C1 spark plug recommendations

[Garry Barnes]

I seem to remember seeing recommendations for AC spark plugs somewhere but don't remember where. I need them to be correct for judging but I also want them to be correct for the type of driving that will be done with my '56....which won't be much for the next year or so. I have seen AC44's, 43's etc. Any recommendations? What ones did the '56s come with? Thanks.
Garry

[Dennis A.]

Re: C1 spark plug recommendations

Garry...

AC44's were standard and perform well...reports of Extended tip AC45S being used, I never tried them.

[Garry Barnes]

Re: C1 spark plug recommendations

Thanks Dennis.
Garry

[Roy B.]

Re: C1 spark plug recommendations

Your's will look like the left one or top one in commercial if it's 57 High horse power engine

[Garry Barnes]

Re: C1 spark plug recommendations

Roy,
Mine is a '56 with the 225/265 engine. Would it not be the one with the four thin green stipes? Thanks.
Garry

[Roy B.]

Re: C1 spark plug recommendations

NOOOOOOOOOOO

[William C.]

Re: C1 spark plug recommendations

Earliest green stripes I found were in a box dated '59 I believe, before than no green stripes, but four ribs, before that, no ribs.

[Garry Barnes]

Re: C1 spark plug recommendations

So, what is correct?

[mike cobine]

According to Motors

the 1955 through 1957 CORVETTE used the AC 43-5 plug, unlike the 1955 and up Chevrolet PASSENGER cars which used the AC 44 and AC 45 plugs.

The AC 44 and AC 45 plugs were not used in CORVETTE until 1958 and up, with the AC 45 being in the lower hp (compression) engines and the AC 44 in the highest hp (compression) engines.

To be correct for judging, you need to see what the judging manual says should be there and get that.

[Garry Barnes]

Re: According to Motors

Thanks everybody!
Garry

[Garry Barnes]

Re: According to Motors

Mike, I checked my jM and no mention of what spark plug should be in my '56 for judging. As I have mentioned before, this particular JM for '56-'57 leaves a lot to be desired in the way of details. Thats why I have to come to this board with so many small and detailed questions. Thanks for trying anyway.
Garry

[Roy B.]

Re: According to Motors

Like I've tried to say they are the same as 55 Corvette in the pic. I posted

[Dennis A.]

Plugs for Fuel Injected engines

Was AC44FF plugs used on 1960 and later fuel injected engines?

[John H.]

Re: Plugs for Fuel Injected engines

It never made it into the owner's manuals or Shop Manuals, but I have a copy of a Chevrolet Service Letter describing that Flint V-8 began installing AC 46 plugs in all '57 Corvette engines in mid-'57 in response to numerous customer complaints of plug fouling with the initially-released AC 44 plugs.

I'd worry less about what's "correct" and more about what suits your driving style, unless you enjoy changing plugs regularly. 43's are WAY too cold for normal street use, 44's aren't much better; I run AC R45S plugs in all my small-blocks, haven't fouled one in years.

[Mike McKown]

If my memoryhasn't failed me

that's a Corvair plug.