Pagoda SL Group
W113 Pagoda SL Group => General Discussion => Topic started by: n/a on April 08, 2004, 07:15:09
-
What kind of plugs are you using in your 280SL? Are they commonly available or do you have a source?
Shawn Rock
Philly, PA USA
1968 280 SL 4 speed
-
The Bosch W7DC gapped at .28 is the only way to go. No substitutes. Available anywhere they sell Bosch. Be careful at autozone, however. They tried to sell me resistor plugs. These should not be used.
Best regards,
Don
280sl
quote:
Originally posted by srock
What kind of plugs are you using in your 280SL? Are they commonly available or do you have a source?
Shawn Rock
Philly, PA USA
1968 280 SL 4 speed
-
I use NGK BP6ES plugs, which cross-reference to the Bosch W7DC. Agree that resistor plugs should not be used.
George Davis
'69 280 SL Euro manual
-
I use the previously mentioned Bosch plugs in my 230SL.
Rodd
Powell, Ohio, USA
1966 230SL, Euro, Auto, Leather, both tops
1994 E420
-
What is the correct gap for these plugs; .28, .35? Someone told me they get better performance with a wider gap.
Bruce; Blaugrun(green) 1970 280SL; IL
-
I use Bosch W8DP platinum electrode.
Have used NGK BP7EVX platinum before but recently one failed on me. The first ever plug failure in my short (40+ year) auto experience :evil:
I believe the good Dr. recommended 0.035" for the red coil.
naj
65 230SL
68 280SL
-
I'll second the vote for Bosch W7Dc. NGK would be good too, but second choice. I've much negative feedback on Platinum plugs in any MB.
tom in CA
-
This is something I've done a lot study on.
I use only Bosch plugs because they're nickle plated and won't gall coming out or remove threads. Avoid zinc plated or black oxide
(Champion or AC)
Bosch plugs come pre gapped at about .035'' which you should leave at that setting. Some books I've seen say .014, .024 and .028 all of which are far too close. I use W9DC mostly and only use W7DC on cars with perfect compression. Older engines that run rich or use oil benifit from a slighly hotter plug. I've had no problems with platinum even if MB doesn't recomend them. Actually the whole thing is very suspect and qustionalble because when I talked to Bosch directly ( I do that fairly often ) they were surprized to hear this.
The black coil really won't put out enough voltage with these resistor plugs. The wire sets often have resistors on the cap and plug ends along with the coil wire - all of which shouldn't be there. Minimal resistance is the key to smoth idle and quick starting.
So to recap:
Bosch W9DC or W7DC
set at .035''
low impedance ignition wires ( no carbon core )
26,000 volt coil ( red )
properly adjusted distributor set at 38 degreees dwell or 30 degrees for aluminum type
no more than 3 degrees dwell loss over the whole range and timing set where the engine runs best
(not always factory setting)
Stand back and look out!
Dan c
Daniel G Caron
-
Hi guys,
There was a discussion in the Yahoo site ages ago on this topic.
One poster said that Bosch plugs had the correct metric thread for the plug holes because they were both made in Germany.
He made the point that there is a difference between German metric and USA metric threads.
The difference has something to do with the machined angles of the thread on the plug and on the engine block plug-hole.
I do not know if there was any strength to the argument but I only use Bosch W7DC plugs (straight out of the manufacturers package) in my 250SL.
Bob (Brisbane,Australia)
early 250 SL, RHD
-
Just for fun, here's the compilation I did from the Yahoo! posts 1 thru 3,500 and 7,000 thru 11,500 (that's right, I waded through 8,000 posts so far and pulled out the gems, copying and pasting, formatting, and sorting into 22 different chapters - some of this is already in our technical articles section):
Stock ignition:
Download Attachment: (http://images/icon_paperclip.gif) Ignition system stock.doc (http://www.sl113.org/forums/uploaded/cees%20klumper/20044994837_Ignition%20system%20stock.doc)
69.64 KB
Electronic ignition:
Download Attachment: (http://images/icon_paperclip.gif) Ignition system electronic.doc (http://www.sl113.org/forums/uploaded/cees%20klumper/20044995039_Ignition%20system%20electronic.doc)
36.35 KB
Spark plug wires:
Download Attachment: (http://images/icon_paperclip.gif) Spark plug wires.doc (http://www.sl113.org/forums/uploaded/cees%20klumper/20044995148_Spark%20plug%20wires.doc)
40.45 KB
If there is interest, I can post all of these files in a post somewhere. It's a couple hundred pages. We will use this material, plus all of the posts on this site, to make a first draft of the W113 Pagoda SL Group's Ownership, Repairs and Maintenance Manual. Achim Ahlert is in charge of that (it's safe to say "massive") undertaking.
Cees Klumper in Amsterdam
'69 white 280 SL automatic
-
Metric is metric. It was the British that couldn't figure out how to run a lathe ~)
Dan c
Daniel G Caron
-
Actually, it was the British who first standardized fasteners back in the early 1800s. This standardization is known as "Whitworth," after its inventor. Prior to that every machine shop and manufacturer made its own fittings and nothing was interchangable. The threads and pitch on all Whitworth fittings are measured in milimeters, only the heads are sized in inches, as most of the world operated with inches and feet in those days. If the Union blockade had not been so effective the Confederacy would have been able to import many more of the much feared and highly accurate Whitworth cannons from England. Whitworth aventually migrated to being called "British Standard" after WWII and pretty much died out in common useage by the end of the 50's. The second standardization of fasteners is called "British Associated" or BA and is still in use today.
There were two metric systems, "French" metric and "German" Metric, mostly distinguished from each other by the degree of pitch of the threads. The French metric system of fasteners pretty much died out after WWI, except in a few applications in the UK between the wars due to a large transfer of French industrial assets to the UK in repayment of war debt. The German metric fasteners ultimately were more widely adopted simply because the German thread pitch made for a stronger fastener.
- Mike Hughes -ô¿ô-
-
Actually, I pretty much know all of that having been a machinist ( well , sort of ) back in the early 70's. The British made some very fine tools and instruments and were a very big player in the industrial revolution.
Not all that much demand for those sorts of skills today except on the ind of work you see on old cars.
It's here where hand skills become a real benifit.
Dan c
Daniel G Caron
-
At Dan recommendation I chose the W9DC and ran them until they were worn out (16,000). I went to get another set in a hurry but they had none so I now have the Beru equivalent. Car seems to start better recently but I'm sure its down to having new plugs rather than the diffferent manufacturer !
Regards,
Ben in Ireland.
'64 230SL 4sp.
'03 CLK Kompressor