Oh, $16 each shipped from sparkplugs.com. Painful...Quote:
Originally Posted by ColoradoSpringsRob
Sent from my SM-J700T using Tapatalk
Oh, $16 each shipped from sparkplugs.com. Painful...Quote:
Originally Posted by ColoradoSpringsRob
Sent from my SM-J700T using Tapatalk
Yes, but if the truck does not burn oil and you use unleaded fuel, it will last for thousands of miles and years. My truck in Germany would fowl the plugs regularly. But it burned oil (valve seals) and needed plugs changed often.Quote:
Originally Posted by ColoradoSpringsRob
I have no idea regarding the history of the plugs that the truck has in it now, so maybe I just leave them alone? I guess once my nifty plug wire tool shows up, I can pull the plugs and have a look and see what I see. I will post those pictures up and you guys can weigh in. Ideally, they would be fine, and I can get more life out of them?
I thought changing plugs and filters and fluids would be a good way to get a baseline, and then figure out what the truck really needs from there.
Im asking same question about the Autolite AER72S, I pulled a plug from my motor, has champio nxmj-17 plugs in it & they have a shorter thread but a shank so long that you cant tighten the water proof coller over the top.
The Autolite AER72S shank is shorter ( im sure I could would have clearance to screw caps down) but concerned about piston clearance. cant find a manual that tells me a clearance over piston - the thread is longer by 1/4 on the Autolite AER72S.
Adding my recent experience to this thread-
I have a lot to update on my build thread (http://www.m715zone.com/vb/showthrea...d-update/page7) but - spoiler aleart - I got it running.
As part of that activity, I was having trouble getting it to start and idle well. Turns out that it was mostly due to choke setting, a trickly idle carb circuit, and crazy advanced ignition timing. Anyway, part of the troubleshooting involved replacing the plugs. They were old and rusty, so why not throw some money at the plugs?
As of mid-2022, there are very few choices for plugs. I read all the old threads on the 'Zone and any source for 2407, etc.. are dried up. Looks like most other vendors were out too, except for Memphis. So I ordered a set of 6 plugs from them.
What arrived are these:
Blue Crown SR8F18P
https://i.imgur.com/pz4S2Pll.jpg
https://i.imgur.com/mQezZnYl.jpg
Here it is compared to my original plug. The originals are too rusty to get a good number from them but they have the knurling like an Autolite of some sort.
https://i.imgur.com/s3OuEIal.jpg
You can see the reach is a lot longer and the electrode stick-out is much greater. The overall length of the Blue Crown is also shorter. I have no idea on the heat range but I suspect it is hotter than what was in the truck. I thought that would help with the poor start/idling and carbon build up. However, the reach was so much longer I was worried about clearance to the piston. So I put one plug in and rotated the engine by hand, and didn't "feel" anything, so I decided to install the set of six.
Partway through the install, I got to plug #5 and realized that Memphis had made a mistake, and sent qty 4 Blue Crown SR8F18P and qty 2 Autolite 2243.
Here are the Blue Crown next to Autolite 2243:
https://i.imgur.com/FpUcRt5l.jpg?1
https://i.imgur.com/g2CoA7vl.jpg?1
The blue crown electrode stick out is more than the Autolite, and the Blue Crown overall length is less.
I contacted Memphis, and they were suprised to see the Blue Crown. They thought all of their stock was the Autolites, since they have Autolite make those plugs for them in batches. They quickly sent me a couple of Blue Crowns to complete my engine.
As I mentioned earlier, the engine is now running, and as far as I can tell runs pretty well. I do have some dieseling at shutdown, which could be due to a hot combustion chamber (i.e. the long reach plugs?) or too fast of an idle. I will start with the idle speed reduction and see if that fixes it.
Anyway, if you are looking for plugs, it seems Memphis has them ($$) and you may even have a choice of the Blue Crown or the Autolite.
With the longer reach, as long as they dont hit which you have verified...they would raise the compression ratio some slight amount...being the stock motor is 7.5, it wont hurt a thing there!