi, idling at about 800 to 1,000 rpm. I have had this problem since it was rebuilt, running 10w40. I went to 20w50 castrol and the psi improves to about 10 to 12 psi at idle.
I pulled the transmission and checked to make sure the oil galley plug was installed and it was.

Any help or opinions.

The motor had great oil pressure before it was rebuilt. They did install a new oil pump.

Motor
455 bored .030 over
Kauffman Dport heads, mild porting
Summit HEI
Edelbrock RPM intake and cam
1.65 roller rockers
780 quick fuel carb

[HWYSTR455]

Sounds low to me. Couple questions:

What's your bearing clearances?

What kind of gauge?

Where is your gauge taking a reading from, the filter housing or by the distributor?

What kind of oil filter are you using?

.

[Custom455]

I dont know my clearances. I will check with my engine builder.
Sunpro gauge from the oil filter housing. Engine builder was reading low on his gauge when it was built.
K&N filter.

[HWYSTR455]

K&N filters need to be changed more frequently, try an AC and see what your pressure is. Ditch the gauge and get a quality one, like VDU, SW, or Autometer.

If the builder saw it was low, what was his comments?

Definately ask build on clearances, it's starting to sound like they are too loose. And he knows it.

Out of the box pumps usually get only 55 psi or so hot, most shim the relief spring to get more right off the bat. Search here for threads about shimming the pump.

Might want to remove the filter housing and block the bypass, or check the bypass. I'm not a fan of blockign them, but it would be a crutch in a case where the psi is low. It might be hung slightly off the seat, or the tab is bent, allowing it to open at too low a pressure.

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[Dick Boneske]

Change the sending unit and/or gage. You cannot rely on readings from these to determine the engine needs to come apart. I've had at least four sending units give false low readings in my years of driving.

[Custom455]

The filter is brand new, prob 60 miles on it.
I will check the oil filter bypass, to make sure it is seated correctly.
The gauge is a mechanical gauge, and I had excellent oil pressure on the motor before it was rebuilt.

[Custom455]

Builder told me he checked the clearances and everything was inline.

[HWYSTR455]

Originally Posted by Custom455

Builder told me he checked the clearances and everything was inline.

So what were the clearances?

Pumps pretty much work or don't, maybe the check ball is hung. Was the pump disassembled, cleaned, and the pump ball checked before install? Who installed it, you or the builder?

.

[Custom455]

A new pump was installed when it was rebuilt, and the builder installed it.
I called my builder last night and he was going to go back and see if he still had the information on the clearances. This motor was rebuilt two years ago and oil pressure has always been low.
Builder said that I should be ok, as long as when I stab the throttle the pressure follows, and maintains 10 psi per 1,000 rpm
I am also having to put 6 qts of oil in it, because they were running out of oil pressure on 5 qts. I assume that the oil pump is too far off the floor of the pan.
Motor has less then 1,000 miles on it, its been one thing after another.

This motor was rebuilt before but was done poorly, incorrect cam setup and many other problems, less then 3,000 miles on it before it was rebuilt.

In all honesty I am starting to question my hobby, getting tired of pulling this motor in and out.

[72LuxuryLeMansLa.]

Originally Posted by Custom455

A new pump was installed when it was rebuilt, and the builder installed it.
I called my builder last night and he was going to go back and see if he still had the information on the clearances. This motor was rebuilt two years ago and oil pressure has always been low.
Builder said that I should be ok, as long as when I stab the throttle the pressure follows, and maintains 10 psi per 1,000 rpm
I am also having to put 6 qts of oil in it, because they were running out of oil pressure on 5 qts. I assume that the oil pump is too far off the floor of the pan.
Motor has less then 1,000 miles on it, its been one thing after another.

This motor was rebuilt before but was done poorly, incorrect cam setup and many other problems, less then 3,000 miles on it before it was rebuilt.

In all honesty I am starting to question my hobby, getting tired of pulling this motor in and out.

You are having to run six quarts because that is the correct amount. The engine holds five and the filter one.

Karl

[HWYSTR455]

It should take 6 qts if you change the filter. In some cases, most suggest adding another qt to prevent from sucking the pan dry.

You need to use a different builder is what I'm thinking. It doesn't sound like he knows some of the Pontiac specific requirements.

My guess is there are multiple issues here, one being clearances. If it was low from day one, sorry to say, you should have fought that battle back then.

Let's see what he says about the clearances, don't let up on him for that info. If he can't provide that, then I would say press him on the subject, and maybe even return the engine to him. Mention that you've contacted Pontiac specific builders and they all say the same thing, most likely a clearance issue.

.

[Bill Hanlon]

Originally Posted by Custom455

I pulled the transmission and checked to make sure the oil galley plug was installed and it was.

Because you removed the transmission to check the oil gallery plug, I'm assuming you are not talking about the pipe plug hiding underneath the distributor. Have you checked it?

[Custom455]

I checked the plug behind the distributor.

[Custom455]

Could this problem be caused by a faulty oil pump?

[A.W.Dille]

I ran into a similiar situation a few years ago on a 400 that had less than 100 miles on it. Another shop had put the engine together. After tearing it down I took the crankshaft to the machinest I was using at the time, and upon pickup he told me that the crank had previously been turned .010-.010 and was .020-.020 when I picked it up. The mechanic that originally put the engine together put standard bearings on a .010 under crank. After I assembled the engine on startup it produced about 70psi cold and around 45 warm until it was broke in. Then it carried consistant 60psi cold at idle and 35 at idle when warm. Sounds like your builder may have done the same thing, if so get a builder that knows how to put an engine together properly and knows how to check clearances properly.

[Custom455]

I called Jeff at Kauffman Racing, too order some parts and he recommended trying a new oil pump. So I think I am going to give it a try.

I checked the bypass on the oil filter housing and it seemed to be seated. I want to put in a new spring, where can I get one, or does someone know what rating to get?

I have not had a chance to put in a new gauge because, the tranny is out. I will put one in on reassembly, along with pulling it from the port by the distributor.