CAT3

iTrader: (9)

Ok, my friend upgraded his fuel pump to a Walbro 340m, and was upping the shot to a 150. He'd currently been limited to a 125. So, he makes a few runs on Friday night...and then Sat makes an NA run, and bangs out another 11.2x, but when he comes back, they stop me and tell e his car is f*ked. I listen to it, immediately notice the ting ting ting...in rythme with valves, and see the engine shaking. Shut it down, pull the Drivers side plugs, and all of them are missing the ground straps, burnt/blown off, and a couple of the center electrodes are extended and missing their ceramic jackets. The TR6's were about a month old, maybe 600miles, gapped at .035 (preset gap), same as the ones they replaced.
I had 3 of my old stock plugs, and ran home to get him one of my old TR6 plugs, enought to get him home. The Pass side, fine, maybe a little lean looking, but no signs of over heated flame travel, or detontation. Once the plugs were all in, yep the fears were realized...theres some valve damage. Either chipped, dented, or bent, but its there. Now, a very similar thing happened to another friend, when he sprayed a 150 shot, all bolt ons, but with a stock fuel pump...resulted in Drvrs side plugs going south as well as a valve or two with little dents in them, or a little bend.

My questions:

1) What else will cause this other than running lean? Maybe too much timing? Gapped too close, but I doubt it.

2) Why is it the Drvrs side in both these scenarios, isnt the drvrs side fed the fuel first, or am I looking in the wrong direction?

Anyway, Drew778 is either ordering the Patriot heads, and selling me his (#241), or we're just throwing in a set of valves, and have the seat redone if needed...Of course I am leanign towards the new heads since we gotta take it down that far but its his money.

TIA, Charlie.

Robert56

iTrader: (2)

What timing was he running stock, special tune? Also, was it wet or dry kit and brand? It could be a combination of a few problems.

CAT3

iTrader: (9)

Sorry for the details.

Predator tuned (just like mine...mine just hasnt broke....yet) and I believe they added timing to his top side, vs. the bottom to help with idle...cant recall the total, but i doubt it was more than 34*, which btw i had run in my car several bottles worth...but every car is different. NX Wet kit.
Weird cause we haev the same mods minus he has the SSRA and I have the FIPK, his 02 to my 2000, i ran more timing, same 92 octane, higher shift points, and old *** plugs (gapped at .038 though) and I never had this problem. Also, thought it odd as how the Left side blows plugs first.

Robert56

iTrader: (2)

Yea, I've heard that #7 runs lean. If I remember correctly you should not run the Predator unless you tell them it's for nitrous then they do a special tune, because I believe your running to much timming. Predator adds over and above stock. The experts say take 1-degree out for every 50hp added and that is from stock timing. Also, I agree with the 38 gap on the plugs and with 150 shot maybe go one step colder. I am no expert but have set-up a few nitrous kits, so I hope we hear from some others for additional opinions. One more thing you might check is to make sure you have the proper jet for your fuel as to small will be lean also. Hope this helps some.

P.S. Your right, some cars can get away with what another can't, that is why run a little rich and take out some timing until you get it dialed in.

CAT3

iTrader: (9)

Well, the Predator Nitrous tune does take out timing and adds fuel, all the same as we have been doing with james anyway. Talking to him now, he said he actually had timing added to the top and forgot to reduce it before the runs. Also, no race gas was used, which is against my recommendations. The gap, maybe, dohn know but it probably helped accelerate the problems. Tr6's should be good for 200shots, or so I have been told..although it is a step per 100hp, and minus the timing 2* per 100shot.

I run, about 26-27* timing, but have run 34* quite a few times---ooops.

383LQ4SS

iTrader: (33)

34* is Waaaaay too much timing. He was having detontion issues. He likely burnt an exhaust valve or two. Unless his fuel pump took a dump. But Id say 34* was the culprit.

Guys....DO NOT be stubborn about reducing timing when spraying. Also a splash of 100 octane in the tank will give you a huge margin for error in cases just like this.

A good local friend of mine that I helped to set up with a sweet dual stage is now running approx a 225 shot ontop of an already stout 417 rwhp heads and cam package.....on the STOCK BOTTOM END!. HE is ~ 600 rwhp and has run several bottles through it without incedent. He has the custom dry tuning to reduce timing on the first stage and always has atleast a partial tank of 100 octane. That stock shortblock would die with minumum detonation at that HP level.

CAT3

iTrader: (9)

Not to be confused, I was the one running 34+* of timing, and since have backed mine off, normally reduce timing to around 27 or so * when spraying. I am not sure of his timing, but no he didnt use high octane or any race gas.

Al, whats the reason for the drvrs side burning up first? Am i looking at the flow of fuel backwards?

CAT3

iTrader: (9)

Ok, fingered this one out i believe:

Those blowing the drivers side plugs n or having valves issues...the Wet kit is taking away too much fuel from the drivers side fuel rail. With stock rails that is. The fuel supplied for the wet kit comes from the Drvrs side and when the go go button is hit, the fuel pressure drops instantly as it feeds the solenoid which although isnt asking for "that much" is more than what the system should be dropping when spraying.

Does this sound right.

Drew778

iTrader: (2)

Hi, I'm the dumbazz.

I'm really hoping and praying just the valves were damaged.

DERTY

Man, if you dropped the center ceramic off your plugs, DON'T RUN THE CAR!!!! Pull the heads right away. That ceramic piece is now bouncing around in the cylinder visiting your piston and head continuously, more than likely crushed by now. It takes about a day to pull the heads and check for damage. I'd hate to see you take it to the track, run it again and chunk a rod through the pan. Just my $.02, but if the plugs were really trashed, don't expect that crap to blow out the exhaust valve.

CAT3

iTrader: (9)

I'd almost agree with you Derty, but after seeing and hearing a few cars go thru the same thing, and so far so good, they end up blowing the **** out the cyl, with little to no damage. But the head is coming off tonight. Damage will be updated.

Anyone with thought on fuel rail feeding nitrous line? Looked at Speeds Fuel Rails, but since I am going with the NXL is mute, but I know someone that might wanna look into them,...right Andrew?

B18B1LS1

iTrader: (12)

Does your friend drive a red SS M6?

Jeffrey

Robert56

iTrader: (2)

Cat3, I think you are on to something, pulling to much fuel from the drivers rail could be the problem, or at least a contributing problem to some of the issues allready noted. Maybe, each small problem by itself wouldn't harm the engine but together on "this engine" detonation, maybe? Any idea what the fuel pressure is normal and when engaging nitrous?

CAT3

iTrader: (9)

no, no gauge hooked up...but the pump being a new Walbro should be flowing the required 58-61psi (a little discrepancy since there seems to be so many different observations). I will check mine out this time next week. I have the same setup pretty much and havent had that problem...yet *knocking on some wood like a chuck!"
I remember reading posts on people spraying and saying their FP was lowering while jucied, but now it makes sense being fed off the rail on that side.

2001-WS6

CAT3 the bit about the Wet kit feeding off the driver side rail dropping preasure there sounds good conceptual, but I don't think that's what happened. The 340 pump tosses way too much fuel to loose preasure like that if it's a healthy pump. The fuel presure shutoff switch on the driver side fuel rail would close the NO2 and the fuel to the wet kit with that kind of drop in preasure.

To put it in perspective, I have the same 340 pump feeding my MTI 422 and dual Stage NX Wet Kit and the presure doesn't budge much at all when I hit the 150 shot.

So I'm guessing something else was causing the problem on the driver side. When you pull the heads, check for a blown gasket, look for signs of oil in there that could be dropping the average octane rating which raises the heat, which causes high speed glazing on the plugs which leave a conductive film on the insulators which spreads the hit and melts the insulator. Think of this scnerio as a self feeding mega detentonation time bomb if that happens while going down the track on NO2.

Rick

The Guy in MY 99TA

I am with Cat on the theory of the fuel rails. and I also understand that even with a Walbro 340 pump it SHOULD keep plenty of fuel there BUT you've got to remember you can only SO MUCH fuel through a line.

I think that is what the problem is b/c I have been hearing about supercharged engines killing the #7 cylinder alot here lately and I don't think this is just going to be a nitrous problem.

Josh S.

CAT3

iTrader: (9)

Rick, one question are you feeding your 422ci twin N2O from stock fuel rails? If so, you got bigger ***** than I do. Heres the idea, the stock fuel rails=1) small diameter, 2)has test port off one rail, 3)cross over mounted mid rail. And oh BTW Rick , no FPSS was used...doh! Maybe these things really do work huh?

Please people dont get me wrong, i am not saying that the fuel rail idea is THE reason his **** quit. He had too much timing, plus only 93octane, I know he has a fair amount of carbon buildup (leads to hot spots and det.), and looking at the high speed glazing a little oil control problem maybe (might be assoc, with the failure).

I am very seriously interested in the fuel rail and its ability to properly maintain balanced, and just pressure and flow at more than stock power levels and spraying bigger shots. If its not the damn rails, then someone answer my question WHY IS THE DRIVERS SIDE FIRST TO GO? It only makes logical sense that the design of the rail, its puny size, crossover location and test port is just not right.

Drew778

iTrader: (2)

No piston or cylinder damage!!!!!



I'm going to run 20* of timing for now on

CAT you going to post the pics?

CAT3

iTrader: (9)

Will have the pics on my link later tomorrow, to late to get them on now.

Basically you can run a pencil thru the #5 cyl's exh valve...when its closed!

1BDHWK

iTrader: (18)

Drew, It was good to here that it was just the valve. Let me know when you are putting the heads back on.