Need a plug equivent for NGK BR6FS

[Suprathepeg]

My boat uses BR7FS plugs and I wanna try BR6FS which I believe is one level cooler. Is there an equivalent plug that is easier to find then the NGK?

 

[Bt Doctur]

AC Delco	10
AC Delco	MR43T
AC Delco	R42CT
AC Delco	R42T
AC Delco	R42TX
AC Delco	R43CT
AC Delco	R43T
AC Delco	R43TX
Accel	263
Autolite	136
Autolite	143
Autolite	144
Autolite	145
Autolite	3265
Autolite	3624
Autolite	3625
Autolite	683
Autolite	684
Autolite	685
Bosch	HR8AC
Champion	BL6
Champion	BL8
Champion	RBL8
Champion	RBL86
Champion	RV12C6
Champion	RV8C
Champion	RV8C6
Champion	RV91MC
Champion	RV9YC
Champion	V4C
Champion stk	35
Denso	5038
Denso	D144
Denso	T20R-U
Denso	T20R-U15
Denso	T20RU
Denso	T20RU15
Denso stk	5038
Denso stk	5039
Eyquem	500J
General Motors	25171349
General Motors	5613353
General Motors	5613354
General Motors	5613438
Mercruiser	33-400
Mercruiser	33-400S
Mercruiser	33-59571
Mercruiser	33-59571B
Mercury	59571B
Motorcraft	AF3
Motorcraft	ARF2
Motorcraft	ARF26
Motorcraft	ARF3
Motorcraft	ARF36
Motorcraft	ASF4C
Motorcraft stk	10
NGK stk	4323
Toyota	90098-20865
Yamaha	90793-20121
Yamaha	94701 00365
Yamaha	94701-00365

 

[Suprathepeg]

I saw that list too. I just couldn't believe there are that many. So is there a preferred brand?

 

[Fun Times]

AC-Delco or NGK is typically the most preferred by the people that work with these engines everyday.

What engine combo do you have that uses BR7FS ?

 

[Alumarine]

That's funny I always find it easier to source NGK over AC-Delco.
btw a NGK 7 is colder than a 6. The lower number with NGK's are actually hotter.

 

[Suprathepeg]

Fun Times it's a 3.0 merc and I made a mistake I need the br7fs not the br6. I found an AC Delco that is cooler than stock but it's not marine grade. I'll run them for a bit and see how it works.

 

[Bt Doctur]

why do you feel the need for a cooler plug? run-on?

 

[Suprathepeg]

why do you feel the need for a cooler plug? run-on?

The mechanic is worried about pinging at high RPM with the stock plugs and more advance.

For the record the only reason I'm messing with the timing is to gain some hole shot with a higher pitch. I know its a hard path but I'm like that I guess.

A 4.3 is more power and if I was going to go that route I'd probably just spring for a 5.7, the cost is the same, in fact V8 drive trains here are less than 4.3 ones. So far everything that I've done has cost me under $20 and some time. A swap properly done is about $5k and a lot of time.

 

[Bt Doctur]

unless your using a points system and hogging out the advance holes you cant just advance the base setting. almost all the electronic systems are 22-24 degrees total advance.
To advance the base timing you need race fuel or 110 LL to try to eliminate and pinging

 

[Suprathepeg]

It is points motor is new but its a 1988 setup. Why can't timing be advanced?

 

[Bt Doctur]

a motor will tolerate additional timing as motor rpm increases. simply increasing the base setting say from 8 to 12 wont work without detonating the pistons.
with a points system and mechanical advance, the total advance and when it happens is governed by the weights and springs.
more weight and less spring tension allow the timing to advance quicker.
more spring pressure and hogging out the holes allows more total advance at a higher rpm.
There are tons of articles written about hopping up a points system, google it.
And with electronic systems this is not possible to create your own ign advance curve

 

[Suprathepeg]

I see what you're saying but so long as we aren't getting pre-ignition, why can't base timing be advanced? We are looking for more performance at lower RPMs to help with hole shot. Wouldn't advancing timing at higher RPMs work counter to this?

 

[smokeonthewater]

Advancing the base timing WILL cause pre-ignition.... Just because you can't hear it doesn't mean it isn't there.

Want better holeshot... Consider smart tabs.

 

[Bondo]

Ayuh,..... Many times detonation isn't "Heard" til it's Waayyy past Too Late,.....

I run AC MR43T plugs,.....

 

[airshot]

Have to agree with "Bondo"....learned that the hard way many years back. I have run both the AC and the NGK and prefer the NGK. I have a 1983 engine, all original and the AC seems to foul easy where the NGK does not. Also find easier starting with the NGK.

 

[ibrw1]

I'm hesitant to put anything in my boat, on my boat, or near my boat that was not suggested by the guy who designed the thing. Wasted most of the summer trying to fix carburetor backfire issue that was ultimately caused by cross-referenced plugs. Good luck man!

 

[bigbob_FTW]

Ngks here. Never had an issue.

 

[Suprathepeg]

Wow the 3.0 really likes the cooler plugs. Ran really nice. Haven't messed with the timing again. I'll probably back it off a bit next time we go out testing.