azbanks

Does anyone know how hot the plug holes get on a 944 S2 16 valve engine when it has been running hard for a while.

I also need to know how hot VAG 2.0 coil packs get when they are working at high output.

Jfrahm

Someone would have to datalog this I suppose. But I also suppose that coil packs from a turbo VAG car like a TTRS would see much higher temps than some random Rabbit 2.5L.

odonnell

I can't imagine it would be an issue, don't people run these coils on highly boosted VAGs all the time?

azbanks

These coil packs come with a rubber sleeve that is short and not the right shape to fill the plug hole or support the top of the coil pack where it sits at the top of the plug hole. The coils packs could vibrate loose and the sleeves don't keep debris out of the plug hole.

I've designed a sleeve that is the right size and shape to stabilize the coil packs and keep debris out of the hole but I'm worried that the material(polyurethane/ninjaflex) I would use to make the sleeve in my 3D printer would melt while the car is running and I would have a big blob of ninjaflex melted in the bottom of my plug hole. Ninjaflex melts at around 220-230 C. I don't want the sleeve to melt against the plug hole walls or against the coil pack. That is why I need to know the temp of both of them. I need the actual surface temps, not internal temps.

Here is a picture of the first design I made. I've created a slightly different design that fits perfectly but I don't want to waste the filament to make 4 of them if they won't work in real world conditions.

V2Rocket

Why not just salvage the boot from an old set of plug wires and modifiy it ?

azbanks

The boot from an old set of S2 wires has a hole that is way to small to fit(13-15mm diameter) and I don't have anything sharp enough to cut a perfect/decent 22mm diameter hole thought the strong rubber of the old boot.

If I can't make a 3D part that will work, I may look harder at modifying a set of old boots.

Or I may start looking for other sources of some kind of rubber grommets with a 38mm outer diameter and a 22mm diameter inner hole.

V2Rocket

how much do you need?
this should do just fine, just cut into segments long enough to give the support you need.
as long as the wire end grips the spark plug, and i imagine the COP gets bolted in place?

https://www.mcmaster.com/#86805K61

7/8 = 22mm, 1.5" = 38mm...

azbanks

Thanks, that looks like it could work.

There is no wire. The coil packs are solid and there is no good way to bolt them in place on the S2. If I can make or buy a sleeve that is the right size, I won't need to worry about bolting them down.

I'm still hoping someone can get me the temps because I picked up blue ninjaflex that is a great match for several other blue parts that will be under the hood.

Here are the coil packs I am using. You can see the small rubber sleeve right under the top plastic part. It almost looks like it is one piece but that is an optical illusion.

https://www.ecstuning.com/Search/07K905715F/ES260102/

azbanks

Ninja flex starts to melt at around 220C which is 428F
If I err on the conservative side of around 210C that is still 410 F.

I can't imagine the the plug holes which are part of the cam cover would get to 410 F or hotter.

Does anyone see a fault in my thoughts here?

V2Rocket

Eric, the further from the actual plug you get the cooler it should be, obviously.
You only need your "sleeve" to fill the gap at the top of the hole where the coil slots in...I would expect that to be certainly no hotter than the engine coolant temperature...but to be conservative I would estimate 250* F.

I would personally be more comfortable with a rubber part than a poly part but if your material has such a high melting point...wouldn't really worry about it.

azbanks

Pics

PaulD_944S2

From the "What have you done to your 944 S2 Cabriolet?" thread, quoting myself:

"I only thing I could suggest is to run the car till hot, park it, pull one of plug caps off and measure it with an IR thermometer (Harbor Freight cheapo) to get an idea. You might even be able to run it after the plug wire is off by disconnecting the injector plug for that cylinder.

I don't think it will be much hotter than between coolant and highest oil temperature, maybe 250 degrees."

AZ, looks like Spencer and I agree. Has to be 250 degrees!