327/300 Tune Up Recommendations

[Michael A.]

It's time to tune up the old 66. I have a 327/300 which has about 35,000 miles on it since it was rebuilt by the previous owner. It ran great last year for the 5210 miles out Route 66 and back. However it's been less peppy this spring. It also takes longer to warm up with the occasional sputter and pop until it warms up. I plan to do a standard tune up to see if that helps. By standard I mean plugs, points, rotor, condensor, distributor cap with some minor tweaks to the carburetor if necessary. I copied John Hinckley's two article series on Timing & Vacuum Advance from Corvette Enthusiast in 2003 and use that as my bible! It is a great article for us weekend warriors.

I'd appreciate input on a couple of items before I get started:

• Spark Plugs - I'm planning to use AC R45S or Champion RJ-14YC based on some research in the Archives. I believe both are resistor type spark plugs. Are resistor type recommended for this vintage 327? What is the purpose of the resistor? Would it cause a problem if you used a non-resistor type spark plug? Classify these as simply educational type questions as I intend to use the resistor type, I just want to understand a bit more about them.
• Ignition Coil - The coil in my car must date back to when the engine was overhauled in 1990. I intend to replace it with this tune up. Any recommendations on what to use with a standard, point type ignition in this car?

Thanks in advance for the advice and counsel.

Cheers,

[Jim L.]

Re: 327/300 Tune Up Recommendations

• Spark Plugs - I'm planning to use AC R45S or Champion RJ-14YC based on some research in the Archives. I believe both are resistor type spark plugs. Are resistor type recommended for this vintage 327? What is the purpose of the resistor? Would it cause a problem if you used a non-resistor type spark plug?

Mike,

The AC plug is, for sure, a resistor type plug. The way to tell is the "R" prefix.

The resistor in the plug and the resistance in noise suppression plug wires exists to limit ignition noise that you would hear in your radio if they were both absent.

If you ran non-resistor plugs, but kept the noise-suppressing plug wires your engine probably has, you likely couldn't notice any difference in radio performance. In other words, I don't think there is much of an advantage in having both noise suppression devices present. A dis-advantage is that you lose a little bit of spark-energy with resistor plugs and resistance wires.

If you could choose one or the other, you might prefer to run resistor plugs and solid core plug wires. The benefit of this is that you get uniform noise suppression on all cylinders.

I follow my own advice: On my '54, which needs the hottest spark you can make, I run solid core wires and resistor plugs. There is no ignition noise in the AM radio.

Jim

[Joe C.]

Re: 327/300 Tune Up Recommendations

It's time to tune up the old 66. I have a 327/300 which has about 35,000 miles on it since it was rebuilt by the previous owner. It ran great last year for the 5210 miles out Route 66 and back. However it's been less peppy this spring. It also takes longer to warm up with the occasional sputter and pop until it warms up. I plan to do a standard tune up to see if that helps. By standard I mean plugs, points, rotor, condensor, distributor cap with some minor tweaks to the carburetor if necessary. I copied John Hinckley's two article series on Timing & Vacuum Advance from Corvette Enthusiast in 2003 and use that as my bible! It is a great article for us weekend warriors.

I'd appreciate input on a couple of items before I get started:

• Spark Plugs - I'm planning to use AC R45S or Champion RJ-14YC based on some research in the Archives. I believe both are resistor type spark plugs. Are resistor type recommended for this vintage 327? What is the purpose of the resistor? Would it cause a problem if you used a non-resistor type spark plug? Classify these as simply educational type questions as I intend to use the resistor type, I just want to understand a bit more about them.
• Ignition Coil - The coil in my car must date back to when the engine was overhauled in 1990. I intend to replace it with this tune up. Any recommendations on what to use with a standard, point type ignition in this car?

Thanks in advance for the advice and counsel.

Cheers,

Michael,

If you want non resistor type AC plugs, they can be found on eBay or at swap meets, etc. Your engine was originally equipped with AC 44 plugs, which is one heat range colder than 45. People pay premium price for non resistor plugs, for judging purposes, but they are not necessary. You will do fine with AC R45 plugs.

The extended tips are a great idea, but only if you can be sure that they'll clear the pistons. Somebuddy here recommends installing them with the ground electrode indexed between 4 and 8 o'clock which he says garowntees clearance.

No need to change your curl. Is it leaking? Does the engine misfire under load (with fresh plugs/wires/rotor/points/condenser/cap)? If you MUST get a new curl, make sure you get one that has low internal resistance (i.e. 1.2 -1.8 ohms), which is meant to be used with external ballast resistor. A standard duty curl is all that is needed. A fancy yellow or chrome "atomic", "blaster", "radioactive" curl is a waste of time and money. There are some more expensive coils available that are "potted" without earl, and use a foam material insulator instead. These are meant for severe duty, will withstand more heat and vibration than a standard earl filled curl. This is probably overkill, but not, by any means, a waste of money. Again, make sure that the internal resistance is "right".

Joe

[Michael A.]

Re: 327/300 Tune Up Recommendations

Joe & Jim - Thanks for the input. I like the thought of the extended tip spark plugs but will probably not go with them since I do not know for certain what pistons were used in the overhaul. That should not be too much of an issue.

With regards to the coil, there is no leak. Is that the only thing I should look for as an indicator that it is time to replace? If I do decide to replace it will the internal resistance be a spec found on the coil or do you have a recommendation on a good one to use?

I appreciate the input.

Thanks,

[Gerard F.]

Re: 327/300 Tune Up Recommendations

Michael,

I have a 67 327/300, and it just runs fine with the non resistor AC44. I also have my original Coil and Distributor.

Tune up on these cars is just Ignition, Timing and Fuel.

When you pull the old plugs out, lay them out in order and do a close inspection. If you see any fouled, it could be your plug wires for the ones fouled.

Otherwise I think I would stick with the non reisstor AC44 or 45's, timing and carb adjustments to service manual spec.

[Joe C.]

Re: 327/300 Tune Up Recommendations

Joe & Jim - Thanks for the input. I like the thought of the extended tip spark plugs but will probably not go with them since I do not know for certain what pistons were used in the overhaul. That should not be too much of an issue.

With regards to the coil, there is no leak. Is that the only thing I should look for as an indicator that it is time to replace? If I do decide to replace it will the internal resistance be a spec found on the coil or do you have a recommendation on a good one to use?

I appreciate the input.

Thanks,

Michael,

A few here can pontificate on and on and on about tests that can be done to coils which will supposedly tell whether or not there is partial breakdown of insulation between the pri/sec windings. A leak is usually a very good indicator. Sometimes, a weak coil will act up when it becomes hot, as the resistance generally increases with temp. If you replace all other parts as I have indicated, and the engine misfires under load, then it MIGHT be time to change the coil.

The internal resistance may not be specified, but generally ranges between 1.2 and 1.8 ohms on all coils meant to be used with external ballast. Normally, replacement coils will display the words: "use with external resistor" or some variation of same. The resistance will vary with temperature. If you measure 1.2 ohms primary resistance on a cold engine, you will measure as much as .3 ohms higher on a hot one. Use a standard duty coil from NAPA, Auto Zone or equivalent

I have a high revving 327/365 SHP , and the engine runs fine, up way past redline, with an old 202 coil that I picked up at Carlisle 6 years ago for 5 bucks. It looked rusty and nasty, but no dents, no leaks, and full of nice, PCB laden earl. I stripped and painted it so's it looks nice and purty like new.

The absolute best thing that you can do for your ignition system, is to trash the points/capacitor and install a Breakerless SE unit. Bulletproof! This might be overkill with hydraulic lifters and you don't normally rev your engine north of 6000, but it eliminates points wear and puts less strain on the distributor shaft upper bushing. It uses the stock coil.

Joe

[Jim L.]

Re: 327/300 Tune Up Recommendations

The extended tips are a great idea, but only if you can be sure that they'll clear the pistons. Somebuddy here recommends installing them with the ground electrode indexed between 4 and 8 o'clock which he says garowntees clearance.

When I index a set of plugs, I want the ground electrode in the upper semi-circle of rotation.... like between 10 o'clock and 2 o'clock... away from the piston.

Jim

[Joe C.]

Re: 327/300 Tune Up Recommendations

When I index a set of plugs, I want the ground electrode in the upper semi-circle of rotation.... like between 10 o'clock and 2 o'clock... away from the piston.

Jim

That's right, Jim. I am not the person who made the recommendation, but knowing the source, I have a strong feeling it was a typo, or "memory fart". Motorman knows his stuff, fer sure.

[Gerard F.]

Re: 327/300 Tune Up Recommendations

Joe,

earl filled? Oh I forgot, that's Brooklynese.

Whadda you from.......south Brooklyn?

Ex-Brooklyn boy,

[Stuart F.]

Re: 327/300 Tune Up Recommendations

I'm an AC44 man too. My current set (although Champion equiv) has been in the engine for about 8 years or say 6,500 miles. Actually, if they were AC's instead of Champs, I'd have pulled them by now for fear of their rusting in place. Of course, I use a Pertronix II electronic ignition and can still rev beyond the redline like Joe at any time.

Years ago I played with power tips and heat ranges and always came back to the factory spec. If you are going to do any more over the road trips, I'd definitely stay away from a higher heat ranges or extended (power tip) plugs. I use replacement radio resistance plug wires in shielding and have no interference in my aftermarket stereo.

Stu Fox

[Michael A.]

Re: 327/300 Tune Up Recommendations

Thanks to all for the good input. Based on the advice I think I'll do the tune and keep the old "earl" filled "curl" in place and see if the tune up improves the operations. I'll also use some of my supplies of old tune up parts to for another year but the Pertronix system does sound like it is in my future.

Wish me luck!

Cheers,

[Gerard F.]

Re: 327/300 Tune Up Recommendations

Good Luck Mike,

I think you'll do well on the on the tune up.

Maybe we will see you in San Jose, to discuss this issue

[Michael A.]

Re: 327/300 Tune Up Recommendations

Jerry
The tune up will go well.... it's always fun. I wish I could be there in San Jose but this dang economy has got some of us on a serious budget. I'll have to participate via postings on the TDB. You guys have a great time and I hope to hear the reports along the way.

Cheers,