Valvetrain sound question: for a 340 6 bbl 1970 (factory AAR or Challenger T/A)

[70Challenger440]

I have a question about what is considered a 'normal' valvetrain sound for the 70 340 6bbl found in AARs and T/As.  (i have a recently purchased AAR). It is a #1 car with everything rebuilt. The sound of the valvetrain is not what I am used to. Admittedly I have only owned simple stock 69 & 70 440 4bbl cars my whole life, so that is the only Mopar valvetrain 'sound' I am familiar with. I am aware these 340 6 packs have different heads and offset  rockers than a normal 340. I do plan to have the car looked at when the weather gets warmer but I know of no mechanics  that are familiar enough with these engines to know what is normal. I will use this thread to hopefully gain info for that.

Question:
The valvetrain has a definite metallic sound to it in that you hear it  noticeably louder than what I am used to with my stock 440 4bbl cars. I would NOT call it a 'tick'. It occurs cold or warm and gets a little louder as you increase RPMs. Oil pressure is fine. I bet someone here has been around of enough of these engines to be familiar to know if this valvetrain sound difference is normal for an AAR/TA engine or not?

[anlauto]

Welcome to our website, the best E Body site in the world !

The AARs/TAs had adjustable rockers....it's quite possible they are not adjusted properly....I would have it checked out before any extended running of the motor and certainly before any bonzi high RPM runs

Tell us more detail about the car, we love AAR Cudas

[torredcuda]

Was the engine rebuilt stock with hydraulic lifters or could it possibly have solid lifters?

[70Challenger440]

Was the engine rebuilt stock with hydraulic lifters or could it possibly have solid lifters?

I was told it was stock, but I do plan to double check when I have the engine evaluated  along with any suggestions I get on this thread. The car even still has points believe it not and no added gauges which means no tach. I would think if someone added solid lifters they would of added a tach. The car seems to be done as a  trailer queen accurate resto. As said, I just got this car.

[Fastmark]

I've owned an AAR since 1976. I've built several motors for it and other 340s. The adjustable rockers on the TA motors are a huge benefit to the motors. I've always have LESS noise with a properly adjusted rocker. The non adjustable can be the noisy ones. You could have noisy lifters too. There are lots of bad lifter going around made off shore and are basically Chinese crap. I've adjusted then different ways. You can rotate the engine till the intake rocker is down and adjust the exhaust on each cly. I adjust to zero preload by rotating the pushrod in my fingers til I feel it start to tighten. Then I tighten it 1/2 to 3/4 turn more. I have also adjusted them with a special valve cover that has the top cut out. I start the engine and back off the rocker nut until the lifter ticks. Tighten it up 1/2 to 3/4 turn and tighten.

[torredcuda]

Stock hydraulics shouldn`t make any noise so if that is what they are I would adjust them. I adjust them to zero then 1/2-3/4 turn more with engine warm.

[70Challenger440]

I did just check through the oil filler hole and the car does have the correct  factory offset adjustable rockers it should for 340 6 pack.

2 final questions:

If it does need the replacement lifters mentioned, which are the best ones to get for this stock AAR engine?

What are your suggested readily available spark-plugs? (factory recommended is discontinued N9Y Champion). I am more concerned about no fouling than attaining the last bit of performance. Bear in mind this car currently has points, but I may or may not switch to the Chromebox Electronic ignition, (mentioning in case this affects choosing a resistor or non-resistor plug).

[Fastmark]

Well, when were talking lifters here, we opened up a new can of worms. Just changing lifters and leaving the old cam in is a recipe for failure. Especially in today's world of Chinese crap lifters. There is only one company that makes good lifters right now. That is Johnson. They are pricey so people like Comp cams don't use them. I have a friend at an engine rebuilding shop where most people go to get a less expensive rebuilt and installed engine. That's all they do is rebuild and install motors and transmissions. He is not a high dollar engine shop. Let's face it, lots of people just can't afford that so they go the cheap rough that will get them by. The shop I use is a former Super Stock engine builder. He has one machine that cost more than more than the other guys complete shop. He cuts no corners. The cheap shop has had problems with cams going flat in new buils because he sources cheaper parts. He had had to abandon that and start uses Johnson lifter exclusively because of the failure  rate. They are pricey and hard to find right now. It was explained to me the other day that since the Mopar lifters are bigger in diameter than Chevy and in less demand, they make more Chevy size. So, don't just change the lifters. I would try to adjust them first.

[anlauto]

Bear in mind this car currently has points, but I may or may not switch to the Chromebox Electronic ignition, (mentioning in case this affects choosing a resistor or non-resistor plug).

If it's a nicely restored AAR and you don't want to affect the factory look, you can add Pertronix to the factory dual point distributor and nobody will ever know. https://pertronixbrands.com/pages/pertronix-ignition-electronic-ignition-conversions

[Ebody Edgar]

I recommend you warm up the engine, pull the valve covers and spark plugs and go thru the valve train lifter preload adjustment sequence. One turn of the screw is 0.040 inches which is 0.040 inches of preload. The typical range of lifter preload where they won't bottom out is 0.080 max preload.  0.040 -0.050 is best in my experience.
Make sure the pushrod cups are not hitting the rocker because the pushrods are too long etc. A worn pushrod cup will make noise.  The key when adjusting the lifters is making sure the lifter plunger is at max ht before adjusting the preload. I would be pulling the intake to do this rather than trying to look into the lifters from above.

[torredcuda]

No need to pull the intake to adjust lifters, just follow the sequence.

[EB3-GranCoupe]

That looks like a handy little guide!

[torredcuda]

That looks like a handy little guide!

It`s how I do my solid lifter 340, I usually go around a second time as a double check.