I teach auto mechanics at a high school and the principal,s son blew the 85 305 engine in his truck. After tearing it down we founfd the block to be ruined. I gave him an old 305 I had and had it bored 030,new pistons new cam bearing,crank kit,rebuild the heads. After getting it started which it started great, I saw we had low oil psi-35psi cold idling, after driving 5-6 miles in gear it,s showing 8-10psi. This is after installing a high volume oil pump and going to valovine 20w-50 racing oil. I called the machine shop back and they assured me the cam bearing were installed correctly. Which I have been using this shop for several years and they do alot of high performance work so I trust them pretty well. Any ideas from you guys I even hooked the gauge up down at the oil gallery right above the oil filter and no change. The crank felt great when we installed it. Oh I already know b-fore someone mentions it I should have went with a 350 but look I,am keeping my 350,s LOL I di:sad:d use the old cam and lifters,the motor runs great no rattles no knocks. I have even tried 2 new gauges getting the same reading on both.Let me know what you guys think?

what oil pan is being used and what about the pick up tube? did you put a spot of weld to hold it to the pick up?

Maybe one of the oil galley plugs under the timing chain popped out.That pressure is dead low for a stock rebuild with a high volume pump and 20/50.

To support Rich's theory, look at the amount of oil at the front rockers verses the rear rockers?

Relief valve stuck open?

hideaway,

What were the main and rod bearing clearances when you assembled the engine ? Did you check them ? I have seen crank kits come with the incorrect bearings before :(

Cam bearings on a small block will not affect oil pressure in the way you are having a problem.

I was wondering by using the old cam could it be hurt around the journals losing psi, he did run it hot and ruined 4 rods.

I was wondering by using the old cam could it be hurt around the journals losing psi, he did run it hot and ruined 4 rods.

Probably not. What were the rod and main bearing clearances ??

By the way, the reason I have asked this question twice is because over 25 years ago a good friend of mine rebuilt a 302 Ford engine for his sons 69 Mustang. He bought a cranckshaft kit instead of having his reground. When they finished everything, it just did not have the oil pressure that it should have, but he did not want to pull it apart again to check anything. This was before I was in the machine shop business. Well, they drove the car almost 10k miles and it ran fine but always had low oil pressure, pretty much the same that your 305 has. They finally decided to do some body work on the car and pulled the engine so we decided to take a look at the bottom end. Well guess what .... the crankshaft had been reground to .020 Rods and .020 Mains but .... the bearings were .010/010 :( Did not hurt a thing, we put the correct bearings back in it and the oil pressure went right to where it belonged. As far as I know he is still driving it.

So ... if you did not check the clearances, that is the first thing you need to do :)