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Product Summary

Universal Fit

  • For use on all 14mm flat gasket seat spark plugs
  • Orients the spark plug electrode opening in the combustion chamber towards intake valve
  • Ten stamped copper washers each of three thicknesses provide ability to rotate plug up to 315 degrees.
  • Washer thicknesses are 0.040", 0.050", and 0.064"
  • Provides an easy way to index your spark plugs for best performance
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Key Specs

MFG. Part #54571910
BrandSpeedway Motors
Material TypeCopper
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Need To Know

Quick and Easy Returns

Return Policy

Speedway Motors 54571910 Details

  • Fits all 14mm spark plugs with a flat gasket seat
  • Made from stamped copper material for proper sealing and heat transfer
  • Indexing spark plugs rotates the electrode ground strap for more complete combustion
  • Can be reused when new plugs are installed if not overtightened
  • Includes three thicknesses with 10 washers in each size (30 total per package)

Quickly Position Your Spark Plugs for Best Performance with Easy to Use Indexing Washers

If extracting maximum horsepower & torque is your goal, consider adding these spark plug indexing washers at your next tune up. Indexing shims allow you to properly orient the spark plug electrode within the combustion chamber of the cylinder head. Proper electrode orientation ensures maximum efficiency (complete burn) and increases the speed at which the fuel is burned (more power).

The object of indexing spark plugs is to position the back side of the electrode (ground strap) towards the nearest cylinder wall, away from the middle of the chamber. This helps to unshroud the spark kernel and face it towards the intake valve. Due to manufacturing processes, there is no guarantee the threads are positioned the same on any two spark plugs, or that the threads in the cylinder head are consistent from chamber to chamber. In other words, chances are if you screw a plug into the head, it won't put the electrode in the same position as all the others. Learn more about performance spark plugs in our Toolbox article.

Indexing spark plugs is quick and easy to do, taking nothing more than a set of indexing washers, a marker, and a little time to line things up. These indexing washers are designed for flat gasket seat 14mm spark plugs only (we do offer 14mm flat gasket seat indexing washers as well). These indexing washers come in three thicknesses, which allow the spark plug to be indexed 105, 210, or 315 degrees of rotation from their non-washer seated position. You can tailor both the position and depth of the electrode using these washers. The kit includes ten (10) copper washers of each thickness (0.040", 0.050" and 0.064"), which may be reused if not over tightened.

CARB Warning

For race/ off road use only

Emissions warning: this part only legal for sale or use in California for racing (competition) vehicles which may never be used, registered, or licensed for use upon a public highway. Any other use renders the vehicle tampered and not legal for use on California public highways (any public street or roadway, public dirt road, public park, or publicly maintained right of way open to the use of the public for vehicular travel). Violations subject to $37,500 penalty per violation per vehicle, revocation of registration, loss of use on California public right of ways, and proof of correction for tampering. There are similar restrictions and penalties under federal law and the laws of all other states with penalties under federal law of up to approximately $45,268 per tampered vehicle and/or engine.

Speedway Motors 54571910 Specifications

KEY SPECS
MFG. Part #54571910
BrandSpeedway Motors
Material TypeCopper
GENERAL
Spark Plug Seat StyleFlat (gasket)
Sold in QuantitySet
Notes.549 ID X .802 OD

Ratings & Reviews

5

9 Reviews

Overall Assessment

Customers appreciate the quality and practicality of our Index Washers for Spark Plugs. The product significantly aids in achieving exact spark plug specifications, providing excellent utility. Its ability to afford just the right amount of clearance needed between the plug and the head is commended. Additionally, its feature to simplify the indexing process stands out. Furthermore, the index washers effectively rectify longer reach plugs, underlining their functionality. Users frequently favor our product over others, and are likely to reorder, speaking to its superior quality and performance.

5

9 reviews

5

9

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I would buy again

5.0

7 months ago

Freddyfairlane

Winnipeg Canada

Verified

Works great for indexing your spark plugs

Would Recommend

I would buy again

5.0

a year ago

Pete

Tennessee

Verified

Worked fine

Would Recommend

If needed I would buy more.

5.0

a year ago

Tony G

KC area

Verified

With each thickness a different color it was easier to achieve the correct thickness to index the sarkplugs.

Would Recommend

Index washers for spark plugs

5.0

3 years ago

RH

Simi Valley Ca

Verified

They shipped super fast, great product and a real good price!

I always go to Speedway first.

5.0

5 years ago

Harper Danger

Christoval. Tx

Verified

Will order again soon!

Would Recommend

Indexing washers

5.0

5 years ago

Ancient karter

Columbus, Michigan

Verified

Worked great. I was able to index my spark plugs to exact spec..no problem.

Would Recommend

Plug spacer

5.0

5 years ago

Mikeinbikes

NY

Verified

Just needed that little bit of clearance from the plug and the head in my flathead build.

Would Recommend

Spark Plug indexing washers

5.0

6 years ago

Tony G

San Diego, CA

Verified

I bought some plugs that were a mm longer reach. I bought these index washers to set the plug back to where it needed to be.

Would Recommend

Perfect to index plugs

5.0

6 years ago

Bill

NJ

Verified

Makes indexing easy

Would Recommend

Showing 9 of 9 reviews

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