CORRECT SPARK PLUG TORQUE - Chevy 3800

[wksracing]

What is the correct amount of torque for a spark plug on a GM (Chevy) 3800 engine. The shop 200 Impala/Monte Carlo shop manual contains a discrepancy.

On page # 6-408. under Exhaust Manifold Installation (left) the manual says to tighten the spark plugs to 27 N-m or 20 lb ft. The same can be said for the torque specification for the right side (page 6-412.)

On page #6-547-548, under Spark Plug Replacement, the manual indicates to tighten the spark plugs to 15 N-m or 11 lb ft (page 6-548.)

Am I missing something here?

What is the proper tightness or torque for a spark plug on a GM 3800 (Chevy) engine - 11 ft lbs or 20 ft lbs?

Thanks in advance for your reply(s),

Bill :-o

[Mars_302]

wrist tight works for me

[Tiffiny]

tighten it till it breaks then bac`k off half a turn jfwy tighten it by hand until it stops then like a quarter turn

[wksracing]

Hand tight/wrist tight would work except that I am indexing the plugs....I noticed about 2% HP gain...Bosch says 15 ft lbs. I guess we'll see.

Thanks for your replies.....

Bill

[Suicidal Racing]

there is 2 diff types of plugs..there is the ones with the lil crush washer on the end and then theres the ones with out..the crush washer ones are like a 1/4 of a turn after there hand tight and the others are an 1/8th of a turn.

you aint going to get 2% hp gain from just changing the plugs or turning one a 1/8th or 1/4 of an inche more.

hope this helps

[wksracing]

WOW...spark plug indexing doesn't affect horsepower....and here I've been wrong all these years....thanks for the heads up!

[Suicidal Racing]

indexing just changes the length of the gap between the strap in the fucking which a ma call it..putting more gap in means that it takes alittle longer for the spark to make a spark..its like playing with timing almost..

[Mars_302]

I think hes referring to having the straps all face the same direction not adjusting the gap. I dont see any benefit on this on a stock n/a 3.8 cept. I know you can buy indexed sets of plugs. And the old style trick was to buy a case of plugs and find the ones that were close and return the rest since every plus will almost the threads in a differnt way