442 Guatemala

Hello many of you know that im restoring my 1966 olds 442 with the 400 engine, I made a compleete overhaul and everithing inside the engine is new

I bored engine at .30 flat pistons, new mondello camshaft with 0.522 intake lift, new stock oil pump, new valves, new lifters, etc

2 days ago I start the engine the first time, I put 5w oil, run the car for 10 mins and presure was ok like 50, then the presure start going down.

I change the oil to 15w 40 the presure goes down: in Idle like less than 10??
I change the oil again to 20w 50 and have same problem.

when I accelerate the car to 2500-3000 RPM the pressure goes up to 30-40 but when I stop accelerate and the car is in Idle like in 1000 rpm the pressure starts goes down rapidly to 10 or less

I have good flow of oil but no pressure ????

what is the normal oil pressur on my engine, does the camshaft affect oil pressure? what I have to check to solve this problem

thanks for any help

f-85

That doesnt sound good. during acceleration you should be between 50-60, and iddle in gear about 25-30 for a fresh engine. Did you prime the engine before starting it the first time?

things to check

check the fittings on the oil pressure gauge. see if it is leaking at the fittings or the line. If thats good. Then i would pull the engine, and check the pump and see if the pickup is loose, then check the bearings.

I had a problem with my oil pressure a few months back. It was real erratic, and would jump up and down. Turned out the pan got dented and the pickup was pushed up, so when the eninge was running it was sucking dry. That doesnt sound like your problem. Good luck with it.

442 Guatemala

The fitting on the oil pressure gauge is ok, no leaking. yes I prime the engine before starting. What is the normal temperature of operating for this engines?

One thing is confussing me: if I have no pressure how is possible to the oil go up to the valve covers? because I can see when the oil goes up?

I think im going to pull the engine and see what is the problem, thanks for the help

f-85

Engines should run between 160-190 depending on cooling system and thermostat. you sid you have low oil pressure thats why it is still making it to the top. If you had no oil pressure then it wouldnt. I just hope its something with the pump. Good luck, and let us know what you find.

442 Guatemala

Did you know if the groove of the Connecting Road have a position, to the block or to the crank shaft

f-85

Im not sure what groove your talking about, i know the pistons have to go one way. Ill ask my buddy SteveO.

442Harv

Are you sure the gage is correct? Also, are you sure all the oil galley plugs were put in? Lots of guys forget the one in the back behind the little frost plug, with a small hole in it to oil the distributor

joe_padavano

I had exactly the same thought when I read this.

442 Guatemala

Hello, today I pull down my engine, and I opened, I could see that the connecting Roads are damaged because of no oil, and the crankshaft just a little bit, maybe with a polish will be ok.

But I dont know yet what cause the no oil pressur, im going to measure the clearances. what clearances I need to have? I remember I leave like 1.5 - 2 is that ok??

The oil pump look ok, but I need to be sure if working ok. Do you recomend to change for a new High pressure Hig volume oil pump?

any suggestions please welcome

citcapp

When you say connecting rods are damaged are you refering to the bearings only? Check the oil gallery plugs as stated below to make sure they are all in place.

442 Guatemala

Sorry, my Main Bearing are damaged, connecting rods are ok.

dan2286

Did you check and see if the oil galley plug is in?

442 Guatemala

I see all the plugs in but I will chek again. someone tell me about oil restrictors, what are they, and where are located? what are they for?

dan2286

The plug that they are talking about is hidden. There is a small freeze plug on the back of the engine in the area where the cam is, and there is supposed to be a plug behind the small freeze plug. I will get some pics to show you what I mean.

The oil restrictors are aftermarket. The purpose of them is to keep oil on the crankshaft. Here is a link, http://mondellotwister.com/OilingSystem.htm They are torwards the bottom of the page.

dan2286

Here are some pics, the hole I am talking about is on the left side of where the cam goes.

DSC00536.jpg

The hole is supposed to have a freeze plug.

DSC00537.jpg

Hope this helps.

442 Guatemala

I see all of the oil plugs in. My main and Rod bearing are damaged.

The only thing I found is one of the Rod Bearing is not sitting properly into the connecting Rod, and it has a little of clearance, specifically on my number 8 piston, but I really dont know if this little thing can cause all the damage???? I need to found if something else is wrong.

citcapp

Could it be that the oil pump failed

442 Guatemala

Hello again, because of my oil pressure problem I need to change Main and Rod Bearings to .020 and cam bearings too. my question is what brand and kind is recommended to use for a HI performance or street-strip car. where is the best place to purchase them.

Also some people are suggesting that I change the oil pressure spring to increase the oil pressure, is that a good idea?

What are the recommended clearances for this bearings?

thanks again