304 knocking

[Bryan hill]

1968 travelall hasn't run for a minimum of 15 years.
Has knock, not tick at idle ( Cold and warm) increasing in intensity with throttle position. Runs really smooth great power , for 1968
Got new clean fuel, mechanical pump blocked. Running electric FP.
Pulled valve covers, rockers all move equally and are getting oil. All but 3 rotate during their travel but not all equally. Oil pressure appears good(on stock dash gauge). Old oil came out good , no chunks or particles, just dark. Sound of knock does not change without covers on.
Alt,PS pump,water pump sound great thru stethoscope.
Any ideas????

 

[jeff campbell]

Did you pull dizzy and pre-oil engine before starting ?

 

[Peter Albrecht]

If the knock is on the passenger side, it could be the valve that runs the exhaust through the intake manifold on cold starts. There is a butterfly valve that is spot welded to a shaft, that weld has failed on two of those units over the years and the round plate rattling around will make a knocking sound which would initially make you think " Oh $#!+, a rod knock !" That unit is located on the passenger side of the engine, between the exhaust manifold and down pipe. The down pipe is flared with a larger opening at the top so the round plate will not fall down into the pipe.

 

[Bill Bennett]

What # oil are you running in the engine and which oil filter?

 

[Bryan hill]

Did you pull dizzy and pre-oil engine before starting ?

Pull dizzy?
I did not pre oil before hand.

 

[Bryan hill]

What # oil are you running in the engine and which oil filter?

Got fresh 5-40 synthetic in it now .
Wix filter

 

[Bryan hill]

If the knock is on the passenger side, it could be the valve that runs the exhaust through the intake manifold on cold starts. There is a butterfly valve that is spot welded to a shaft, that weld has failed on two of those units over the years and the round plate rattling around will make a knocking sound which would initially make you think " Oh $#!+, a rod knock !" That unit is located on the passenger side of the engine, between the exhaust manifold and down pipe. The down pipe is flared with a larger opening at the top so the round plate will not fall down into the pipe.

I've seen your earlier post on this subject, heat riser turns free and definitely stops in open and closed position so I figured the disc was in position, I've got it temporarily wired open because its warm out and don't know the condition of the passages in the manifold.
I'll put a stethoscope on it today.

 

[stroker3]

Got fresh 5-40 synthetic in it now .
Wix filter

(No need to start another oil debate.) Big fan of synthetic. Not so much in an old engine. It may be worth your time to search threads on oils that could/should be used in these old engines. There's been a bunch here.

 

[Bryan hill]

Pull dizzy?
I did not pre oil before hand.

Pull dizzy, took till 3rd cup of coffee to sink in. Nope haven't touched it, cept for sparking parts.

 

[sdhachey]

Check the timing. Consider dropping the oil pan to mine for bearing fragments, make sure oil pump stuff is tight. I have a good running 1968 304 for sale but I hope it doesn't come to that... and I can't tell where you're located.

 

[72soa]

Could be your fuel pump. I would just drive. What type of oil pressure does the engine have? Engine vacuum? I have disconnected the accessories - alt. power steering pump - and run engines before to isolate noise. If it has power and good vitals it should be ok.

 

[jeff campbell]

Check the timing. Consider dropping the oil pan to mine for bearing fragments, make sure oil pump stuff is tight. I have a good running 1968 304 for sale but I hope it doesn't come to that... and I can't tell where you're located.

Mn

 

[kdsmit]

Does it have an auto trans? A friend and I bought a nice car for 75 bucks, because the owner was sure it had a rod knock. We pulled the transmission and found that the center of the flywheel was completely broken away from the outside of the flywheel. As it wore, it started to sound just like a rod knock.

 

[RinTX]

One thing - not the source of your knock but you are running the wrong oil for these old engines.
Try your stethoscope in the vicinity of your fuel pump.

 

[Bryan hill]

Mn

Yes, MN