How about some spark plug education?

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Many of my posts and comments about tuning, especially spark plugs, get lots of questions. Here is a pretty solid article about reading your plugs. This is a mix of some Wiki articles, my own discoveries and some knowledge gained from many a gray haired old race car mechanic before me. One suggestion is once you start tuning your car, always try to stick with the same brand of spark plug. Different manufacturers use different coatings, plating, etc and that can change or mislead your diagnosis or tuning efforts.

Let’s go to school, kids!

The spark plug’s firing end is affected by the internal environment of the combustion chamber. As the spark plug can be removed for inspection, the effects of combustion on the plug can be examined.

An  “reading” of the characteristic colors and markings on the firing end of the spark plug can indicate conditions within the running engine. The spark plug tip will bear witness to what is happening inside the engine. This helps to know what is going on inside an engine running at peak power.

Engine and spark plug manufacturers publish generic charts containing information about the characteristic appearance of spark plugs after being subjected to various normal and abnormal conditions. Such charts are useful for general use but are of almost no use in reading racing engine spark plugs, which is an entirely different matter.

A light brownish discoloration of the tip of the block indicates proper operation; other conditions may indicate malfunction. For example, a sandblasted look to the tip of the spark plug means persistent, light detonation is occurring, often unheard. The damage that is occurring to the tip of the spark plug is also occurring on the inside of the cylinder.

Heavy detonation can cause outright breakage of the spark plug insulator and internal engine parts before appearing as sandblasted erosion but is easily heard. As another example, if the plug is too cold, there will be deposits on the nose of the plug. Conversely if the plug is too hot, the porcelain will be porous looking, almost like sugar. The material which seals the central electrode to the insulator will boil out. Sometimes the end of the plug will appear glazed, as the deposits have melted.

An idling engine will have a different impact on the spark plugs than one running at full throttle. Spark plug readings are only valid for the most recent engine operating conditions and running the engine under different conditions may erase or obscure characteristic marks previously left on the spark plugs. Thus, the most valuable information is gathered by running the engine at high speed and full load, immediately cutting the ignition off and stopping without idling or low speed operation and removing the plugs for reading.

A lighted magnifier is the best tool to have on hand for reading your spark plugs.


Remember when reading plugs…

  • The “Ground-Strap” = Heat Range
  • The “Plug’s Base-Ring” = Jetting
  • The “Porcelain” = signs of preignition/detonation

You can also verify heat range by the threaded area. The threads will show a dull burnt-looking color change, 2-3 threads is ideal.

  • To increase the number of burnt threads, increase the heat range of the plug
  • If you have 4-5-6 threads burnt you need to get a colder plug

Next, we examine the “fuel ring”. (and the porcelain)

On the air/fuel ring, you’re looking for a complete ‘full turn’ of discoloration. Ideally this should be lightly colored soot.

As the fuel ring soot darkens, this indicates a richer air/fuel ratio. If you’re tuning the engine for maximum horsepower, the ring should be very light and not make a full circle around the ring.

The second place to inspect for the air/fuel ratio is the the porcelain. Being too rich leaves light to dark color rings on the porcelain. Ideal conditions leaves the porcelain like new to shiny white.

Here is a quick sample plug.

  • 1 is a timing indicator, you’ll see a definite color change on the ground strap right about at the arrow. Too much timing and the color change will be very close to the body of the plug, too little timing and it’ll be closer to the tip. Ideally it’ll be right at the 90 degree bend on the ground strap, in this image timing and temperature look good.
  • 2 indicates the base timing is ideal.
  • 3 shows another timing indicator; usually there’s a brown ring right at the tip of the porcelain. It should be a sharp defined ring about 0.020″ wide. A wider ring indicates not enough timing. If the ring is smaller, incomplete or nonexistent (like shown here), that could indicate too much timing.
  • 4 is a heat range indicator seen at the threaded portion of the plug. Looking at the threads you’ll see that a few toward the end are a dull burnt looking color, and the rest are black and shiny. You want about 2 threads showing the heat on the end of the plug and the rest of the threads to be shiny. If you’re using a longer reach plug, 2.5 to 3 threads is optimum. Too few colored threads indicates a too-cold plug; too many colored threads indicates a too-hot heat range.

Next time, I will cover some basic carb tuning for the Edelbrock.

Trying something new… and cool.

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Other than photography, I have never considered myself an “artist” or a designer. recently, just as a joke, I threw together a T shirt design with my beloved Thermoquad on it. I mean, I do rebuild a bunch of these for clients.


And then the idea struck me…why not make some attempt at branding the 71 car and soon to be it’s little brother.


So now… I’ll keep working on my Illustrator skills and learn how to produce some great products for vintage NASCAR fans.

For now… all the cool goodies can be found on our merch page here.  I am slowly working on trying to pick the best vendor so we can officially open up




Feeling pretty stupid ….maybe.

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So the car is on the ground, and the engine runs like a mad banshee! Success! (sort of) The transmission started leaking on the first good highway run, and the more I drove it, the worse the shifting to 4th gear got. Replaced the rear seal and …she still drips oil.

But… good news first. The shifter that I fabricated works awesome!

I am still waiting on the shifter ball to arrive, but otherwise I am really happy with the operation. I may go back later and replace the Ford tie rod end with an actual Heim joint.

Now, back to that transmission. I researched this thing to death when I set out to do the conversion. I knew the NV3500 was what I wanted due to availability and the tall 5th gear. I found one on Facebook Marketplace for a few hundred dollars. I got it home and it sat for nearly 8 months without me touching it. In December I set out to install it behind the new motor. I had to fabricate that mount I talked about in the last posting. Everything is married up and off we go down the road.

So this thing… let me tell you about this thing….

Now that I started having issues, I started doing the Google search from hell. Nothing I found married up, not even the rear seal. SO now… here I am feeling like an idiot, how in the hell did I buy and install an AX15 transmission without even realizing it! JHC! Now I started feeling sick. But… as a mechanic I started working on solutions. The opinions on the AX15 are split down the middle with the NV3500. The oil leak … well that is because the slip yoke that came with the trans is worn out completely. Close to .100 smaller than the new one. Ok, so that’s an easy one. I have a yoke for it. The gear clashing… well it appears that the AMSOIL GL5 synchro oil I put it is absolutely the WRONG oil for the trans! So.. fingers crossed that the 4th gear synchros have survived and I’ll have it sorted out with the new Redline MT90 arives from Amazon.

I have a line on an actual NV3500. (Luckily they are paretty much a plug and play swap except for the slip yoke) Otherwise, I’ll just wait and see what happens after the new slip yoke and oil change. I’ll continue to kick myself in the ass for the next few months for missing this in such a HUGE way!



Wish me luck!

More gears, more speed…..hopefully!

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Almost a year in planning, the NV3500 has found its home behind the new 5.9. (More on the engine later) Of course, like everything with this car, the mount for the new five speed had to be custom fabricated one piece at a time.

Once the motor was out, I set it in the approximate position and started taking a few measurements.


Then I had to drop it out and get the engine bay cleaned up and get that new 5.9 dropped in. Once it was home, the fun started! I had to drop the Torsion Bar cross member out of the way, measure up and cut the original transmission cross member and let the engineering begin! Here I had just tacked up half of the bushing mount that attached to the transmission and had the side supports in place so that I could set the pitch angle of the transmission and tack the lower mount into place.



She’s all welded up and bolted in. I used two bushings mounted longitudinally that mate face to face and a support bolt ran through them. I am hoping this will allow for a little more flex and keep me from breaking another bell housing.


Two notes here. Yes, I am going to fabricate a short throw, remote shifter that will be more sports car like and less like a dump truck. Secondly, you do have to massage the trans tunnel to get this ting in place. I’ll have to fabricate a new one to finish out the deal.


Finally got he driveshaft in place this week. It took a special U joint from Moog. Part number 319, to mate the NV3550 yoke up to my driveshaft. Hopefully by the next installment, we will be making some noise!


Reading Them Bones!

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The great Smokey Yunick was probably the pioneer of spark plug reading when it comes to racing. Today’s younger generation are all about an AFR gauge and a lap top. Truthfully, a well trained eye can get more from observing the tip of the spark plug than the AFR alone. I have been trying to perfect my skill, not only as a race car tuner (of carbs and distributors) but also as a spark plug aficionado. During the initial tear down of the motor from the 71, this is what all 8 plugs looked like:

Just from what I have learned, I can tell the mixture is just about as spot on as I can get. If anything maybe a few .0001 lean. 🙂 The black around the top of the face and the darkened center electrode means its a bit rich at idle and the deposits on the ground strap are most likely oil. (as this engine has a LOT of hard miles on it. It takes some time and patience to make all of the best adjustments to get a carb to perform like it should.

This is not intended to be a tutorial as there are hundreds of opinions out there. One of the better tutorials can be found here: 

And an even better tutorial at HotRod magazine! 


The man and the master of his art.

All cracked up!

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Some of you that follow me on Social Media ( know that I have been chasing this mystery trans leak on the 71 car. The thing would go for days and weeks and not leak a drop unless I parked it for a week. This is after the car sat for two weeks. It dumped the bulk of the trans fluid onto the garage floor. I have looked it over front to back and could not find a real source of this issue. Some forum guys said it was the TQ converter draining down while parked and overflowing to the vent.


Soooo… since we have the new 408 engine in work and the swap to a five speed, I pulled the engine and trans out and this is what I saw once the pressure was off the transmission:

The case was cracked about 90% of the way around! It split almost on the pump line. With the engine against the trans, it most likely kept the crack from opening up. The bell housing was so loose I could nearly break it off by hand. With the new NV3500, I have to fabricate a mount so I am hoping to eliminate the torsion issues by a longitudinal pivot style mount.


Here’s hoping!


BTW, the initial test fit of the new trans went very well!

The more I listen to this guy….

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I have an hour and fifteen commute each day to my wonderful job as an airline tech specialist. It’s an almost straight shot from my house in Daytona to the Orlando airport. I get bored quickly, so I will throw on YouTube and let it play. Yeah, yeah. I listen to it ok. I have become a fan of a lot of the classic car and car guy channels but one stands out above the rest. Uncle Tony.

The more I listen to him, the more I realize this is me. Well, minus the fantastic mullet and smoking habit.

Seriously though, Tony embodies everything that is old school hot rod. While I have never been a drag race guy, I can appreciate the philosophy of build it rather than buy it. Nothing like building a carbureted engine with points ignition that eats up new cars at the track. It gave me some new inspiration for a build you will be hearing about soon! Guaranteed it will have a points distributor and a Holley carb!

I’ve watched most every video on his channel. Don’t discount him and his knowledge. He presents it in a way that even my ex wife can understand.

For the love of &^$%*@%^

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Headed home from Darlington, somewhere just past the Hardeeville exit it happened. Running 90 in the outside lane I hear a bang and then a vibration so hard I though the car was coming apart. The exhaust got noticeably louder as well so I really thought I had blown the damn motor. Racing home, trying to beat the beginnings of the hurricane and here I was on the side of the road in low country South Carolina.

Walk around… nothing. Open the hood…nothing. WTF?! Looked under the car..nothing right off till I saw the rear U joint had exploded. I am guessing all of the parade burnouts and shenanigans were too much for it. Luckily for me Progressive has an awesome road side assistance program. I was too far south for any of my Street Legal Stock Car folks to come rescue me. I popped out my car show camp chair and set down in the woods off the road and waited on a ride.

They tried to take me on to a Dodge dealer. Um no! Took me like a minute on Google to find a good old South Carolina shop. J&C Auto in Hardeeville are seriously the best folks I have ran into in quite a while. They were busy as hell, and actually ended up just loaning me their car to go grab the part and loaning me a jack to get under the car. This place was packed with cars and you can tell the locals loved them. I can’t say enough praise for the shop.



Between looking for the parts and what not, it took about six hours to get back on the road. All in all, it worked out just fine and I beat the hurricane home. It’s all part of the adventure.


Racing in the “I’ve lost my damn mind 500” … a Darlington road trip.

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I was invited to bring the 71 car up to Darlington, SC for the 2019 NASCAR Hauler Parade. What? Oh hell yes! One problem. I don’t have a car hauler yet. What to do? Well, jump in a 1970’s NASCAR replica and drive 350 miles from Daytona to Darlington, SC to meet up with the rest of the Street Legal Stock Car group from Facebook. Had I lost my damn mind? Well anyway, the parade was on the 29th, so I headed out on the morning of the 28th. After a week of looking the car over and making it the best I could, packing up a bunch of tools, some spare parts, and a few qts of oil, off I went!

First gas stop, in somewhere Georgia. The car was running like a beast. No issues at all, not even the gas mileage was alarming. Yep, the trans still has a leak somewhere, but who the hell cares. A quick pit stop and I was back on the road. The weather was perfect and it wasn’t even that hot as long as I was moving. Did I need better ear plugs?

Second gas stop was just an hour south of Darlington in Santee, South Carolina. All was well. Added a qt of oil, filled the tank and took a much needed leg stretching walk around the car. Now… about those ear plugs! OMG I was going deaf! I was running about 85 for most of the second leg, which was turning near 4,000 rpm. Holy shit was this thing loud. I pressed on!

I rolled into Florence, SC with plenty of daylight left. Let me tell you, the Super 8 there is decent. Cheap, no frills, and did the trick for under $50 a night. That’s Preacher Franklin’s bad ass 17 car parked next to mine. and… I am deaf. My freaking ears were ringing so bad I could not even hear the TV  in the motel room! The poor waitress at Quincy’s had to wonder while I was yelling at her! All I wanted after that meal was to go sit quietly in the motel room for a few hours!

Now let’s get on to the fun stuff! The next morning I was up, and Preacher and I headed out to get some ear plugs for the ride home! We grabbed our cars and headed over to the Florence Convention Center to meet up with the rest of the crew. Little did I know that the first part of the day would be reminiscent of the old  race car days with swapping out a transmission right there in the parking lot! (Hey, at least it wasn’t MY transmission!) It was good to hang out with gear heads l like me. Guy who weren’t afraid to get dirty, and know their car like the back of their hand. JB had the trans swap done in a few hours. Now imagine… that far from home and a few phone calls and he had a new four speed and clutch ready to go. All from a fellow racer in SC!

Jim Boyle drove this thing from WAY up north, like Connecticut north. Now I don’t feel nearly as nuts for my part in this weekend! The trans swap was on, a little tune up on the #9 Ford Thunderbird belonging to Chad and we were off to lunch. We showed back up around three for the start of the big show. Please do not let anyone tell you that NASCAR is dead in the south!

(Photo Credit Thomas Blackstone)
NASCAR is certainly not dead in South Carolina. I am guessing I had 100 kids, and a handful of grown women crawling in and out of this car for photos over the hours we were set up on display. I mean, that’s what the heck I built this thing for any way! The towns of Florence and Darlington came together in a way that made me homesick for the Carolinas for a bit. No racism, no BS, just out and out NASCAR fans coming to see their favorite driver’s rigs and take in some cool race cars.

Photo Credit: Thomas Blackstone
I can’t even begin to accurately describe the amount of money sitting in this parking lot and what an honor it was to be asked to be a part of it. I am ready to do it again next year! ow we haven’t even got to talk about the parade yet!

Stay tuned for part 2 coming up soon!

Feeling like the luckiest guy on earth!

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All I have to do is look at these photos and I realize I am one of the luckiest guys alive! Racing at Daytona had been a dream of mine since I was a kid. While the SCCA track Night isn’t technically racing, except against my own best lap time, I am still driving the most famous speedway ever! I’ve gone 145 mph on the most famous speedway ever! I’ve challenged my car to its limit now. This means that I can spend the rest of the year working on a new motor, getting the new five speed set up, and making it all ready to do this again next year.

I don’t take a second of this for granted! I know that I am lucky to have the skill to build a car like this, the time and money to get to the track, and a wife that somehow understands the addiction.