Spark plug blew up!???
Printed From: CorrectCraftFan.com
Category: Repairs and Maintenance
Forum Name: Engine Repair
Forum Discription: Engine problems and solutions
URL: http://www.CorrectCraftFan.com/forum/forum_posts.asp?TID=43213
Printed Date: April-28-2024 at 4:42am
Topic: Spark plug blew up!???
Posted By: adkrock
Subject: Spark plug blew up!???
Date Posted: July-22-2018 at 7:38pm
|
Went for a ride last night in my 98 SNOB and cruising at 44mph. There was a 2mph drop in speed and then BANG! and pop pop pop pop. The ceramic part of a spark plug blew out and the threaded end stayed put. The popping was from the plug leaving a hole over the piston. Anyone have any ideas what caused this? Thanks! ------------- adkrock |
Replies:
Posted By: KENO
Date Posted: July-22-2018 at 8:02pm
|
Did all of the plug insulator including the center electrode blow out or did some of it stay in the cylinder. I imagine you found the piece or pieces that blew out. A picture would go a long way toward maybe answering the "why" if you have any internal damage, it's already happened so a compression test would be a good start to see if there's damage. |
Posted By: Duane in Indy
Date Posted: July-22-2018 at 9:46pm
|
Bet it was not near as exciting as this plug failure was. The part on the right was the piece that was left threaded into my cylinder head Notice you can see the electrodes thru the hole. Oh, by the way, it happened at about 3000 feet on takeoff in my plane. All came out good. Sure needed to change clothes though  ------------- Keep it as original as YOU want it 1978 Mustang (modified) |
Posted By: gun-driver
Date Posted: July-22-2018 at 10:22pm
That's why you shouldn't be in the air in anything that has plugs and carbs. 
|
Posted By: 75 Tique
Date Posted: July-22-2018 at 10:24pm
|
Exact same thing happened to me many years ago, with the added excitement of a fire under the engine cover. Same thing, ceramic section shot out of the metal base. Ignited gas followed. No damage. Was attributed to a plug not tight in the socket. Dont know if that is a real thing or not or if mine was really loose. I was concerned about debris in the cylinder. It was scoped and appeared to be fine. Ran it, and it was. But it did get my attention (tho probably not to the extent had it happened in a plane) ------------- _____________ “So, how was your weekend?” “Well, let me see…sun burn, stiff neck, screwed up back, assorted aches and pains….yup, my weekend was great, thanks for asking.” |
Posted By: MACS81SN
Date Posted: July-22-2018 at 11:40pm
|
For what it’s worth, my $.02 is that it’s a defective plug. Toured the Champion spark plug plant in high school. Plug is assembled by inserting metal seal, gasket, electrode, and insulator into the top the of the metal shell. Everything held together by a small rolled crimp on top of shell. Probably a bad crimp that held for awhile. Decided during tour that I was never going to work on a factory assembly line. Never did. ------------- Mark 1999 -SN - 502 Python 1981 - SN Owned 33 years - Sold 1968 - Mustang - Sold |
Posted By: gt40KS
Date Posted: July-22-2018 at 11:43pm
|
Several possibilities come to mind as to a cause. Suffice to say a little research would be prudent before simply installing another plug and firing it up. One thought that comes to mind is a lean condition during high rpm run that ultimately caused a detonation. If so, the plug blow-out was a lucky outcome - could have been much worse. I'd pull the other plugs to see their color & condition as a start. Any engine work done recently? ------------- JCCI 1995 Ski Nautique GT40 |
Posted By: Duane in Indy
Date Posted: July-23-2018 at 12:11am
|
In my case I attributed the failure to the radius in the corner being too sharp and causing a stress riser. Of course Autolite never would agree but they did send me 12 new plugs. Not bad considering over $20 each. (They also kept my failed plug) ------------- Keep it as original as YOU want it 1978 Mustang (modified) |
Posted By: adkrock
Date Posted: July-23-2018 at 12:18am
|
Thanks for all the feedback! Will do a compression test and take a look at other plugs. Hoping there is no cylinder damage. Was suggested by a friend mechanic that it does occur but rarely. Got a week of rain in the forecast so plenty of time for diagnostics. Thanks again!! ------------- adkrock |
Posted By: Duane in Indy
Date Posted: July-23-2018 at 12:21am
Oh now that's funny I worked very closely with the Failure Analysis Department with Allison Engine Company later known as Rolls Royce. You can usually limp back home with a dead cylinder but not with a turbine that spit blades out the exhaust. (at least with a single engine turbine) Saw many turbine engine failures, fortunately most were on the test stand. ------------- Keep it as original as YOU want it 1978 Mustang (modified) |
gun-driver wrote:Posted By: gun-driver
Date Posted: July-23-2018 at 12:37am
|
That’s why we have two
|
Posted By: adkrock
Date Posted: July-24-2018 at 8:33am
|
554045175.jpg Tried to post a pic and this is all that came up. How do you post a pic from your pictures? ------------- adkrock |
Posted By: 8122pbrainard
Date Posted: July-24-2018 at 8:58am
|
Rockne, Use the post reply or click on the full reply editor icon (arrow pointing to 2 o'clock) to open up all icons. Then click the tree with the up arrow icon. A browse box will come up allowing you to select anything off your computer. ------------- /diaries/details.asp?ID=1622" rel="nofollow - 54 Atom /diaries/details.asp?ID=2179" rel="nofollow - 77 Tique 64 X55 Dunphy Keep it original, Pete < |