How do these plugs look
06-03-2016, 06:30 PM
#1
How do these plugs look I've used nitrous for a while, but never tried to dial it in until now. Ive always ran the jetting the manual said and it was what it was...
Until now, im actually trying to get the most out of this applicaiton.
I have a Jet boat with a 5.3 i've made a few posts on here about it. Specs are
Gen 3 5.3 SBE with ARP Rod bolts and new plasma moly rings
BTR Stage 4 NA Cam (235/242 .621/.595 111)
Victor Jr intake
Demon 850 (this has been changed)
NOS Cheater system jetted 72n/64f
Magnafuel fuel system
BR7EF
VP 110 for both motor and nitrous pure not mixed (when on the bottle)
I do have a wideband gauge
If you arent familiar with how a jet boat runs, it runs at a constant RPM. For example, 5000 rpm at WOT NA, and in my case about 6200 on the bottle. Kind of drives like a very loose convertor.
I know my 850 is to big for the 5.3 I have ordered a 750 and am waiting for it to get built/here.
Here are a couple of pictures of my plugs after a short nitrous run. I think im rich, the air/fuel gauge shows im in the high 11's on the bottle. The main thing im asking for, is your opinion on my timing mark. There are two of them, im assuming one from on motor (cruising on my way to the spot) and the other you can see where i backed the timing out.
My little bit of experience i think i am way under advanced... On Motor im at 30* of timing, on the bottle i was at 22* (backed 8 degrees out for the 200 shot)
Shouldnt the timing mark be closer to the bend of the ground strap? Thats what i think i've read.
FWIW i did have the boat on a 150 shot up until now, and i would spray the 150 shot at 30* with no sign of detonation on the plugs. I went with the 22* because i wanted to be safe when upping the nitrous.
Im guessing ill probably want to be somewhere around 26-28* based on my knowledge, but im asking you guys for your opinions too. This seems way high on timing compared to what im reading for what you guys are using. But maybe i can get away with more timing because im running the straight 110? Also, my water temp is barely 140* I dont know if that has anything to do with it
Until now, im actually trying to get the most out of this applicaiton.
I have a Jet boat with a 5.3 i've made a few posts on here about it. Specs are
Gen 3 5.3 SBE with ARP Rod bolts and new plasma moly rings
BTR Stage 4 NA Cam (235/242 .621/.595 111)
Victor Jr intake
Demon 850 (this has been changed)
NOS Cheater system jetted 72n/64f
Magnafuel fuel system
BR7EF
VP 110 for both motor and nitrous pure not mixed (when on the bottle)
I do have a wideband gauge
If you arent familiar with how a jet boat runs, it runs at a constant RPM. For example, 5000 rpm at WOT NA, and in my case about 6200 on the bottle. Kind of drives like a very loose convertor.
I know my 850 is to big for the 5.3 I have ordered a 750 and am waiting for it to get built/here.
Here are a couple of pictures of my plugs after a short nitrous run. I think im rich, the air/fuel gauge shows im in the high 11's on the bottle. The main thing im asking for, is your opinion on my timing mark. There are two of them, im assuming one from on motor (cruising on my way to the spot) and the other you can see where i backed the timing out.
My little bit of experience i think i am way under advanced... On Motor im at 30* of timing, on the bottle i was at 22* (backed 8 degrees out for the 200 shot)
Shouldnt the timing mark be closer to the bend of the ground strap? Thats what i think i've read.
FWIW i did have the boat on a 150 shot up until now, and i would spray the 150 shot at 30* with no sign of detonation on the plugs. I went with the 22* because i wanted to be safe when upping the nitrous.
Im guessing ill probably want to be somewhere around 26-28* based on my knowledge, but im asking you guys for your opinions too. This seems way high on timing compared to what im reading for what you guys are using. But maybe i can get away with more timing because im running the straight 110? Also, my water temp is barely 140* I dont know if that has anything to do with it
06-03-2016, 06:33 PM
#2
The other thing to this, and the reason i decided to get a smaller carb, is if i just cruise around i am very rich. So rich it'll foul the plugs in about an hour.
Itll end up fouling them and start to have a hesitation... then they end up looking like this.
Itll end up fouling them and start to have a hesitation... then they end up looking like this.
06-04-2016, 02:49 AM
#3
To get an accurate reading on the plugs you're gonna need to take a few sets with you next time. Cruise to the spot on an old set, swap in new plugs and make a nitrous hit shutting it down just after you let off. Make sure there is virtually no idle or cruise time on them and you'll be able to get a good look at the fuel ring and timing mark. There is too much cruise time on the plugs you posted to get an accurate reading.
06-05-2016, 07:43 PM
#4
To get an accurate reading on the plugs you're gonna need to take a few sets with you next time. Cruise to the spot on an old set, swap in new plugs and make a nitrous hit shutting it down just after you let off. Make sure there is virtually no idle or cruise time on them and you'll be able to get a good look at the fuel ring and timing mark. There is too much cruise time on the plugs you posted to get an accurate reading.
06-09-2016, 03:56 PM
#5
Ill try to do a new set of plugs this weekend
Let me ask, is there a cylinder thats usually "leaner" than the rest in these ls engines?
I'd like to put in a fresh set, then bring a few extras and just pull one and replace it if that makes sense?
I have a fresh set in now that havent been run and i have another set that are new. I could essentially do 8 runs and check on 8 new plugs if you follow what im trying to say
Let me ask, is there a cylinder thats usually "leaner" than the rest in these ls engines?
I'd like to put in a fresh set, then bring a few extras and just pull one and replace it if that makes sense?
I have a fresh set in now that havent been run and i have another set that are new. I could essentially do 8 runs and check on 8 new plugs if you follow what im trying to say
06-10-2016, 12:27 PM
#7
Ill try to do a new set of plugs this weekend
Let me ask, is there a cylinder thats usually "leaner" than the rest in these ls engines?
I'd like to put in a fresh set, then bring a few extras and just pull one and replace it if that makes sense?
I have a fresh set in now that havent been run and i have another set that are new. I could essentially do 8 runs and check on 8 new plugs if you follow what im trying to say
Let me ask, is there a cylinder thats usually "leaner" than the rest in these ls engines?
I'd like to put in a fresh set, then bring a few extras and just pull one and replace it if that makes sense?
I have a fresh set in now that havent been run and i have another set that are new. I could essentially do 8 runs and check on 8 new plugs if you follow what im trying to say
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06-13-2016, 06:44 PM
#8
Got the boat out with the new Carburetor sunday. It is hard to put into words the difference in drivability. I seem to have gained a bit up on the top end too.
I did not get a chance to spray it (water conditions were to rough) but, my plugs look much better for my NA tune. Maybe a tad bit lean, might need a little bit more fuel.
But my AFR is good. WOT AFR was about 12.8 cruise was mid 13's.
Heres a bad picture, but the only picture i have of the "leanest" plug.
I'll be spraying it this weekend if all goes well.
The picture, it looks a little lean to me, but the AFR doesnt say so. And i went a little fatter on the secondary side and lost some top end power (about 300rpm). Flash was on in the picture, ill get a better picture tonight
I did not get a chance to spray it (water conditions were to rough) but, my plugs look much better for my NA tune. Maybe a tad bit lean, might need a little bit more fuel.
But my AFR is good. WOT AFR was about 12.8 cruise was mid 13's.
Heres a bad picture, but the only picture i have of the "leanest" plug.
I'll be spraying it this weekend if all goes well.
The picture, it looks a little lean to me, but the AFR doesnt say so. And i went a little fatter on the secondary side and lost some top end power (about 300rpm). Flash was on in the picture, ill get a better picture tonight
06-13-2016, 09:00 PM
#9
Your going in the right direction for sure. That looks alot better than the previous plug pics. On boats I usually end up 12.5-12.8 depending on how the plugs looks and what the motor likes best. Your timing will also play a role in that. If you can get the cruise leaned out a little more I think it will like it. Once you get the fueling cleaned up (off to a great start) then you could start tinkering with the timing.
06-13-2016, 09:03 PM
#10
Your going in the right direction for sure. That looks alot better than the previous plug pics. On boats I usually end up 12.5-12.8 depending on how the plugs looks and what the motor likes best. Your timing will also play a role in that. If you can get the cruise leaned out a little more I think it will like it. Once you get the fueling cleaned up (off to a great start) then you could start tinkering with the timing.
Where I usually use the boat is about 350 ft elevation. This weekend I was at about 1400 ft. Thinking the drop in elevation might make it perfect.
I'll have some better pics soon
