| Author | Message | ||
     Eugene Oleinik New User Username: eugenerus Post Number: 5 Registered: 8-2009 |
I looked at the cross-reference table in the technical section before asking this question. I am trying to figure out a more cost-effective local alternative for the spark plugs (Champion or Bosch is what I can get over here) The build history for my Spur II says the installed spark plugs were NGK BPR4EVX. I didn't find this particular number in the cross reference table. Would anyone know what this corresponds to in Bosch or Champion? By the way, sparkplugs.com gives a different part number for NGK: Stock no. Part No. OE Gap Autolite Traditional spark plug 65 65 .040" Bosch Bosch Super Plus Spark Plug 7913 WR9DCX+ .040" Champion Traditional spark plug 405 RN14YC .030" Denso Traditional spark plug 3031 W16EXR-U .035" NGK V-power spark plug 3459 ZFR5N .040" Splitfire Spark plug SF6E SF6E .040" | ||
| Paul Yorke Grand Master Username: paul_yorke Post Number: 400 Registered: 6-2006 |
Bosch WR9DPX+ = BPR4EVX FR8DPX+ same plug-ish with a smaller HEX. The NGK ZFR5N or BPR5EIX are the newer Iridium plugs (not available when the car was built.) To be honest though - Even the Basic NGK's BPR4E or BPR5E are far superior to any of the others. | ||
| Udo Hoffmüller Frequent User Username: udo Post Number: 53 Registered: 2-2008 |
Eugene, BPR4EVX corresponds to Bosch W8DP or W9DP, they are very similar. The letter "X" of the NGK code stands for a certain electrode distance. Here http://www.gs-classic.de/download/ZuendkerzenVergleich01.pdf you find a cross refence list of all (or a lot of) spark plugs. Hope this helps! Regards - Udo | ||
| Richard Treacy Grand Master Username: richard_treacy Post Number: 1936 Registered: 4-2003 |
Actually, the NGK Iridium BPR4EIX is by far the best for all SY and SZ cars. It is the upgrade of the BPR4ES (plain) and BPR4EVX (Platinum), although Platinum plugs are all but obsolete. It has been superseded by the GR4IX new generation Iridium plug. Whilst Bosch may cross-reference, Crewe recommends NGK exclusively. Personally, I can understand why too. I would never use anything but NGK on any make of car. The Japanese have been way ahead of the Europeans, and especially the Americans, in spark plug technology and quality since the 1960s. The GR4IX applies to all SY and SZ cars. See the Technical Library for details. http://rrtechnical.info/miscellaneous/ngksparkplugs.pdf It is also covered mant times on this Forum. RHT. | ||
| Richard Treacy Grand Master Username: richard_treacy Post Number: 1937 Registered: 4-2003 |
Also see the cross-reference table in the Tecnical Library: In HTML: http://rrtechnical.info/miscellaneous/sparkplugcr.htm Or download the PDF: http://rrtechnical.info/miscellaneous/sparkplugcr.pdf RHT. | ||
| Richard Treacy Grand Master Username: richard_treacy Post Number: 1938 Registered: 4-2003 |
Note that there is a 1992 Crewe Service Bulletin advising that all SY and SZ cars are best fitted with BPR4EVX Platinum. A later bulletin supersedes that with BPR4EIX Iridium, and finally its successor the GR4IX. As Paul notes, any NGK BPR4E** will do, but you can't beat the GR4IX. If you can't buy NGK locally, that in itself highly unlikely, simply mail order from abroad. It's worth the additional two day wait for delivery to go with NGK. For example, GR4IX is available for US$5 in the USA from many outlets by mail order. Just google it. RHT. | ||
| Eugene Oleinik New User Username: eugenerus Post Number: 6 Registered: 8-2009 |
Paul, Udo and Richard, many thanks for the clarification and advice! I was confused since the cross-reference didn't have the number that was stated in the Build Records. | ||
| Richard Treacy Grand Master Username: richard_treacy Post Number: 1948 Registered: 4-2003 |
By the way, even PriceGrabber.com and Amazon.com list the GR4IX at $7.21, and you can do better. http://autoparts.pricegrabber.com/engine-parts/NGK-7149-Spark-Plug-GR4IX/m61543536.html | ||
| Benoit Leus Prolific User Username: benoitleus Post Number: 130 Registered: 6-2009 |
Am I correct in assuming the gap for the NGK GR4IX spark plug on my 1979 Silver Shadow should be 0.040" (1.0mm) ? Regards, Benoit | ||
| Brian Vogel Grand Master Username: guyslp Post Number: 698 Registered: 6-2009 |
Benoit, If I recall correctly NGK recommended that these plugs not be re-gapped, but it appears that they're waffling on this. See this from NGK on gapping Denso still sticks to its recommendation not to adjust the gap on iridium plugs: Denso Iridium FAQ Brian | ||
| Benoit Leus Prolific User Username: benoitleus Post Number: 131 Registered: 6-2009 |
Hi Brian, I was asking this question because there seems to be some confusion. In this document the recommended gap is 1mm (0,040") http://rrtechnical.info/miscellaneous/ngksparkplugs.pdf but when I emailed the technical departement from NGK they told me it had to be 0,8mm (0.031"). So I'm not sure what to do. Benoit | ||
| Paul Yorke Grand Master Username: paul_yorke Post Number: 1151 Registered: 6-2006 |
31 thou is correct Benoit. | ||
| Benoit Leus Prolific User Username: benoitleus Post Number: 132 Registered: 6-2009 |
Thank you, Paul. | ||
| Benoit Leus Prolific User Username: benoitleus Post Number: 181 Registered: 6-2009 |
I have been using NGK GR4IX iridium spark plugs on my '79 Shadow. However, when I recently checked the NGK Europe website they recommend the BPR5EIX for my car. For the GR4IX they don't even mention Rolls Royce anymore. Does anyone have any experience with the BPR5EIX and would it be better suited to the car ? http://www.ngk.de/nc/en/product-finder/produktfinder/PKW/ZK_BENZINER/ROLLS%20ROYCE/SILVER%2520SHADOW/BPR5ES/17600/ Regards, Benoit | ||
| Brian Vogel Grand Master Username: guyslp Post Number: 1116 Registered: 6-2009 |
Benoit, You've stepped into one of those territories where there are a multitude of opinions, including Crewe's own, that differ from what the actual spark plug manufacturers are saying. A lot of this territory was also covered in a thread I started last year entitled, Spark Plug Augury (and/or History Telling) Way back when these cars were originally made they used good old Champion RN14Y spark plugs. Much later, Crewe issued a service bulletin applicable to all SY & SZ cars (this predates the Seraph):  If you search the NGK spark plug parts finder page, this what turned up for me, from that page, mere moments ago:  which is clearly not the same thing that the European page you supplied the link to states. I have no idea why they'd go one temperature step cooler on that site than the one shown in the screen shot above. It seems that Crewe has been pretty consistent with a temperature rating of 4. I bought the BPR4EYs for my Silver Wraith II, but since the engine was running very rich, they fouled in short order. When the mechanic I had helping me with the car replaced them, he went back to Champion RN4C plugs. I could swear that at one time on one of "my" theads there was a long conversation where several people who work on these cars for a living stated that "good old copper plugs" are more than sufficient for these cars. That might have been on the US forums, though, but I know that it happened somewhere. I find it most peculiar that two different NGK sites are going for two spark plugs that have a different temperature rating. Brian | ||
| Mark Aldridge Prolific User Username: mark_aldridge Post Number: 179 Registered: 10-2008 |
Benoit, I have Iridium 5's in my Shadow 1 and Bentley S1 and Iridium 4's in my Wife's Bentley 8 (Fuel injected) and my 1983 Bentley Mulsanne (carb; non turbo). There does not seem to be a lot of difference and all cars are used for town and motorway driving. I purchased the plugs from Rockauto in the USA a lot cheaper than here in the UK including carriage.We purchase about 60 plugs and the cost worked out about £3 per plug a few years ago. Mark | ||
| Bob uk Unregistered guest Posted From: 94.197.122.87 |
The reason that there are so many different opinions on which plug to use is because engines are often not fussed about what plugs are fitted and on low tuned engines such as shadow 1 even odd plugs and different makes hardly effect the running. I have worked on cars with a champion N9Y and a NGK 4ES. Also short reach in long reach holes the combinations of odd plugs is endless. Plug gaps. Rule of thumb coil ignition with points 20 to 30 electronic 30 to 40 thou. Magneto 15 to 25. The spark plug attracts myths and garage inventors and many misconceptions. Over the years I have seen vee groove twin electrode surface discharge and so on. When these plugs are fitted often the only difference is because the plug isn't faulty like the one it replaced. Some engines are designed with a particular type such as platinum for Ford cars and will misfire if not so fitted. But where an engine runs on normal plugs from design super duper hot fire plugs mean zero advantage. My plugs are NGK as listed and work fine. The plugs on a shadow will go for at least 10,000 miles and maybe 20,000. To check a plug look at the electrodes when their square edges are gone replace. Plugs do not need removing and wire brushing. In fact it damages them. The heat of the combustion should make the plug reach self cleaning temperature. However if a plug is blacked up and sooty then heat up to burn the muck off. (Message approved by david_gore) | ||
| Paul Yorke Grand Master Username: paul_yorke Post Number: 1329 Registered: 6-2006 |
just found this . . Din't double click it . . . again :/ Hi, The 4 is slightly hotter running than the 5 so is less likely to foul. So BPR4EVX or IX or BKR4EVX or IX are good if you get fouled plugs or do lots of cold starts. One has a smaller Hex so slightly easier to get in to the trickier spots. BPR5E or BPR4E are fine if fouling isn't a problem. Quater the price and do the same job on a Shadow. | ||
| Benoit Leus Prolific User Username: benoitleus Post Number: 182 Registered: 6-2009 |
Ok, thanks everyone. I'll keep using the the GR4IX plugs then. |
