I have a 1964 valiant with a 170 engine 1 barrel. It is running horribly. I removed the plug wires one by one to see if all cylinders were firing. Two were not. The plugs and wires are fairly new. Any suggestions on what i should check next. Everything is original except the electronic ignition..thanks for your replys...Mark

I would guess that you need to do a valve adjustment. The missing can be caused by valves which are too tight. Tightness is usually indication that the valves are worn out and is common because the engine was built for leaded gas.

Do a search for 'valve adjustment' for more opinions and info. Since you are brand new to this, I will do one better and explain it here.

Go purchase a replacement valve cover gasket (rubber is better than cork if you can get it) You'll also need to find a .010" and .020" feeler gauge. Almost any basic feeler gauge set will have both sizes.

Remove the valve cover.

For your first time, you will want to adjust without the motor running, and then repeat the process with the engine running. It's sometimes difficult to get the adjusters moving the first time in 30 years.

Intake valves use the .010" gauge. Observe the intake manifold is aligned with the intake valves, so you can easily see which are intake or exhaust. Notice that they are not arranged every other valve, intake/exhaust because that would lead to improper adjusting.

Removing the spark plugs will make it easy to turn the engine by hand with the fan, or you could randomly crank the starter and just keep track of which valves still need adjusted until you've got them all. It's your choice.

Select an intake valve which is in the closed position and the rocker arm should be loose enough that you can tap it back and forth a little. Now insert the .010" gauge between the rocker arm and the valve stem at the top of the spring. If there is a great deal of extra clearance, you should tighten the adjuster until the gauge slips in and out easily, but fills all of the gap. A little loose is better than too tight, so stay on the side of caution for your first time adjusting. What we are really looking for is an exhaust valve which is too tight.

Repeat the process for all of the intake valves, cranking or turning the engine in turn until each is in the closed position and adjusted. Now move to the exhaust valves and use the .020" gauge. Tight exhaust valves may have little or no clearance and will cause poor engine performanc. Check the two 'dead' cyclinders and be prepared to loosen the adjuster until the gauge fits again. The other exhaust valves might need adjusted in either direction.

Now, once you've adjusted every valve, clean up the engine bay and start the engine with the valve cover still removed. You should notice that the valves are not as loud, but some ticking is normal. You shouldn't be afraid to check your work with the engine idling. Slip the gauge into the clearance and it should move easily except for an instant while the valve opens each cycle. Check them all.

If you are feeling very confident about your work, you should allow the engine to warm up for a bit and then do a hot adjustment with the engine running. It's a little more tricky to turn the wrench with rockers moving, but once you get the feel for it, you'll be able to adjust much more quickly and accurately than the beginners method that I have described.

I think we all did it cold and not running our first time.

An adjustment might make the engine run much better for a while, but if several of the exhaust valves were too tight, then the solution will be to have the head rebuilt or replaced.

Wow that was long. Who wants to turn it into an article once and for all.

_________________
1980 Aspen 225 super six

Which cylinders? Have you done a compression check? What's the history on the car? years of storage? Here's a really stupid question, but are the plug wire going to the proper cylinders they don't run right with miswired caps. Good luck

Thanks to all who answered. I did a valve adjustment on a car when i was about 18, that was 35 years ago, so i will do it exactly as you described. Unfortunately i bought this car and have no history on it. The wires are correct because i had already checked that. I will also do a compression check but to tell you the truth i suspect that is fine. My first inclination was the valves so i appreciate the confirmation. Ill keep you all informed. Maybe a stupid question but I will ask anyway, if i have the head redone will the valves come cold adjusted? Then i do a hot adjustment with it installed?..thanks for the patience and understanding.. the reason i bought an old car was so could work on it. Little did i know how much I have forgotten since the good ole days of youth..thanks again

The cost and time for replacing the head on a slant six is extremely cheap compared to just about any modern engine. Adjusting valves is a normal tune up procedure for these motors, so try the adjustment and see what happens.
Nope, there's no way to adjust until it's installed on the motor, since pushrods and head gasket thickness comes into play. Don't worry, it took almost as long for me to explain it as it should take to actually make the adjustment.

_________________
1980 Aspen 225 super six

my no 3 cylinder wasn't firing and i checked everything. turned out to be a plug wire that was faulty from the box. if you have some extras you can test with, or you can change the plugs and wires from a cylinder that is firing to one that isn't, you can check quick and cheap.

_________________
God took you away, then brought you back to me.

I have to agree with slant6ram about the insane cost of rice heads. Yesterday an old galant came in with a complete set of bent intake valves and a couple exhaust valves. The owner is looking at approx $2000 parts and labor.

you could buy a complete rebuilt engine for less than that

a big thanks to slant six ram..you were right about the valves needing adjusting. Two of the exhaust valves were so tight i had to back them off quite a bit just to start getting the feeler gauge in. By the way it was pretty easy once i started. Other than forgetting to put the spark plug back in that I took out so i could turn the engine all went well with start up and hot adjusment. I still think the engine is tired but it sure runs a lot better now...thanks again

Glad to help.

If you have a couple of burnt valves, the adjustment will help for a while, but you should keep in mind, that you should start saving/looking for a new cyclinder head.

Even well adjusted burnt valves don't really seal that well, and your gas mileage won't be as great. My pollution tester wasn't very happy either.

Now you've got some time, so enjoy the ride and keep a look out for a good replacement.

_________________
1980 Aspen 225 super six

Can I have this one rebuilt? If so how long does it usually take, knowing thats a loaded question. Everything on this car is original and eventually I would like it to stay that way..thanks again

I know a couple of guys who have waited months for their head to come back from the performance shop. If you can find a good local shop, they might be done in a couple of days/weeks, but I haven't heard of any 'good' shops that where that hurting for work, sitting waiting for you to drop by.

Factory correct cores for replacement heads are available without much searching. Even if you're going for #'s matching restoration, they didn't stamp the vin on the head anyway, so even a judge wouldn't care. This way you can have it done right and still have a running car till it comes back.

_________________
1980 Aspen 225 super six

Hi valiant...

There is a real good reason you can expect to pay $300 to $500 for a well done head...ported, viton seals, hardened seats, new guides, stainless valves, 5 angle grind, milled, and magnafluxed...reaons is it's worth it. It takes about a $40,000 worth of fine equipment to do it right and years of skill. The cost is so minor in regard to the return you won't believe it! I always have a completely done spare tucked away for good luck, too. An $1100 crate long block rarely has a really good head and as you see on this forum the rest of a running engine is hard to give away...I have used heads with plug ubes, without tubes, with and without smog holes, with tapered plugs and straight plugs...for my money you might well get one of the totally new ones from ebay seller robzet and use your rocker arms. a junker will run $35,new about $70...to quote mopar..the rocker arms are miracles of engineering. A good head will go a long way to making your engine work so well you won't believe it. If the head is off, put in a new set of lifters at about 40 bucks and a set of pushrods at about 25. Then look at the timing chain and gear...another 25 bucks new. We have a NASCAR shop here in NC that will turn a head around in a week or 10 days, if no one in Pittsburgh is cool with them.
rock
'64d100