somthing went wrong if your tune up was the exact same as other runs. was it super cold? diffrant gas? longer run? etc

 

I logged the car on motor after it detonated. The A/F started ok then as the rpm raised the a/f did also it was 14:1 when I got out of it. It surely acts like a bad fuel pump, regulator, plugged fuel filter. I changed the pump now I will try it. If its still lean I will change the filter then the regulator if need be. All cylinders detonated it is a fuel delivery issue.
Other than needing travel limiters the car has been running really well. finally getting it to hook up. this was a 1.34 60'

 

Mine did that once too, had to pull the head to retap the spark plug hole and there was no damage to anything, dunno how the hell, but was happy, and that was around the time I had just put it together, ran it for another 1.5 years before I had my problem that hurt it!

 

Damn you lucky bastards, wish I could lift the wheels like that on my goat. Even when I run my 150 shot, I doubt I'll even be able to get a wheel up 1mm

 

This is how mine was. Broke a ring land, just out cruising on a hot summer night. It gave no warning other than over heating. Never once felt it detonate and the plug was fine.

 

Thats an awesome 60'!!

Mine did the same **** earlier this year on the 150 shot... I believe the NANO regulator is what caused mine as the pressure jumped to 1400 psi.

Plugs 3, 5, and 6 here.

 

The wrong plugs and timing is the more likely reason.

 

That's why I say screw that nano BS, that's nothing but trouble IMO.

And please stop spraying on tr6 plugs... for the last time. #7 or greater unless it's a stock car with a 100 shot, in that case they are fine. Any more then that, please go to a #7 or higher (colder heat range)

 

Well, on the street I only run a 100 shot and run the TR-6's... But, this happened at the track when running a 175 shot. I was told they would be fine but I dont want to take any more chances.

So, I am going to buy some TR-7's (NGK BR7EF is the part number I found) and install them for the track next week when i throw the 175 shot back in the car and shoot for a low 10 sec pass. So, thanks on the heads up. Hey, so what gap you recommend on the TR-7s??

Apparently the NANO regulator got damaged when filling up the N20 bottle the day before. So, they recommend to simply disconnect the hose so no back pressure travels up to it. Im assuming the check valve got stuck open for a brief moment.

 

Ray,
Car looks great. Sorry to here about the issues..
Dave

 

I'm not real big on that nano thing. Letting the car richen up a little at the top can help save parts in alot of cases..........

That being said, get some autolite AR 3933's, and put them in at the track (after the car is warmed up) and pull all of them after one run, see what they look like, if all is good put them back in, run again and then pull again and look.

They are a cold #9 plug, and will probably foul out if you try to cold start the car with them, but one thing I am sure of , running a plug that's too cold isn't gonna hurt stuff, running too hot of one, that's a recipe for disaster.

If you don't want to go that cold, AR 3934, that is a #8. I have had very good luck with them, been running these plugs (the #8 n/a, the #9 and now the #10 with nitrous) for over a year, and have had nothing but good to say. NO extended tips = good thing

 

Thanks for the help and sorry for being off topic.. I was looking at this chart in the sticky. So, you think I should use the TR-8's then? Like I was saying before I only run 100 shot on the street and plan on doing the 175 shot at the track.. I do have a wideband in the car so I can see my AF..
And do you know why they recommend different plugs/part numbers for AFR VS Dart heads? I have Dart heads.

LS1 Stock and AFR
Thread – 14mm
Reach - .708”
Socket – 5/8 hex
Seat - Taper
Stock Heat Range: 5
Gap: .060
Plug: NGK TR55 (stock number 3951); NGK TR55IX (stock number 7164); Autolite 764; Denso IT-16 (stock number 5325)

Nitrous (one step colder)
Heat Range: 6
Gap: .035 - .038
Plug: NGK TR6 (stock number 4177); NGK TR6IX (stock number 3689); Autolite 103; Denso IT-20 (stock number 5326)

Nitrous (two steps colder)
Heat Range: 7
Gap: Consult
Plug: NGK BR7EF (stock number 3346); NGK TR7IX (stock number 3690); Autolite AR94; Denso IT22 (stock number 5327)

Nitrous (two and a half steps colder)
Heat Range: 8
Gap: Consult
Plug: NGK R5724-8 (stock number 7317); NGK TR8IX (part number 3691); Denso IT-24 (stock number 5328)

Nitrous (three steps colder)
Heat Range: 9
Gap: Consult
Plug: NGK R5724-9 (stock number 7891); Autolite AR93; Denso IT-27

Nitrous (four steps colder)
Heat Range: 10
Gap: Consult
Plug: NGK R5724-10 (stock number 7993); Autolite AR92


LS1 w/ Edelbrock and Dart Heads
Thread – 14mm
Reach – 3/4”
Socket – 5/8 hex
Seat – Gasket

Stock – MFG Recommendations: approx under 9:1 compression
Heat Range: 4
Gap: Consult ignition mfg.
Plug: NGK FR4 (stock number 5155); NGK BKR5EIX (stock number 6341); Autolite 3926; Champion RC12YC (stock number 71); Denso IK16 (stock number 5303)

MFG Recommendations: approx 10.5:1 compression
Heat Range: 5
Gap: Consult ignition mfg.
Plug: NGK FR5 (stock number 7373); Autolite AR3924 (Racing Plug); Autolite 3924; Champion RC9YC (stock number 2075); Denso K20PR-U (stock number 3145); Denso IK20 (stock number 5304)

MFG Recommendations: approx 11:1 compression
Heat Range: 8
Gap: Consult ignition mfg.
Plug: NGK R5672A-8 (stock number 7173); Autolite AR3911; Champion C63YC (stock number 796); Denso IQ24 (stock number 5314)

MFG Recommendations: approx 12:1 compression
Heat Range: 9
Gap: Consult ignition mfg.
Plug: NGK R5672A-9 (stock number 7405); Autolite AR3910; Champion C61YC (stock number 785); Denso IQ27 (stock number 5315)

MFG Recommendations: approx 13:1 compression
Heat Range: 9 - 10
Gap: Consult ignition mfg.
Plug: NGK R5671A-9 (stock number 5238); Autolite AR3933; Champion C59CX (stock number 296); Denso IK27 (stock number 5312)

MFG Recommendations: approx 14:1 compression
Heat Range: 10
Gap: Consult ignition mfg.
Plug: NGK R5671A-10 (stock number 5820); Autolite AR3932; Champion C57CX (stock number 295); Denso IK-31 (stock number 5321)

**NOTE: Use chart for static compression and adjust heat range for nitrous use accordingly.

 

Ray I cant believe that damn car ran as good as it did with the plugs looking like that! We both had some issues..looks like our track rental got canceled for tomorrow too Call me later and let me know how it goes!

 

The autolite AR 3910 is what I would use. It is a nascar style plug with a cut back ground srap that is a little stronger, so they will take 2 runs to really show the heat, I would start off with the #8 ngk plug because it will show heat after one run alot better, but once you know your tuneup is good then go to the autolite plug, they don't seem to foul as bad, the tips aren't protruded, that type of thing.

I don't know what ya have for compression, but I look at it like this:

11 to 1 or over n/a #6
11 to 1 with 100 shot #7
11 to 1 with 200 shot #8
11 to 1 with 300+ #9

once you get to 13 to 1, I'd go to a #7 n/a, and for 100 shot a #8, 200 a #9, etc.etc.

Personally, I'm on a 13.5 to 1 compression motor, and am running a 150 shot, I run a #9 plug. I'm gonna start playing with the jetting a little, therefore I got some #10 plugs for a little added safety net.

Each heat range you go down lowers the combustion chamber temps by about 100 degrees (rough rule of thumb) so that may be enough to save you from some damage. Noone ever hurt anything from running too cold a plug, ya just foul them out easier.

I gap everything at 35, gap them too tight and the car gets a little harder to start and whatnot, plus this is a way to be consistant to see what just the plug change does.


I dunno about running different plugs in different heads, I'm running ET heads and am running the AR 3933 normally, and have some AR 3932's to go to for my next outing/testing session.

 

Im at ~11.5.1 CR with milled 59CC Dart 205's, .040 gakets. I also run 100 octane at the track as well.

Thanks for your input. Ill call around and see if I can locate some TR-8's then.. I was pulling 5* out as well, that good enough?

 

why the projected tip plug?you might want to try the non projected tip

 

can some post pics of projected and nonproject plugs. btw, this is a great thread.

 

That should be fine. We pulled 5 degrees for my 150 shot, but I'm using 118 Nos blend fuel.

If possible, use a leaded fuel. I know the O2's don't like it, just tune the car in open loop and turn them all off, no more problems there, and I assume that you have no cats on the car so that doesn't matter either.

You can never hurt anything running too good a fuel.

 

I have a sad excuse for a camera, but I will try to get a picture of the plug I use today, if I can find an NGK plug in the garage, I'll take a pic of that too, when you see the difference, you will understand.

 

out of couriosity, what plug would you recomend for my setup? it consists of ls6 heads 59cc, .045 gasket, and a 125 shot tuned to 11.8-12.0. i usually run 27 degrees na and 22 on the jug with 104 unleaded in the tank. thanks.