news2me

I want to change the plugs on my '77. The car is all original, with heat shields, AC and P/S. Just by looking at it, I know its going to be a pain in the butt. Is there an easy way to do it. I have a lot of **** in the way..

hugie82

You can get to most easily from under the car and thru the wheel well. The wires are a pita but you can pull the boots off. Tape the new and old wire together and pull it thru.

DUB

Also..I carefully take a small screwdriver and carefully slide it between the boot and wire and break the seal loose so I can remove spark plug boot. I do this for cylinders 1,2,3 and 4. This is so I can run them through the motor mount area easily and then I put a little bit if dielectric grease on them and slide the terminal back in the boot.

SPARK PLUGS: Raise up the car and do cylinders 5,6,7 and 8 from under the car.
Cylinder 1,2,3 and four can be gotten from up top or sometimes you can take the wheel off and if you have long extensions ans swivels...you can get to some of the plugs through the wheel house area.

Clean the porcelain and write on it with a 'Sharpie' what cylinder you took it out of. This way, if you have a spark plug that looks not so good...you can always go back and reference it.

MAKE SURE you check and verify the GAP is correct and the pawl is correct to the electrode. Improperly gapped plugs being installed is a waste of time. Electricity travels the path of least resistance....so if the pawl tang is not correct...you can not expect that cylinder to have the best spark cone when the plug is firing...and then 'wonder why' the car is not running right.

And for what it is worth...not knowing what is going on with the engine and its performance...but I would seriously check out and OHM your plug wires.

IF replacing plug wires. The lower heat shield that look like hockey stick really need to be removed so if there is any oil on the block..you can wash it off and run the new wires correctly. ALSO...if the car is still correct...there is a special 'U' shaped clip that is hidden under these shields and if you try to pull wires through there...they can get cut and all messed up. Just words given from experience.

DUB

509 rat

for the tuffones I just get a cheap socket and cut it down and use a open end wrench, works great.

SWO vette

This may be sort of off topic but..... After working on later model vehicles I am finding that my 72 has more room than some of the late models do. Just take your time.

Peterbuilt

About the spark plugs, should I use something like a points file to get the ground electrode perfectly flat before gaping the plug? Or is that just a waste of time and energy?

SWO vette

Just gap it.

Easy Mike

Pay someone to do it for you.

yyz1970

Take your time
Skin a few knuckles
its Fun

7T1vette

Replace the spark plugs with irridium replacements. They will last a LONG time....meaning it's worth the extra money so that you won't have to change plugs for 50K miles or more. You don't need to 'message' the electrodes or ground lugs; just gap them appropriately to the ignition system you have.

Jud Chapin

PITA for sure, but just use iridium plugs as mentioned and you may just never have to do the job again. If the wires are old, may as well swap them out also.

SWO vette

It looks worse than it is. I remember back in the 70s when I tried to change the plugs I thought there was no way in heck to change them. Fast forward to now it is not difficult. Some you change from above and the rest below. Can't remember which....sorry. The only bad thing about the 70s to now is that the springs must have sagged as I can't get under it as easy as I used to

DUB

A waste of time doing that. I have a set of spark plug gap pliers and once I get the gauge set to what I am looking for. I can do all the plugs really fast and they are all the same....as long as I use the tool the same on each one.

ON ANOTHER NOTE:

The choice of spark plug is up to that person..and I pass no judgement. But I can write from experience that if EVERYTHING is good. The factory plugs will last a very long time. And I have been seriously burned when a customer brings me a set of plugs that are not stock and it runs goods for a minute and then falls on its @ss. JUST WRITING...IT CAN HAPPEN. And when I remove those plugs and go and put in the factory plugs...the engine runs like a striped ape.

And for those customers who are looking to make sure the engine is at its best. If I get them back in and pull spark plugs and see how they are firing and working. Sometimes I will increase the heat range and then check them again.....because it is totally INSANE to think that an engine with 100K+ miles on it does not need some special attention. And I even will check them when I can on new engines that come in for service after its initial installation.

AS I hope we all know...even the BEST ignition system can not work correctly if the cylinders are low on compression and having oil leak issues from rings or valve seals. Spark plug gap is so important....maybe not as touchy in the older Corvettes...but the newer ones...it does make a difference on how it effects the coil(s) ,etc.

DUB

7T1vette

NGK sells irridium plugs and makes direct replacements for those recommended for your C3 engine. They are a good quality product...much better than the quality of the GM Delco or A/C brands which are all purchased from secondary vendors these days.

Mick71

ddawson

Yep, It's not truly your car until you bleed on it.

Paul L

So what difference do they make over Delco R45TS? I believe the NGK equivalent is YR5IX.

7T1vette

I believe the primary difference is that the electrode material and coating is different. I've had irridium plugs in another vehicle of mine (the specified plug for it) and they are spec'd to last 100Kmiles. After changing mine out at 100K, the electrode tips still looked like new.

I've never seen anything like that with any A/C Delco plug. So that's what I used at my last plug change in my C3. I don't expect to have any plug wear-out for the rest of my life.

Paul L

Sounds promising.

DUB

Something for me to look into...and hopefully if I install them in a later model Corvette..I am not ripping them out and putting what I know works. I guess I can give it one more try and see how well it works...depending on how the plugs I pull out look. Having a forum member using them with great success is a good sign

DUB