Alfa Romeo Forums banner

1 - 9 of 9 Posts

·
Registered
Joined
·
204 Posts
Discussion Starter #1
Does anyone know the correct gap for Bosch WR70P plugs for a "93 164L? The counter man at Advance said 2.5mm but that seems a bit much. Out of the box they are about 0.675mm. Someone put in a set of NKG plugs and when a miss developed, I tries to pull them for inspection and found that the factory plug wrench wouldn't work because they are 5/8 hex. When I tried to put them back in with my 5/8 spark plug socket they would not release from the socket and the extension would come off the socket leaving it too far down to reach with anything I had..Plugs are still good but am replacing with normal stock plugs.
 

·
Premium Member
Joined
·
27,373 Posts
does anyone know the correct gap for bosch wr70p plugs for a "93 164l? The counter man at advance said 2.5mm but that seems a bit much. Out of the box they are about 0.675mm. Someone put in a set of nkg plugs and when a miss developed, i tries to pull them for inspection and found that the factory plug wrench wouldn't work because they are 5/8 hex. When i tried to put them back in with my 5/8 spark plug socket they would not release from the socket and the extension would come off the socket leaving it too far down to reach with anything i had..plugs are still good but am replacing with normal stock plugs.
0.025" or 0.028" max.
 

·
Premium Member
Joined
·
16,227 Posts
Modern big name plugs always come properly gapped at the industry standard of 0.025 inch. I've checked them for years and have had none out of spec. You don't have to worry about that. Use NGK plugs that are for that car and you will not go wrong.

The sparkplug access passages in Alfa V-6's always seem to be slightly smaller in dia. I use Sears sparkplug sockets, which are slightly smaller in diameter/wall thickness than the other brands I've gotten through the years. I have had no clearance problems. Measure to be sure.
 

·
Registered
Joined
·
3,120 Posts
That would be 0.6 to 0.7 mm so those factory gapped pugs are right on the money.

Some brands of engine (not Alfa but say a SAAB turbo) go as high as 1.0 mm which is 0.039 in (though I get better running if I gap my SAAB's plugs at 0.89 mm) . I have never heard of a plug gap approaching 2.0 mm, much less the 2.5 mm you were told which would be close to 0.1 in !!!!.
 

·
Trained (ex)Professional, , 1953-2018 RIP
Joined
·
16,232 Posts
Some 70s/80s GM products used 2.0mm gap plugs.
 

·
Premium Member
Joined
·
16,227 Posts
Maybe, but we are not talking about those weird cars, lol. I go by the sparkplug manufacturer book. If it calls for .025 inch gap, it always has been with their plugs.
 

·
Premium Member
Joined
·
4,762 Posts
curious. I've always stayed with the Lodge Plugs. Benefits all'ya'll find with other brands types? chris, ciao
 

·
Premium Member
Joined
·
27,373 Posts
Why I use copper plus Champion 415 plugs

PRICE! Champion 415 aka RN9YC set at 0.028"

I can usually buy them on ebay for about a buck a piece. I buy 12 at a time (3 boxes).

Champion RN7YC plugs came in a 91L engine in a salvage car I bought with 6096 miles on it and are listed as the plug of choice for 164 and 164L in USA shop manual on page 05-16. Manual calls for NGK PGR6A for 164S.

Page 00-32 same manual states golden Lodge 2HL were installed at the factory in 164-164L models.

I use THE one heat range hotter 415's and never had a problem even with my oil using 164B.
 

·
Registered
Joined
·
4,054 Posts
The inexpensive Champion 415s have worked as well for me as the expensive and now hard to get Golden Lodge 2HLs. Nice idle and smooth power under revs. The side benefit of the Champions, you can find them just about anywhere like a hardware store.
Charles
 
1 - 9 of 9 Posts
Top