wrong plugs used

grumpyvette

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Staff member
" GRUMPY?
I Have a 1970 chevy 350 with 333882 heads. Autolite 26 spark plugs were in it and engine ran good. Spark plugs were replaced with new set of Autolite 26. I do not believe that these are the correct plugs for this engine but here is what has got me stumped. After turning the engine over and the engine not starting number 1,3,5, and 7 spark plugs were checked and the ground/side electrodes were found to be bent in towards the tip/center electrodes while the number 2,4,6,and 8 plugs showed no sign of being deformed. What could cause this to happen on one side of the engine but not the other? Thanks "


I don,t know why you did not have issues previously, and use of the wrong spark plugs is most likely your problem, but I can tell you this, the proper spark plug for #882 cylinder heads is

Part Number: R45TS

Weight: 0.1 lbs
Hex Size: 5/8 in.
Thread Size: 14 mm.
Electrode Core: Copper
Resistor: 2-12 - 220
Heat Range: 4
Electrode Tip: Convert
Insulator Type: Ribbed
Seat Size: 14 mm.
Rib Configuration: 1 fat, 3 skinny
Thread Reach: 0.433 in. (11.00 mm.)
Terminal top fixed or threaded: Fixed
Seat Type: Tapered
Shell Type: Black oxide00



YOU USED

Autolite 26 spark plugs

Spark Plug, Copper Core, Tapered Seat, 14mm Thread, .460 in. Reach, Projected Tip, Resistor, Each

these extend a bit more than they should too far into the combustion chamber

heres a picture showing how plugs should extend into the combustion chamber

your totally correct, if you read this and think, he screwed up the math, I made a mistake ,I misplaced a decimal point, but its still true the plugs too long and the wrong plug being used
plugreachza.jpg

threadplug1.jpg
 
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