Spark Plug Heat Shields Too Short

[Homer318]

Simple job has turned out to be a real puzzler.

We have a 1996 3500 with a 318 and thought it would be nice to treat our baby to some new plug wires. Turns out this simple job isn't so simple as we thought - available wire sets have plug ends that are too long for the installed spark plug heat shields. We've tried 6 different suppliers and they are all include spark plug boots that are about 3/4" longer than our factory boots. When pushed tightly onto the spark plugs, this extra length leaves them sticking out of the heat shields.

One local Chrysler dealer finally figured that we might have a "heavy duty" 318 and could likely replace the present heat shields with normal (I expect that means longer) heat shields and could use the standard wire sets. He didn't have the normal heat shields in stock so couldn't give me a dimension to compare to our 2 7/16" shields.

Is there such a thing as a "heavy duty" 318?

Why are there 2 different lengths of heat shields?

Can I just convert to the longer shields and run with the wire sets that every manufacturer seems to produce?

Thanks for your thoughts.

[QQB825]

i hate those heat shields...

[koihito]

I hate those heat shields too, they are a pain!

But frankly, I don't see how running those wires with the shields you have are going to make any appreciable difference. 3/4" shouldn't kill anything; if you found shorter boots you would have bare wire from the heat shield on and with longer boots you have wire covered in a boot.

[Homer318]

koihito

I'm with you guys and not liking these heat shields too much myself at this point.

My problem is that this machine has short heat shields and short plug boots on the factory wires. Installing any of the available standard replacements leave the plug boot sticking out of the heat shield. If I want to install new wires, I have to do something and remain confused about these shields:

Is there such a thing as a "heavy duty" 318?

Why are there 2 different lengths of heat shields?

Can I simply convert to the longer shields and run with the wire sets that every manufacturer seems to produce?

[koihito]

I've never heard of a "heavy duty" 318, but thats not proof there isn't one.

My point is, why change the shields? So what if the boots are longer? The plug wires run into the boot all the way to the connection, the boot is just a boot and if the short heat shields are adequate longer boots will only give you longer boots and no less heat protection or functional difference.

I'd just stick the longer booted wires on and not worry about it. I suspect that after market wire makers only make the long ones because shorter ones are not necessary. I just don't see how a shorter boot length or longer shields will help your van run better, last longer or be more reliable.

[Dodgevanman]

I replaced my wires on my '94 with a set of the Autolite Professional grade wires and they fit great. I don't remember the heat shields being a problem, but that was like 2 years ago. :)

[Homer318]

Hi guys,

These heat shields sure make for an interesting problem. Got a complete set new shields from Chrysler today and they're all longer than my originals. I'm going to replace the originals with the new shields and install a nice new set of Bosch wires. Problem solved and as soon as I can spare a bit of sweat, we'll be ready for Texas!

Many thanks all and once again - I really dislike these heat shields!

[Mazdax605]

My 2001 Ram Wagon only had one heat shield when I did a tune up last month.It was on the left(drivers side) front plug only.Does this mean someone in the past took all the other ones off?

[Dodgevanman]

My 2001 Ram Wagon only had one heat shield when I did a tune up last month.It was on the left(drivers side) front plug only.Does this mean someone in the past took all the other ones off?


Certainly sounds like it. Unless Dodge changed something.

[Mazdax605]

Should I worry that my van doesn't have these heat shields?

[Dodgevanman]

I wouldn't worry about it. I've had much older Dodge vans with V8's that didn't have the heat shields and they were fine. My '72 doesn't have heat shields around the plug boots.