Packard Forum Index » V-8 (1955-56)

How many miles on tbe timing chain?!??? Somewhere about the same time kf the above link i posted there shojld be another thread with pics of ann oiler tube i rigged for the timing chain. About july fourth of 2012.

Any loss of power or vibration when the ticking sets in????

The timing chain is NOS, less than 500 miles on it still. No discernible vibration or loss of power with the noise. Sitting in the garage with the motor turning 3000-3500 RPM, it almost sounds like a fuel pump knock, but I run an electric pump only. Definitely coming from the front area of the motor, toward driver side.
Thanks,
Joe

Possible sticking valve. Most likely exhaust. Thsts why i said to check valve seals. Try a can of CD2. Black label for sticky vslved. Not red label. I hsve a similar chronic problem with a F 2.0 four cylinder. I know in fact sticky valves. Exhaust. CD2 will clear it up every time.

Problem only occurs at 40 to 50 mph. Otherwise just fine below 40mph

I worked on one cylinder at a time, and used a rope through the spark plug hole to hold the valves in place. Removed the spring, then discarded a .030" spacer, then swapped the old OEM type black seal for a softer, more modern red seal with spring re-enforcer.
With the rope in place, the valves would still drop down about 1/4". I checked each valve carefully for sticking, and they all spun freely and moved up and down easily.

I still like your idea of the special cleaner CD2 Black, and will try to find it locally. It can't hurt.

Since the noise was not there before I swapped the heads, cam, lifters and timing chain, I am thinking its something related to the swap, but am out of ideas as to what.

I am just gonna drive it, but stay local for now. Hopefully it will get bad enough to give itself up, whatever the gremlin is.

Thanks Again,
Joe

I know you said heads.... But could it be a developing piston slap.

Quote:
If you have an air compressor, there is an adapter (some with hoses) available that will acceept a 1/4" NPT hose or - better yet - quick connect fitting that will hold the valves closed with air pressure. In many cases, a single adapter fits either 14mm or 18mm plug holes. Cost is about $10.

Thirty years ago, I made it a point to purchase a compressions gauge set that included just such a fitting, and used it to replace the valve seals on a SBC.

The compressed air method is great method. But it requires at least 100 psi and a compressor big enuf to keep up with loss pasf the rings. I' ve had a little bit trouble makeing it work at 100psi. 125 to 150 psi work great.

One problem is that most home shop compressors are not big enuf to keep up with.the constant loss past the.rings without running almost constantly.

Joe, since you replaced several rocker arms and pushrods, we're assuming you carefully inspected those you re-used.

Even so, that's the easiest avenue of investigation. Pull the rocker covers and with a mechanic's stethoscope, try to determine which valve/rocker/pushrod/lifter/cam lobe is causing the tick.

When it is identified, replace the rocker and pushrod.

Good luck.

jack vines

Keith -

You bring up a good point, but remember that you're only applying compressed air to one cylinder at a time. If you stop after finishing one cylinder, but before starting on the next, there's no need to keep anything pressured up overnight.

However, a complete loss of air supply, which could happen unexpectedly and in the middle of working on one valve, would be a problem.

If the keepers and springs are gonna be off for an extended period, you could slip a piece of rubber hose over the keeper grooves at the top of the stem and put a vise-grip over that.

Now that I think about it, we lost a keeper for the last intake valve on that SBC, when the parts stores were all closed, and we did something just like that to ensure that the valve stayed up overnight.