Which Spark Plug Set

slow944s · 06-01-2009, 08:27 AM

I just got my new head for my 87 944S on Friday and was wondering what would be a good set of spark plugs for this car? Would you use the bosch platinum? Also would you replace the wires and rotor and cap since I'm replacing the plugs? Thanks in advance......Jerry

thekidd · 06-01-2009, 10:09 AM

I use the Bosch PLatinum. Wouldnt be a bad idea to do the wire to (I get the Magnacor from Pelican Parts section), the D-cap and rotor is for your disgrestion. I would say NO, but I dont have the money to go all out. Also depends on how many miles are on the the things.

HondaDustR · 10:27 AM

+1 on the magnecor wires. They cost half what the OEM costs and are very high quality. The 100% silicone wire jacket lasts forever and the conductors are non-resistive, but are also specially wound to eliminate EMI. The plug connectors can be a little tricky to get on correctly, but they're fine once they're on and it's a minor nuissance I'll put up with any day for the quality and the price. Read about them here. They're pretty cool and about the best you can get. http://www.magnecor.com/

As far as plugs go, I had some Bosch Platinum2's and they were pretty good and still looked fine after 30,000 miles. I replaced them with NGK iridium IX's a year ago and I overal like the NGK's better. I wanted a set of the Denso iridium power plugs (the $15 a piece ones with the 0.9mm iridium tip center electrode

) but they had to be special ordered. I've heard these engines don't really like the Bosch Platinum +4 style tip, and after switching from the paltinum2's (same as the 4's only with 2 ground electrodes) I would say that's probably true. The +4's seem to do well in a 4 valve symetrical combustion chamber with the plug straight up and down in the middle, but the angled, wedged chamber on the 944 just seems to like standard tipped plugs better.

You can usually scrape the points inside the distributor clean a few times before they finally get too pitted and eroded to reuse, and it's definitely worth it at $40 a pop for a new one.

Razorback1980 · Razorback1980's Garage

Porsche designed the engine for copper plugs and I have found them to work the best and I run NGK. A lot of people will tell you magnacore plug wires but they were not built for this engine. They are a stranded wire with resistance but the engine was designed for solid core wire 16 gauge if I remember correctly with the resistance in the end cap and that is what works the best. OEM for both. When it comes to mechanical engineering...hard to out do the Porsche engineers.

Replacing dist cap and rotor strictly depends on condition. No way to tell unless you show us a picture. My thought is usually they pay for themselves in gas consumption if they have been on for any length of time.

pjburges · 06-02-2009, 10:12 AM

Good reply Razorback!

However an argument could be made that some technology was not available to the engineers at the time, and that the S engine (with its symettric combustion chamber and vertical spark plugs) could benifit. Hard to say though. YMMV. In my N/A motor Ive run Bosch Supers with great success. Im building an S motor and will probably run the same. Karlyn STI is an excellent wire manufacturer and they have a very consistent product, which is why Porsche chose them as OEM supply.

slow944s · 06-02-2009, 10:38 AM

Thanks for the replies. My mechanic says that the platinums will work fine and the wires cap and rotor are still in pretty good shape so don't need to do at this time. Anybody know where I can find the black end caps for the head, the one I bought is missing a couple. Thanks again for the replies....Jerry