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agn178
United Kingdom
57 Posts |
 Posted - 21/04/2008 : 18:51:30
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Sorry if this topic has been flogged to death but can anyone let me know the best type (& codes) for a "normal" J2...
Can I use long reach (NGK B6es) or Short reach.
Will I damage the car by using long reach plugs?
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LewPalmer
USA
3244 Posts |
Posted - 22/04/2008 : 03:05:32
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I've been using Champion L86YC for years with no trouble (attributable to plugs). These are a short reach plug.
Lew Palmer
Registrar, NAMMMR |
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JMH
United Kingdom
911 Posts |
Posted - 22/04/2008 : 18:08:47
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B6ES - isn't that a "long thread" plug? You'll do the head no good at all with those. We have used NGKs in J2396 for years - NGK are supposed to have a wider heat range for each plug than Champion (if you believe the blurb) & they're generally cheaper too. We have BPR6HS fitted at present. The code decipherd is: B-18mm, P-Projected Insulator, R-Resistor, 6-Heat range, H-12.5mm thread reach, S-Std 2.6mm electrode.
The 6 heat range should be fine for a std J2, but you want an HS not an ES. Unless of course there's a batch of recently cast heads out there which take an 19mm reach threaded plug! - but I don't think there is. With our heads a BP or just a B prefix should not make that much difference.
Remember the heat range on NGK is opposite to Champion with the low numbers being "hot" & the high numbers being "cold".
JMH
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tholden
United Kingdom
1638 Posts |
Posted - 22/04/2008 : 19:11:35
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I agree with Jeremys advice except that for a reason I cannot recall NGK recomended against the use of a resistor plug in our type of engine. I therefore use the BP6 HS plug which works brilliantly but you can also use the the B6 HS - the non projected nose version and this will also perform well.
As a matter of interest those nice guys at NGK technical recently sent me a set of their top of the range Iridium IX plugs to test and I have had them in the car for about 1000 m. They are in the same heat range and have a precious metal tip. I believe they are also expensive.
They have been performing extremely well but I cannot say they give any better performance than the standard plug. They are also a resistor type plug against the NGK recomendation. I think they are probably more suited to high performance engines so are probably not worth the extra expense for our engines.
Terry Holden |
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JMH
United Kingdom
911 Posts |
Posted - 22/04/2008 : 20:30:23
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Terry,
I must confess; I havn't a clue why we are currently running the resistor plug! But, they've been in there several years now & don't seem any different to the non-R item. Maybe it was just the result of an ad which claimed extra bhp, fuel consumption, plug life, or increased attractiveness to women etc etc?
Regards
Jeremy |
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Mike Allison
United Kingdom
196 Posts |
Posted - 23/04/2008 : 16:38:19
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Hi all J2 owners.
B6HS or BP6HS is what I would use, the P is for Projected nose, and I find these have a better resistance to oiling that the conventional recessed head. You can use the longer reach plugs, but need a spacer to pull the plug back to where the points should be (0.25" thick) and I have made some of these from copper bar for use with racing plugs: the spacer should be threaded so that it is a screw fit onto the plug threads, but NGK plugs are so easy to buy that this should not be necessary as a rule.
If you are going to use prolonged open throttle, then you may find the engine spits back through the carburetters, and this is a sign the plugs are too soft, in which case go up to B7HS.
For all (NGK) plugs, you can buy some with "HV" suffix. These have a very fine centre electrode of semi-precious metal (It used to be platinum, but I don't think it is now) and B6HV would work well on J2's.
Thats all for now.
Mike |
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tholden
United Kingdom
1638 Posts |
Posted - 23/04/2008 : 16:58:32
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Hi Mike
You are right the HV plugs were the best I have ever used and were particularly good in a blown engine. The J3 is still running on my last set of 7HV's but when I last tried to get some more from NGK they had stopped making that range. The Iridium ones I mentioned are the replacement range but I have not yet tried them in a supercharged engine.
Terry Holden |
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Colin McLachlan
United Kingdom
991 Posts |
Posted - 01/05/2008 : 16:24:35
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quote:
Originally posted by Mike Allison
Hi all J2 owners.
If you are going to use prolonged open throttle, then you may find the engine spits back through the carburetters, and this is a sign the plugs are too soft, in which case go up to B7HS.
Mike
I recently fitted 8.5:1 compression pistons to my PA/B, and found exactly this problem using BP6HS plugs. The switch to BP7HS has cured the spitting, but now I have to play boy racer at the traffic lights to prevent oiling & misfiring. Ah well, it's all part of the fun!
Colin. |
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