spark plugs?

[WTPhantom309]

im gonna change the plugs in my 77 140hp its got theL77JC4 Champs in it are these correct and should I gap them at 40 or 32. thanks fellas


Derek

 

[OBJ]

Re: spark plugs?

What you need to be using are Champion UL77v's which are a surface gap. Alternate is a L16V, also a surface gap.

 

[WTPhantom309]

Re: spark plugs?

What you need to be using are Champion UL77v's which are a surface gap. Alternate is a L16V, also a surface gap.

hate to sound like a moron but what is surface gap

 

[OBJ]

Re: spark plugs?

It's cool Lineaman......take the partial addy below and past it to the address bar with a "www." in front of it. It'll take you to a page that explains the surface gap.

.edelbrock.com/automotive/sparkplugs.html


J/Rudes uses the surface gap in several models. Do remember to use the Champs in your enigne. No.....I don't have stock in Champion Spark Plugs but J/Rudes like them since they were designed around them.

If you have any other questions, don't hesitate to post them....and good luck!

 

[WTPhantom309]

Re: spark plugs?

Ok OBJ I read the edelbrock page and from the picture it appears the plug doesnt have a hook thingy so assuming im looking reading and to my understanding the "annular" gap doesnt need gapping. if so ive never seen anything like this, do they use this because of the high engine speed? are they reliable , Im lost man, I spent most of my life in big diesels . I hope i can find these plugs cause i kinda live on the corner of BFE and West Texas. thanks for your help


Derek

 

[Joe Reeves]

Re: spark plugs?

Personally I pefer the Champion QL77JC4 plugs gapped at .040 .

 

[Texasmark]

Re: spark plugs?

Thanks Joe. Not only did you save me from asking about surface gap performance, you enlightened me on some other things about plugs.

Mark

 

[F_R]

Re: spark plugs?

Just for the record, the factory parts book lists the correct plug as L77J4 (now called L77JC4) @ .040. They also list the UL77V plug as an "alternate for sustained full throttle operation" My personal experience is that the L77J4 is a much better all-use plug. Too much misfiring with the surface plugs at anything under sustained high speed. QL77JC4 plugs came out since the book was printed and are OK too. They have an inductive suppressor built in. Probably gap them a little closer, .030

AC M40FFX (equiv. to L77J4) is also listed in the factory parts book and both AC and Champion came factory installed in the motors when new.

 

[steelespike]

Re: spark plugs?

You can't go wrong with Joes advice on OMC systems and QL77JC4 plugs.
The surface gap plugs have been around for a long time.As a gimmick for cars way back and I think Merc started using them in the 60s.