Long Reach Plug

jeepguy1948

Well-known member
Bought a new set of Edlebrock 8.5 heads which take a long reach plug. I would like some advice on what plug to run. We are using one of Charlie’s SBC distributors with points. Max 1 cam, Reds tube headers, for now a Stromberg 48, a 4 V later after break in. I can’t think of any other details I should add. This is a strictly street, daily driver type of build. Ron suggest’s the H10 for a 1/2” reach but nothing specific for long reach. Thanks
 
The H10's are 7/16 reach and I stopped running Champion plugs quite a few decades ago. Since these newer heads have 3/4" reach plugs, here are a couple to choose from - depending on your ignition and the heat range you want to run:

Note: On NGK, the higher the heat range the colder the plug - exactly the opposite of Champion!

Note: These are both non-resistor . . . which is what I run as I could care less about noise and I get more spark energy than with a resistor plug.

1) 5 Heat Range:

BP5ES-11

2) 7 Heat Range - Racing Plug:

R5671A-7
 
I’m running NGK GR4’s which are 3/4” plugs. Stock #2635
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Just curious why everyone hates on the champions? I’ve been running them in my Flathead for about 400 miles now and they seem ok. I did however just buy the ngk’s yall mentioned. Curious to see how different it runs. Being my first flathead I have nothing to compare it to but see a lot of hate for the champions.
 
Just curious why everyone hates on the champions? I’ve been running them in my Flathead for about 400 miles now and they seem ok. I did however just buy the ngk’s yall mentioned. Curious to see how different it runs. Being my first flathead I have nothing to compare it to but see a lot of hate for the champions.

Lately, they seem to foul way too easily and quickly. Switching to NGK's solved that problem for a lot guys.
 
I’m running NGK GR4’s which are 3/4” plugs. Stock #2635

That plug is fine for most situations - depending on your heads, spark plug location and cam/valves. It is running a "Projected Tip" which puts the electrode down in the chamber. That is fine as long as there is nothing to hit it! LOL.

The heat-range is '4' - which is a bit hot for my liking . . . so if you see any issues with the plug as far as the electrode wear, short plug-life or pre-ignition, etc.. - go to a cooler heat range. I tend to run heat ranges of around '6' in most of my street flatheads.

Also, that plug is a resistor plug - which does sap some spark energy. Depending on your ignition and wires that may or may not be good.

I've found with Harman Collins crab dual-coils that I try to always run solid-core wires and non-resistor plugs. When you get too much resistance in the circuit it is very common for the yellow "mid plate" to leak secondary voltage and cause 4 cylinders to have misfires.

Best of luck!
B&S
 
I also use NGK GR4 #2635. Length of threads is 3/4 in.
Length from bottom of washer to tip of electrode is 1 in.
They came with the heads I bought in 1999 from Mark Kirby (RIP).
 

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Guys,I used to run Champions in the 70's in all my stuff cars,hotrods harleys yamahas untill i heard and read about how they had fallen apart.in my '37 v8 i run autolite 18mm 386,s. also iv'e also had to check the gaps on every plug as some come properly gapped and others not so much. Tom.
 
Short story on Champion Plugs:

Background: I have seen quite a few instances over the years where when a Champion plug is "washed down" (by too much fuel) that it will not fire afterwards. I have no idea as to the why of this - but have seen it quite a few times. (going back to when I was 15 with my first flathead performance build).

Fast-Forward El Mirage Racing - The 'FlatCad' (blown flathead Cadillac).
One of the members of our Bonneville team obtained a small sponsorship from Champion - they supplied us with racing plugs for our engine. I let the guys know that I was not a fan of these plugs, but they were free.

FlatCad Engine: This is a very special build - just for land speed racing. It started out as a 1940 or so flathead Cadillac V8 - has an unimaginable amount of work and all custom parts put into it. There is not a single component in the engine that originally came in the engine - except for the block. We run a 6-71 blower with 20 lbs of boost an Enderle injector with both hat and port nozzles and we run on alky. The engine uses two ignitions, but for this story the one that was in the car is a MSD ProMag 20 AMP unit. It puts out one Hell of a lot of spark amperage - which is a good thing for Alky and our boost levels.

Back to Elmo . . .

Anyway, the rest of the guys arrived at Elmo earlier than I did and when I arrived in the early afternoon before the race started, the guys had the car out of the trailer and were all sitting around in chairs all "Hang Dog". The car was just sitting in the dust . . .

I asked "What is going on?" They said "The ignition is toast! We tried to start the engine and it popped a few times and then nothing. We think the Mag is gone and we don't have a spare".

I asked "What plugs are in it?". They said "those new Champions". I said "You guys know I don't like those and the issue is probably the plugs. You guys washed them down with too much Alky and now they won't fire".

They all pushed back at me saying "Oh BS Hays, these were brand new plugs, gapped correctly, the issue has nothing to do with them!". And they continued to sit and grumble away in their chairs . . .

I went into the trailer, grabbed and gapped a set of NGKs, put them in the engine and asked for some help starting it. They all looked at me like I was nuts - and wasting their "seat time". Buddy got up and I ran the fuel bottle while he cranked the engine over.

She started right up!

They couldn't believe it - but they witnessed the whole debacle with their own actions and eyes.

Needless to say, they didn't question us running NGK plugs from this point forward!

Anybody want some free Champion plugs? :rolleyes::rolleyes::rolleyes:


Here are a couple pictures of the beast:

EngineBlowerDriveMockup101.jpg

dyno1.jpg
 
B&S: That engine is a work of art. Simply beautiful.

For your viewing pleasure:

1) Here is a video of the FlatCad on John Beck's dyno - 653 HP at 5700 RPM

https://www.youtube.com/watch?v=c12HEMcP4ls

2) Here is a look at the dyno stats for that run:

https://www.youtube.com/watch?v=LigLEXjme2s

3) Here is a longer video about the whole project that 'Speed and Chrome' did on us . . . kind of long, but hey, you may be bored. It shows a lot about the car, engine, team and other such nonsense . . .

https://www.youtube.com/watch?v=NG7uYqtvXNw
 
B&S: That engine is a work of art. Simply beautiful.

Thank you sir . . . it took about 2 years of my life to design, build and test it - was worth every minute of it.

I've just got the long-block back together (after some updates) - the car is being reworked/refreshed. We won't be back this year (some team health issues) - hopefully next year!
 
Ditto what Jim said, Dale. Incredible work as usual! Curious, what made the team select a Flat Cadillac? Is there a record you guys are chasing.
 
Ditto what Jim said, Dale. Incredible work as usual! Curious, what made the team select a Flat Cadillac? Is there a record you guys are chasing.

The original reason is that when we started, there were no records set at Bonneville with a flathead Cadillac engine . . . ever. Seemed like a good challenge.

I had never worked/built one, so I had the owner of the car send me a bare block and crankshaft. From there I looked at the port arrangement and decided that it could make horsepower - especially with a blower. Because ALL the ports come out the top of the block, it provided me a means to port the Hell out of it and really gain some flow with it. It is the ports that enable us to make the 650 HP that we make.

It only has 3 mains, so I designed a thick girdle that picks up the whole lower part of the block and also made steel main caps that tie into the girdle. Crower worked with me to design the crank. I changed the main bore location, increased the bearing size to BBC, moved the thrust to the rear, etc.. I used a Ford FE crankshaft design for the rear of the crank and a BBC design for the snout. This allowed us to use some aftermarket parts - instead of having to make custom flywheels and cam gear drives.

The initial goal was to make 500 HP on gas (which is not easy). We made about 575 so we were all impressed.

The engine is a beast - with the 4 5/8 stroke billet crank and 3.52" bores, it is almost 370 cubic inches. The rods are over 8" long (billet Crower pieces). It has a tremendous amount of torque and power . . . really fun to drive!

Enough out of me!
 
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