Old new engine

[cheese1]

In a previous thread I wrote what turned out to be a flat cam lobe and that I had purchased a rebuilt 304 that had never been run and put on a pallet for 12 years.
The motor is on a stand and I pre-oiled the motor per the instructions here. I had taken all the lifters out and primed them then coated with assembly lube. While priming the motor with a drill and flathead bit I saw I had good oil flow from the passenger rockers. As I was rotating the motor (spark plugs removed) to check the drivers side rockers for flow I heard a noise that sounded like a relief of pressure or tension. Sort of like an air drier on a semi. Not as loud but noticeable. The motor did continue to turn and did not bind up or get harder to turn. Any ideas on what it could be?
The motor is at the farm and this happened shortly before leaving. I checked for a broken valve spring but did not notice anything broken.

 

[Michael Mayben]

I fully understand what ya described, but can't think of anything immediately that caused the noise.

When you continued to rotate the engine to allow cam oil spit hole line-up for the driver side oil flow test, was that successful? Did ya have an equal amount of oil emerging from all rocker positions on the driver side?

What's the oil pressure spin up to when running on the drill motor at full drill rpm???

All the things below are simply wags and longshots:

1) oil pump pressure relief valve "stuck" then "un-stucked".

2) air entrained in filter assembly/galleries/rocker shaft assembly that suddenly "burped" (that is a good thing and side benefit from the pre-oil operation!).

3) did yore dawg layin' under the rig fart or burp like mine do?

I have experienced similar occurrences on various engines when rotating with the plugs installed, but you mentioned your plugs were removed.

How long have you run the drill motor/pre-oil process? I'd lock down the drill trigger and let it run for say 30 minutes while continuing to "slooooowwwwlllyyy" rotate the crank to allow the camshaft oilspits to align and alternately oil the rockers, longer the better! Carefully observe oil pressure throughout and see if the noise reoccurs. If it does not, then move on and blame it on bush as a onetime deal.

 

[cheese1]

I primed the motor again this weekend and rotated the motor slowly and the sound did not return. I have oil at both rockers at 50psi. Last week when the motor made the noise I had just installed the fuel pump, maybe the fuel pump farted or it was the dog.

 

[Michael Mayben]

I primed the motor again this weekend and rotated the motor slowly and the sound did not return. I have oil at both rockers at 50psi. Last week when the motor made the noise I had just installed the fuel pump, maybe the fuel pump farted or it was the dog.

Oil pressure don't git no better'n that!!! Congrats!

The oil pump is "regulated" to approximately 50psi output so you are right on target for a cold motor running off the drill at relatively low pump shaft rpm!!!

Things are finally going your way!

 

[cheese1]

It runs!

I purchased this rebuilt motor on craigslist for 150 bucks. Rebuilt 304 which had sat on a pallet for 12 years. Never been fired. I took the intake from my 69 304 and other parts and installed on the new 304. Except for the allen head set screws that plug the old air tubes above the exhaust ports you wouldn't know it was a 76 304.

I (we) installed the motor last weekend at the inlaws farm. My 66 year old father inlaw who has bone cancer (in remission) helped install the motor in 92 degree heat. One bad ass old school farmer. After installing the motor he picked up a shovel and went to work in the garden. Couldn't believe it. I was wiped out and he went to work in the sun.

Didn't get the motor started because I broke the starter solenoid cap. Went out this past Friday night and finished up the wiring and at 10pm fired the motor up. Smoked like hell for a few minutes and ran a little hot but made it through the break in.

Started the motor again Saturday morning, set the timing, adjusted the carb, adjusted the clutch linkage, bolted up the clutch and flywheel covers and went for a spin. Sure enough I drive 1 mile and a 6" 40yr old rubber fuel line breaks. Had to call the wife to tow me home.

Replaced the fuel line Sunday morning fired it up and went for a spin. Drove about 20 miles on back roads. Varied rpm and speed and made it home.

I've got alot more work to do but finally a step in the right direction. Thanks for all the help, especially Mike mayben. Your advice has been invaluable.

 

[Michael Mayben]

Outstanding dude! Another success story!

When us old farts git tired of scruuin' with old iron...we just go to the garden (or to the couch for a nap).

I dam shore don't miss the heat/humidity in yore corner of the world though...hill kuntry is perfect in March and November though!