AC Spark Plug deal

[two2go]

I saw this eBay posting for AC 41-983 and 41-993 plugs at a good price. LINK
Disclosure: I have no affiliation with this seller nor have I purchased any. After reading 100's of posts, I still don't know which plugs to get. No vehicle reference lists 993's for the 8.1 engine, so why are they recommended?

[Jeff H]

We have the 983s with the Taylor wires...so far so good!

[JC2]

Quote:

Originally posted by two2go: I saw this eBay posting for AC 41-983 and 41-993 plugs at a good price. LINK Disclosure: I have no affiliation with this seller nor have I purchased any. After reading 100's of posts, I still don't know which plugs to get. No vehicle reference lists 993's for the 8.1 engine, so why are they recommended?

It's my understanding that the 41-983 plugs are stock plugs and gapped @ .060. A hotter plug was the 41-932 and was gapped at .045. These have since been replaced with the 41-993 and are also gapped @ .045. You might consider going with either the 983 or 993 plug and gap them accordingly. The price indicated appears to be about 1/2 of normal cost as is the plug wires mentioned. If it were me, I would change the plugs(AC41-993)(.045) and plug wires and keep a couple of spares each on hand. Due to some coaches design, inadequated airflow in the engine area can result in higher heat and burnt plug wires. As you can see from my sig, I went with the 932 plugs, Taylor 409 Plug wires, (http://www.summitracing.com/) and the UltraPower Upgrade, (http://www.brazelsrv.com/). Our power noticeably increased and our MPG went from 7.5 to 8-8.5 after several thousand miles. You might also go to this website and get additional info on the plugs and wires.
http://oemys-performance.com/

[Tenn.Vol.]

Several years ago I ordered my 41-932 from a vender on E-Bay. When I went to install them
I checked and regaped them as I was installing. The first bank went in without a problem.
Then while regappig the fifth plug I noticed that the CENTER ELETRODE was off center.
You could look down from the ground electrode and see half of the center electrode. that
was the metal part of electrode. On checking the other 3 plugs all was off center but
not as bad as the fifth plug. Without a dought these were REJECT PLUGS. So off I went
to advance and bought 4 new 41-932. You could say I did not make any money on that deal.
And I still have the 4 E-Bay plugs on one bank, and 4 advance plugs on the other. Tenn.

[two2go]

FWIW, I've taken a chance and ordered the 993's. We'll see if the quality is better than Tenn.Vol. experienced. All the guys who spend a lot more time under their Workhorse than I do seem to go with 993's. I will put them on the shelf next to my new Taylor wires while I wait for some extra mad money to get the ECM power tune. A surprise root canal and crown set me back a couple months.

[two2go]

Update. I received the 993 plugs from the eBay seller fast and as advertised. They are first quality and pre-gapped at .045. The Denver weather is looking good this week (mid 60's), so I will be headed to the storage lot with my new plugs, Taylor wires, and OEM fuel filter adapter kit to do a little maintenance. Thanks to all the valuable information I have gotten from this forum, I feel confident that I can make these changes.

[JC2]

Be sure and put some anti-seize goop on the plug threads and a little dielectric grease on the plug wire connections then you'll be good to go.

[two2go]

The job is done - 3 bruises, 3 cuts, less than 15 drops of blood, no dropped parts - not bad!
Dang those plug connectors are hard to get off, especially when there is so little lateral room. I did the whole job from the top via the doghouse.
The OEM plugs were 983's. A couple had some crust build-up around the center insulator, nothing much. The main thing is they were uniformly blackish indicating a bit too cold, I guess. The new 993's should help there.
The OEM wires looked good. No sign of overheat. They all measured between 1124-1183 ohms with one at 1240. The new Taylors went on OK. I cut a half-circle notch near the end of a 3 ft. 1x2, put the notch on the end of the connector, and applied a bit of leverage against the side of the doghouse until I felt a snap contact.
The engine started up fine and seemed smooth. I will have the shop check the exhaust gas for any indication of a cylinder not firing when I have the brake system flushed out. And the weather was nice.
/edit/ I have 19,700 mi. on the coach.

[oemtech]

It's whole lot easier to do plugs and wires from under the coach.

[two2go]

Quote:

It's whole lot easier to do plugs and wires from under the coach.

Not on my Dolphin. The main frame members are right there out from the plugs, and NRV added some steel going up. Then I have rubberized fabric "skirts on the outside of this framework up to the floor, so no way to come in from the sides. Directly up from the bottom looked like very little clearance compared to down from the top. Those skirts help channel air, and are probably why I had no heat issues.

[DriVer]

Quote:

Originally posted by two2go: The job is done - 3 bruises, 3 cuts, less than 15 drops of blood, no dropped parts - not bad!

two2go, I resemble that remark .....

[oemtech]

I have done more than 1 NRV and I still do them from under the coach. I just replace the tie wraps that hold the covers in place.

DriVer... remember the band aids in Tenn!

[DriVer]

Quote:

Originally posted by oemtech: DriVer... remember the band aids in Tenn!

Dale, Live and learn; much easier down under and no stinkin band-aids. The motorhome looming over my head can be intimidating ... talk about Damocles.