Topic: Tired of burning up plug wires
in Forum: C3 Engines
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I've run into a continuing problem with my engine. The 350 has a mild cam, punched .030 over, flat tops and some other stuff, nothin special really. I am currently running the factory rams horns attaching to the side pipes. I have considered adding headers, but it would take shorty's to even try to match up. The side pipes match up great to the rams horns.
The problem is, whenever we go on a long cruise (Bowling Green, Eureka Springs, etc) I end up burning at least 2 or 3 plug wires.
A combination of 4, 6, 3, &/or 5 are the usual suspects, although on the BG trip, 8 & 7 also showed signs of burning.
I don't really like the heat blanket sock look and was wondering if the heat shields are still available for these engines somewhere.
Ecklers has a right front only for 9.99. MidAmerica has a kit for $35, but it only goes to 1979. Corvette Central has several, but they aren't for an '80. Bairs has some kits, but all stop at '79 or older.
Have any of you guys had this problem and what have you done to rectify it. It was interesting to try and find a tree for shade at the Museum to change the plug wires out.
Any thoughts/help/advice appreciated.
The problem is, whenever we go on a long cruise (Bowling Green, Eureka Springs, etc) I end up burning at least 2 or 3 plug wires.
A combination of 4, 6, 3, &/or 5 are the usual suspects, although on the BG trip, 8 & 7 also showed signs of burning.
I don't really like the heat blanket sock look and was wondering if the heat shields are still available for these engines somewhere.
Ecklers has a right front only for 9.99. MidAmerica has a kit for $35, but it only goes to 1979. Corvette Central has several, but they aren't for an '80. Bairs has some kits, but all stop at '79 or older.
Have any of you guys had this problem and what have you done to rectify it. It was interesting to try and find a tree for shade at the Museum to change the plug wires out.
Any thoughts/help/advice appreciated.
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Lawrenceville, GA - USA
Joined: 10/25/2002
Posts: 100
Vette(s): 1968 427 coupe and 96 LT4 six speed Gran Sport clone
Hi Flandy here, you might wanna try some 68-69 427 wires. They have a stainless steel braided cover to prevent your problem. Made by Electric Unlimitrd on my 69 big block as best I can recall. Bad thing is these are only 7mm wires and I think you need 8mm for the hei-Phil
Hi Dennis,
Saw this in Corvette Central online http://www.parts123.com/parts123/yb.dll?Parta~ShowPicTxt~Z5Z5Z50000050g~Z5Z5Z5PFTJ
Hope this helps.
Jim
Lifetime Member #140

Moderator
Duncanville, TX - USA
Joined: 11/8/2003
Posts: 20214
Vette(s): #1-1974 L-48 4spd Cp Med Red Metallic/Black deluxe int w/AC/tilt/tele./p/w-p/b/
Am-Fm/map light National/Regional/Chapter NCRS "Top Flight"
#2-1985 Bright Red/Carmine Cp.L-98/auto
Member: NCRS, NCRS Texas, Corvette Legends of Texas
Dennis, are your wires run the way they're supposed to be, UNDER the heads? If they are, then I don't see why you would keep melting them. The factory heat shields from just about any year will work. The main difference is the "V" shields(boom-r-rangs) that bolt to the block underneath. The shields that fit around the sparkle-plugs are pretty much all the same, far as I know...
You don't need the RF shields that fit over the rear set of plugs...just the 4 heat shields.
You don't need the RF shields that fit over the rear set of plugs...just the 4 heat shields.

Joel Adams
C3VR Lifetime Member #56
My Link
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"Money can't buy happiness -- but somehow it's more comforting to cry in a CORVETTE than in a Kia"
Dennis,
Cookie (C3VR=Warbird) had the same problem with his '74 big block. After burning through 3 or 4 sets of plugs (even with the sock-type insulators) he finally purchased a set of plug wires from Jacobs.
The Jacobs' wires come with hard ceramic boots that cover the plug near the manifold/header. He hasn't had a problem with the wires since, and they're not that noticeable.
They may seem expensive, but when you consider buying new plug wires 2+ times a year, they're worth it for peace of mind.
I could be wrong, but I think that the stainless braided big block wires were made that way mainly to counteract radio interference, not heat.
Good luck,
Anthony
[QUOTE=Adams' Apple]Dennis, are your wires run the way they're supposed to be, UNDER the heads? If they are, then I don't see why you would keep melting them. The factory heat shields from just about any year will work. The main difference is the "V" shields(boom-r-rangs) that bolt to the block underneath. The shields that fit around the sparkle-plugs are pretty much all the same, far as I know...
You don't need the RF shields that fit over the rear set of plugs...just the 4 heat shields.
[/QUOTE]
Joel;
I routed the wires down and under, next to the block and turned the wires in toward each other. I then zip tied them to keep them as far away as possible.
The burning is serious on the caps and the first inch of wiring. Brian (redwingvette) saw the mess at the NCM. The vehicle runs REALLY rough as they start to go away (obviously). The engine has no heat shields currently so I was looking to find a set. As you saw above, everything I found stopped before '80 however, the block is not original to the car and based on what you say, the regular shields should work.
I'll check around here at some of the local shops and see if I can find an old set rather than getting a new set and see if that will do the trick.
If that doesn't work, I may try Anthony's suggestion for Jacobs' wires.
Thanks guys!
You don't need the RF shields that fit over the rear set of plugs...just the 4 heat shields.

Joel;
I routed the wires down and under, next to the block and turned the wires in toward each other. I then zip tied them to keep them as far away as possible.
The burning is serious on the caps and the first inch of wiring. Brian (redwingvette) saw the mess at the NCM. The vehicle runs REALLY rough as they start to go away (obviously). The engine has no heat shields currently so I was looking to find a set. As you saw above, everything I found stopped before '80 however, the block is not original to the car and based on what you say, the regular shields should work.
I'll check around here at some of the local shops and see if I can find an old set rather than getting a new set and see if that will do the trick.
If that doesn't work, I may try Anthony's suggestion for Jacobs' wires.
Thanks guys!
Manufacturers almost never put anything on a car that isn't needed, especially in the engine compartment. GM engineers made the heat shields specifically to solve the problem you describe. Pop the hood some dark night right after a nice hour or so drive. The manifolds have this beautiful cherry glow kind of like an element in your electric range. Without the heat shields, the manifold bosses think your plug wires are a nice apple pie needing a good cooking.
Also, you've juiced up the engine a bit and if it's running even a little bit rich, the manifolds get a LOT hotter.
Those heat shield sets are available on Ebay, or you could find a cheap, nearly new set at almost any junk yard.
Dennis, do you have the wire covers between the manifolds and the plug wires? I am not talking about the chrome covers but the metal heat shields that bolt on the heads and sheild the heat from the plugs. I don't remember seeing them when we were in BG.
Redwingvette 2007-12-31 16:56:49
Brian - NCM Lifetime Member
73 coupe L48, Flat-top pistons, Performer RPM Heads, Crane Cam and roller rockers, Holley 650 vac sec. Performer intake,
3.55 gear BTO 200-4R trans,
Leather seats, Seatbelt Plus 3point seatbelts, Pioneer CD player
Magnaflow Exhuast System
Dewitt radiator and dual electric fans
Borgeson Steering box

Brian;
I don't have them. I talked with the local vette guy here and he has a box of junk that I can go thru to see if I can find them.
Also, a C3VR angel PM'd me and told me he would send the two he had to me and wouldn't even take a check for shipping. Maybe that's because he knows the polymer my checks are made of


Seriously, I really appreciate it! I've got new valve covers coming thanks to Mom & Dad (pix when they get here) so I'll do all this at the same time.
I don't have them. I talked with the local vette guy here and he has a box of junk that I can go thru to see if I can find them.
Also, a C3VR angel PM'd me and told me he would send the two he had to me and wouldn't even take a check for shipping. Maybe that's because he knows the polymer my checks are made of



Seriously, I really appreciate it! I've got new valve covers coming thanks to Mom & Dad (pix when they get here) so I'll do all this at the same time.
in Forum: C3 Engines
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