SAAC Forum

The Cars => 1967 Shelby GT350/500 => Topic started by: charlie D on September 01, 2018, 08:51:44 AM

Title: GT500 spark plug change
Post by: charlie D on September 01, 2018, 08:51:44 AM
What have you used to remove and replace spark plugs on a 67 G500? How about reattaching the wires to the plugs? I cannot get my hands anywhere near #8 and for the most part none of them are easily reached so I know there has been a satisfactory wire to plug seal. Read many posts on another site where some say just keep trying your hands can get there. Forget it. Mine don't! Thanks for any help. Maybe this is one of those tasks you let someone else do?
Title: Re: GT500 spark plug change
Post by: rhjanes on September 01, 2018, 09:37:03 AM
Welcome to Big-Blocks stuffed into small chassis, issue number 1!

They make a tool to assist in removing the spark plug boots/wires.  When I put wires back on, I put some dielectric (electrical) grease inside the boot that will be on the spark plug.  that will make removing them NEXT time, slightly easier and will also assist in getting them on.

On the plugs....everyone has different tools.  I have a spark plug socket that has a made-on-it, swivel.  I then have different lengths of extensions, from 2 inches to 18.  Then a "loose" swivel, another spark plug socket.  Each plug on a big block, requires different tools, combinations and effort.

Good luck. 

Addition.   Have fun with it....take your time.  I have a 1969 Mustang with a 302 in it.  From unlocking the shop, getting the plugs down and gaped, putting on a fender cover, removing all 8, putting in new ones, cleaning up, locking the shop......an hour, maybe 1.5 if I got distracted.
My 428 Mach?  At the 1.5 hour mark I might have the 2 easiest ones swapped out.  At the 2 hour mark, I might have 3 plugs done.  Decide my back is hurting?  Lunch time?  Shop is getting warm?  Ball game on?  Go inside.  I don't need the car to get to work.  Finish it later tonight, tomorrow....heck....finish it next weekend. 
Title: Re: GT500 spark plug change
Post by: 427heaven on September 01, 2018, 10:00:27 AM
^^^^^ And that my friends covers the basics. One thing added to this equation is PATIENCE... You CAN DO IT! :)
Title: Re: GT500 spark plug change
Post by: 8T03S1425 on September 01, 2018, 10:53:32 AM
I have a '68 GT500, without the pollution control stuff, and I:


Getting that valve cover bolt under the brake master cylinder will be a problem, but the use of a box wrench, a ratchet, a swivel and socket, and a suitable extension will get the job done.

Good luck,
Steve
Title: Re: GT500 spark plug change
Post by: Bob Gaines on September 01, 2018, 11:34:48 AM
Suggestions in reply #1 and 3 are on the mark. Without the smog tubes you don't have to jack each side of the engine up but with the tubes that helps some.  Swivel spark socket and extension or socket with separate swivel knuckle and extension are essential for your sanity.  Yes if you can't get on the #8 plug  you may need to resort to another tool - smaller hands from a friend or offspring.
Title: Re: GT500 spark plug change
Post by: charlie D on September 05, 2018, 11:06:10 AM
Thanks to all for the responses. I am a newbie to the forum so here is a little background. My wife is the original owner or the car. She used it to commute to work as an elementary school teacher and administrator for about 10 years. I have been a recreational "shade tree" mechanic for most of my life, mostly working on Little British Cars. The Shelby has a few modifications over the years--MSD electronic ignition system, headers, lowered a-arm pivot, bat rolled fenders, external electric booster fuel pump switched for full throttle, and few other odds and ends. It has been reliable until recently when it became hard to start. There was a "pop" sound at idle, reminiscent of a wet plug. Then it would not start. The MSD ignition box was dead so I replaced it. The terminals on the MSD distributor cap were corroded and the plug wires attached to it were also corroded. I cleaned up the plug wires and since the inside of the distributor cap was also corroded, it was replaced. I checked for spark from coil to distributor, all good. Pulled a plug wire, got spark so that was good. No start. Sprayed ether, cough, no start. Checked fuel flow, all good. Figured what the heck, plugs must really be fouled so that's where I am now. I have pulled #5 plug and it is not wet, but has some light brown build up all around. Not encouraging that the plugs are the problem, but I may as well finish replacing them. Thanks for suggesting removing the valve covers. I can lift the left one up and tilt it back enough to have better access and vision. The shock tower brace does not allow me to lift it high enough to clear the valve train, not sure if that is the result of lowering the a-arm pivot point. Anyway the gasket is intact so I should be able to use it as is. Any other suggestions are welcome. I do find advice from those of you who have "been there and done that" most helpful. Thanks again.
Charlie D


  repla
Title: Re: GT500 spark plug change
Post by: 2112 on September 05, 2018, 02:44:55 PM
Quote from: charlie D on September 05, 2018, 11:06:10 AM
Thanks to all for the responses. I am a newbie to the forum so here is a little background. My wife is the original owner or the car. She used it to commute to work as an elementary school teacher and administrator for about 10 years. I have been a recreational "shade tree" mechanic for most of my life, mostly working on Little British Cars.
Charlie D

This story sounds very familiar. Was your guy's story published in Mustang Monthly or similar?

BTW; Welcome.
Title: Re: GT500 spark plug change
Post by: jguyer on September 05, 2018, 07:40:15 PM
Quote from: charlie D on September 01, 2018, 08:51:44 AM
What have you used to remove and replace spark plugs on a 67 G500? How about reattaching the wires to the plugs? I cannot get my hands anywhere near #8 and for the most part none of them are easily reached so I know there has been a satisfactory wire to plug seal. Read many posts on another site where some say just keep trying your hands can get there. Forget it. Mine don't! Thanks for any help. Maybe this is one of those tasks you let someone else do?

As far as #8 is concerned, best approach is put arm though the left of the master cylinder. Not sure if this is good with clutch equipped vehicles. Also I have long arms. :D
Title: Re: GT500 spark plug change
Post by: corbins on September 05, 2018, 08:36:09 PM
See reply #3... get the valve covers off for sure.   And a 1/4 inch drive ratchet, extension and socket will get the rear v/c bolt, but you have to put a tad of glue or grease in the socket to hold the bolt in place while trying to get it placed back in.
Patience ...
Title: Re: GT500 spark plug change
Post by: 427heaven on September 05, 2018, 10:35:57 PM
Duct tape or electrical tape rolled up sticky side out, does wonders for holding bolts-nuts in place. :)
Title: Re: GT500 spark plug change
Post by: 6s1802 on September 06, 2018, 01:03:44 AM
This is why we buy G.T. 350's
Title: Re: GT500 spark plug change
Post by: shelbydoug on September 06, 2018, 07:49:15 AM
This could be a contest held at Convention time. You could win an autographed picture of Kopec and Parde. Maybe of the group picture of the Board? Nah...a pair of Banquet tickets would be better. That is if you are done by then?
Title: Re: GT500 spark plug change
Post by: roddster on September 06, 2018, 10:25:26 AM
 I'll guess in a year or so I'll find out about this.  The last big block Ford I touched was the 390 in Dad's old 61 Galaxie.  But, I'm not adverse to sawing off wrenches to reach hard to get at fasteners.
Title: Re: GT500 spark plug change
Post by: pbf777 on September 06, 2018, 11:27:11 AM
     Decades ago, I use to know an old Ford dealer mechanic, we were drinking beer and B.S.ing, and he told me that when the '67's came out with the FE in the Fairlanes and Mustangs, all of their mechanics went out and bought hole-saws to drill thru the inner fender aprons for socket w/ extension access, in order to change the spark plugs. This process turn the job that initially no one wanted due to the time required, to a good money maker.     :o

     Scott.
Title: Re: GT500 spark plug change
Post by: 427heaven on September 06, 2018, 11:43:24 AM
Its not that big a thing if you have any wrenching skills whatsoever. The few that drilled and cut on customers cars back in the day were met with an unsavory response. :'(
Title: Re: GT500 spark plug change
Post by: roddster on September 07, 2018, 04:31:36 PM
 Unsavory respose = Lawsuit
Title: Re: GT500 spark plug change
Post by: charlie D on September 09, 2018, 07:06:50 AM
Update on the spark plug change. After I spent too much time trying to get around the tight spaces, I decided to take the shock tower support bracket off. That let me lift the valve covers off easily and exposed the spark plugs for an easy removal. Like most projects, now that there is room along the firewall, I can more easily install the new heater assembly and clean up some of the wiring along the firewall. So the initial effort to expose the plugs for replacement makes the rest of this easier and worthwhile.
Charlie D
Title: Re: GT500 spark plug change
Post by: corbins on September 09, 2018, 08:40:06 AM
We all live and learn  ;) Glad it worked out .
Title: Re: GT500 spark plug change
Post by: pbf777 on September 10, 2018, 02:17:32 PM
     Such "short-cuts" are perhaps more common than one might think; a by-product of the flat-rate paying system, particularly if a warranty rate is being paid, coupled to unsavory ethics practiced by some of the mechanics, and even some management within the dealerships, to keep production up.   ;)

     Next time you get any work done on your vehicle, review or critique the execution visible, you might find it really amazing how many thing you can find......... F"""-UP!    :o

     Another, buddy I used to know, who worked at the Pontiac dealership back in the '80's, told me that to replace the heater core in the F-Body Firebirds, requiring nearly the entire interior and dash removal, a job that took twice the book time allotted to execute, aka a "looser",  it was often turned into a "winner" of a job buy choosing an alternate process from that outlined in the manual. Instead, remove the right front wheel, inner wheel liner, take a cut-off wheel and cut an opening in the firewall & heater box, extract & replace heater core, paste up holes with the cutouts & adhesives, reinstall liner & wheel, done.   ::)

     Can't say I agree, but beware, such is still practiced today, I assure you.   :(

     Scott.