The Stovebolt Site Forums The Shop Area Engine Shop 216 Stovebolt engine tapping noise

Hi all from down under in Perth.
I have just picked up a 1952 Chev Coupe utility with the small 216 engine. It has a very distinct tapping noise and misfires etc. Starting to think a sticky valve and potentially bent push rod. Any tips on my next move. I’m a bit of a novice when it comes to this stuff.
Cheers
Max

Take off the valve cover and the side cover to inspect the pushrods.

Yep, figured this is next move. Kinder looking forward to it as something new for me.
Interestingly ( well not really, been happening since man was invented).
Sellers ad.
Perfectly running vehicle, a pleasure to drive.
Buyer. ( me the mug)
Turns up, likes look of the Ute, try’s to start, flat battery.
Gets jumper leads, eventually starts car with “ start you bastard spray”
Car misses and carry’s on and seller states dicky spark plug.
Novice buyer tends to agree.
Notice slight tapping noise then.
Eventually agrees to buy.
Pick up days later and tapping noise louder.
Figured it was more then plug but keen to have car.
Here we are now and keen to get into fixing her up.
Let you all know what I find.
Cheers
Max

I am deeply annoyed that you can't buy Start You Bastard in the states.

Stovebolt engines in general, and 216's in particular have a nasty habit of getting sticky valve guides, and bending pushrods. An engine that's not started on a regular basis or one with stale fuel in the tank is extremely likely to have sticking valves. That can cause low compression on one or more cylinders, resulting a miss. Job number one will be to pull the valve cover, rotate the engine by hand or tapping the starter pedal repeatedly, and checking for a rocker arm with more than normal clearance when the valves close. A badly bent pushrod will be obvious- - - -one with only a slight bend will not spin as the engine idles. Good luck!
Jerry

Ok, lessons learnt today. You can pull a spark lead off the plug and not get a boot as long as you don’t touch any other part of the car.
Result is number 4 playing up. Suspected stuck inlet valve.

Rocker cover off revealed number 4 inlet valve floating about all over the place.

It had derailed from whatever was down near the cam. Now know it’s called a camm follower.

Checked the rod and it’s not bent.

Valve not stuck. Gave it a few good whacks to prove its was ok and yes I ensured piston was at Bdc.
Refitted push rod, re gapped and gave it a go.

Purring like one of our 4 pussy cats.

Why it derailed I have no idea. Anything else I need to look out for?
Cheers
Max

I'm assuming you mean the pushrod was displaced, not the valve, right? Most likely, the valve stuck in its guide momentarily and allowed the cam follower (AKA "lifter" or "tappet") to get disengaged from the rocker arm and pushrod. I'd suggest adding a quart or two of Diesel fuel to the sump, overfilling it enough to make the crankshaft and connecting rods splash down into the diluted oil like a washing machine agitator. Run the engine at fast idle, 1500 RPM or so, for about 15 minutes. The diluted oil will clean out any gum or varnish that has accumulated over a few decades, including any deposits in the valve guides. Drain the oil with the engine hot, replace the filter element if the engine has one, and refill with fresh oil.

DO NOT DRIVE THE VEHICLE, OR PUT THE ENGINE UNDER ANY LOAD WITH THE DILUTED OIL ONBOARD!
Have fun!
Jerry

Thanks Jerry
Will do

Maxleggett what Jerry advises is good advice have had the pleasure of meeting him a few times and what he doesn’t know about Chev engineering isn’t worth knowing welcome to Stovebolt from Newcastle NSW myself

Hi Jerry and others
My 216 has Autolite 4194 plugs with .050 gap.

Is this ok?

Shop manual suggests .035" gap . Really enjoyed reading your written comments, Max. I also agree with Fibonachu on the starting fluid. Thanks for the humor, its needed when dealing with these old trucks.

Not unless you have an updated ignition system such as HEI that is designed for spark plugs with this large gap.

The industry standard for plug gap for many years was .035". It takes approximately 8-10 KV to fire a clean spark plug with that gap. A .050" gap will require at least double that voltage, which might not work well, especially with a 6V ignition system.
Jerry

Forgot to mention guys that it’s been converted to 12 volt with an alternator.
Dizzy and coil look original but not sure.

Forgot to say I’d rather go away from the Autolite plugs as they not readily avail in Oz.
What do you guys recommend out of Champion or NGK?

Champion sucks. I'd use NGK if those are my only choices.

Pretty sure I can get any NGK plug.
What brand do you recommend besides NGK?

AC Delco

Thanks
AC 45

That's the one...gapped at .35.

Better at .035

Opps…my bad…fat-finger typing

6 shops today in Perth and no Delco or NGK plugs to suit.
Fact no Delco plugs full stop.
Not desperate as what’s in it is working fine.

Got hold of guy who acquired vehicle after its 30-40 year layover in a museum and he informed me he never flushed/ cleaned any of the drive chain. Just topped up if it needed it.

Plan to add ATF to engine oil and run it up for 10-15 minutes, then drain and refill .

What should I do with gearbox and diff? Warm them up then simply drain and refill?

Cheers
Max ( apparently we are called Ozbolters )

AC only, the Delco part of the brand name was dropped years ago, as far as spark plugs. And AC spark plugs are no longer being produced. Here's a possible source: Link
Spark plugs are pretty generic nowadays, as long as they're the proper configuration, any brand should work fine, IMO.

Tks for that.

My plugs Autolite 4194 which have a heat range of 2

Ok brains trust
My plugs are Autolite 4194 with gaps of 0.024

Car runs pretty ok but shudders when you put your boot into it.
It’s not a smooth acceleration, bit jerky.

Is it the plugs, something amiss in the carby ?

Your plugs should be gapped at .035”. That will increase you spark and could be your problem.

I did a search on the internet for AC Delco-45 spark plugs cross reference here.

Your autolite plugs may not be correct.

They are also on Amazon here. The R is for resistor which is what I am using. They came out with resistor plugs to cut down the noise the engine created on an AM radio.

Ok thanks, will re gap them.

The stutter you're experiencing on acceleration is often a miss caused by bad spark plug "wires". Metal core wires have been replaced by carbon-infused string decades ago. That's a good thing, as metal core wires caused rapid wear on distributor rotors and caps due to the high current they conducted to the spark plugs. A carbon core wire can have a resistance value of up to 1000 ohm per inch, so a 12" wire can have up to 12 K ohms of resistance. Higher than that value, and the wires should be replaced.
Jerry

Tks for this Jerry.
Will test my wires. Probably change them regardless anyway.

Got all plug lines with ohms of around 5.5k now. Take for a run tomorrow