ok, so to make a long story short i rebuilt my first motor a few months back. motor has about 1,000 miles on it. i kinda goofed up on one ring and it was tight in the piston. well that cylinder was burning oil and had low compression. 240,240,190,240. i decided to throw some nitrous on it anyways, if it goes it goes. well it went. but i expected a different outcome. heres pictures. this is a ls crank, ls rods, usdm type r pistons and a gsr head. n/a i have been running the car to 9000-9500 rpm's it's never given me a issue. i've dogged the **** out of it for 800 miles. i put nitrous on it 3 days ago and bumped it on the street a few times. never really got on it hard. just bumped it to fill the spray for a couple thousand rpm's well tonight at the track first pass it started missing. here is the outcome. do you guys think this is from detonation, the motor making too much power with the ls rods/crank and pushing the valves into the piston or what? the plug for that cylinder looked like ****. i'd have to take a picture of it. almost looked like all the valve metal was melted on the plug. enough of the rant. and sorry for putting this topic here. i didn't see a nitrous section

 

Do you have a tune? This is a combination of too much rpm's and detonation from a shitty or non existent tune. You cant just throw an ls vtec together, spray the **** out of it, rev it to the moon and back, and not have problems

 

http://s232.photobucket.com/albums/e...ion=postupload


this is the plug that came out of that cylinder.

 

was a small shot of nitrous.

and why do you say too many rpms?

 

Is the nitrous shot at WOT?

What brand of nitrous "kit"?

What kind of spark plugs, [make and model]?

The side electrode of plug looks like it melted away indicating a lean burn when nitrous was sprayed, why just on one cylinder I am not sure, or do all plugs show damage? 94

 

what kinda plugs are those??

this a wet shot or a dry shot?

my guess is..... you were already running lean in that high of an rpm, then you hit it with a 75 dry shot on ngk iridiums, and your weakest link went.

its detonation.
deffinetly not a problem with motor making to much power to break components.
you could hit a stock b16 with a 250 shot and run atleast 15-20 passes before you broke anything.
thats if you pulled correct timing, correct plugs and a/f was in check.

 

Yep I believe a lean cyilinder caused ur problems. If ur running a wet kit u cant expect to have even distribution on ur dry manifold. Our manifolds are not meant to evenly distribute fuel although Iv never had a problem with mine. But like someone else said u could of already been on the lean side. U need colder plugs and u need to retard timing by a couple degress when ur spraying. Usually the valve is the first to go when a lean condition is encountered, ur electrode and valve debries beat into the piston a few times and looks like the tip of the piston (the sharpest parts always start to melt first) had started to melt also

 

9-95k is to many rpms with stock rod bolts, stock cams, retainers, springs, and without a tune. Ur block still might be ok though it doesnt look to bad to me. Iv burnt one valve in my life, took the head off, replaced the single valve, threw it back on, and sprayed some more

 

it was a wet shot that should have been a little fat. nitrous 37/ fuel 22
the plugs in the car were all ngk race plugs 2 steps colder than the factory plugs sept that cylinder. that cylinder had a autolite factory number 6 plug in it. however the "nos" website says that the 75 shot could be ran with factory plugs to 1 step colder. that cylinder was burning oil hence me putting the factory plug back in it. he car was missing about 4-5k and hesitating a little before it blew. i dunno if it was running lean or not. i'm not completely sure. the fuel line has a T going to the fuel rail and fuel selenoid and there is a walboro 255hp in tank fuel pump. i think i've answered all your questions. the nos kit is a nos brand nitrous kit with nozzle in the intake tube.



"edit" the motor has arp rod bolts and arp head studs. i was putting off a tune till i got cams and fixed the rings on number 3 cylinder.

the timing was at 15.5 degrees which was stock. i was told it didn't need retarded because i wasn't running advanced timing in the first place

the manifold is a skunk2 intake manifold not the stock gsr intake manifold and it's got cheap 2.5 inch headers.

"edit" again. yes the nitrous is a wot switch!

 

Yeah i think u should of had colder plugs and def retard timing 1-2 degress with that shot. factory recommendations for a 75 shot i believe is 36n/24f so ur shot wasnt that "fat" but granted I think its perfectly safe. Oil getting into that cylinder will degrade ur gas and can def lead to detonation. Im not sure what really went down but I say fix all the things we just named and ul b good to go. U do have a better fuel pump right?

 

I have been running a dry 75 shot in my 94 LS for 7 years, [autocross] without any problems.

I am beginning to think the bad oil ring was the problem here, probably contributing to a lean burn situation in the one cylinder, possible carbon build-up on the valve may have caused a "hot spot".

Valves can take a lot of "abuse" as long as it is uniform, a hot spot would blow chunks off a valve. 94

 

uv been adding extra fuel to supplement the nitrous through the injectors though right?

 

i've posted on the nitrous forums. i found out the hard way that oil will cause detonation. the plugs were all 2 steps colder, "nos only calls for one step colder" sept that cylinder. that cylinder i had the stock plug in. i think oily cylinder+stock plug+15.5 degree timing= detonation. i should have had the timing retarded a little more than it was.


"edit post" fuel pump is a walboro in tank 255hp fuel pump!


"edit again" second of all, the car is currently running a type r fuel map. the type r fuel map and the 255 fuel pump i do believe makes the car run rich n/a i've seen the plugs and felt the change and the way the car rides vs the standard gsr map. when i let off the gas a little bit it backfires= unburnt fuel. i'm pretty sure it's running pretty rich

 

I don't know about a lean condition, the pistons usually get damaged pretty badly and the porcelain in the plug is usually pretty white.

Your stuff looks like it just got REALLY hot and melted the ground strap. Probably from deposits accumulated from all the oil contamination. If your car would have been built and tuned properly, you may have been ok with that stock plug, but not with the temps that cylinder was seeing. When the air/fuel mix gets "dirty" like that, sometimes it doesn't burn, but basically smolders instead.

Same with the valve. If deposits got between the seat and the valve, that hot combustion gas leaks by and basically blow torches that area, melting away the valve. I have a valve at the shop which suffered that same event, and it looks a lot like yours.

 

this motor only had 1000 miles on it. i just screwed up installing one of the rings, it was the first motor i put together so i stuck it together anyways.

 

No, other then an adjustable FPR, [and air in/exhaust out] and a 190 LPH Holley fuel pump, the fuel system is stock the ECU and programing is stock, other then air in/exhaust out the engine is a stock B18B1, [well other then the 5 quart oil pan] and still running with NGK ZFR5F-11 plugs, [tried many others], timing is pretty much stock except when I am auto-crossing and that's a secret, [my "tuner"
said "don't tell the competition"].

Although driven hard, [7 years of 6lb-10lb of spraying per event] since I got it, [new] it has been well taken care of and at 227,000K it still runs like a dream, burns no oil, has no "engine" issues. 94

 

well either u car is runnin stupid pig rich off of nitrous or ur just full of **** cause a 75 shot without extra fuel will torch a valve in milliseconds.

 

i don't think he's full of ****. he has no reason to lie in this thread? just my opinion.

 

Well let me share some facts with you. If u run a 75 shot with no added fuel it will burn a valve within a second...period. If ur riding around with ur fuel pressure turned up (for when ur spraying nitrous), ul b running like *** super pig rich cause it takes quite a bit of fuel to supplement a 75 shot....period. These r facts no way around them.

 

i agree i had to get 310 injectors(75 shot) for my d17 motor to spray safely + i got a tune with hondata

 

LOL, did you learn a lesson?

 

Yes lol. i'll be more careful next time.

 

you trying to tell me you had to get 310cc injectors to spray a 75 "wet" shot safely?

 

well the s300 has awsome features like three nitrous aux input/outputs. So if he had a full throttle switch or he could just use the arming switch wired into these inputs (and the nitrous solenoid throught the output), the ecu will automatically switch maps once the nitrous is turned on. In other words he has two tuned maps, one for off of nitrous and one for one nitrous. I would assume he was using a dry kit but either way the hondata is beneficial cause it will automatically adjust the timing for him if he was using a wet kit (but yes, if he had it that way there would be no need for bigger injectors).

 

what does [air in/exhaust out] mean anyways? u sayin u had intake and exhaust?