Spark Plug Help

[Ron1200]

Went into Shucks and asked for NGK spark plugs fitting a 71-73 510 L16 (thats what I was told to ask for). I received the B6ES. When I pulled out the plugs, I found that they are BPR6EY.

Any suggestions on what plugs to run (or, conformation that the BPR6EY is the correct plug).

 

This is what I have:

L16

W58 closed chamber head

260 cam

SSS 38mm SU's

electronic ignition

header

 

I have a bit of dieseling going on. Thought not the only reason, the wrong plug could cause this.

 

Thanks

[Laecaon]

Im running the B6ES

[metalmonkey47]

BPR6EY is a hotter plug I believe. Also a copper plug if I'm correct.

I love my platinum plugs

Edited September 1, 2011 by metalmonkey47

[Laecaon]

BPR6EY is a hotter plug I believe.

 

Not hotter. The number is the rating for that. Since they both have 6 they have the same rating.

[Ron1200]

That's what I thought...

 

I think this is how the numbers work.

American plugs Colder 6, 7, 8, 9, etc .Hotter

Japan plugs Colder 9, 8, 7, 6, etc. Hotter

[Laecaon]

http://www.ngksparkplugs.com/docs/tech/partnumberkey.pdf

[datzenmike]

B.... 14mm

P.... Projected insulator type

R.... Resistor type

6..... Heat Range..... 2 is HOT, 11 is COLD

E..... Thread reach...19mm 3/4"

Y...... V groove center electrode.

 

 

(ah, you beat me)

[Ron1200]

Thanks for posting the NGK info... The two plugs appear to have the same dimensions and heat range...

B.... 14mm

6..... Heat Range.

E..... Thread reach...19mm 3/4"

 

So what are the practical advantages of the following features. I'm thinking more features on BPR6EY (vs. BP6ES) is bettter, right? :) I don't have a clue on the benefits of a projected tip.

P.... Projected insulator type

R.... Resistor type

Y...... V groove center electrode.

[racerx]

Runt them for awhile and read the plugs..

[racerx]

Okay just checked mine and its B6ES, NGKs.

[metalmonkey47]

Shit nope, you guys were correct, I didn't have my NGK book handy.

 

 

I R noob and I've been pwned

[bananahamuck]

http://www.strappe.com/plugs.html

[Ron1200]

I took the BP6ES back and exchanged them for the BPR6EY before reading your posted link bananahamuck (thx BTW). After reading the benefits of a projected tip plug, I'm glad I did. And Bonus... the V-Powers were half the price of the BP6ES. :) Now can someone provide a gap recommendation for an L16 with an electronic ignition and MSD coil? I think stock is .032.

 

Excerpt from How you can read spark plugs and select them - by Gordon Jennings (follow the above link to read the whole article)

 

One very useful variation of the standard spark plug has its insulator nose and electrodes extended from its metal shell. The projected-nose configuration moves the spark gap a bit farther into the combustion chamber, which tends to improve efficiency by shortening the distance traveled by the flame front and also making the combustion process more regular. But there is a more important benefit: the projected-nose plug provides, in many engines, what effectively is a broader heat range than you get with the conventional flush-nose type. The projected nose is more directly exposed to the fire in the combustion chamber, and quickly comes up to a temperature high enough to burn away fouling deposits after ignition occurs. Then during the subsequent intake phase this plug's exposed tip is cooled by the swirling air/fuel mixture. In this fashion the higher temperatures existing at full-throttle operating conditions are to some extent compensated by the greater volume of cooling air, and the net effect is to make the projected-nose plug better able to cope with the conflicting demands of traffic and highway travel. It should be evident that the projected-nose plug's effectiveness depends on the pattern of incoming mixture flow. Four-stroke engines often have intake ports angled to promote turbulence. If the plug is positioned directly in the path of the intake flow there will be a large amount of heat removed from the plug's tip by this direct air cooling, and that is just what you get in most four-cylinder motorcycle engines. Indeed, any hemi-head four-stroke engine gives its plugs' tips quite a useful blast of cold air during the intake stroke, and we think projected-nose plugs probably should be in wider use in bikes than is the case. Two-stroke engines can benefit from projected-nose plugs' fouling resistance which they get simply through the sheer length of their insulator (it's a long way from the center electrode's tip back up to the metal shell). However, the two-stroke's incoming charge doesn't always do a good job of cooling its plug, and you have to be very cautious in using projected-nose plugs in the valveless wonders.

 

Some four-stroke hemi-head engines' domed pistons extend up into the combustion chamber too far, at TDC, to leave room for plug tips that extend inward. This can prevent the use of projected-nose plugs; it's something you check by covering the plug nose with modeling clay, shaping it so you have a 360-degree electrode contour, and inspecting for signs of contact after you've installed your "clearance" plug and cranked the engine over a couple of turns.

[Laecaon]

.042

[Ron1200]

.042

 

Thanks

[ggzilla]

BP6ES and BPR6EY are both projection type (P)

 

BP6ES is factory spec for an L16. BPR6EY is not.

 

The V-groove is cheaper because they are trying to get rid of them. That fad has passed. They work just as good as the BP6ES.

[Ron1200]

BP6ES and BPR6EY are both projection type (P)

 

BP6ES is factory spec for an L16. BPR6EY is not.

 

The V-groove is cheaper because they are trying to get rid of them. That fad has passed. They work just as good as the BP6ES.

I typed the wrong plug number,,, sorry. I should have typed B6ES not BP6ES.

Thanks. Maybe I should buy an other set of the BPR6EYs. :)

[racerx]

I have an L18, not sure what year it came from, is B6ES okay or is BP6ES better.

[Burabuda]

funny BP6ES is used on mitsu's too

 

not sure why they're recommending large gap .44 when the service manual states .30

 

btw, rockauto has good prices on the higher end plugs

think i'll treat my baby to IRRIDIUM :cool:

[racerx]

yeh, not sure why the big gap..

[Laecaon]

Big gap is for the electronic ignition. It is recommended. Basically EI provides more energy, so it can provide the same hotness of spark, but at a larger gap thus providing a better combustion.

 

Here it is on old datsuns, look at the 79-80 L20b: http://www.davidcmurphy.com/olddat/html/tech/620L20.htm

[bananahamuck]

I would go with a smaller gap because if you are having problems with plugs fouling / loading up with gas, a larger gap will only exacerbate the problem.

.If you go and fix carbs and in 200 miles it starts missing and you pull plugs and they are fouled ....which caused it, carbs or plugs being gapped to the extreme.? You will find you will chase your tail on that one ,,kinda like the chicken and the egg idiom. Run .035 till you are certain that the carbs are working correctly ( at least few hundred miles ) then start gapping plugs wider then you will KNOW . and not be counting on something you read in a book or website.

[Burabuda]

^that's good advice

starquest (mitsu starion site) recommends smaller gap, and all those mitsu engines run efi

 

still don't know why ngk decided to override the manufacturer's specs for plug gaps tho :huh:

[ggzilla]

Who recommended 0.044 inch gap? L16 is .031 to .035. Gap narrow for performance or wider for economy/smoothness. If you gap .035 you will have to re-gap sooner.

 

Irridium doesn't make any more power, but they keep the gap a good long while (100,000 miles on EFI engines).

[racerx]

yeh you can go with a bigger gap if you have Elect. ignition like Petronix, but that's a lot of gapping. Pertronix said not more than .005 so that would be like .0325,I also checked one of my Datsun books and gap is .028 - .032., looks like the bigger the gap the later the years..