Colder Spark Plug for the 8.1 ??

[max49]

I'm so tired of the heroic measures to keep the 8.1 happy. Fans blowing on the #5 wire. That was for my old engine, now my new 8.1 moves over and burns #6. How many blowers do I need for this underpowered engine. I may have another, after so many burnt ones, I may be imagining the "dreaded shudder" that we get when running on 7 cylinders.
Does any one know if there is a one step colder heat range SP that works on the 8.1? If so, I'll be the tester if no one else has tried it.
The 180* thermostat is a keeper, for me, but only because it takes a min. or so to go from 180* to the stock 195* and when climbing any hills the temperature keeps climbing faster than the MH climbs, still saw 214*, but maybe it stayed there for a min. or 2 less time. Not much when you're reving 4000 RPM @ about 25 or 30 MPH for 30 min. straight, but I guess it helps.
I don't like it when strangers are risking all of our lives passing me on the 65 MPH 2 lane roads , but many are friendly and and toot their horn and wave with one finger. I'm too afraid to pull over for them before I get to the top, because I may not be able to get going again on the mtn. , especially if I get the dreaded "shudder"

[Mr_D]

Lower heat range plugs won't keep plug wires from burning, good quality high temp wires will.
The 180° thermostat will defeat some of your smog control, may reduce mileage and may be illegal is some areas.

[max49]

Thank you, Taylor Supremes lasted less time than the cheap wires. Thanks for the warning, hope I don't get arrested.
Now I'd like to try a colder spark plug, can any one help?

[max49]

I'd be more worried about that Banks kit on your ISC 350 being illegal. You might try the Taylor Supremes on your DP, they did'nt last long on my gasser.
A little help on a colder range SP for the 8.1 will be appreciated.

[DAN L]

Quote:

Originally Posted by max49 I'd be more worried about that Banks kit on your ISC 350 being illegal. You might try the Taylor Supremes on your DP, they did'nt last long on my gasser. A little help on a colder range SP for the 8.1 will be appreciated.

which plugs do you have in it now?
have you tried the iridium plugs from oemy?

[oemtech]

A colder plug is not going to fix you problem.... Max, your trying to fix the symptom. You need to fix the air flow problem and the burnt wires will go away.

[max49]

I just got home last night, they are the stock spark plugs, I'll pull 1 today. I've never heard of different heat ranges for SPs for our 8.1s, maybe there isn't one.
They do have different heat ranges for motorcycles. For example, an NGK BR9ES would be the recommended "colder" SP. An NGK BR8 or BR7ES would be hotter SPs that burn hotter and cleaner but are more likely to burn pistons or other damage but would never oil foul and were better at slower speeds.
I'm thinking that with the pressure mfgrs. get about emissions, they feel they have to sacrifice durability in order to get their engines to burn as clean as possible.
I'm sorry, I'm on my 2nd engine and it's not working for me or my engine.
If Dale's SPs are a colder heat range, I'll call and order some.
I hope someone here knows what I'm talking about. I don't really think GM designed this engine to pull 20-26,000lbs up mountains for 20+ min on at 4000+ RPM and hold it back for 20+ min, then start all over again for 8 hrs.
Southwestern CO mtns are beautiful but they are muthas on the MH.

[iRV4FUN]

Max49,

A new engine and then another burnt P wire... Makes ya wounder?

What caught my attention was that your engine heats up when in slow speed situation. Your crawling up the Rockies @ 35 mph with high rpm's and that is a recipe for a high heat buildup.

My Damon body is very similar to yours and I've thought about removing the engine access hatch from the front. It has six screws on the hinges. This would open her up. I see the UPS and USPostal trucks with a wide open front grille's with a mesh wire screen or honey comb plastic grille to catch some of the bugs and rocks. I plan to place a rock screen in place of the hatch.

Good luck! Sounds like the million dollar highway is a million miles away.

[wa8yxm]

Underpowered? I have driven SEMI TRUCKS with less horsepower than the 8.1. (60 HP less in fact)

There are two things that help... First some folks have benefited from a special modification to a poorly designed RV, not the motor, but the RV that is wrapped around it, a workhorse authorized center can help you here, it is not, however Workhorse's or GM's fault it's the coach builder that messed up.. (Else we would all have this problem)

and the High-Temp wires others have mentioned.

[Joe Gilbert]

I agree with Wa8YXM. The burnt wire issue is not Workhorse's fault; it is a design issue with the coach. I have 46,000 miles on my W22/Dolphin and have not experenced a plug wire problem. For the record I also cross and recross the Rockies nearly every year.

In regards to power. I'm happy with the power and torque of the 8.1. Considering the weight, I think my RV performs well. It is seldom that a Diesel coach passes me on a long. steep climb, and I've never been passed on a climb by a Ford V10.

JoeG

[max49]

I really don't think it's an airflow restricted issue. I came home with the hood wide open, made no difference. I reach in the wheelwell and pull the SP wires on the side of the road, how open is that?
GM sold these engines to WH without warranty because they knew where they were going. GM warranties medium duty trucks for 12/12, that is all. WH had to warranty longer to compete with Ford.
There are so many smart engine guys here, any one have any idea why I think a colder heat range plug might help? With my engine borderlining on meltdown, it can't hurt.

[max49]

Quote:

Originally Posted by wa8yxm Underpowered? I have driven SEMI TRUCKS with less horsepower than the 8.1. (60 HP less in fact) There are two things that help... First some folks have benefited from a special modification to a poorly designed RV, not the motor, but the RV that is wrapped around it, a workhorse authorized center can help you here, it is not, however Workhorse's or GM's fault it's the coach builder that messed up.. (Else we would all have this problem) and the High-Temp wires others have mentioned.

Yea, right, come on out west.

[Clay L]

The difference between cold and hot plugs is that the tip of a colder plug doesn't extend quite as far into the combustion chamber as a hotter plug.
Why do you think the colder plug will prevent the plug wire from getting too hot?

[Joe Gilbert]

I'm not sure if the "come on out West" was intended for me. I love the west and travel over the Rockies, on the way to Moab, nearly every year.

It is still true that some motorhome models have never experenced the plug wire failures. After I retired I drove my cousins 1 ton Chev. truck, pulling a 5th wheel trailer, delivering log-home logs. This truck has an 8.1 and has never had a plug wire issue. The fact that you can see the side of the engine through the wheelwell on your RV does not mean that air flows over the engine to remove heat.

The plug wires fail for one reason and only one reason. Too much heat. It has nothing to do with the heat range of the spark plugs. I do think a 180' thermostat would help your problem though perhaps not cure it.

JoeG