65gregg

Help, I need suggestions. I am working on a L33/4L60 swap into a 65 C10. I took the engine to a local machine shop to have an assessment on what was needed to freshen it up. Per the machine shop a quick hone, rings, and bearings would do the trick, do it, was my response. He used a "house" set of bearings, rings and gaskets. I questioned the oil pump and was told it's a rebranded Melling. That's fine in my eyes. I added a TSP low lift cam, springs, lifters,3/8 pushrods and long tube headers hoping for a decent performing truck.
Fast forward to initial startup everything is good except the oil pressure dropped from 55 to 15 in about 10 minutes of run time. My first thought was to check the gauge so I installed a mechanical unit, same story. My next thought was the blue O ring on the pickup, I pulled the motor and installed a red one because the blue one wasn't a snug fit. Reinstalled the motor, same low pressure issues. At this point I called the shop he said bring it back and he'd go thru it and look for the problem. The bearing clearances were fine but the cam retention plate looked like it was allowing oil to bypass the seal so he replaced it and felt it should fix it.
Today I started it up and STILL have low pressure. I'm at a loss and need some input please. Sorry for the long post

RonSSNova

iTrader: (3)

Did you put the mechanical gauge where the stock one goes? Or did you put it in the side of the block up front?

So did they take the whole engine apart?

Hows the oil look?

I've had 2000 Camaro on the dyno for the last week. Was fine for all the break in and part throttle tuning. But after I leaned on it hard, it lost 20-30 psi of pressure and is glittering the oil.
Boss is going to change the oil pump. I highly doubt that's going to fix it......

Keep us posted

65gregg

I put the mechanical gauge in the stock location.
The shop pulled rod and main caps to check clearances.
The oil looks great, I have been using Brad Penn break in oil, no stripper glitter.
Good luck with your project.

pantera_efi

iTrader: (1)

Hi, my first direction would be to ask the Brand/Part # of the Main Bearing fitted.
Most here have fitted bearings on a "standard" crankshaft.
Thus many here know the clearance with a given part.
We can guess though I am sure it will be accurate.

What did the Oil Pump inspection state of the rotor condition ?

Lance

RonSSNova

iTrader: (3)

Thanks. You too!

65gregg

I'll be in touch with the builder/shop first thing in the morning. I want to check every angle before I have to pull the engine again. If I put the sending unit in the plug in the oil galley on the drivers side front or in the cover above the filter and still get a low pressure reading would that point to a pump problem since those are in direct line with the pump?

RonSSNova

iTrader: (3)

They should all read the same. So either there is a pressure leak somewhere, or the pump isn't pumping.
there isn't much to a pump.

gagliano7

Could also be too much bearing clearance.

65gregg

I let the engine idle yesterday afternoon for about 25 minutes which allowed the pressure to drop to almost zero on fresh oil and filter. This morning I pulled the filter and inspected the oil from the filter and cut open the filter, I found some glitter in the oil and a few slivers in the filter. With that said I'm about 30-60 minutes from having the engine out, tomorrow is a new day. So far the shop is still being apologetic and calling to see what I'm finding as I keep diagnosing what I can. I'll update this thread when we find what the problem is. Thanks for the suggestions.

RonSSNova

iTrader: (3)

Good that they are helping you!

65gregg

This morning I pulled the pan and didn't find anything that was scary, we flipped it on the stand, filled the oil galley and pumped air thru the system. Immediately the oil and air blew out past the rear cam bearing, I think I may have narrowed it down. It's on it's way to the shop now.

RonSSNova

iTrader: (3)

Bearing may have walked out of its bore.
I told my builder to leave the cam bearings alone in my L33. Been more than a few issues when replacing these in alum blocks.

Our Camaro project is headed out the door. Low oil pressure and all. Not my call, I just work there.....

65gregg

The machine shop called with the answer to my problem today, apparently the rear lifter bores are extremely worn and oil is bypassing from there. Crap!!! My new 5.3 block from Summit shipped this afternoon....

RonSSNova

iTrader: (3)

Now that's a new one!
they should have noticed that upon assembly.
Good luck with the new setup!

65gregg

In fairness to the shop, they built the shortblockand I completed the heads and valve train. I didn't notice anything when I put the lifters and trays in so i guess that's on me

codyvette

iTrader: (24)

That sounds very odd. Why don't you have the lifter holes bushed?

gagliano7

Sound like the machine shop is covering its a$$.

65gregg

Who in this area can bush these? I will still have the block sitting around.

RockinWs6

I'd love to see a pictures of this.