Thread: fresh rebuilt 350 overheating rapidly and extremely low oil pressure

Tweet

Yaa'all over thinking it.

I say radiator. It's a common issue. Your rebuilt motor is way more efficient now, and cooking that dino to higher BTUs. Your old rad can't keep up. Have it serviced or replaced.

Oh yeah, a hose CAN cause overheat. Look at the lower hose with motor running. If it collapses, it will cause flow restriction. It's best to have a wire coil in the bottom hose. ( looks like a spring )

Originally Posted by firebird77clone

Yaa'all over thinking it.

I say radiator. It's a common issue. Your rebuilt motor is way more efficient now, and cooking that dino to higher BTUs. Your old rad can't keep up. Have it serviced or replaced.

I don't agree. This is a mild build, not that far from stock and an old radiator may have reduced capacity but it's not going to exhibit the fast temperature spike described. A radiator problem will be one that keeps creeping up and cannot handle capacity over time, IMO. You're saying that you can't even get past startup and the temperature is spiking. Here's link hat shows the back side of the two styles of pumps, and you can tell by the flow path which one you have. The impeller may not be so easy, but as noted at the bottom of the page it doesn't "cup" water, but creates a pressure difference that slings the water out the ends - Direction of water pump | FlowKooler Water Pumps - Chevy, Dodge, Jeep, Ford, & more There may be better links out there, but this one popped up early in the quest.

Originally Posted by aahx2011

Installed a new water pump, thermostat and sent the radiator out for cleaning and some minor repairs. .

From post 1.. Radiator was cleaned.

BTW, welcome to the club, good to see you here and good luck on your "issue"!

Can you verify / check coolant flow into the radiator? can you see the fluid moving?
If you have the thermostat out, and if you don't have the coolant to high, you may be able to see what kind of flow the pump is making.

If you do break it down. Be careful to verify the head gaskets have all the holes lined up with th eholes in the block.. that's my guess as to the real issue..

Oil pressure--
Verify pickup is installed correctly // hasnt fallen off

Was the short block checked to verify the torque required to turn the engine over? Usually after the short block is assembled, you put a torque wrench on the crank and measure the torque....excessive torque suggests stuff like tight bearings, bent crank, tight pistons, etc.

Mike

Okay got both issues resolved thanks to all of the help from everyone on here. Alright the oil pressure issue was my dumb mistake I left the oil galley plugs out of the front of the engine, A mistake that I am pretty safe in saying will not happen on my next build. Oil pressure is now 60 psi at an idle cold or warm. The overheating was due to a bad fan clutch replaced and now the engine runs at 180 with out a thermostat, which it is getting as soon as I get to the store today. I would like to say thank you for all of the help and great input received on here. I am going to be starting another engine as soon as I get the old block back from the machine shop and have all of the specifications on it. I have started another thread under small block chevy and would take any all input on setting it. Now I get to wonder if I did and how much damage I did to the engine by me mistake.

Good to hear you got things working, it's usually the simple and obvious that gets missed!!!

Ok got that done now ever since the first start up I am getting a lot of lifter noise from the engine. Not sure if I got the valves adjusted right, if some damage has been done with the previous problems, or if this is a normal break in noise for new lifters. Any suggestions on what to look for and I will be resetting the valve lash again just to be sure I got it right.