Plug Readings on N20, Plug Heat Range, etc.

[marc1166]

Originally Posted by redcam622

3933 is colder not 3931..ngk10 crosses to 3933,,,i've used both..NGKs are easier to read,but perform the same.

You might want to recheck your facts there...

AR - NGK
3931 = 5671-11
3932 = 5671-10
3933 = 5671 -9
and so on...

[fofo]

Marc, you are right on the Heat Ranges. We are staying with the 3932 Autolites, 10 Heat Range, but will adjust our tune-up...i.e. taking some n20 Jet out of the #2 cylinder due to the BBC running a bit Lean in that cylinder.

Thx to SJ for the phone conversation today! Can't wait to be back running next weekend, with our new tune-up. The Lil Sumptin will FLY, and it should be a more reliable tune-up too.

[marc1166]

Originally Posted by fofo

Marc, you are right on the Heat Ranges. We are staying with the 3932 Autolites, 10 Heat Range, but will adjust our tune-up...i.e. taking some n20 Jet out of the #2 cylinder due to the BBC running a bit Lean in that cylinder.

Thx to SJ for the phone conversation today! Can't wait to be back running next weekend, with our new tune-up. The Lil Sumptin will FLY, and it should be a more reliable tune-up too.

No problem. SJ will steer you right! You'll find that 2 and 5 will run a bit leaner. 6 and 8 are timing sensative. Hell, the entire 'even' side of the motor is.

While it's apart, take a look at everything to help make tuning decisions next time out as well. Things like header coloration, exhaust valve coloration, how much carbon 'black stuff' is on top of each piston, top ring tension, and the list goes on. All this stuff will help tell the tale of what has been going on in the motor.

[BBF]

Are you cutting the threads off the plug to read how are you doing it? The wrong heat range in the plug can give incorrect reading of A/F (fool ya). You take nitrous out of that cylinder and leave the fuel I bet it happens again. Rich is just as bad with nitrous! Look to see if the rings are butting too. The C-16 and VP import is more for heat I would use Q-16 it might lean it out some for you.

[Mike Beck]

Originally Posted by fofo

This Rich condition was aggravated by the Bottle Pressure (verified via the Data Logger) dropping from Launch at 980# to crossing at 888#...richening the tune-up even more than 1/8 mile test hits (I use two 10# bottles!).

I have found that with a 100psi drop on my system (in the 1/4 mile) the A/F drops about .4 to .5 at most. I doubt your bottle pressure had much of an effect during the run.

If you are running below 11.5 A/F and trust your wideband I can see how you hurt it.

I run mine much leaner than you are running yours, but that really doesn't matter.

Plugs can lie to you too. They can look rich when it is simply a matter of too cold of a plug and/or not enough timing.

They can look lean to you when the plug is too hot and/or you have too much timing.

I like using a wideband to get the A/F ratio in the ballpark and then tune off the plugs and the time slips myself.

[bottlefed1]

FoFo,

I missed this thread somehow, if you had a nitrous solenoid that was sticking....well lesson learned never run a nitrous car with a suspect nitrous component. The solenoid could have only been opening partway due to a weak coil or bad plunger crap in the system etc. any of these would cause it to run rich and cause all sorts of problems.

As far as the passenger side getting beat up worse thats normal for most V engines.

After you get it back together work up slowly on your tune and do not be afraid to jet the cylinders differently if needed to even up the mixture.

NGK plugs while a lot weaker than autolites will often show errosion on the strap if you look closely and often if caught early this errosion will take place before the piston becomes plastic, the Autolites rarely deteriorate much before the pistons.

Lastly and most important, if you got Steves ear, as good as the some of the guys on the board are, Steve is the guy you should be listening to since while many may know their setups or a certain type of motor very well Steve has experience with a great number of motors and also has had the experience to ask the right questions and interperet the answers to the questions correctly

Richard G


Also set your base at 30 degrees so you are not pulling so much and your rotor phase will be better. And I also like to look at the color in the pipes to see the tuneup.

[kgiblin]

I agree with marc 2 and 8 will normally let you know if your tuneup is off first. Timing sensitive and a/f problems also. But there is ways around this Steve will fill you in on how to get around it I am sure. As far as the motor not being hurt I doubt it but you may get lucky depending on piston design. I have had guys nip just the tip on AR and be ok but any more than that and its normally to late. Good luck.

[fofo]

Thx for the time & comments, guys.

Pistons & Rings & Gaskets are ordered, and after conversation with SJ & my engine builder, we will make some changes, and start the 'tuning" process all over again...baby steps, starting with 330' hits. If all goes really well, I hope to back at the track next weekend testing.

Thx to SJ & Charlie for their help & patience, and thanks to YB members for the tips.

[KNOTHEAD MOTORSPORTS]

Fofo, sorry to hear about the troubles, but I have to say.... Way to give it hell, and I hope you can crack that seven second pass out of the ole Camaro soon buddy...

Seth

[fofo]

Hey Seth, all part of Racing, when trying to accomplish the goals I've set for the Lil Sumptin. Nobody said it was going to be a rose garden. Think about what the Brodix aluminum 598 Big Duke will do vs. the baby 540 Conventional headed motor now in...100# LESS weight & 200 MORE HP! Ordered the PS SV1 Carb from Patrick Monday.

Just returned from CBS's shop tonight, and turned out we have 5 hurt Pistons...front & back (1,2,7, & one other one. It seems from the assessment of the Piston & Ring damage that we were TOO RICH, with about 5.50 - 6.00# FP. The Ring Lands on #2 & #8 (the worse Pistons Damaged) were lifted, causing a hole to be burned in the Piston near the Intake pocket & ring land. The others were a plain jane case of lifted Ring Lands, with minimal Piston Damage. Compression was ZERO on #2, 75# on #8, and down very slightly at about 140-150# on the others damaged.

We hope to have the damage repaired shortly...waiting on Pistons from Diamond, and need to hone the cylinders & check the valves.

I have a call in to SJ, but we are already in agreement to lower the n20 jet on #2 to a 4 vs. usual 6 jet spread, and possibly then lower the FP from 5.50-6.00 (1st & 2nd stages) closer to 5.00 & 5.00, respectively. We plan on taking 2* more out of the 1st to 24* & 2nd to 14*, and test again with plug reading & data logger feedback.

The Lil Sumptin should roll...it dropped the #2 cylinder at 7.83 seconds in to the 8.01 @ 171 pass!

Hope to see ya at the track soon...get your Camaro running soon!

[trap]

Originally Posted by jonesy1

Whats up Trap???? I would agree possibly pinched it on the run prior and burnt it on the next one. I have been having some issues with the "even" side of my motor too!!! come to find out that I had a bad continuous duty relay on my second system. I found it only after hurting the motor twice both times on the "even" side. I knew that our tune up was ok so we went thru each system till we found this relay!!! Each time that I cycled the 2nd system on the 3rd try each time this realay would start humming however when the car was running you couldn't hear it, and it just so happenened that the motor burnt up the 3rd pass each day at the track. I will be checking those a whole lot wore than before. FoFo are you using theses relays too?????

Not much here, just trying to get motor sold and start working on next year.

[KNOTHEAD MOTORSPORTS]

Originally Posted by fofo

Hey Seth, all part of Racing, when trying to accomplish the goals I've set for the Lil Sumptin. Nobody said it was going to be a rose garden. Think about what the Brodix aluminum 598 Big Duke will do vs. the baby 540 Conventional headed motor now in...100# LESS weight & 200 MORE HP! Ordered the PS SV1 Carb from Patrick Monday.

Just returned from CBS's shop tonight, and turned out we have 5 hurt Pistons...front & back (1,2,7, & one other one. It seems from the assessment of the Piston & Ring damage that we were TOO RICH, with about 5.50 - 6.00# FP. The Ring Lands on #2 & #8 (the worse Pistons Damaged) were lifted, causing a hole to be burned in the Piston near the Intake pocket & ring land. The others were a plain jane case of lifted Ring Lands, with minimal Piston Damage. Compression was ZERO on #2, 75# on #8, and down very slightly at about 140-150# on the others damaged.

We hope to have the damage repaired shortly...waiting on Pistons from Diamond, and need to hone the cylinders & check the valves.

I have a call in to SJ, but we are already in agreement to lower the n20 jet on #2 to a 4 vs. usual 6 jet spread, and possibly then lower the FP from 5.50-6.00 (1st & 2nd stages) closer to 5.00 & 5.00, respectively. We plan on taking 2* more out of the 1st to 24* & 2nd to 14*, and test again with plug reading & data logger feedback.

The Lil Sumptin should roll...it dropped the #2 cylinder at 7.83 seconds in to the 8.01 @ 171 pass!

Hope to see ya at the track soon...get your Camaro running soon!

I promise you buddy, I am trying... I have most of my parts, and I just got everything back from the machine shop, I just need to put it all together when I get some time off.... Work is crazy, but we hope to be out there after the 1st of the year....


Seth

[R347GT]

This thread is really good info by all!!

[gbm]

We run anywhere from 5.5 to 4.5 fuel psi with a 4 spread . That car will fly once you lean it out ! I believe you are way fat , without seeing any of your plugs.Good luck!