'66 200 - valve ticking noise / rocker arm question

Hi, I'm new to the site and to Inlines.I have a 66 Mustang coupe with a 200 in it. Mods so far are pretty simple:
- Pertronix ignitor and flamethrower coil
- Carb rebuild(autolite 1100)
- Dual outlet header and duals from Waldron's

Recently I have developed a valve ticking noise and I'm trying to figure out the fix, without going too deep into the motor. I'm kind of a rookie at engine work, but I'm pretty handy and typically understand how things work if explained.

So far I have:
-Ran some Marvel Mystery oil in it to try to clear out any clogged oil passages, etc
-Pulled the valve cover to check for good oiling and anything obvious(Bent rod, Etc)
-Rockers are not adjustable
-Checked the exhaust for leaks(has classic inlines dual header)
-Did a compression test(all were within 10 lbs at 105-115)

Also, I was recently forced to buy 93 octane gas, the station was out of 87, and I was out of gas.... Could this have contributed to the ticking noise I'm hearing?

I was considering pulling the head to replace a (minor) leaking head gasket anyway. So I was thinking this would be a good time to go ahead and do a valve job. I am considering the 1.62 ratio rockers when I put it back together, to give the engine some more air flow and allow for future adjustability. Its a stock engine now but I plan other upgrades(not sure what just yet, maybe 2v carb - Probably no cam work), this is why I'm thinking about the 1.62's now while the head is being rebuilt.

Looking for opinions on the valve noise and what is likely causing it. Also looking for someone with experience using the 1.62 rockers to see if there is a noticeable difference in performance.

Thanks!

Do you know for sure it's coming from the head? Try taking a tube like a piece of hose or something, put it up to your ear, and move the other end around the engine to hear where it gets loudest. I had a bad ticking sound on mine that I thought was a lifter, and after doing that I realized it was just a burnt out header gasket.

I had an exhaust shop look at it, who installed the header and duals, and they could not find a leak. A mechanic there also took a piece of tubing and put it in the valve cover breather hole. It seemed like you could clearly hear the noise coming from inside of the valve cover. I will also do a check myself and see if I can rule out the header gasket. Thanks for the suggestion.

Also, forgot to mention in the original post that the ticking noise starts after the engine warms up.

Sounds like a nice Mustang. Hope you find the source of the noise and you came to the right place.

Howdy 60s Mustang:

While the valve cover was off did you run the engine to observe oil flow to the rockers- especially the #1 rockers? With the engine off did you feel for any looseness between the rockers and the pushrod/valve tip?

I doubt the higher octane gas would cause a noise. Your thought about adjustable rocker arms is a good one and most likely the main contributor to the noise. The higher ratio rocker arms only makes sense if you do not plan to add a high lift performance cam in the future. The only down side is the price.

Keep us posted on your progress.

Oh, and welcome to The Forum.

Adios, David

David,

I did not run the car with the cover off, I couldn't get it to idle and didn't think about the vacuum leak created by the PCV valve being off till I had it back together again. The rocker arm looked well oiled though. I did check for "play" in the pushrod/rocker arm/valve tips. They seemed pretty tight up and down, but the pushrods could still be rotated, depending on where the crank was aligned obviously.

Question:

1. So the high ratio rocker arms are doing basically the same thing as a larger lift cam would then? More air in, more air out through the valves. If so, this is what I though and why I was thinking of doing them instead. The bottom half seems pretty solid right now and I didn't really want to get into it if I don't need to. That's why I was going to go with the high ratio rockers and a valve job for now.

2. Would you suggest a cam over the high ratio rockers instead? If so why and what cam size. Like I said I'm pretty new to all this internal engine stuff. Looking to end up with a mild performance engine that doesn't mind a long drive if needed.

Thanks!

That compression seems a little low. Did you test with a warmed up engine and the carb fully open?

If you do run it with the valve cover off I'd suggest you do NOT rev it at all.

I'm wondering about perhaps a loose or worn valve guide.

69.5Mav":31lpnj6c said:

That compression seems a little low. Did you test with a warmed up engine and the carb fully open?

Click to expand...

The engine was warm, carb was not open though, during the compression test.

Any opinions on cam VS. high ratio rocker arm?

Some success....I think

I warmed up the car till the ticking noise started again, removed the valve cover and ran the engine. I was able to isolate the noise to the third valve back from the front, the number 2 intake I believe. With a screwdriver I am able to hold down slightly on the top of the valve spring retaining washer and the noise stops. When I hold down on the actual rocker arm on either end there is no change. Does this mean its the valve itself tapping in the head, valve guide maybe as Jackfish suggested?

The noise does not start until the engine is completely warmed up.

All the pushrods had good oil flow over them and the oil outlet near the front of the rocker arm was flowing good also.

Any ideas on a fix other than removing the head and a valve job?

I would expect somewhere around 160. Retry it with the throttle open. Also try it with one teaspoon of oil in each cylinder. If your reading doesn't come up the maybe someone did a valve job and replaced the head gasket with a thicker one.

As for the ticking with what you described I would be very careful. You could have a bad set of valve spring keepers and if they let go it could cause serious damage. You may need to remove the head to address this if you can't solve it any other way.