Gapping Bosch Platinum plugs

[Anonymous]

I was wondering.. I read an article on Bosch Platinum plugs that said "Not to Gap" these plugs as they are set at the factory for an optimum heat range.

Since I am running an MSD Duraspark ignition I gapped them to .50...

has anyone ever heard this before?
and should I use them gapped, or not, or try another brand?


Just curious?


Also, since I am running a higher compression engine, I would like to run a colder plug than stock, but the CD's at the local stores cannot find colder plugs or even extended tip plugs, which I have been looking for for some time... does anyone have a plug number that is one or two steps colder than a stock 200 plug, and maybe in an extended plug? I have read about this in the Falcon Handbook, but have not found any yet?
Maybe in a Champion, Autolite or other brand? I am not loyal to Bosch?

Jim

 

[Junk-Falcon]

i gap mine at

 

[Anonymous]

BSA6200

Me too on the indexing!

 

[BIGREDRASA]

Jimbo, you don't need a colder plug unless you see blistering. Considering the problems you're having with running rich, you shouold check out a hotter plug for now.

 

[Anonymous]

What would a hotter plug be?

 

[Anonymous]

Hi Jimbo,

Typically, extended tip and colder are mutually exclusive. An extended tip plug will reach deeper into the combustion chamber and run hotter. A hotter plug will run cleaner, but wear quicker. To hot and you'll get pre-ignition. I would go with the plug Ford recommended for the DII you're using.

Steve

 

[65coupei6]

Jim: Nice to see the car is just about done. I havn't been around lately and just got a chance to catch up on some posts.

Anyways, as Steve said running a hotter plug usually leads to pre-ignition. Normally when raiseing compression on an engine you would go with a colder plug. Also, copper conducts heat better than platinum this will also help with pre-ignition. I know NGK use's a higher number for a colder plug. I am not sure about Bosch, but the platinum plugs will not do much except last a little longer.

Lastly a note on extended tips. Depending how much you milled your head I would suggest against it. My head is basically at its limits. Since it now sits closer to the block I had to index my plugs so the tip would not hit the pistons. ( I was wondering why my gap was always closing ) I am not sure how much space you have to play with but a extended tip might cause a problem.

 

[Anonymous]

i,m running ngk with 60 gap !!!!!!!!!!!!!!! did replace them with bosh , car did run hotter . so i wil keep to the NGK ,s car is starting and running great , even with the 60 gap , got msd 6A ,mallory coil and dura 2 !

 

[Anonymous]

Yeah I started thinking about the extended tip plugs and thought against it... I am REALLY close on the clearance issue... I am at the minimum safe distance with the valves as is... the plugs may not be a smart idea.


I like the idea of the NGK plugs... does someone have a part number?

and are the plugs different for the 78 DSII ignition as opposed to a stock 68 200?
Nope! they are the same, only the gap is different... NGK 2438

Jim

 

[Anonymous]

Yo Jimbo I see things are going along nicely with Bronze Thunder still can't get over the sound way cool! Got the 2003 hip installed and am getting it dialed in still jerky in the morning but is smoothing out quite nicely after it warms up haven't been able to drop the hammer on it just yet but looking forward to it oh yeah the pain is gone and that is the coolest. hang in man when you get it all right you are gonna love it Joseph

 

[Anonymous]

Glad to hear you are doing well... I was thinking about you the other day!

Just take it one step at a time, and you will be racing around soon enough... better to break it in slowly!

I am getting things together, takes some time, but I will get there.


Jim

 

[Anonymous]

We have had marginal luck with the bosch platinums. they are very finicky plugs and tend to accumulate deposits. The best luck we have had is with the Autolite ap45 and ap44. With the MSD the platinum plugs are needed to have any type of life. I was going through regular 44's every 10k miles due to the extremely hot spark. So far I have 23k on the autolites with numerous runs at the strip and virtually no wear. Plug gaps over 50 thou put un needed wear on the coil and ignition box and are not advised by MSD. The higher the compression the more load is put on the ignition system therefore the smaller the gap is needed. On our 14 to 1 drag boat we use .35 as a baseline yet on most of the 9.0 to 10.0 200"s we build we run .45 to .50 with a MSD

Todd

 

[Anonymous]

I was at the parts store the other day asking about the same thing. Evidently the plugs from a 300 I6 are the same size, just one heat range cooler. You can also get truck plugs with bigger contacts for the 300 I6. They are made for heavy duty or racing applications and would probably work very well with an MSD system.
-Brian

 

[Anonymous]

Brian is right.

The 240/300, 170/200/250, and old 260-302 used the same plug designs, our motors just got a hotter heat range.

Actually, Bosch Platinums are colder than stock. Check the book if you like - same thing for the 289 as the 200. NGKs too.

If you want to try an extended tip design, check out the plug for '95/'96 EFI 300s. BSF44C is the Motorcraft #