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TR2/3/3A Anyone running NGK spark plugs?

karls59tr

Obi Wan
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I installed a set of BPR6HS plugs (used to be BPR"5"HS that was recommended?) and now the car seems to idle and run a bit rougher than when I had the older BPR5HS plugs in. I had the old plugs gapped at .032 and it seemed to run smooth there. I'm going to put the older plugs back in to see if that makes a difference. If the gap is the issue the "6" NGK's have a recommended gap of .025.
What else should I check in regard to ignition? When I had the old plugs in they ran well with the newly installed points and condensor.
 
The 6 is a harder plug than the 5, that is it runs a bit colder and is marginally less tolerant of contamination, like oil.
Why did you change to 6?
 
I changed to 6 because that is what the NGK online site has listed. I wonder if the 6's are are the new uprated 5's??? I reinstalled the old (not really that old and a nice tan color) BPR5HS plugs and the motor ran smoother. Maybe i will try the 6's at .032 and see what happens?
 
No, the 6s are the 6s and the 5s are the 5s. They have slightly different specifications. All manufacturers have plugs with different heat ranges, you moved from one range to another.
If your engine runs rougher, it may be you have an occasional misfire. Might be plug gaps, you could try the 6s with a larger gap, but it might also be the heat range. How old is your engine, how many miles since a rebuild? Is it oily, blue smoke exhaust? Lots of questions, but if it were me I'd go back to the 5s.
 
The "5"s are hotter, which have a tendency to burn off deposits easier than colder plugs. If you are running rich, that may be why the engine is running smoother with the "5"s. I'd also put the gaps at 0.025", as that is the factory spec. It was initially 0.032", but it was changed early on due to mis-firing.
 
I went with the 6's because when because Jeff at Advance did my distributor I bought the Cap(side exit),wires,rotor ,points and plugs from him and Its what he recommended.
No problems .I change them every 5k or so and I usually keep the old ones for spares because the look like new.
Tom
 
I also have an Advance distributor and NGK have the "6"s listed as the plug to use for the TR3 on their website so I am wondering if the engine is running rich? Maybe I should lean out the carb mixture a bit?
 
I used the 6s in a 2ltr GT6 with no problems, don't know about the TR. The Jag shop I worked for used NGK for everything. My favorite is Champion, never had but one failure in 53 yrs. Had one separate the porclein from the metal on a V-12 Jag. Thought I dropped a valve, new plug andball was well.
 
I've been using Bosch Platinum plugs in the TR6 with no problems and burning the right color showing a correct mixture.
 
I did the same with my Spits and GT6. You will find that NGK plug cleanable after fouling and running bad fuel. Just about the only plug that is cleanable. I run Champion in everything else. Been with Champion since 1964 and ran NGKs for some 20 yrs in the Spits and GT6.
 
Oddly enough, the Porsche 912 takes the same size plug as the TR4. There is something of a consensus on Porsche boards that the NGKs are among the best plugs, but not agreement as to whether the 6s or 5s are better, if that makes you feel better about it. I think you just have to go with what works for you.
 
I ran BP6HS for years, always with carbon buildup and shifted to 5’s, which seemed to have worked. My plugs are a nice brown/tan color.
 
Karl What make & year is your car? NGK is the best plug and the iridium is the BEST of the best!
Len Fanelli
Abingdon Performance Ltd.
 
First have you double checked the float level &/16". What needles are in the carbs & what is your altitude above sea level?
The jets should be set .040" below the bridge, making sure that the choke returns to OFF with the jets firmly up to the adjusting nut. (Rock Auto ( Chicago) has the best NGK prices.
 
Remove the dashpots & piston ( chamber assembly) and with a dial vernier caliper measure the distance from the "Bridge" or venturi to the top of the jet, making sure that every time you release the choke that the jets return 100% off , jet firmly up against the adjusting nut EVERY time! With not even a .002" feeler gauge between the jet & nut.
 
Remove the dashpots & piston ( chamber assembly) and with a dial vernier caliper measure the distance from the "Bridge" or venturi to the top of the jet, making sure that every time you release the choke that the jets return 100% off , jet firmly up against the adjusting nut EVERY time! With not even a .002" feeler gauge between the jet & nut.
Thanks for the info.(y)(y)
 

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