Standard vs Shorty Spark Plugs

[themechanic]

FYI,

Here are some photos I took of the ACCEL 437S shorty/header plug beside the AP85 Autolite plug. The difference in length of the plug boot end is about 1/4".

I bought a set of 4 to solve a problem with non-flexible ceramic plug boots with 2" TTIs on a 440. The old wires were Firecore 50 45 degree and would flex just barely enough to get them over the standard length plugs on #2 and #4. The ceramic 45 degree boots hit the shock tower.

FYI, I ordered 2, 90 degree ceramic boots. Hopefully, problem solved.

 

[Oldreddodge]

Chebbie monkeys have them,didn’t think mopars did

 

[mopar 3 B]

How does the plug heat range compare to the rest? Everyone claims the TTIs are the best. Surprised to hear of the plug clearance problem from all the great reviews.

 

[themechanic]

How does the plug heat range compare to the rest? Everyone claims the TTIs are the best. Surprised to hear of the plug clearance problem from all the great reviews.

You'll have to look it up. Most reviews are for the 1 7/8" headers, I believe. The TTI header fitment is top notch. Plug clearance and ease of changing plugs, on the other hand, makes people want to go back to HP manifolds. Including me.

 

[mopar 3 B]

You'll have to look it up. Most reviews are for the 1 7/8" headers, I believe. The TTI header fitment is top notch. Plug clearance and ease of changing plugs, on the other hand, makes people want to go back to HP manifolds. Including me.

To me that's part of fitment. If the plugs and wires don't fit why bother? The way people brag about them you would not think they had any problems. This one is good to know.

 

[themechanic]

To me that's part of fitment. If the plugs and wires don't fit why bother? The way people brag about them you would not think they had any problems. This one is good to know.

It didn't matter since they were the only shorter plugs I could try. At the time, I was facing having to buy 2 individual 90 degree wires for $26 each until I found the 90 degree boots by themselves for $10 each.

 

[RJRENTON]

If header tube to spark plug boot becomes an issue, perhaps you should consider using NGK BPMR5 or something with a colder (hotter) heat range for your operating conditions. These plugs, and the Champion equilivant such as CJ-7Y or CJ-8Y (projected core nose) etc, or Champion CJ-6, CJ-7, CJ-8 are both 3/8" reach 3/4" hex design and are inexpensive, readily available everywhere, generally under $2.50 each. Autolite as well as AC markets equivalent heat ranges. These plugs are not the trendy platinium electrode designs but were designed for lawn mowers and chain saws and will work just fine. Look at the manufacturer's heat range chart for whatever brand you prefer and make your own decisions on heat range for your engine's operating conditions. Do not let the auto parts store counter person make the decision for you...do your own due diligence. This also applies to your next door's neighbor's brother-in-law's uncle's cousin's friend's best buddy's sister's husband as well. Just my opinion of course.
BOB RENTON

 

[themechanic]

I just re-installed the longer plugs that were in there and made some 90 degree wires. All is well again.

 

[RemCharger]

If header tube to spark plug boot becomes an issue, perhaps you should consider using NGK BPMR5 or something with a colder (hotter) heat range for your operating conditions. These plugs, and the Champion equilivant such as CJ-7Y or CJ-8Y (projected core nose) etc, or Champion CJ-6, CJ-7, CJ-8 are both 3/8" reach 3/4" hex design and are inexpensive, readily available everywhere, generally under $2.50 each. Autolite as well as AC markets equivalent heat ranges. These plugs are not the trendy platinium electrode designs but were designed for lawn mowers and chain saws and will work just fine. Look at the manufacturer's heat range chart for whatever brand you prefer and make your own decisions on heat range for your engine's operating conditions. Do not let the auto parts store counter person make the decision for you...do your own due diligence. This also applies to your next door's neighbor's brother-in-law's uncle's cousin's friend's best buddy's sister's husband as well. Just my opinion of course.
BOB RENTON

Good post Bob. Here's some pics to add

Significantly shorter

 

[Geoff 2]

I have been using 3/4" reach plugs in 3/8" reach heads for more years than I can remember.
Few reasons:
- smaller 5/8" hex head for easier access
- much greater range in design, such as the ISO design that puts the electrode further into the cyl
- available in Plat, Irid etc.

I machine a steel spacer 3/8" long to take up the additional length. Remove washer, fit spacer, re-fit washer. Don't forget to machine a slight inner chamfer on the spacer where it fits against the plug body.