Inliners International Forums General Discussion Engines Bosch Plugs? HELP NEEDED

Plugs are not available @FLAPS with a GOOD # provided by C-Dan-D-Luxe in an earlier post. What gives? They don't even list it, and you sure as hell can't tell them that it's a '56 235 engine (actually I did, and they couldn't cross reference from an AC plug). I'm needing a better part # for a WR 78 G BOSCH SUPER 4 PLUG.

Anybody been there, done that? Thanks, Cosmo.

Yes, I ran into the same problem, but I have a
nephew at Pep Boys who is trying when time permits to computer search a cross reference from Bosch. I think the problem might be that Frank is in Germany and the catalog #'s might be different there.If I get any info I'll post it.

Cosmo somehow the mail keeps bouncing back so I write it here:

The Super/Platinum Plugs sold in the US are different from the Super4 plugs with the 4 electrodes sold over here.

I can do 2 things.
First I check my cross reference tables on Monday and will come up with a key
for you.
I´m not sure if that helps.
RapRap from the Inliners forum already talked blood out of the ears of the NAPA
guys.
They ended up with the question "do you know someone in Germany?"

So I bought 2 sets and shipped them to him.

Maybe we should collect some more orders in the inliners and stovebolt forums.
I may get them cheaper if I buy - let`s say - 20 sets.

But one of you guys would have to handle the distribution over there.

Frank

Gentlemen;

It doesn't make ANY difference who makes the plugs. The important thing is: Is it the right heat range and set properly??

This is true for any engine, anywhere in the world, from sea level to 5,000', in the 'artic' or desert.

Now; To determin this, install & set what the factory had and operate your vehicle as you choose. After 2,000 miles 'or so' inspect them.

One of three things will appear. 1) to hot, 2) just right, 3)to cold. Then you make adjustment(s).

As a "general rule" AC works best in GM cars, Autolite in Ford, Chysler & American Motors and Champion for industrial engines.

If you have a Jap car, call Tokyo or Uncle Ben.

Good luck.

I didn't know champion worked good in any engine.jmo of course. Cheers!!

Dear JM;

Champion plugs were used exclusively by FMCO for many years and by the "racing crowd" too.

When Autolite won the contract in the 60s that all changed etc.

I use them in my APU (emergency generator) which has an air cooled engine. Perhaps because they came in it and you know the basic rule.

"If It's not broke, don't fix it".

John, Your point is well taken and is exactly why I want to try the new Bosch 4 plug. I've run AC, Champion, and NGK, always searching for the plug that burns the best.

Just My 2cents worth. I run AutoLites In My chevys always have For many yrs.(25plus yrs) I have also run champions. But The autolites Have always Been the Best for me. Esp. In my L6s. One Plug My Motor HATED the worest is the NGKs(race plug)so to me NGK=No good Krap LOL

One thing else Not many know about is there is a .010 variance in each plug that is made. I found this out from a autolite Rep. When I was trying to find my Old race Plug. which the numbers had changed This is why i could find it in the stores. But Long story short I was smashing Plug tips and couldn't figure out why Even thow the Numbers where all the same On the Champions I was running at the time. So for those that Run a Pop-up pistion this is something you need to watch out for. My piston to Plug clearance was .050-.055 So My Max. gap couldn't be More then .045 If I tried to gap them at .05 I'd just barely Tag the tips. And When I ask teh Autolite Rep. about this Problem That was his answer to me. So I done some Checking with different Plugs To see How true this may have been. Well It turned out He was right. But with Non Pop-up Pistons This never Be a issue,And most people would Never Know there is a .010 difference in plug lenght.(tips)

So just a little more food for thought when Looking for a Plug If running a Pop-up piston.

I first learned this lesson Back in 84 when I first Built my L6 when I tired to install The same Plugs I was Useing Before my Pop-up Build.

John, I have heard that "general rule" before and always thought it was true but when I worked as a parts manager in the late '70s and General Motors had a choice of 19 engines in their vehicles in 1979. So for some of the least common engne sizes that required a different type of plug, rather than go to the expense of making up the plugs and inventoring themselves, they bought them from Champion, packaged and numbered in a AC Delco box. These plugs did not have the three green stripes around the porcelain body. I got this info from one of my friends in purchasing when we were having backorder situations at the time. Even the box stated "Packaged for AC Delco". Some more trivia that you might already know is that "AC" stands for Albert Champion??
But like you said the best way is to run your plug for a couple thousand miles and pull them and read them. They will tell you if you have the correct range and setting.

Albert Champion; Well that's a new one for me. Maybe that's why there called "AC Delco".

We used to call AC= "always correct"....but that was just BS around the shop & strip.

Drew; Bosch parts cater to the Europian market. This might be a problem.

Good luck.

Yes, I agree that it it will probably be for naught buying those plugs in the US. I'm thinking of doing what RapRap did and take advantage of Frank's nice offer to shop and ship them here.Still searching though.

Larry, That's really interesting about the discrepencies in plug tip length.No wonder you racers have to check everything constantly. That would get real expensive poking holes in pistons.

O.K. I checkd my lists to decode the Numbers

German Part Number: W R 78 G

It goes like this:

W = Thread diameter 14 x 1,25 wrench size 21
R = Resistor
7-8 = Heat range
G Thread lenght 12,7 milimeters

Instead of WR78G you can also take a
FR78G. You only need a smaller socket.
Also you may skip the Resistor F75G

The important numbers are only Heat range and thread size.

An aditional X/W or Y marks the gap size 0,.9/1 and 1,1 millimeters.

Hope this helps.

Frank

I believe the only reason for the four grounds is for the plugs to last longer.
Airplanes have simular plugs, just so they last longer.
No performance gain, they will actually cover up the spark more.
Can't index those plugs.
2 cents
Like Larry said, Autolites are great plugs!
Hank

I second the vote on Autolite. I use Autolite in all my vehicles and over 60 pieces of rental machinery at work. Autolite is by far the best.NGK for Honda motors and Bosch for Stihl. You will not see a "C" plug in my inventory. JMO of course. Cheers!!!

John