RobH Posted August 30, 2022 Report Share Posted August 30, 2022 (edited) 20 minutes ago, BlueTR3A-5EKT said: ( not sure what the R bit means beyond I know it is classed as a resistor plug - what does that mean to us TR owners? ) As per my post a few above yours Pete. The resistors plugs are to suppress electrical noise by slowing down the spark rise-time. You only need a resistor plug if the HT leads are plain copper and the plug caps are not suppressed either. Even then you don't really 'need' them - it's just being kind to people with old fashioned analogue radios. Incidentally the BR5HS is not the same as a BP5HS - the tip is more recessed in the body. Edited August 30, 2022 by RobH Quote Link to post Share on other sites
BlueTR3A-5EKT Posted August 30, 2022 Report Share Posted August 30, 2022 14 minutes ago, RobH said: As per my post a few above yours Pete. The resistors plugs are to suppress electrical noise by slowing down the spark rise-time. You only need a resistor plug if the HT leads are plain copper and the plug caps are not suppressed either. Even then you don't really 'need' them - it's just being kind to people with old fashioned analogue radios. Incidentally the BR5HS is not the same as a BP5HS - the tip is more recessed in the body. Thank you for that Rob. I had not read through all the posts or would have not posted such a daft question. I now recall the NGK numbering system. The P is for projected nose. So BPR5 HS would be a BP5 HS with a resistor. Peter W Quote Link to post Share on other sites
BarrysTR Posted September 2, 2022 Report Share Posted September 2, 2022 Update on my previous post... In my case, (for road use with the modified engine and Weber's) the BP5 HS are definitely better than the BP6. (I guess it's possible the BP6 could be the plug to switch back to for racing use). Note that the webers are set up to give just a very slight richer setting - more on this below. So far, the BP5's are maintaining a consistant spark and none have yet died - but they do still get somewhat blackened on the short journeys - but obviously not quite enough (yet) to get contaminated and die. The improvement I'm seeing with the hotter plug has however triggered my interest. So, if the BP5's do eventually get fouled up and die, I might go even further and try a set of BP4's. Crazy I know, but with the change in fuel E5 - E10, there is a need to increase the amount of fuel in the mixture (i.e. richen) to maintain the same amount of power in naturally aspirated engines (due to the lower energy density of these fuels). This will be especially true with modified engines to work properly and deliver the goods. Barry Quote Link to post Share on other sites
Trumpy3 Posted September 2, 2022 Report Share Posted September 2, 2022 All very interesting. I have only experienced plug failure when I first fitted my EFI system and kept flooding the engine while trying to tune it. As indicated by Green Plug Co, I needed to fit a new set of plugs each time. Spent a few dollars on plugs during that period and spent a lot of time chasing misfires.Now I know why new plugs need changing after flooding. I run 4 x 45mm Throttle bodies and over the years have run both the NGK 5 and 6 plugs. also about 4 years running the equivalent Bosch. This running included all types of running from track work to the freeway car parks, no misfires. I am though running EFI coils. The R (resistance) plugs are used on EFI engines to reduce any chance of electrical interference to the EFI system. It works like the old black plastic gadget we fitted to the HT leads to prevent static on the radio. For the TR it makes no difference and they are interchangeable, This is probably why NGK has stopped making them...no need. Brian Quote Link to post Share on other sites
Hamish Posted September 2, 2022 Report Share Posted September 2, 2022 On 8/29/2022 at 8:18 PM, Hamish said: Agreed. local to me and has always tried to do the right thing for the old car fraternity they have expanded their range over the years too. I have just ordered the 5 and 6 versions as a result of this thread. Should have picked them up as not arrived yet ? Quote Link to post Share on other sites
Opie Posted September 12, 2022 Author Report Share Posted September 12, 2022 I ordered my BP5HS’s from Green Sparkplug, as their website had a USA portal link for a reasonable price including shipping. In the meantime, I have driven my TR3A for 8 days after increasing the plug gaps to 0.031”. Removal of the plugs today showed light tan color and very little carbon fouling. This is all part of the mystery to me of how our autos can be different from car to car and also from one time to another time. Also, different according to style of driving, mine now being little short jaunts around the neighborhood. I ran 0.025” gap for years on end with no fouling during my early years with the TR. So, I think it all goes to say that our older carburetted cars have distinct personalities and each may need slightly different care and adjustment. What one owner does may not exactly fit another situation. Quote Link to post Share on other sites
Opie Posted January 21, 2023 Author Report Share Posted January 21, 2023 (edited) It's been a few months of running NGK, BP5RHS plugs at "0.032 and they remain tan colored at the point. I could not be more pleased. No more soot. I ordered more on Ebay US, under "NGK set of 8 for Buick Skylark V8". They advertised BP5HS but they came with the resistor. Still, they work great. Very surprised that such a small change could make a difference. Edited January 21, 2023 by Opie Quote Link to post Share on other sites
monty Posted January 22, 2023 Report Share Posted January 22, 2023 On 8/26/2022 at 8:29 PM, AndyR100 said: I haven’t had an issue with running on - although I do normally use V-Power/Tesco-99 …… Andy +1 Quote Link to post Share on other sites
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