SPARK PLUGS

[SIMPLEXUSA]

Anyone know a spark plug number for a 1948?  I think its an H motor. I tried to find a B4H. (NGK) no part stores had them. will any other plugs work? thanks.

[pd]

BP4HS should run nicely in these motors . The protruded tip should be advantageous to a better burn .
Being such a low compression motor , I can't imagine the tip would be a problem .

You can see how they compare :

[SIMPLEXUSA]

Thank, but it did not work. electrode too long.  it hits the piston.  available room is 17mm before it hits the piston.  in need a 16mm or so. the plug you recommended was 17.5mm.

[Ricks]

Champion J8C available at Walmart.

[SIMPLEXUSA]

Thanks,  just picked up the AC DELCO version .  Part # R45 thanks for all the help

[pd]

Thank, but it did not work. electrode too long.  it hits the piston.  available room is 17mm before it hits the piston.  in need a 16mm or so. the plug you recommended was 17.5mm.

Well , learn something new every day . I really did not know . Sorry to have sent you on a goose chase , but now we all know . Thanks for the information .
I've never had a protruded tip interfere . But , I never tried one in an older designed chamber either .

Pete .

[Shifter]

Will the champion J8C work for all motors? I have an M motor 55' I think.

[Ricks]

Will the champion J8C work for all motors? I have an M motor 55' I think.

That's what I have.  I think they all use the same plug.

[pd]

So , I'm just guessing that Champion plugs work OK in our motors , performance wise .

Normally , Champion plugs would not be my first choice , but ...

Pete .

[Ricks]

So , I'm just guessing that Champion plugs work OK in our motors , performance wise .

Normally , Champion plugs would not be my first choice , but ...

Pete .

I have run NGK, champion and a motorcraft and I could not see a difference.

[pd]

Good to know that we shouldn't have to shy of using one plug or another .

Pete .

[rldebuse]

Simplex OEM plugs were Autolite.  2HP engines (Pre-war) used a B-5 (now 386), 3 HP engines (iron cylinder with zinc crankcase) used an A-5 (now 303), and later aluminum engines used an A-7 (now 295).  I prefer the Autolite over Champion because Champion has a higher resistance than other brands.  It makes any weakness in your ignition worse.  I have had  ignition problems with several engines that I finally traced to defective Champion plugs.  I have had fewer problems since I stopped using Champion plugs.  Many professional mechanics also will not use Champion plugs for the same reasons.  Also do not use resistor type plugs in any vintage engine.  The resistor shortens the spark duration to reduce potential interference with aircraft communications, as mandated by the federal government.  It takes away some of the spark from both ends of the fire.   

[pd]

I will not use Champion plugs , unless nothing else is available , which isn't very often these days .

[Mike Sal]

Hmmm....that's interesting.  I've used Champions for years without issue. I bought the entire parts department from an AMC dealership a few years ago & have enough Champion plugs to last my lifetime (plus a few autolites too).  I have Champs in the simplex now, but I guess it would be cool to have original brands that were used in it.

I'll have to finish my plug wrench I stared last week (I took one of those sheet metal tube type plug wrenches that come in a jap motorcycle tool bag & bandsawed down the length of most of it to create a handle to bend over...I just have to put a little weld on the bend to make it strong enough).

BTW, those one piece autolite plugs made for Model T's (and IHC farm tractors) sure don't hold up in a Model T like the 2 piece Champion X plugs.
Mike Sal

[Ricks]

My grandfather owned a service station for years and always swore by champion plugs.  To each his own.  Like I said, I have tried 3 different brands and could not tell a difference.