AKS Racing

I blew another boot on #1 cylinder today. With the MSD, this makes the ignition basically go to ground, which means no power. I am running TPIS 1-3/4" longtubes, AFR210CP L-98 angle, and Accel 8.5MM plugs with a straight on #1 with the thermashield (chinese finger cuff?). When it blows, there will be a little white spot on the thermoshield, a 1/8" hole in the boot, and a 1/2" soft spot in the boot. There is probably a 1/16" clearance between the thermoshield and the exhaust pipe. This last boot lasted roughly 20 miles of hard driving. It always happens to #1. That sounds convinient until you figure that the blower inlet piping has to be pulled to access that plug wire.

Anyone found a solution to this problem with a similar combo.

Thanks in advance,
Aaron

norvalwilhelm

I had the exact same problem on my bigblock so I went with accel short plug in that cylinder and a Jacob ceramic boot. They were $40 per wire but I just replaced two and they have a life time warranty. Never had a problem again

85vet

Where did you purchase the accel short plugs and the ceramic boot? I have a similar problem with #7 after installing the TPIS long tube headers on 85. :chevy

norvalwilhelm

The short accel plugs were no problem. The local speed shop stocks them. I normally run 276 but in the short it is S276. They are about 3/8th of an inch shorter then stock. For the ceramic boots i looked up Jacobs on the internet, phoned them or e-mail them and they give you the nearest place that sells their products. They are univeral wires with the ceramic end installed and you cut and install the distributor end. They are guaranteed for life and will NOT burn through.

ex-gold87

Norvalwilhelm is right, the Jacobs wires will not burn. I had to use them on my car, the ceramic boots are really nice too.

gcrouse

I got my Jacobs ceramic boot wires from Jeg's; the whole set is around $200 ouch! But it fixed the burn-thru problems with the headers.

Just curious why you have a straight boot on #1; it's usually for #6 for dipstick clearance and #1 should be 90 degree.

AKS Racing

Update:
#1 boot thermoshield is a double layer nomex type material. I unfolded the material and wrapped several layers of the thick foil between the two layers. With a new boot installed, no blow through on #1. I use an Accel 8.8 vari-angle straight (bent to like 150°) on #1; it provides more clearance than just an Accel 8.8 90° boot.

#7 blew through. It has an Accel 90, replaced with a spare boot off a new Accel SS 7mm wire. Blew through within 1 minute of start up. Replaced with an Accel 300+ 90° boot. Blew through. A vari-angle nor a straight will work. Installed a new Accel 300+ 90° plug boot and wrapped with foil. Jury still out, and looks cheesey.

#6 blew through. Running Accel 8.8 vari-angle (bent to like 150°). Installed end off of a factory wire set. Does not appear to have blown, but may not be sealing around plug.

None of the others plug boots are close to the headers, but the ignition is somehow intermitantly going to ground. I would bet that I lose nearly 50-70% of the hp of the engine when it goes to ground.

I have contacted Summit and Jegs, and both recommended that I contact Jacobs direct due to the fact that Jacobs does not list any C4 Corvettes in their application listing. I have left numerous messages at Jacobs, they have not returned any calls. I found another, just tech, number and it is always busy. I may just have to buy the complete 90° set and/or the complete straight set to make what will work for my application. The sets retail for like $140 and $165. This seems very expensive, plus they are preassembled. What I would like to have is like (2) 90° wires and (1) straight wire without distributor boots attached, so that I may install the accell sheathing and shrinkwrap, so they will somewhat match my other wires.

Any thought on where I might find individual wires like I am looking to locate?

Thanks,

Aaron

scorp508

May I ask what causes this? Super high-powered ignition?

AKS Racing

What causes blown plug boots, are plugs that are too close to the headers. This seems to be common with larger (ie high flowing) heads. I have heard quite a few complaints with the AFR 210/220 heads. I still have not heard from anyone who knows where to buy single Jacobs ceramic boot plug wires.

Aaron