1974 Ford BB360

[Matt Weltz]

I have a big-block 360 in a friends farm truck that is a total nightmare!!! I rebuilt the motor last June with a basic .060 over rebuilt kit. Got the motor back in the truck and had it running for about five minutes. At that time, there was a loud snap and we immediately shut it down. I pulled the motor back out and apart to find that the Melling oil pump had locked up and the snap was the oil pump drive shaft breaking in two and falling into the oil pan. Replaced with a high volume Melling pump and HD drive shaft. Also checked all bearings again to make sure there was no damage. Got the truck going again and it ran great until about a month ago. Friend brought truck back to me saying it wasn"t running good and had a knock. Turns out the ignition coil went bad and the charging system was no longer working. Replaced the coil, battery, alternator and voltage regulator. Upon further inspection the two-piece harmonic balancer had deteriorated and needed replaced. Then assumed the knock (only knocked at idle after warmed up) was probably the front main bearing. Pulled the pan and plasti-gauged the main bearings twice again. Ironically, they were all still good along with the rod bearings that were also checked at that time. Put the pan back on and drove the truck around (knock is now gone). After a good 30 minutes, the truck was good and warmed up and I noticed that it was showing no oil pressure at idle. Shut down again, pulled pan and removed oil pump. Had the pump tested and it was bad! Now have replaced with a Federal Mogul high pressure pump. When truck is first started up, it has about 80lbs. of pressure and half an hour later it has 12lbs of pressure at idle (reading from manual pressure testing gauge - not gauge in truck dash). Truck is not leaking or burning oil so not sure why pressure is so low. Sorry for the long post but justed wondered if you guys had any ideas and wanted you to have the full story. Thanx!!!

 

[rustyfarmall]

My first thought is the cam bearings are worn. Did you replace them when you rebuilt the engine?

The next thought is maybe the oil pump to engine block gasket? Just thoughts, I may be way off.

 

[Matt Weltz]

The cam and cam bearings are new along with all seals and gaskets. Block was professsionally bored and boiled and heads were completely rebuilt by professional. All bearing/clearance tolerances are within spec.

 

[mowr]

If the oil pressure relief/control valve is stuck, it cannot regulate the oil pressure. I've run into this before, especially on Fords.

 

[Matt Weltz]

Yeah but isn't it kind of unlikely that two different NEW oil pumps from two different manufactures would have faulty pressure relief valves??? I can't just keep putting new oil pumps in - surely there has to be something else that I'm missing???

 

[El Toro]

My co-worker had that problem on a 1962 Ford car with the 352 cid engine. We were changing a broken valve spring on my 1957 Chevy and went out in his car to find a used spring which we did. When he pulled up in his driveway the engine oil light came on and the lifters started to rattle.
After we installed the valve spring on my car we pushed his into the garage. Pulled the sending unit for the oil and installed a gauge and had no pressure. He took leave the next day and pulled the pan and pump. Called me at work to pick up a new pump. I went over and helped him to install the new pump. Didn't have much room to work. The old pump was bypassing the oil was stuck open. I think short runs may have cause this.
We looked at one rod bearing and they looked good. No problems after that. Hal
PS: The car was only 2 or 3 years old when this happened.

 

[Matt Weltz]

No pressure at all or just very little? This shows 12lbs.of pressure with the motor warm and idle set at 750RPM's (manual transmission). Valves are not rattling either, wondering if I should just put a little heavier oil in it and turn the idle up a little bit and call it good??? It is just a farm/work truck and doesn't see more than a few miles of highway here and there.

 

[El Toro]

I would just run it. Those old 216cid Chevy engines with the babbitted rods and dippers ran 100000 miles with 12 pounds of oil pressure. I think you will be ok. Hal

 

[RossIL]

Just to check the obvious did you plastigage the bearings? The only other thing that comes to mind is the cam bearings?

 

[RossIL]

Rusty, If you look at our post times I'd say great minds think a like but I don't want to insult you by putting us in the same class.
Ross

 

[Anonymous-0]

Is there a chance that when they hot tanked the block they left the oil galley plugs out and forgot to put them back in the front of the engine. They take them out and rotor root out the oil passages and don't put them back in sometimes. I have seen it happen on 3 different engines and also seen 3 crate engines that didn't have the plugs installed. Caused a lot of grief. Oil just pumps around and falls out the front of the block and back into the pan. Not much pressure is created. Good luck

 

[mowr]

Forgive my ignorance on this one but I don"t know whether or not the pressure relief valve on the 360 is mounted in the oil pump or elsewhere. I believe I"ve seen engines with them mounted elsewhere (in the front cover and/or the oil filter mount, for example).