Patient is a 5.0 Mercuiser or 305 Chevy 2 Barrel in auto speak.
I started changing the plugs in my boat, got mostly done then noticed I put the wrong plugs in it. The ones that came out had about twice as many threads between the taper and electrodes.
Hatch has been closed and it fired right up. I will go back later and put the right ones in. How bad will this run? My optimism tells me they will just act like anti-foulers. The devil in me tells me it will run like a four cylinder.
Annnnnnnnnd the hive says.....
Won't be the end of the world. You are sheilding the spark from the air fuel, but that's what the compression stroke is for.
It's a SBC. It'll survive nuclear war along with the roaches.
Ok
That's what I figured, not ideal but it won't leave me dead in the water.
Three plugs were a nice deep brown and the drivers side rear most was kinda black. No relevance just an observation.
You see I let the water separator/filter go bad again. 90% humidity and an aluminum gas tank makes for moisture in the fuel. The one place on earth that some ethanol in the gas would be a good thing and they only sell rec gas. Why is that?
You now have built in non-foulers.
Pete. (l33t FS) said:
You now have built in non-foulers.
My thought exactly!!!
Ya know,!I saw them for sale on rock auto, yesterday. Surprised me.
Noddaz
PowerDork
7/29/22 8:45 a.m.
The only bad thing that might happen is that carbon might build up on the exposed threads in the head and cause you to possibly strip out threads or break a new plug when you change the plugs out years from now.
Noddaz said:
The only bad thing that might happen is that carbon might build up on the exposed threads in the head and cause you to possibly strip out threads or break a new plug when you change the plugs out years from now.
Yep, a little bit of carbon will build up. If you let a hammer mechanic, or typical "parts changer" put the correct length plugs in, they might not notice, and break stuff. Any competent person, will not have any problem. Anything from a bit of care installing new plug, up to using a thread chase. Several things to try. No worries 
