AC 44 spark plugs

[Stuart F.]

Re: AC 44 spark plugs

Bill;

Where do they have emission tests on old Vettes? If they are doing it in some states, I'd like to know where so I can avoid them. I lived in Illinois last around Chicago and even my old 87 Caprice out grew them so I wonder where they are reaching back to the 50's and 60's. If they test my 63 it will blow their gauges off the scale.

Stu Fox

[Bill M.]

Re: AC 44 spark plugs

Bill;

Where do they have emission tests on old Vettes? If they are doing it in some states, I'd like to know where so I can avoid them. I lived in Illinois last around Chicago and even my old 87 Caprice out grew them so I wonder where they are reaching back to the 50's and 60's. If they test my 63 it will blow their gauges off the scale.

Stu Fox

Stu:

My comments related to the difference between a 44 and R44 and why GM went to an R44. There should be no difference in performance between the new (unfouled) plugs even though the measured resistance is different.

We no longer have any emissions tests in Michigan.

My '65 396 is "stinking" rich and HC probably measures in billions of parts per million!

[Clem Z.]

Re: AC 44 spark plugs

We no longer have any emissions tests in Michigan.

My '65 396 is "stinking" rich and HC probably measures in billions of parts per million![/quote]
becareful what you post as we have a new clean air police force in washington dc

[John D.]

Re: AC 44 spark plugs

Another spark plug thread recommended AC Rapidfire plug #7. Has anyone tried them ?

[John D.]

Re: AC 44 spark plugs

I recommend using the extended tip plugs and indexing them as Clem has suggested. AC 45S or AC 46S. Now if you foul those out you have issues with the engine and or the ignition. JD

[Duke W.]

Re: AC 44 spark plugs

Tim:



A non AC brand that seems to work well is the Denso WU-14. It is the equivalent of the AC 45.....non resistor and 5 heat range.


Larry

No, it's Denso W14-U. Or the NGK B4. Both are equivalent to the out of production non-resistor AC 45.

I spent years cleaning "fouled plugs" - AC 44 or equivalent - until I found that most of my high rev ignition breakup problems were due to the sloppily assembled Delco single point distributor, and about the same time I started running the hotter AC 45 or equivalent. That was back in the early seventies. End of problem!

Duke

[Bill M.]

Re: AC 44 spark plugs

becareful what you post as we have a new clean air police force in washington dc

No worries. I'm sure that when they pass the "clunker" law, Joe Biden and I will trade in our mid-years on hybrids.

[Duke W.]

Re: AC 44 spark plugs

If you are talking about an L-75, well, ok go on the cheap. You don't need the new plugs above 5000 RPM. If you are talking L-76 or L-84, then you need the new plugs - unless you don't mind the cutting out and missing above 5000 RPM.

See my above post. The primary cause of the high rev ignition breakup is the single point distributor. After I "blueprinted" mine, the AC 45s lasted virtually forever by comparison. When I hot lapped race tracks I installed AC 43s for the day.

In an episode of the first season of "Route 66" Todd is running his '61 at Riverside, and in one segment he gives a technically correct explanation of why colder plugs should be installed for road racing events. (They must have had a good script consultant.) Maybe that's how I learned that back in 1961!

Duke

[Timothy B.]

Re: AC 44 spark plugs

I will let everyone know how my 67 runs with cleaned plugs. I installed the breakerless ignition and quickened the advance curve also.

[Larry M.]

Re: AC 44 spark plugs

No, it's Denso W14-U. Or the NGK B4. Both are equivalent to the out of production non-resistor AC 45.

I spent years cleaning "fouled plugs" - AC 44 or equivalent - until I found that most of my high rev ignition breakup problems were due to the sloppily assembled Delco single point distributor, and about the same time I started running the hotter AC 45 or equivalent. That was back in the early seventies. End of problem!

Duke

Duke:

Thanks for the correction.....I guess my dyslexia is acting up again!

Actually, I got the incorrect number from another post on Chevy small block spark plugs. I should of double-checked that source before posting the number. But it sounded right.

Larry

[William L.]

Re: AC 44 spark plugs

Tim; This is what I use to clean my spark plugs. Circa 1955, came out of the GSE shop Delta Airlines and it still works great today.

[Gerald C.]

Re: AC 44 spark plugs

I have a 300HP 1963 and the JM calls for AC Delco #44. Can anyone tell me the difference between #44 and #44S? I have a set of original 44S's and was wondering if they are appropriate for judging AND driving around town?

Thanks

[Dave S.]

[Leif A.]

Re: AC 44 spark plugs

I have a 300HP 1963 and the JM calls for AC Delco #44. Can anyone tell me the difference between #44 and #44S? I have a set of original 44S's and was wondering if they are appropriate for judging AND driving around town?

Thanks

Gerald,
If you're just "driving around town", you might consider going to the next higher heat range and install 45 heat range for better performance.

[Gerald C.]

Re: AC 44 spark plugs

Thanks Dave. I found 6 45's. now I need two more! Going to Hershey in a couple of weeks. Hopefully, I'll find them.