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Hello Gents, I have a HT 308 with a WB Statesman electronic ignition system. I have NGK BPR5FS-15 plugs fitted, do these sound correct?
What gap do I want?
Thanks
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Spot on. BP5FS is the right plug.
The -15 is 1.5mm pre-gapped, which is correct. |
Cheers,
Mick
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I'm with Mick. I would use BP5FS instead of BPR5FS. The 'R' type (resistor) spark plugs are unnecessary for this application & more expensive.
Also on carby motors I've found that a gap of 1.3mm gives better results, than the factory setting of 1.5mm.
So I would use BP5FS-13, they are pre-gapped at 1.3mm.
Dr Terry
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Thanks Gents, I closed the gap up, and the engine does seem happier (I also found that the vacuum advance tube had come off, this was not helping much).
Regards
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There are benefits to playing with plugs & gaps. In my straight-LPG stroker I'm running a different heat range (BP6FS) and I have to run 1.0mm gaps to get it to run sweet. It doesn't like the larger gaps that petrol quite happily runs. |
Cheers,
Mick
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Now the full story.
I'm trying to get this thing running on NOS (silly bet between people old enough to know better). It just breaks down when I hit the go-go button. I'm thinking the higher compression with the extra fuel and NOS may be preventing the spark from jumping the 1.5mm.
There were no istructions with the kit I bought and I've struggled to find any info.
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Running NOS is like using a supercharger or turbocharger, you have to be careful of detonation.
Retarding ignition timing, especially at the top end, is paramount.
We ran NOS on a very stout SBC at the drags for several years in the early 80s & I can tell you from bitter experience how much damage to head gaskets etc., wrong ignition timing mixed with NOS can cause.
Dr Terry |
If at first you don't succeed, just call it Version 1.0 |
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