Let me get this right you used a 40 yr. old pick up tube and screen?

 

Oh, that really makes me feel stupid. I examined the screen, washed it, and the tube, and it all seemed solid and in good shape. I asked the mechanic in case there was something special about them which I did not know, and he said to reuse it. But when it goes back together the second time, it will have a new one, that is certain.

Also, I wanted to say, I bottle brushed and blew air through all the oil passages. But no, the machine shop did not champfer them.

DOES ANYONE KNOW ABOUT THE HIGH VOLUME OIL PUMPS? GOOD, BAD? I know that doesn't solve the pressure problem, but I'm just curious.

 

First off, I dont see a problem with useing a 100 year old pickup... It is a simple tube, no moving parts, Your fine with that in my book... No holes, mounts up OK screen is clean, Use it...

I always use a high volume oil pump, in everything, including if I do a stock rebuild, or simply if I am doin a pan gasket, I alway reccomend doing the pump since I am there, and, always use High volume. (melling, or TRW) pump...

What would you like to know, other then, it probably will solve most of your issues.

As posted before, the guage cannot desifer high volume, or high or pressure, so it reads pressure, and says its high... Same with low volume, or pressure, will show as low pressure.

 

[QUOTE=Mustang6147;7884003]Something stinks in denmark...



I put a melling pumps in all my rebuilds. QUOTE]

Ill second that!!!!!!

 

What is your pressure when driving, you only say what it drops down to. It looks like it might be 15 psi per one post. If you always have low pressure (which for those who don't really know "is the resistance to flow") which means there is no resistance to flow in your engine. This is typically caused by bearing clearance being to big, wiped out main or rod bearing typically, oil pressure spring in the pump being to weak (not common) or being stuck open by a piece of crud (more common). One of the biggest problems with low oil pressure for any engine after a rebuild is either a missed oil galley plug or one that has came loose or out because it either was not "staked in" or tightend.

Your mechanical gauge may be off but it wont be that far off. There is nothing wrong with re-using an oil pump pick-up as long as it is not bent, obstructed, or dirty. Clearancing or reaming bearings is common and not a problem if done right. Chamferring oil passages on the crank journals is not needed on a stock, low rpm rebuild as long as when the crank was turned they deburred the openings so that there was no sharp edges to "eat" the bearing.

It sounds like you got an issue inside this engine, open it up and find out what it is before you have to start all over.

 

You have to champferr oil passages on a new turned crank.. For the same reason you have to champfer ports on a new bored 2 stroke cylinder...

Not optional....

 

When I'm driving down the road on the freeway, at about 60 mph, the pressure is about 39 psi, and that is with 15/40 oil, on a 100 degree day. I checked the crank real well before bearing installation, and all the oil passages were clean and the edges had been machined.

Today I dropped the pan and pulled a rod and main cap. The bearings looked good, with streaks of shiny polished areas, and the rest a dull lead color. The cam looks good, with all the bearings neatly in place. I don't know what else to do other than plastigauge each one and see where it is at.

The oil pump looked clean and nice, but I could see where the gears had been wearing a ring in the cover plate slightly. I was able to move the pressure release rod with a screw driver and hear it make a pumping noise. I will put on a high volume pump when I resemble it, but hell, I wish I could find something wrong before putting it back together to have the same problem.

I'm kind of at my witts end and could really use a bit of help.

 

I tried to get a new pick up tube,but they kept sending the wrong one.Could not find one that match the one that came out of the motor.We just through it in the hot tank a couple of time and cleaned it up real good.Nothing wrong with it,but yeah wanted to put a new one in it.And this is out of my 79 with a 460.

 

With 15-40 oil that pressure sounds a little low to me, but it sounds like things are looking good inside the engine. It very well could be a weak spring in the oil pump for regulating oil pressure which you will fix with the new pump. The only other things that come to mind are rod side clearance (but typically that is not an issue) and oil galley plugs leaking or missing. Another cause could be oil that is contaminated with fuel from the fresh motor not being seated(rings) but that will also be corrected wen re-assembled. You old pick up should be fine as long as it clean and straight on the mating surfaces also make sure it and the pump seal tight to their respective mating surfaces.

Good Luck.

 

Are you saying the pickup tube is out of a 460? Are they the same for a 300? I don't have a clue but now I'm wondering if maybe there was something behind it when "they kept sending me the wrong one." Or am I just reading this wrong?
Sorry, just realized 2 different people and vehicles. Ignore this post.

 

I changed to a high volume pump, but within days I have 12 psi at idle coming off the freeway.

Fuel did get in the oil. I changed the fuel pump, which was new. I also examined the carburetor, but could find nothing wrong with that. I am changing the carb today because of a multitude of issues, and going with a new edelbrock 500.

I have also decided to change out the mains and rod bearings next weekend. Gas got in and thinned the oil, wore the bearing enough to lower the pressure. There are worn past what the book says is maximum. It should take me 2 days next weekend to do it.

 

Make sure you Plastiguage the new bearings this time. Just because they are new doesn't mean they will be correct and you won't be wondering should the unthinkable happen and they get wiped out as well.

 

Thanks for the tip. Of course it makes twice the work, but worth it.

One question: with the plastigauge instructions, it says to lay the strip 1/4" off center. I assure that is because of the thrust of the pistons on a v8 being on a slight angle. But with an I6, wouldn't you want to lay the plastigauge on the center of the bearing because the thrust of the pistons is straight down?

 

Instructions, we don't need no stinkin' instructions. The thrust on a V-8 is way more than 1/4" off-center, so that's not it. I think it has to do with bearing crush which would be the same dynamic. Personally, I put 3 strips in varying locations on a crank that I haven't miked. This can help to pick up any out of round and assures me of an accurate reading. This may be a bit of an overkill, but even my budget allows for buying 3 times as much Plastiguage.