78911SC

I'm ready to put new plugs in (I think!)...

The Bentley manual says:

.028 to .032

That's +- .05 from end to end.

What should it be? I've got new Bosch Platinum plugs.

Thanks,

Charles

Bill Gregory

The factory spec for your '78 is .032 inch. With copper plugs that one might put in and not look at for awhile, there's a thought that you gap them a little tight, so the metals can wear some and still be in spec. Not sure if or how that applies to platinum plugs or not.

78911SC

Hmmm... These are WR 8 DP's that say .036" on the box. I got them from my trusty NAPA guy.

I told him I had a '78 911 SC.

Are Platinum plugs not optimal? I remember my buddy who lived down the road from my girlfriend in High School telling me he used Platinum plugs in his '72 911T (converted to S)...

Thanks Bill,

Charles

Bill Gregory

Charles,

The WR8 Bosch plugs are the right plug for the 1978 SC. I would just tamp down the arm so it's closer to the platinum electrode until you get to a gap of .032. Platinum plugs should work just fine.

78911SC

Just a hypothetical question, of course...

Say someone went a head and put the plugs in gapped as they came (.036ish).

What might that cause?

I did a compression test... all in the 132- 140 range... The plugs didn't look bad. Just a bit of very fine white ash (very thin, barely covering the normal color of the plug.)

I'm feeling like I'm having a dejavu of the previous owner. Someone changed the fuel filter, someone changed the plugs, the oil is fresh, etc...

How do you tell if the vacum advance on the distributor is working? I'm sure I've got a timing issue, or fuel.

It runs hmmmmmmmmputhmmmmmmmmputputhmmmmmmmmmmmmmmput

I got this thing because I thought I could work on it if it needed anything, not because that's ALL I wanted to do

Thanks again Bill...