Vtg Set of 6 Fire Injector Spark Plugs Hot Rod Auto Truck V6 inline 6 Surface Fire, couldnt find an application chart , any of you know?? number on plus is 18-5t number on box is 901757
full set of 6, unused and still wrapped in their wax paper. They were either sold or manufactured by International Automotive Sales Corp and made in the U.S.A., Connecticut
some info about them
Good review here from a 1968 Popular Mechanics article;
Base test (stock car): 10.755 mpg, acceleration 25-70 mph - 8.4 seconds
With "fire injectors": 10.6 mpg, acceleration 25-70 mph - 8.55 seconds
"Surface fire" plugs are in use today in super high performance applications. The absence of the ground strap allows for more squish without risk of the piston bumping the strap and also it eliminates one more sharp angled item in the combustion chamber to create a heat spot that would lead to detonation on some more extreme engine combos like massive amounts of nitrous (which in nitrous leads to a blow torch like situation that cuts the head clean off of your valves depending on where the ground strap is pointing). It is used pretty extensively on factory motorcycle road race teams and in 150+ hp shot drag and land speed racing bikes, including my own 150 wet shot lsr bike.
Downfalls to the plug, extremely expensive if you require a resistor plug, NGK resistor surface fire plugs retail for 80ish dollars each but can be found for 40 dollars or so each
selling as pictured.
more than welcome to pick up at shop in butler pa & save shipping.
022525 cg