Which Spark Plugs?

[VaCat33]

Hi All

Getting ready to tune up the Tiger and I was wondering about which spark plugs are correct. I see the Workshop Manual says Autolite BF-42.

In the notes I received from the PO, he says BF-32.

I have a Mk1 with a 260. A few performance options added to include a 465cfm Holley 4bbl, F4b intake manifold, a hi-performance Cam and Pertronix ignition.

Any recommendations on which plug I should use? Also what type tip?

I have noted that the BF-32s are a bit more difficult to find.

Thanks as always.

Jim

 

[TigerBlue]

How do the old plugs look?

I would pull a couple of the easier ones and if see if they are what you like to see. Not a lot of black soot (too cold) and the electrodes are not burnt/eroded alot (too hot) then the plug installed might please Goldilocks. (Just right replace with the same.)

 

[Pooloo]

Hello

Just my little contribution;i just changed the sparks of my 260(4bbl too,f4b)and brian from sunbeam spares co in uk send me dr7bc from bosch,they fit perfectly and,until now,any problem !
The old sparks were autolite bf 45,normally they should be bf 42,it s just another heat,i believe.
Cheers

Paul

 

[VaCat33]

Thanks for the replies. The BF32 and BF 42 have been superceded long ago by the Autolite 45, which they claim is the replacement for the BF 32 & 42. That of course is crazy since one plug can not match the heat range of two different plugs. I did a bit more research and found that the Autolite 124 is a a bit cooler than the 45 and a closer match to the BF 32.

I am leaning toward the 124, although TigerBlue is correct...the final determination will be based on the read gotten from the old plugs once they are pulled.

Thanks again for the input.

Jim

 

[0neoffive]

Another opinion

There can't be more than umpteen factors involved in picking out the correct fuel ticklers, but T. Blue has the best overall method: read the darned plug and move up or down the scale as needed. Fuel mix ratios, cam duration, compression, etc.etc. and then there's your basic habitual habits just to layer a few more factors on the table. It is also very common to find a few cylinders behaving differently, so you could easily end up with a variety of plugs per hole. amen