The Stovebolt Site Forums The Shop Area Engine Shop Pinging under load

Yes, I’m anxious to see as well
We can’t actually buy “lead replacement petrol “. I think what they’re referring to is one of the many products available that you can add to your petrol to supposedly do what the lead use to do. It’s not expensive and I figure it can’t hurt. Some people I know with veteran cars use a small amount of 2-stroke oil

OK, which phase are we in currently- - - - - -"WAG","SWAG", or "T.L.A.R." ????? I don't think I've seen any actual documentation of measurements being made, or any effort at a logical approach to solving the problem being in process.
Jerry

Not sure what you mean Jerry. I’m about to see if pulling the choke out makes any difference.
If that doesn’t work I’ll try your hot water method

WAG- - - -"Wild (donkey) Guess
SWAG- - - "Scientific Wild Donkey Guess"
T.L.A.R.- - - - -"That looks About Right"

None of those methods are a substitute for accurate measurements and proper diagnosis.
Jerry

I don’t have access to any modern day diagnostic tools, so I’m using what they had in 1946.
I backed off the advance a few degrees and no difference.
Bearing in mind that even when it was running at the recommended settings of 5 degrees BTDC it was no different.
Pulling the choke out when it starts pinging makes no difference at all.
I’ve tried one of those combustion chamber cleaners a bit like your Seafoam, and it’s better. Not perfect but better.
The only way to stop it pinging completely is to back off the throttle.
In a modern car I’d just change gears, but with this 3 speed box changing down to 2nd above about 10mph is not an option.
Until I can take the head off and clean the combustion chambers and valves I might just have to live with it.

You said the Seafoam made a slight improvement. I think that may be a clue that carbon buildup is at least partly responsible for the problem. Do the water dribbling thing and you might not have to take the head off.

What are the compression test numbers? They had pressure gauges in 1946.
Jerry

97, 110, 105, 107, 112, 98

.......similar problems for me turned out the lack of fuel when it needed it. How about accelerator pump problem when you need more gas.

Pulling the choke out doesn’t make any difference and pushing the accelerator just makes it worse

AChipmunk's talking about the accelerator pump inside the carburetor, not pumping the accelerator (pedal).

So let me go at the mechanical advance issue in a different way. Its not a question of whether its advancing, its a question of whether its advancing properly. If the springs are weak or one is broken, the advance will come in too soon, if too stiff or gunked up, the advance comes in too late. Not too long ago I had a new old stock 2403 distributor on my Sun distributor machine. The advance was coming in way late. Took it apart, all gummed up. Good cleaning and fresh lubrication, back in specification. The mechanical advance has to not only be working, but working properly.

You are spit balling a little here. You apparently repaired the original vacuum advance but you don't know the specification for the advance. The mechanical advance is advancing but you don't know the curve and do not have the tools to sort out how fast, or slow the advance is coming in, or to what extent in terms of total distributor degrees. Couple that with I am not 100% sure that the flywheel bb is accurately positioned to indicate tdc at the bellhousing pointer. Is the flywheel original to the engine? is it original to the bellhousing?

I am not trying to be critical here but hanging parts, pouring concoctions into the fuel, is not the best way to sort this out. I think you need to go at this a little more methodically. You need a base line to get started and that means you have to first get a handle on true tdc. Not guessing, speculating, but determining true tdc. Everything relative to the ignition system is dependent on knowing that specification. From there you can confirm that the octane selector plate is installed at the 0 hash mark at tdc, confirm that the rotor is pointed at the No.1 plug wire tower on your cap. Once you know tdc, you can start methodically knocking off the rest of the low hanging fruit.

You should take the top of the distributor apart, inspect, clean and lubricate the mechanical advance. Put it back together, adjust the points, get it started, hook a tach and dwell meter up (don't have one? then you need to go get one. Indispensable for point ignitions. Used units are pretty cheap on ebay) and confirm that the dwell is within specification. If not, readjust the points until it is. Now set and confirm your timing with a timing light. Same deal. You don't need a fancy light, plenty of used working units on ebay for not a lot of $$. Now you can move on to adjustments to the carb, set the idle speed, valve adjustments, etc. But it all starts with an accurate tdc, in my opinion anyhow.

Pinging is almost always related to ignition and advance issues. If you have checked and double checked the ignition system, then you know the issue lies deeper, cracked piston, leaking water in combustion chamber, something other then ignition. .

Ok, thank you gentlemen, you’ve given me lots of good advice and information. Now I’ll take a step back, buy or borrow some tools , and get a bit more methodical about this dead horse

bajintas, Great plan! Lots of people don't take that route and end up chasing their own tail looking for easy magic quick fixes which don't exist.

Keep us posted, looking forward to hearing your updates.

Is it possible you have an exhaust leak between the head & ex. manifold that sounds like pinging. I can't imagine Stovebolt engine having a pinging problem like that. They only had about 6-1 compression ratio.
Does it have to run quite a while & get plenty warm before it starts or will it do it with the the engine cool?
Did it start doing it suddenly or did it slowly get worse?

Geore

George, I've recently had both manifolds off to fix the heat control valve issue, and put them back on with a new gasket. The problem hasn't changed before or after that.
I usually let it warm up a little before I drive it anywhere, but whether it's warm or hot doesn't make any difference.
It's done it the whole time I've been driving it, about 12 months. It sat in my shed for 4 years prior to that. I know nothing of it's history before that.

For those wondering about fuel issues, the Carter W-1 carb has been professionally rebuilt by a guy generally recognised here as the best in the business.

Now, I'm going to take a step back and look into a bit more methodically. I'm started to wonder if it is actually pinging or just making a pinging like sound from some other problem. As I say, it runs great in every situation other than labouring up a hill. If I could change gears I'm sure it would be fine, but 2nd gear is so low, changing to 2nd at 20 mph is not an option

When you are experiencing the noise going up hill is the throttle basically full open, trying to maintain speed but loosing speed because the engine's power is limited?

Is there a way that you could take a video/sound bite for those of us trying to understand what is happening and how best we can help?