273 spark plug mishap

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HotLines

HotLines

Realist - Free Thinker
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Why would anyone use Autolite #85 spark plugs in a 1965 273 engine?

First off, the spark plug itself is 1/2 the thread length of a #66 or a N14Y for that matter..

Could anyone explain the reason for this?

Could anyone explain how this vehicle even ran and ran a thousand miles?

Thank you
 
Champion copper core is what I run in my 273. Work s great, I was running ngk but didn't run right. Switched to champion coppers much better. I'm sure it only needs a small spark to excite the fuel, but I'm sure your motor was lacking in a good spark and a slight cc loss in chamber area.
 
Sent you a P.M... As for real world,you gotta pay attention closer tha your pinstripes. I'm a parts guy,read thd p.m..
 
The shorter thread length may not let the spark plug stick out enough to get a good spark to the cylinder, it may be too deep into the hole....
 
HotLines said:
Why would anyone use Autolite #85 spark plugs in a 1965 273 engine?

First off, the spark plug itself is 1/2 the thread length of a #66 or a N14Y for that matter..

Could anyone explain the reason for this?

Could anyone explain how this vehicle even ran and ran a thousand miles?

Thank you
Click to expand...

Do you have a Power Pack engine with the higher compression and 4 barrel?
Use the Champions and use the N12Y's for the 4 barrel and 14's for the 2 barrel. It seems the Autolites are colder than the Champions for the same application. I rebuilt my HP 273 and used 63 Autolites per their charts. I never could get it to idle clean. I converted their numbers to Champion and found the heat range equal to a N8Y which was WAAAAY too cold for my 9.6/1 273. I screwed in a set if N12Y's and it immediately ran like a different engine. tmm
 
You guys are on the wrong track here An 85 Autolite is a SHORT REACH PLUG
 
Most likely bought at a big chain auto parts store and installed by someone who didn't pay attention to what they took out.
 
The car was bought from this website FABO and first looked at by two FABO residents who both said to me, it was beautiful.

There is a problem, yet in regards to the replies which do not answer these two simple questions, I could only believe that most here know as much about their own cars as I know about space travel..

This hasn't been the first time questions I've asked have gone unanswered by stumped Moparians and I am sure it won't be the last..
 
Install the correct Champion plugs and run it. Pull a few plugs after a few thousand miles and "read" them. What more of an answer can someone who doesn't own "your car" tell you what a previous owner did and why? I apologize for my crystal ball being out of order at the moment.:eek:ops:
 
HotLines said:
Why would anyone use Autolite #85 spark plugs in a 1965 273 engine?

First off, the spark plug itself is 1/2 the thread length of a #66 or a N14Y for that matter..

Could anyone explain the reason for this?

Could anyone explain how this vehicle even ran and ran a thousand miles?

Thank you
Click to expand...

OK, I'll bite and answer your questions:

#1 Why would anyone use them? Because they didn't know any better
#2 Why is the thread length 1/2 a 66 or N14Y? It was designed that way
#3 Why did it run 1,000 miles? Could be a number of reasons, one of which is probably dumb luck.

There, now your questions are answered. Hope you didn't expect more, since the first two were rhetorical and inane. While the third question could illicit an interesting discussion, it really can't be answered positively. But, given the tone of your first two questions, it's a good guess that your third was offered in the same spirit as the first two.

Next time, ask questions that really can be answered before calling the rest of us stupid.:violent1:
 
When I look at a car and don't buy it, I would not know what plugs are in it unless they were out. Very seldom would anyone pull plugs unless they were very close to buying. I hope you didn't expect FABO members to do your due diligence
 
H20loo said:
I hope you didn't expect FABO members to do your due diligence
Click to expand...


x2


You can't push the blame on other people. Ultimately, you were the one who bought the car and handed over the money. You have to take responsibility.



Why didn't you take it to a certified mechanic for an evaluation before you bought it?


If I told you about a very nice bridge in Alaska that is not doing much, would you buy it????
 
i'll bet its an oil burner and the short plugs were used to pull the plug away from the oil. they used to make plug spacers to do the same thing years ago..

as far as having someone look at a car goes.. unless i really know the person and trust his opinion there is no way i'm sending anyone to look at a car for me. too many guys see shinny paint and thinks its a nice car even if its as wavy as the pacific ocean.. :)
 
Quote: Next time, ask questions that really can be answered before calling the rest of us stupid.
Not as insane as you may think and it can be answered positively.. ...

The reason someone may install a shorter plug is to lessen oil fouling of the spark plugs when consumption of oil is at it's worse... This isn't a cure to rebuilding an engine, but can certainly extend it's life if adding a quart to every tankful as gasoline if only to have it running when selling it..

Someday you too will have a problem and you'll post it here expecting common sense, yet receive the same answers you've given to me.. Good luck

BTW, Thank you 67Dart273, you at least tried to post them in the correct direction and Joe, that's why I called you, you are a genuine motorhead...
 
There are no good reasons to use the wrong spark plug. Could have bought the incorrect plugs or because of oil or fuel fouling. That is an excellent question to ask the previous owner - please let us know the answer.

There are many factors that go into the dimensions and specs of the plugs. I can't say anything specific about that particular plug but we can assume it was for a much different application.

How did the car run? Apparently there was enough spark to ignite the fuel air mixture but that doesn't mean it ran as good as possible. An improvement in fuel economy, performance, idle and starting might be seen with the proper plugs and tune-up.
 
SSVDP, they used to make a spark plug which was shorter yet had an extended threaded tunnel like thing so the threads would not get a carbon build up or oil fouled while running..

65cuda360, evidently honesty is hard to find, as well as enthusiasts with knowledge of what to look for..
I am lucky in a way not to have been suckered in a way which I cannot straighten things out. I do have many years of experience, knowledge, car buddies and complete engines in which to swap.

Just a little aggravated of putting monies into hands of those who know very little, while seeing things shine..
 
Years ago there was a brand of plugs (ALDOR?) that were sold as "oil burners". They were a sure sign of a problem being covered up. We also sold cards of "non-foulers" that were plug extensions to keep a plug firing in a cylinder with bad rings.
 
Just put the correct ones in. It doesnt take much to light off a cylinder. I run a long reach AMC/late Imperial plug on my slant...wrong plug, right performance gain. Its farther reach puts the kernal farther into the combustion chamber. Putting the kernel deep in the hole is a oil foul prevention technique. First thing I always do on a used car purchase is a wash and wax, complete tune up, brake pad change and oil change. Its all on me after that and a great way to get to know your "new" car
 
Isn't this the car that was going through a massive amount of oil when your son was driving it to Oregon or am I thinking about a total different car?
 
Yes that is the car. It died in Susanville California at a stop light, so we drove down with a trailer and rescued the kid and car...

Pishta, After seeing it in person, a wash and wax wouldn't have done anything for it and as far as the plugs, judging with a flashlight, the threads have dissolved from the combustion, so a thread chaser would not make it right. They didn't use just one or two in the oil burning cylinders, they used a complete set of plugs..
 
I bet there are NO valve seals left on that 273, they are in the pan as petrified pieces. I have yet to take any LA head down and find 8 valve seals. You can install a set in about 2 hours with a simple 'on head' hand valve spring compressor and some rope to stuff in bore to prop up valve. That and a whole can of sea foam ingested through the power brake hose and allowed to soak in over a long lunch.
 
If you can't clean up the spark plug threads with a thread chaser or tap, then you may need to replace the heads and make sure that the threads are good in those.


If you are going to try tapping the spark plug heads, it would be best to remove them first so you don't get a bunch of crap in your cylinders.
 
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